Protecting the Nation's Groundwater fromContamination—Vol. I

October 1984

NTIS order #PB85-154201

Recommended Citation:Protecting the Nation Groundwater From Contamination (Washington, DC: U.S. Con-gress, Office of Technology Assessment, OTA-O-233, October 1984).

Library of Congress Catalog Card Number 84-601126

For sale by the Superintendent of DocumentsU.S. Government Printing Office, Washington, D.C. 20402

Foreword

Contamination of groundwater is the focus of public attention nationwide—it is be-ing detected with increasing frequency, it has been detected in every State and often nearheavily populated areas, and it is linked to adverse health, economic, environmental, andsocial impacts. At the same time, groundwater is being increasingly relied on for manytypes of uses and currently supplies the Nation with one-half of its drinking water. Thesense of public urgency is reflected in the hearings and debates of the 98th Congress toreauthorize major environmental laws including the Resource Conservation and RecoveryAct, the Safe Drinking Water Act, the Clean Water Act, and the Comprehensive Envi-ronmental Response, Compensation, and Liability Act ( "Superfund" ).

The objective of the OTA study, as requested by the Senate Committee on Environ-ment and Public Works, is to assess the current status of the Nation’s knowledge aboutand experience in dealing with groundwater contamination problems. Overall, the studyshows that much information is available about sources of contamination, impacts, andtechnologies to guide national policy. In particular, the analysis indicates that, despite theestablishment and expansion of numerous Federal and State programs in recent years,these efforts have a narrow focus from a groundwater perspective and, consequently, arelimited in their ability to protect groundwater quality.

The study itself focuses on existing contamination problems because of the absenceof a coherent technical foundation for understanding—i.e., integrating, analyzing, andinterpreting —information about the problems caused by groundwater contamination froma national policy perspective. At the same time, OTA recognized that the prevention offuture contamination would also need to be explicitly considered in order to develop apolicy framework for comprehensive resource protection; for example, as experience withhazardous wastes has shown, the cost to clean up contamination can be enormously greaterthan the cost to prevent contamination. Thus, the structure of the study evolved aroundthe concept of protecting groundwater quality —comprised of activities to detect, correct,and prevent groundwater contamination—even though the details focus on the detectionand correction of existing problems.

Many individual topics related to groundwater contamination, such as preventionalternatives, the effects of specific sources on groundwater contamination, and the effec-tiveness of specific laws and programs have been explored in greater detail in other OTAstudies. Interested readers are referred to, among others, Assessment of Technologies forDetermining Cancer Risks From the Environment (June 1981), Use of Models for WaterResources Management, Planning, and Policy (August 1982), Technologies and Man-agement Strategies for Hazardous Waste Control (March 1983), The Information Con-tent of Premanufacture Notices—A Background Paper (April 1983), Water-Related Tech-nologies for Sustainable Agriculture in U.S. Arid and Semiarid Lands (October 1983),Managing Commercial High-Level Radioactive Waste (in press), Cleanup of UncontrolledHazardous Waste Sites Under Superfund (in progress), and Hazardous Materials Trans-portation: Technology Issues (in progress).

The viewpoints of the private sector, environmental groups, academia, the technicalcommunity, and public interest organizations were sought in conducting the study. In

Ill

addition, over two dozen Federal agencies and offices were contacted for the analysis ofFederal laws and programs, and each of the States responded to the OTA State survey.OTA thanks the numerous people—advisory panel members, reviewers, advisors, andconsultants— who gave so generously of their time and expertise in support of the study.As with all OTA studies, the content of the report is the sole responsibility of OTA.

Director

OTA Project Staff— Protecting the Nation’s Groundwater From Contamination

John Andelin,Science, Information,

Assistant Director, OTAand Natural Resources Division

Robert W. Niblock, Oceans and Environment Program Manager

Project Staff

Paula J. Stone, Project Director

Joan Ham Howard Levenson Francine Rudoff

Administrative Staff

Kathleen A. Beil Jacquelynne R. Mulder Kay Senn

Contractors

Woodward-Clyde Consultants, Inc., Walnut Creek, CA

Environ Corp., Washington, DC

The University of Oklahoma, Norman OK

GeoTrans, Inc., Herndon, VA

Peter N. Davis, University of Missouri-Columbia Law School, Columbia, MO

v

Protecting the Nation’s Groundwater From Contamination Advisory Panel

Thomas Maddock, III, ChairmanProfessor, Department of Hydrology and Water

University of Arizona, Tucson

Harvey BanksConsulting Engineer

Rodney DeHanAdministrator, Groundwater ProgramState of Florida Department of Environmental

Regulation

Robert HarrisProfessorCenter for Energy and Environmental StudiesPrinceton University

Allen V. KneeseResources for the Future

Jay H. LehrExecutive DirectorNational Well Water Association

Perry McCartyChairman and ProfessorDepartment of Civil EngineeringStanford University

James MercerPresidentGeoTrans, Inc.

David W. Miller

Resources

PresidentGeraghty & Miller, Inc.

Mary Lou MuntsState Representative76th Assembly DistrictState of Wisconsin

Michael A. PierleDirector, Regulatory ManagementMonsanto Co.

Anthony Z. RoismanExecutive DirectorTrial Lawyers for Public Justice

Lawrence SwansonDirectorGreat Plains Office of Policy Studies

James T. B. TrippEnvironmental Defense Fund

NOTE: OTA appreciates and is grateful for the valuable assistance and thoughtful critiques provided by the advisory panel members. Theviews expressed in this OTA report, however, are the sole responsibility of the Office of Technology Assessment.

vi

Contents

chapter Page

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2.

3.

4.

5.

6.

7.

8.

9.

10.

11.

12.

Protecting the Nation's Groundwater From Contamination: Findings . . . . . . . 5

Groundwater- Contamination and Its Impacts . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Federal Institutional Framework To Protect GroundwaterFrom Contamination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

State Institutional Framework To Protect GroundwaterFrom Contamination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

Hydrogeologic Investigations of Groundwater Contamination . . . . . . . . . . . . . . 111

Federal Efforts To Detect Groundwater Contamination . . . . . . . . . . . . . . . . . . . 145

State Efforts To Detect Groundwater Contamination . . . . . . . . . . . . . . . . . . . . . 165

The Correction of Groundwater Contamination: Technologies andOther Alternatives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177

Federal Efforts To Correct Groundwater Contamination . . . . . . . . . . . . . . . . . . 197

State Efforts To Correct Groundwater Contamination . . . . . . . . . . . . . . . . . . . . 205

Federal Efforts To Correct Groundwater Contamination . . . . . . . . . . . . . . . . . . 215

Overview of the States and Prevention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235

Index , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243

Volume II of this report contains the following appendixes:

A. Groundwater Contamination and Its Impacts

B. Federal Institutional Framework To Protect Groundwater

C. State Institutional Framework To Protect Groundwater

D. Hydrogeologic Investigations of Groundwater Contamination

E. Federal Efforts To Detect Groundwater Contamination

F. Corrective Action: Technologies and Other Activities

G. Federal Efforts To Correct Groundwater Contamination

H. Federal Efforts To Prevent Groundwater Contamination

vii

Report Summaryand Findings

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Chapter 1

Protecting the Nation’s GroundwaterFrom Contamination: Findings

Contents

Page

Chapter Overview . . . . . . . . . . . . . . . . . . . . ...............................:.. 5

Federal and State Approach to Groundwater Protection . . . . . . . . . . . . . . . . . . . . . . . . 6Detection Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8Corrective Action Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8Prevention Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Technical and Non-Technical Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

National Policy Implications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Funding. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Technical Assistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12Research and Development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Chapter 1

Protecting the Nation’s GroundwaterFrom Contamination: Findings

—

CHAPTER OVERVIEW

Contamination of groundwater—by organic andinorganic chemicals, radionuclides, and/or micro-organisms—has occurred in every State and isbeing detected with increasing frequency. For along time, the land surface and subsurface wereconsidered safe and convenient depositories formany of society’s wastes and non-waste products.Only recently has the limited capacity of naturalsoil processes to change contaminants into harmlesssubstances, before they reach groundwater, becomewidely recognized.

Detailed quantitative estimates of the nationwideextent and effects of groundwater contaminationare not now, and probably never will be, available.The time, costs, and technical requirements to de-velop nationwide estimates would be prohibitive.In addition, information necessary for predictingfuture contamination problems—about future usesof groundwater, potential sources, and types ofcontaminants—cannot be known with certainty.

Contaminants found in groundwater—particu-larly organic chemicals— are associated with adversehealth, social, environmental, and economic im-pacts. Although only a small portion of the Nation’stotal groundwater resource is thought to be contami-nated, the potential effects of this contamination aresignificant and warrant national attention.

Public health concerns arise because some con-taminants are individually linked to cancers, liverand kidney damage, and damage to the centralnervous system. They also arise because informa-tion is not available about the health impacts ofmany other individual contaminants, or of mixturesof contaminants as typically found in groundwater.Uncertainties about human health impacts arelikely to persist because impacts are difficult tostudy; for example, impacts may not be observableuntil long after exposure.

Social impacts are often related to anxiety andfear about exposure to contaminants. Exposure canoccur unknowingly because even if groundwateris contaminated, it may be odorless, colorless, andtasteless. Exposure can also occur over many yearsand in many ways—by drinking, eating, bathing,and breathing.

Environmental impacts include the quality deg-radation of not only soil, but also air and surfacewater because of interrelationships among environ-mental media (e. g., groundwater can provide base-flow to streams). Vegetation, fish, and wildlife canbe affected adversely.

The economic costs of detecting, correcting, andpreventing groundwater contamination at even asingle site are high; for example, corrective actioncan be tens of millions of dollars or more. Economiclosses that occur from impaired groundwater qualityinclude decreases in agricultural and industrial pro-ductivity, lowered property values, the costs for re-pair or replacement of damaged equipment andmaterials, and the costs of developing alternativewater supplies,

Adverse impacts from groundwater contamina-tion are likely to increase. Contaminated ground-water is often located near industrialized, heavilypopulated areas, which increases the likelihood ofhuman exposure. Groundwater is also increasinglyrelied on as a source of water for many uses;withdrawals for all uses increased from about 35billion gallons per day in 1950 to almost 90 billiongallons per day in 1980. Groundwater is now asource of drinking water for approximately one-halfthe Nation’s population. It also fills about 40 per-cent of the Nation’s irrigation requirements, about80 percent of rural requirements both in the homeand for livestock, and about 25 percent of self-supplied industrial purposes (other than hydroelec-tric power).

5

6 ● protecting the Nation’s Groundwater from Contamination

Current information about the Nation’s ground-water contamination problems may not describe theactual situation as much as it reflects the way inwhich investigations are conducted—which con-taminants have been looked for, where they havebeen looked for, and where they have been found.Because substances found as contaminants in ground-water are used throughout society, more widespreaddetection of contamination can be expected as ef-forts increase to monitor known problems, locateas yet undetected problems, and monitor potentialproblems. Known sources of contamination includenot only the commonly recognized point sourcesassociated with hazardous wastes (as defined byFederal statutes) but also non-point sources andsources associated with non-hazardous wastes andnon-waste products.

Examples that reflect the diversity of knownsources of contamination include: injection wellsand septic tanks, which are designed to dischargepotential contaminants into the ground; storagetanks and landfills, which are designed to store,treat, and/or dispose of potential contaminants;pipelines and transfer operations, which transportpotential contaminants; agricultural practices,which include pesticide and fertilizer applications;production wells, which provide a conduit for po-tential contaminants to enter groundwater; and salt-

water intrusion, which can be induced or worsenedby human activities.

Groundwater contamination problems will con-tinue, and probably increase, as long as there aresources, contaminants, and users not being ad-dressed. Despite the paucity of quantitative details,sufficient information is available about the natureof groundwater contamination to justify nationalaction to protect groundwater quality—described inthis study as involving choices among activities todetect, correct, and prevent contamination—in or-der to minimize associated adverse impacts. Policyoptions generally relate to the development and im-plementation of Federal and State protection pro-grams and include a broadening of programs to thosesources, contaminants, and users not now coveredand the provision of adequate and sustained Federalsupport to the States. Unfortunately, the costs andtechnical uncertainties associated with detection andcorrection activities effectively preclude the investi-gation and correction of all known and/or suspectedcontamination problems. Therefore, prevention iscentral to any long-term approach to groundwaterquality protection. In general, selection amongdetection, correction, and prevention activities—given limited funds and technical capabilities—willdepend on policy decisions regarding which and towhat extent groundwater resources will be protected.

FEDERAL AND STATE APPROACH TOGROUNDWATER PROTECTION

Numerous Federal and State programs for pro-tecting groundwater quality-for detecting, cor-recting, and preventing contamination-have beenestablished and expanded in recent years. Theseefforts have made a significant contribution to theprotection of groundwater. For example, sourcesof contamination have been identified, inventoriesof selected sources have been conducted, numer-ous incidents have been documented, and scien-tific advances have been made in understandinggroundwater flow.

At the Federal level, at least 16 statutes authorizeprograms relevant to groundwater protection, andmore than two dozen agencies and offices are in-

volved in groundwater-related activities. All 50States are concerned about contamination and haveprograms, at varying stages of development, to pro-tect groundwater. As many as seven agencies withgroundwater responsibilities have been identifiedin a single State.

Despite growing Federal and State efforts, pro-grams are still limited in their ability to protectagainst contamination. For example, there is no ex-plicit national legislative mandate to protect ground-water quality; and although the groundwater pro-tection strategy of the U.S. Environmental ProtectionAgency acknowledges the need for comprehensiveresource management, the details of the strategy

Ch. 1—Protecting the Nation’s Groundwater From Contamination: Findings ● 7

do not fully provide for it. Most authorized pro-grams are in their early stages, and some are at least10 years from being fully in place. Groundwaterquality-related programs among, and within, in-stitutions are often not coordinated, nor are theycoordinated with programs for groundwater quan-tity or surface water even though groundwater andsurface water quality and quantity are intercon-nected.

From a groundwater protection viewpoint, ex-isting Federal and State programs also generallyhave a narrow focus with respect to sources, con-taminants, and users. Essentially, the programs areconcerned with managing selected sources of con-tamination, selected contaminants, and the usersof public drinking water supplies.

Narrow Focus on Sources. —Federal and Stateprograms generally focus on managing only selectedpoint sources of contamination, particularly pointsources associated with hazardous wastes. The pro-grams vary in their approaches to protection ofgroundwater quality and generally do not take intoaccount the potential of the sources to contribute togroundwater contamination. Further, the non-haz-ardous waste, non-waste, and non-point sources thatare known to contaminate groundwater are usuallynot covered.

Narrow Focus on Contaminants. —This studyhas documented the detection of over 200 sub-stances—both natural and synthetic—in ground-water. Yet the Federal Government has establishedonly 22 mandatory water quality standards, 18 ofwhich are for specific chemicals. These Federalstandards, developed under the National InterimPrimary Drinking Water Regulations of the SafeDrinking Water Act, are inadequate, as substantiatedby State responses to the OTA State survey. As a re-sult, many States have set their own standards fordrinking water and groundwater quality; both thetypes of contaminants addressed and the stringencyof standards vary from State to State.

Narrow Focus on Users. —Federal and State pro-grams are directed primarily at the protection ofpublic drinking water supplies. Yet as much as 20percent of the Nation’s population may rely on pri-vate wells for drinking water. The extent to whichpeople relying on private wells are being exposed togroundwater contaminants is unknown, and data aregenerally not being collected to find out. Data arealso unavailable about the impacts of groundwatercontamination on non-drinking water uses.

As a result of the narrow focus of Federal andState programs with respect to groundwater pro-tection in terms of sources, contaminants, and

Photo credits: State of Florida Department of Environmental Regulation (left) and Office of Technology Assessment (right)

Sources of potential groundwater contamination are diverse and include the most commonly addressed point sourcesassociated with hazardous wastes as well as sources associated with non-hazardous wastes (e.g., open dumps, which

are usually point in nature and may also contain hazardous wastes) and non-wastes (e.g., product pipelines,which are non-point).

8 ● Protecting the Nation’s Groundwater From Contamination

users, related activities to protect against contam-ination are also narrow in focus. Examples are de-scribed below.

Detection Programs

The focus of both inventorying and monitoringefforts is on selected point sources of contamina-tion, primarily on sources of hazardous wastes. Fed-eral inventories of specific sources are limited tosurface water impoundments under the Safe Drink-ing Water Act and to hazardous waste sites andopen dumps under the Resource Conservation andRecovery Act. State inventories are directed pri-marily at sources designed to store, treat, and/ordispose of wastes (e. g., landfills) and at sources de-signed to discharge potential contaminants into thesubsurface (e. g., injection wells). In general, onlyrecently has groundwater monitoring begun to in-clude organic chemicals and trace metals. Routinemonitoring is required only for public drinkingwater supplies, as opposed to private drinkingwater supplies and supplies for non-drinking waterpurposes.

Corrective Action Programs

Few corrective actions have been undertaken todate relative to the number of sites identified as re-quiring such action. For example, although feder-ally funded corrective actions authorized by theComprehensive Environmental Response, Com-pensation, and Liability Act (CERCLA, also knownas “Superfund”) could potentially address a broadrange of sources and contaminants, actions thus farhave been restricted to primarily hazardous wastesites; in addition, such corrective actions have gen-erally not involved the cleanup of contaminatedgroundwater. Overall, the provisions of Federal pro-grams for corrective action vary. Two programsestablish standards for cleanup (the Resource Con-servation and Recovery Act and the Uranium MillTailings Radiation Control Act); other programs(e. g., CERCLA) establish cleanup standards on acase-by-case basis.

State corrective action programs are similarly atan early stage of development. The greatest numberof State programs relate to spills and accidents andto leaks from storage; other activities tend to be asso-ciated with point sources that are designed either to

retain (e. g., in landfills) or to discharge (e. g., viainjection wells) potential contaminants into the sub-surface. Many State corrective actions result fromcomplaints rather than systematic efforts to identifycontaminated sites.

Prevention Programs

A limited number of potential sources are ad-dressed in Federal and State programs to preventgroundwater contamination. The programs focusprimarily on sources associated with hazardouswastes and other toxic materials. Implementationand enforcement of most program requirements arestill in their early stages. Differences among pro-grams have little relationship to the potential fordifferent sources to cause contamination. Currentapproaches to preventing contamination includeprovisions for the design, operation, siting, re-stricted use, and closing of sources. The approachesmay be either mandatory or voluntary. Additionalapproaches to the prevention of groundwater con-tamination from specific sources include use ofalternatives to the contaminating activity (e. g., toland disposal), process or product changes for re-duction of waste hazard levels and volumes, andwaste recycling and recovery.

A focus on sources is one approach to preventcontamination; other types of approaches have notbeen widely applied to groundwater. For example,few efforts have been made to control activities lo-cated in recharge areas (i. e., portions of a drain-age basin that replenish an aquifer). Approachesthat are not source-specific are most suitable whenthere is no single identifiable source or when highvolumes of groundwater or large areas are involved(e. g., non- point sources or a clustering of pointsources). The Federal Government does providesome support for the protection of selected rechargeareas through the Sole Source Aquifer Programunder the Safe Drinking Water Act; selected rechargeareas are also being protected by some States andlocal governments through land use controls andland acquisition.

Another approach to prevent groundwater con-tamination is through restrictions on the manufac-ture or generation, distribution, and use of thecontaminating substances themselves. This ap-proach recognizes the fact that any one substance

Ch. 1—Protecting the Nation’s Groundwater From Contamination: Findings ● 9

can be released into groundwater from many dif- posal. Although both the Toxic Substances Con-ferent sources. To illustrate, pesticides may be trol Act and the Federal Insecticide, Fungicide, andintroduced from non-point sources such as land ap- Rodenticide Act authorize regulation of potentialplication, non-waste sources such as storage tanks, groundwater contaminants, application of associ-hazardous waste sources such as landfills, and non- ated programs to groundwater has been limited.hazardous waste sources such as residential dis-

TECHNICAL AND NON-TECHNICAL CONSTRAINTS

The effectiveness of Federal and State programsto protect groundwater from contamination hasbeen limited not only by their narrow focus but alsoby technical and non-technical factors.

Underlying all groundwater protection activitiesis the hydrogeologic investigation which is used,for example, to detect existing problems, monitorthe performance of corrective actions, and moni-tor the effectiveness of preventive activities. In gen-eral, the technologies for obtaining hydrogeologicinformation are available. Nevertheless, there willalways be some degree of uncertainty about con-tamination because of inherent difficulties in deal-ing with a phenomenon that is inaccessible to di-rect observation. Many advances have been madeto improve the reliability of results (i. e., to reduceuncertainty), but they often increase the costs andtime required to conduct the investigation.

There are major constraints on hydrogeologic in-vestigations in some situations. For example, thetechnology for conducting reliable investigations incertain geologic environments such as fracturedrock, which occurs throughout the United States,is lacking. Investigations can also be very costly andtime-consuming depending on site conditions andthe level of detail required by the investigation ob-jectives (e. g., investigations just to define a con-tamination problem could cost anywhere from$25,000 to $500,000 and take many months to com-plete). In addition, the reliability of a hydrogeologicinvestigation depends on highly skilled personnelbecause investigations must be tailored to the site-specific nature of any groundwater contaminationproblem. Adequately trained personnel are gener-ally in short supply.

Many of the constraints associated with hydro-geologic investigations—costs, time, inadequate

Photo credit: U.S. Environmental Protection Agency

In general, techniques for conducting hydrogeologicinvestigations are available for most environments.Here a drilling rig provides access to undisturbed,uncontaminated samples of a deep aquifer; a hollow-

stem auger holds the drilling hole open while asampling tube is lowered inside and pushed

into undisturbed aquifer material.

supply of trained personnel, and technical uncer-tainties—also apply to detection, correction, andprevention activities. The importance of the con-straints to these activities varies, however, and ad-ditional constraints also become relevant.

—

10 ● Protecting the Nation’s Groundwater From Contamination

Detection activities are primarily constrained bythe high costs of monitoring. For example, the an-nual collection and analysis of groundwater qualitysamples from the 12-14 million private wells in theUnited States could cost $7 billion or more depend-ing on the techniques used; and such a samplingprogram would still provide only a snapshot of data,at discrete places and for one point in time, thatconveys little information about the sources of anyexisting contamination or the potential for furtheror future contamination. One institutional con-straint on some States is their lack of authority toobtain data about particular sources of contam-ination.

Techniques for analyzing groundwater qualitysamples are biased in terms of which of the con-taminants present they detect, and some contami-nants cannot be readily measured at low but po-tentially harmful levels using routinely availablemethods. Water quality data can also be difficultto analyze and interpret, especially if trace levelsor mixtures of contaminants are present or if con-taminants have changed chemically and biologicallyinto substances different than those expected.

Major constraints on alternatives for correctiveaction include: uncertainty about the effectivenessof various techniques to improve groundwaterquality; the dependence of technology performanceon the amounts of both money and time available;the high costs of taking corrective action of any sort;the need for suitably trained professionals to de-sign and implement measures appropriate for site-specific conditions; and the lack of experience, espe-cially with the large areas or large volumes of con-taminated groundwater that are typical of non-pointsources. The nature of the contaminants is anotherconstraint; for example, treatment techniques canbe costly depending on the contaminants present,and their performance is uncertain when there isa complex mixture of contaminants and/or concen-trations change rapidly. Based on experience-to-date, correction alternatives-containment, with-drawal, treatment, in-situ rehabilitation, and man-agement options— appear to be selected accordingto how rapidly they can be implemented, howrapidly they become effective, the extent to whichthe uncertainties inherent in their performance can

beto

Photo credit: U.S. Environmental Protection Agency

Protective clothing is worn to prevent exposure tocontaminants while undertaking corrective measures.

reduced, and whether there is clear authorityimplement the selected strategy.

Institutional constraints on corrective actionsrelate to ease of access to the site, availability ofalternatives for disposal of any contaminants with-drawn or excavated, and ability to implement somecorrection activities (e. g., withdrawal via pump-ing) given established water rights. Corrective ac-tion can also have environmental side-effects. Forexample, the management option of closing wellsresults in the continued presence of and potentialfor further migration of contaminants, and excava-tion may transfer contaminants to another site orother environmental media (e. g., surface water andair).

Major constraints on prevention efforts includethe lack of funds to implement existing programs,uncertainty about the technical adequacy of avail-able methods and ongoing efforts, and incompleteunderstanding about the relationship between landuse and groundwater quality. Some techniques usedto prevent contamination are the same as those usedfor correction (e. g., containment measures such asliners), so that the same uncertainties about per-formance are pertinent.

Ch. 1—Protecting the Nation’s Groundwater From Contamination: Findings ● 1 1

NATIONAL POLICY IMPLICATIONS

National policy options generally relate to the de-velopment and implementation of Federal and Stategroundwater quality protection programs.

The existing Federal statutory framework ap-pears to have the potential to protect the Nation’sgroundwater from further contamination. How-ever, the realization of this potential will depend onbroadening the coverage of authorized programs tothose sources, contaminants, and users not presentlyincluded and on effectively implementing programs.Many approaches for broadening and implement-ing programs are possible, such as mandatory re-quirements, voluntary procedures, and/or incen-tives and disincentives. Effective implementationwill also require the coordination of activities amongand within agencies (e. g., health departments, Stategeological surveys, and departments of environ-mental protection) for both groundwater and sur-face water quality and quantity. Ultimately, ground-water quality protection will also depend on politicaljudgments about both the appropriate role of theFederal Government and the importance of allStates making comparable progress in their abilitiesto detect, correct, and/or prevent groundwater con-tamination.

Fundamental to the development of any nationalpolicy related to the protection of groundwater fromcontamination is recognition of the site-specificnature of the problems. Efforts to detect, correct,and prevent contamination must be tailored to thefull range of conditions found at any site, includ-ing sources, contaminants, and users. National pol-icy must be flexible in its ability to respond to andaccommodate different groundwater quality prob-lems characterized by varying site conditions. Forexample, the choice of appropriate monitoringparameters, locations, and frequencies cannot berigidly specified apart from site conditions; how-ever, the factors that need to be considered in mak-ing this choice could be specified. A major functionof the Federal Government would be to provide ade-quate and sustained support to the States for detect-ing, correcting, and preventing groundwater con-tamination. The principal areas for Federal support

to the States that would be the most helpful in achiev-ing groundwater quality protection are funding,technical assistance, and research and development.

The need for flexibility in national policy isunderscored by the vast differences among Stateapproaches to protecting groundwater. States varyin their perception about their contamination prob-lems, priorities among sources and users, capabil-ities, stages of program development and imple-mentation, and institutional arrangements. Landuse considerations, essential for preventing con-tamination from non-point sources or from clustersof point sources, have traditionally been addressedat the State and local levels.

Current Federal laws and programs have gen-erally helped the States with their groundwater con-tamination problems. However, based on responsesto the OTA State survey, the level of Federal sup-port to the States is not adequate; nor is it directedat all of the States’ problems. In some cases, cur-rent Federal laws and programs have created prob-lems: surface water quality problems have beenreduced at the expense of groundwater quality be-cause Federal programs fail to recognize the inter-relationships among environmental media; Federalprograms fail to accommodate variations in Stateconditions; and the lack of an explicit nationallegislative goal to protect groundwater quality hasled to uncoordinated Federal programs and hashandicapped the States in obtaining authority toaddress certain problems.

Funding

Currently no Federal program has earmarkedfunds specifically for the protection of groundwaterquality. In addition, funding for programs that havesupported groundwater-related activities has beenreduced or eliminated (e. g., funding under Section208 of the Clean Water Act, for State solid wasteprograms under Subtitle D of the Resource Con-servation and Recovery Act, and for the RuralAbandoned Mine Program under the Surface Min-ing Control and Reclamation Act). As a result,

12 ● protecting the Nation’s Groundwater From Contamination

groundwater and other water quality programs arecompeting for limited State grants (e. g., under Sec-tions 106 and 205(j) of the Clean Water Act). Be-cause of the high costs associated with groundwaterprotection, Federal funding assistance is desired bythe States for both the development and implemen-tation of State initiatives.

Technical Assistance

Technical assistance to the States can includetraining programs, the development of criteriaand/or guidelines, and information exchange.

Qualified personnel are essential for protectionactivities because activities need to be tailored tosite conditions. The supply of qualified technicalpersonnel appears to be limited and to be an impor-tant constraint on the Nation’s ability to protectgroundwater quality. Federal support for trainingand education is required for a rapid increase inthe Nation’s technical capabilities. The States havebeen assisted by the Cooperative Program of theU.S. Geological Survey, and they would like to seeit and other technical assistance programs con-

tinued. Establishment of professional certificationprograms or other criteria (e. g., by the FederalGovernment, the States, or professional societies)for ensuring that personnel possess minimum tech-nical qualifications would also help to develop—andto provide a check in the hiring of—qualified tech-nical manpower.

Although contamination problems require site-specific judgments, they nevertheless have commonfeatures that are amenable to the development of Fed-eral criteria and/or guidelines. From a national per-spective, the goal of these criteria and/or guidelineswould be to ensure that at least a minimum set ofconsiderations is being taken into account for pro-tection of groundwater quality. Further, they wouldalso be an efficient means of providing informationrequired by all States in handling their groundwatercontamination problems; for example, generalguidelines could be developed for assisting theStates in setting priorities for allocating scarceresources among alternative protection activities.In addition to criteria and guidelines, the FederalGovernment could provide direct assistance toStates in specified situations.

Ch. 1l—Protecting the Nation’s Groundwater From Contamination: Findings ● 1 3

Technical assistance could include:

● With respect to detection:— Criteria and/or guidelines to assist the

States in conducting reliable hydrogeologicinvestigations under different site condi-tions and in addressing, for example,monitoring of the flow system, samplingand analysis, and data interpretation.

— Criteria and/or guidelines for addressingcontaminants for which there are no Fed-eral standards, including for mixtures.Standards development for these contami-nants is also needed (see Research and De-velopment, below),

— Criteria and/or guidelines to assist theStates in setting priorities among sourcesand in determining which sources they willmonitor and inventory.

● With respect to correction:Criteria and/or guidelines to assist theStates in selecting and implementing cor-rective action under various conditions.Criteria and/or guidelines for settingcleanup standards on a site-specific basis,incorporating such factors as the limita-tions and likely performance of technol-ogy and current and/or potential users.

● With respect to prevention:— Criteria and/or guidelines for preventing

contamination from all potential contami-nating sources; for a given source, per-formance criteria and/or guidelines for ad-dressing its siting, design and operationduring its active life, and closure. Alter-natives for reducing the wastes generatedby a source, and for waste recycling, alsoneed to be considered as part of prevent-ing contaminant ion from sources.

— Criteria and/or guidelines for consideringprevention alternatives apart from thoserelated to specific sources, e.g., for the pro-tection of aquifer recharge areas and forestablishing an institutional memory forthe locations of sources, contaminants, andland uses.

Because of the complexities of groundwater con-tamination problems and because efforts to protectgroundwater are generally in their early stages,there are several important opportunities for the

Photo credit; John Gilbert, EPA Environmental Response Team

Training of staff is required for dealing safely andeffectively with site-specific groundwater

contamination problems.

Federal Government to facilitate information ex-change among the States. Information exchangewould not necessarily include the details of site-specific case studies; rather, programmatic infor-mation about State approaches to protection wouldassist the States in learning from the successes, andfailures, of each other.

Research and Development

Some research and development activities canprovide timely information that would support allof the States in their groundwater protection efforts.Key activities include:

● With respect to detection:Research on toxicology and the adversehealth effects of contaminants that are be-ing found in groundwater, with particu-lar emphasis on the synergistic effects ofmixtures of contaminants.Development of water quality standardsfor substances known to occur in ground-

74 ● Projecting the Nation’s Groundwater From Contamination

water that are not now covered; these stand-ards could be applied in State drinkingwater and groundwater quality programs.

— Research on assessment of the environ-mental and economic impacts of contam-ination.

— Research on less costly techniques forhydrogeologic investigations in generaland development of reliable techniques forconditions that cannot now be addressedadequately (e. g., fractured rock).

● With respect to correction:— Research on the behavior of individual

contaminants in groundwater and, in par-ticular, on the potential for the chemicaland biological transformation of organicchemicals.

— Research on chemical and biological reac-tions in fluids that would be necessary, forexample, for the development of tech-niques for treating water with multiplecontaminants.

● With respect to prevention:— Opportunities and mechanisms for pre-

venting contamination, including ways ofreducing the generation (e. g., by processor product changes) and disposal (e. g.,through resource recovery and recycling)of potential contaminants.

Ultimately, the protection of groundwater fromcontamination will also depend on raising the con-sciousness of the public as has been done for litter-

Illustration credit: Sacramento County, CA

Some communities have implemented householdhazardous waste collection programs as part of their

efforts to protect groundwater quality.

ing and air and surface water pollution. All seg-ments of society need to understand how theiractivities affect groundwater quality and, in turn,how they may be affected. Public confidence willgrow only as the Nation makes timely efforts todetect, correct, and prevent groundwater contami-nation from all sources and contaminants, to pro-tect all of the public’s interests.

Background

Chapter 2

Groundwater Contaminationand Its Impacts

Contents

PageChapter Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Extent and Nature of Groundwater Contamination . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20Assessing the Nationwide Extent of Groundwater (contamination . . . . . . . . . . . . . . . . . . . . 20Substances Known to Occur in Groundwater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Health Impacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23General Issues. ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23Adverse Impacts of Chemicals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32Potential Toxicity or Potency of Chemicals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33Interactions Among Multiple Chemicals, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34Biological Substances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34Radioactive Substances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Non-Health Impacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... . . . ... 36Economic Impacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36Environmental and Social Impacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Concentration and Frequency of Substances Found in roundwater . . . . . . . . . . . . . . 38Concentration of Substances in Groundwater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38Frequency of Occurrence of Substances in Groundwater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40Concentration and Frequency Data in Relation to Governmental Standards . . . . . . . . . . . . 41

Potential But as Yet Undetected Substances in Groundwater . . . . . . . . . . . . . . . . . . . . 43

Types of Sources and Associated Substances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43Types of Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43Association o! Substances Found in Groundwater With Sources . . . . . . . . . . . . . . . . . . . . . . 44

Factors lnfluencing a Source’s Potential To Contaminate Groundwater . . . . . . . . . . . 47Release Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47Geographic Location: Pervasiveness and Regionality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49Numbers of Sources and Amounts of Material Flowing Through or Stored in Sources . . . 51

Potential for Sources To Contribute Substances to Groundwater . . . . . . . . . . . . . . . . . 55Modeling the Potential of Sources To Contaminate Groundwater . . . . . . . . . . . . . . . . . . . . . 55Identifying Sources With “Significant” Potential To Contribute Substances

to Groundwater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Chapter 2 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

TABLESTabIe No. Page1. Substances Known to Occur in Groundwater, Ranges of Detected Concentrations,

Exceeded Standards, Examples of Uses, and Quantitative Estimates ofCarcinogenic Potency and Noncarcinogenic Toxicity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

2. Examples of Economic, Environmental, and Social Impacts Resulting FromGroundwater Contamination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

3. Examples of Economic Costs Resulting From Contaminated Groundwater . . . . . . . . . . . 394. Potential Groundwater Contaminants Displaying Serious Adverse Health Effects . . . . . 445. Sources of Groundwater Contamination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 456. Sources and Classes of Associated Substances. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 487. Summary of Source Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 508. Numbers of Sources and Amounts of Material Flowing Through or

Stored in Sources, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 529. “Important” Sources of Groundwater Contamination

Based on Selected Sets of Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Chapter 2

Groundwater Contamination and Its Impacts

CHAPTER OVERVIEW

Groundwater is an increasingly important re-source in the United States—it is relied on for about50 percent of drinking water supplies; it is used tosupply water for almost 80 percent of rural domesticand livestock needs, about 40 percent of irrigationneeds, many commercial activities, and almost 25percent of self-supplied industrial needs (other thanthermoelectric power); it is used for stream flowmaintenance and as a barrier to salt-water intru-sion; and it is both an intentional and unintentionaldepository for society’s waste and non-waste prod-ucts (USGS, 1983a).

The degree of reliance on groundwater varies sig-nificantly around the Nation. For example, ground-water withdrawals for public water supplies varyfrom 11 percent in the Great Lakes region to 75percent in the Rio Grande region, for rural usesfrom 12 percent in the Upper Colorado to 100 per-cent in New England, and for irrigation from 1 per-cent in the Upper Colorado to over 90 percent inthe Upper Mississippi.

Contamination of the Nation’s groundwater re-source has recently become an issue of widespreadpublic concern. This chapter analyzes currentknowledge about the nationwide extent of con-tamination, the substances known to occur ingroundwater and their associated impacts, andknown sources of contamination. Specific topicsaddressed are:

● the extent of groundwater contamination anddifficulties in its assessment;

● substances known to occur in groundwater andtheir uses;

● health impacts of contamination;. non-health impacts of contamination (e. g.,

economic and environmental impacts);

1 Substance is defined in this study as any organic or inorganic chem-ical, micro-organism, radionuclide, or other material (e. g., sediments).Whether or not a substance is a ‘ ‘contaminant’ depends on its asso-ciation with adverse impacts and on other site-specific factors (e. g,,hydrogeology).

●

●

●

●

●

concentration and frequency of compounds ingroundwater;potential but as yet undetected substances ingroundwater;types of sources and their associated sub-stances;factors influencing a source’s potential to con-taminate groundwater (including estimates ofnumbers of sources and amounts of materialflowing through or stored in sources); andthe potential for sources to contaminategroundwater.

Major conclusions drawn from this information aresummarized below.

The portion of the Nation’s groundwater re-sources that is contaminated is believed by expertsto be small. No matter how small, this portion isnevertheless significant because of its location nearheavily populated areas and because of the manyuses of and increasing dependence on groundwater.The site-to-site variability of contamination, com-bined with the expense and time required to inves-tigate potential contamination problems, meansthat a detailed nationwide description of ground-water quality may never be attainable.

A variety of adverse impacts due to groundwatercontamination is possible—including effects onpublic health, the environment, agricultural pro-ductivity (e. g., due to increased salinity in irriga-tion water), and on the output of industries requir-ing high-quality water. Public attention has focusedprimarily on the potential for health effects; becauselittle information is available on other impacts, thischapter focuses on potential damage to humanhealth.

Even if a comprehensive description of ground-water quality were available, the magnitude andexact nature of public health effects resulting fromcontamination could not be estimated with confi-dence. At best, evidence would involve the docu-mentation of effects attributable to contamination,

19

20 • Protecting the Nation’s Groundwater From Contamination

with predictions regarding the magnitude and typesof future effects. This type of information is typ-ically obtained from risk assessment analyses,wherein data on: 1 ) the adverse effects and 2) tox-icity (i. e., dosage levels at which adverse effects areobserved) of substances are linked with 3) exposuredata to identify probabilities of adverse impacts onhuman health.

Data limitations preclude a risk assessment of themagnitude of public health risks from groundwater.Some of the data required for risk assessment analy-sis of groundwater contamination are available, pri-marily regarding known or possible hazards andknown toxicities, but much of this information isnot precise enough. Almost no data are availableon human exposure to the substances of concern.These types of data are not likely to be obtainablein sufficient detail in most cases because of the in-herent limitations of epidemiological investigations.For example, data would be needed—and, again,are probably unattainable—on the amount of ex-posure to substances from only groundwater (e. g.,as opposed to exposure to the same substances fromother media such as air and surface water), on thenumber of people exposed to various concentra-tions, and on interactions among substances whenmore than one substance is present.

Although the magnitude of the impacts of ground-water contamination cannot be estimated with con-fidence, the nature of many impacts is known.There is also a substantial body of indirect evidenceindicating the large potential for groundwater con-tamination and subsequent health effects. Over 200substances have already been detected in ground-water—substances that are used throughout society

in a multiplicity of commercial, industrial, andhousehold activities. For some, but not all, of theseknown substances, information is available abouttheir adverse effects on laboratory animals andhumans, toxicity levels, and the range of concen-trations found in groundwater. Many of the sub-stances present in groundwater can cause liver andkidney damage, damage to the central nervous sys-tem, cancers, and eye and skin irritation.

The pathways by which substances eventually en-ter groundwater are diverse and extremely com-plex—i.e., they can enter during production, han-dling, storage, processing, disposal, transport, anduse. One focal point along these pathways, whichCongress has started to address in recent legisla-tion, is the sources from which contaminants en-ter groundwater. Sources of contamination are con-venient for assessing possible detection, correction,and prevention actions. At least 33 major sourcesare known. There is a vast diversity among sourcesin terms of their associated substances, releasecharacteristics, amounts of materials, geographiclocation, and role in society.

So far, most attention given to sources has con-cerned waste discharges (particularly hazardouswastes) from point sources. As shown by OTA’Sanalysis, many potential sources of contaminationalso are associated with both non-hazardous wastesand non-waste products; and contaminants can en-ter groundwater from both point and non-pointsources. Important advances have been made inthe information base concerning sources since theU.S. Environmental Protection Agency’s 1977 Re-port to Congress on waste disposal practices (EPA,1977),

EXTENT AND NATURE OFGROUNDWATER CONTAMINATION

Assessing the Nationwide Extent of and the Safe Drinking Water Act—groundwaterGroundwater Contamination contamination has historically received little atten-

tion at the national level. One major reason wasAlthough contamination of surface water has the common belief that groundwater was pristine,

long been of concern to the public and to Con- i.e., that potential contaminants percolating throughgress—as demonstrated by passage of the Federal the subsurface would adhere to the soil or be de-Water Pollution Control Act (the Clean Water Act) graded by natural processes and, therefore, would

Ch. 2—Groundwater Contamination and Its Impacts ● 2 1

} Unsaturated zone

Unconfined aquifer (fresh groundwater)

Confined aquifer(fresh groundwater)

Confined aquifer(brackish groundwater)

Credit: Geraghty & Miller, 1983

Pathways of groundwater contamination vary depending on the source. Examples of sources are shown here for eachof OTA’S six source categories (I-VI) (see the section on Types of Sources and Associated Substances, below).

not enter or greatly affect groundwater quality.Thus the subsurface, and groundwater, had beenregarded as a safe and convenient depository forthe wastes and non-waste byproducts generated bysociety.

But there is a growing consensus that the qualityof groundwater is in decline. Incidents of contami-nation are being reported with increasing frequencyand have now occurred in every State. Althoughthe activities and practices that cause contamina-tion are varied and were often begun many yearsago, groundwater contamination recently has cometo the attention of the public, primarily in the con-text of threats to human health. Most of the atten-tion has focused on sources associated with hazard-ous wastes (e. g., landfills, surface impoundments,and waste piles) because of the severity of their im-pacts on surrounding populations and environ-ments—groundwater has been seriously contami-nated by toxic chemicals associated with thesesources in at least 34 States (CEQ 1981). How-ever, non-hazardous wastes and non-wastes alsocontribute to the contamination of groundwater.

A small amount of the Nation’s groundwater isgenerally believed to be contaminated (estimatesrange from about 1-2 percent). Although this por-tion may seem very small, it is significant because

contamination is often near heavily populated areasand groundwater is being increasingly relied on fora variety of uses.

The extent of groundwater contamination is alsolikely to be greater than 1-2 percent. Descriptionsof groundwater quality problems often includeanecdotal or non-comparable data, making themdifficult to interpret and analyze. In addition, muchof the current information on the extent and mag-nitude of contamination reflects only the nature ofinvestigations —where and which substances havebeen looked for and where they have been found.For example, groundwater that is not used for pub-lic drinking water supplies is not always tested, andmore information is generally available about haz-ardous waste sources than about non-point sourcesand sources with non-hazardous wastes and non-waste products. Further, substances known to con-taminate groundwater are used throughout society;thus, more widespread detection of contaminationcan be expected as efforts increase to monitorknown, as yet undetected, and potential problems.Little is known about how much contamination isreversible and how rapidly new sites and sourcesof contamination are being created.

A complete description of contamination wouldrequire detailed information about groundwater

“ ” ” ” ” ” ” ” - – – - - ,

Thirty-four of the 100 largest cities in the United

quality on a site-by-site basis throughout the Na-tion and about associated site-specific hydrogeologicconditions (e. g., the vulnerability of groundwaterto the entrance of substances). A difficulty in assess-ing the extent of groundwater contamination is thatnot all substances entering groundwater may haveadverse impacts. Whether the presence of sub-stances in groundwater results in a contaminationproblem depends on site-specific hydrogeology, thepotential for adverse impacts (health, economic,environmental, and social), current and futuregroundwater use patterns, the exposure of humansto the substances, the availability of alternativewater supplies, and the feasibility of correctivemeasures including management alternatives.

The lack of data about groundwater quality stemsfrom the technical complexity of groundwater.Groundwater and associated problems often can-not be directly observed and are not easily meas-

Photo credit: State of Florida Department of Environmental Regulation

States rely completely or partially on groundwater.

ured, and the behavior of substances in ground-water is not well understood—the movement ofsubstances varies temporally and spatially in dif-ferent hydrogeologic environments, and chemicaland biological processes can alter the nature andsubsequent behavior of substances. For these rea-sons, groundwater contamination problems arehighly site-specific. Given this complexity and thecosts and time that would be needed to gather data,a complete description of groundwater quality maynever, for all practical purposes, be attainable.

Substances Known to Occurin Groundwater

As part of the OTA study, information wasgathered that documents the presence of over 200substances known to occur in the Nation’s ground-water. Specific substances detected in groundwater

Ch. 2—Groundwater Contamination and Its Impacts ● 2 3

thus far, and examples of major uses of these sub-stances, are shown in table 1. These substances in-clude about 175 organic chemicals, over 50 inor-ganic chemicals (metals, non-metals, and inorganicacids), biological organisms, and radionuclides.

The presence of substances in groundwater andan understanding of how, why, and where they arepresent are directly related to their use and/ordisposition. As shown in table 1, many substancesfound in groundwater are widely used by indus-try, agriculture, commerce, and households. Po-tential contaminants can thus enter groundwaterat numerous points as materials flow through so-ciety. Although most points-of-entry are associatedwith particular sources, the sources themselves arenot the only places for controlling the entry ofsubstances to groundwater (preventive strategies arediscussed in chs. 11 and 12). However, focusingon sources is convenient to, assess how substancesenter groundwater. The relationship between sub-stances and specific sources is discussed below inTypes of Sources and Associated Substances.

HEALTH

General Issues

Many naturally occurring and synthetic sub-stances can cause biological injury, disease, or deathunder certain conditions of exposure. Whether in-jury or illness occurs depends on many factors, in-cluding properties of the substance, dosage of andexposure to the substance, and characteristics of theindividuals exposed. Many of the diseases and ef-fects associated with groundwater contaminants arediscussed below; however, data are insufficient fordetermining the relative importance of these con-taminants in causing various effects.

Relationships between health impacts and dif-ferent groups of substances-organic and inorganicchemicals (non-radioactive), micro-organisms, andradionuclides— are not understood with the samedegree of knowledge and certainty. For example,there is a long history of public health efforts to un-

Detection of substances in groundwater is biasednot only by sampling and analytical limitations (seech. 5) but also by the circumstances that prompteddetection and reporting. There appear to be twomajor circumstances under which substances arebeing detected in groundwater: 1) as the result ofplanned activities (e. g., regulatory compliance,analysis and data management activities, routinemonitoring, research, and liability protection); and2) in response to apparent impacts (e. g., citizencomplaints stemming from the observable or fearedpresence of substances, accidents, and aerial pho-tography) (University of Oklahoma, 1983). Thetwo most frequently cited reasons for detection ofsubstances are regulatory compliance as a plannedactivity and response to public complaints. Relianceon public observation probably will not lead to thedetection of many substances—most substancesof concern are odorless, colorless, andunobservable without use of specialequipment.

IMPACTS

derstand and address micro-organisms,. . .

otherwiseanalytical

albeit pri-marily in surface water, and many sources of dataare available. Radionuclides have been studied ex-tensively since the 1940s, and much is now knownabout their health impacts, although not often atlow concentrations. In contrast, health effectsresulting from exposure to many chemicals are notwell understood, in large part because of the rela-tively recent occurrence of and exposure to certainchemicals in the environment. Health effects ofchemicals are of the greatest concern because chem-icals are pervasive and persist in the environment.

Assessing risks from substances in groundwaterrequires information about adverse effects, toxicity,and exposure (extensive details on risk assessmentare available in NAS, 1983, and Environ Corp. ,1983; a brief summary is presented in app. A. 1.);and available data are often insufficient to conductsuch an assessment. Thus human health impair-

Table 1 .—Substances Known to Occur in Groundwater, Ranges of Detected Concentrations, Exceeded Standards, Examples of Uses, andQuantitative Estimates of Carcinogenic Potency and Noncarcinogenic Toxicitya

Carcino- Noncarcino-

Contaminant Concentration b

genie genieStandardC Examples of usesd potency e,f toxicititye,g

Aromatic hydrocarbons. , . . . . .

Acetanilide-A!kyl benzene sulfonatesAniline

AnthraceneBenzeneBenzidineBenzyl alcohol

ButoxymethylbenzeneChryseneCreosote mixtureDiben[a.h.]anthraceneDi-butyl-p-benzoquinoneDihydrotrimethylquinoline4,4-DinitrosodiphenylamineEthyl benzeneFluorantheneFluoreneFluoresceinIsopropyl benzene4,4’-Methylene-bis-2-chloroaniline

(MOCA)MethylthiobenzothiazoleNaphthalene

o-Nitroaniline

Nitrobenzene4-Nitrophenoln-NitrosodiphenylaminePhenanthrenen-PropylbenzenePyreneStyrene (vinyl benzene)Toluene

1,2,4-Trimethylbenzene

Xylenes (m,o,p)

(parts per billion)—

1 8h

0.6-20,230

10

0.9-4,00031

290

6.7-82

18-471h

48

0.1-6,400

0.07-300

Oxygenated hydrocarbonsAcetic acid

photographic chemicals, insecticides

LowHigh

Low

Low

Low

Moderate

LowLow

Low

Low

●

Table 1 .—Substances Known to Occur in Groundwater, Ranges of Detected Concentrations, Exceeded Standards, Examples of Uses, andQuantitative Estimates of Carcinogenic Potency and Noncarcinogenic Toxicitya—continued

oOxygenated hydrocarbons (cent’d) (parts per billion)

IAcetone 1O-3,OOO Dyestuffs, solvent, chemical manufacturing, cleaning and

drying of precision equipmentOrganic synthesis, odor fixative, flavoring, pharmaceuticalsSolventPlastics, intermediatePlasticizer, solvent, adhesives, insecticides, safety glass,

inks, paper coatingsChemical manufacturing, solvent, analytical chemistry,

anesthetic, perfumesPlastics, explosives, solvent, insecticides, perfumesSolvent, rubber cements, paint and varnish removersIntermediate, solvent, lubricantPharmaceuticals, plastics, disinfectants, solvent, dyestuffs,

insecticides, fungicides, additives to lubricants andgasolines

Plasticizer for polyvinyl chloride and other vinylsSolvent, lacquers, paints, varnishes, cleaning and detergent

preparations, fumigants, paint and varnish removers,wetting agent, cosmetics

Polymers, acrylic paints, intermediateDyeing and finishing, chemicals, manufacture of fumigants,

insecticides, solvents, plastics, refrigerantsChemical manufacturing, solvents, automotive antifreeze, fuelsSolvent, lacquersSolvent, paint removers, cements and adhesives, cleaning

fluids, printing, acrylic coatingsNal

Resins, solvent, pharmaceuticals, reagent, dyestuffs andindicators, germicidal paints

Dyestuffs, medicine, perfumes, reagentChemical manufacturing, solvent, deicing agent, pharmaceu-

ticals, perfumes, lacquers, dehydrating agent, preservativesSolventSolventPaint and varnish thinner

Low

Low

Low

BenzophenoneButyl acetaten-Butyl-benzylphthalateDi-n-butyl phthalate

I

10-38470

●

●

wDiethyl ether

Diethyl phthalateDiisopropyl ether2,4-Dimethyl-3-hexanol2,4-Dimethyl phenol

20-34

Di-n-octyl phthalate1,4-Dioxane

Ethyl acrylateFormic acid

Methanol (methyl alcohol)MethylcyclohexanoneMethyl ethyl ketone

High

Methylphenyl acetamidePhenols (e.g., p-Tert-butylphenol) 1O-234,OOO ●

Phthalic acid2-Propanol

2-Propyl-1-heptanolTetrahydrofuranVarsol

Hydrocarbons with specific elements(e.g., with N, P,S,Cl,Br,l,F)Acetyl chlorideAlachlor (Lasso)Aldicarb (sulfoxide and sulfone;

Temik)AldrinAtrazineBenzoyl chlorideBromacilBromobenzene

Dyestuffs, pharmaceuticals, organic preparations● Herbicides● Insecticide, nematocide

190-1,70038-405

ModerateHigh

HighModerate

ModerateModerate

● Insecticides● Herbicides, plant growth regulator, weed control agent

Medicine, intermediate* Herbicides

Solvent, motor oils, organic synthesis72-1101.9-5.8

(e:g., with N,P,S,CI,B;,I,F) (cent’d) (parts per billion)—

1.4-1102.4-1104-160

0.3-18,700

2.7-411.4-1,890

—44

83

2.4—

2.1-551-137

—35-300

44.9—2.7

0.6-0.7

0.01-0.8

0.05-0.22

0.5-11.330

●

●

●

Low

ModerateModerate

Moderate

Moderate

Low

Moderate

Moderate

Moderate

Low

High

Low1,1-Dichloroethane r

Ch. 2—Groundwater Contamination and Its Impacts ● 2 7

cl o ).- .-1 1

. -x

l

5-E%—

)—

* ● ☛ ● ● ● * * ● ● 0

E-0.-—

oo

o0 II I I I

n—

II

I-.

Hexachloroethane

Trichlomethanes (1,1,1 and 1,1,2)1,1,2-Trichloroethylene (TCE)

(parts per billion)6

3.8

0.5-43

4.6

7.44.6——

8-40—

3,400

5,–m4

717-2,405

1-5702

37

0.2-26,000210-37,000

26——

● Insecticides

● Insecticides

● Insecticides

●

●

●

●

●

●

●

Intermediate for resins, dyestuffs, pesticides, fungicides,pharmaceuticals

Solvent, pyrotechnics and smoke devices, explosives,organic synthesisN Ai

PesticidesInsecticidesInsecticidesFumigants, pesticides, organic synthesisInsecticidesInsecticidesInsecticides, fungicides, bactericide, algicides, herbicides,

wood preservativeInsecticides

●

•●

●

Flame retardant for plastics, paper, and textilesHeat-exchange and insulating fluids in closed systemsHerbicidesExplosivesHerbicidesN Ai

Degreasers, paint removers, varnishes, lacquers, photo-graphic film, organic synthesis, solvent, insecticides,fumigants, weed killer

Degreasers, drycleaning, solvent, drying agent, chemicalmanufacturing, heat-transfer medium, vermifuge

InsecticidesHerbicidesSolvent, dyestuffs, insecticides, lubricants, heat-transfer

medium (e.g., coolant)Pesticides, degreasers, solventDegreasers, paints, drycleaning, dyestuffs, textiles, solvent,

refrigerant and heat exchange liquid, fumigant, inter-mediate aerospace operations

Solvent, refrigerants, fire extinguishers, intermediateFungicides, herbicides, defoliant

● Herbicides, defoliant

Low

LowModerate

Moderate

Moderate

Low

Moderate

LowLow

Moderate

High

Moderate

HighModerate

ModerateLow

Moderate

Ch. 2—Groundwater Contamination and Its Impacts ● 2 9

)

● ● * ● * * ● ☛ *

I I I

t-0-

Metals and cations (cent’d)Chromium

Cobalt

Copper

IronLead

LithiumMagnesium

ManganeseMercury

MolybdenumNickelPalladium

PotassiumSeleniumSilver

Sodium

ThalliumTitaniumVanadium

Zinc

Nonmetals and anionsAmmonia

BoronChlorides

Cyanides

FluoridesNitratesNitritesPhosphatesSulfatesSulfites

(parts per million)0.06-2,740

0.01-0.18

0.01-2.8

0.04-6.2000.01-5.6

—0.2-70

0.1-1100.003-0.0”

0.4-400.05-0.5

—

0.5-2.40.6-209-330

3.1-211

——

243

0.1-240

1-900

—1,0-49,500

1.05-14

0.1-2501.4-433

0.4:330.2-32,318

—

●

●

☛

●

●

●

●

●

●

●

●

●

●

☛

●

●

●

●

●

●

●

●

●

Alloys, electroplating, electronics, automotive parts, fungi-cides, roofing, cable wrappings, nutrition

Fertilizers, chemical manufacturing, refrigerants, syntheticfibers, fuels, dyestuffs

Alloys, fibers and filaments, semi-conductors, propellantsChemical manufacturing, water purification, shrink-proofing,

flame-retardants, food processingPolymer production (heavy duty tires), coatings, metallurgy,

pesticidesToothpastes and other dentrifices, additive to drinking waterFertilizers, food preservativesFertilizers, food preservativesDetergents, fertilizers, food additivesFertilizers, pesticides

High

High

Moderate

High

Low

HighHigh

Moderate HighLow

HighHigh

HighLow

High,moderateModerate

High

Moderate

Pulp production and processing, food preservatives

●

Table I.—Substances Known to Occur in Groundwater, Ranges of Detected Concentrations, Exceeded Standards, Examples of Uses, andQuantitative Estimates of Carcinogenic Potency and Noncarcinogenic Toxicitya—continued

Carcino- Noncarcino-

(parts per million)— ●

(picocuries permilliliter)

—

6.4

Iron 59 —

Lead 210 —Phosphorus 32 —

Plutonium 238, 243Radium 226 0.8-25Radium 228 12.5Radon 222 — ●

Ruthenium 106 —Scandium 46 —Strontium 90 0.817 ●

Thorium 270 —Tritium 150-353 ●

Uranium 238 10-500 ●

Zinc 65 —

genie genieExamples of usesd potency e,f toxicity e,g

Gamma radiation source for certain foodsDiagnosis of blood volume, blood cell life, cardiac output, etc.Radiation therapy, irradiation, radiographic testing, researchMedical diagnosis, therapy, leak detection, tracers (e.g., to

study efficiency of mixing pulp fibers, chemical reactions,and thermal stability of additives to food products),measuring film thicknesses

Medicine, tracerN Ai

Tracer, medical treatment, industrial measurements (e.g., tiretread wear and thickness of films and ink)

Energy source weaponryMedical treatment, radiographyN Ai

Medicine, leak detection, radiography, flow rate measurementCatalystTracer studies, leak detection, semi-conductorsMedicine, industrial applications (e.g., measuring thicknesses,

density control)NAi

Tracer, luminous instrument dialsNuclear reactorsIndustrial tracer (e.g., to study wear in alloys, galvanizing, body

metabolism, function of oil additives in lubricating oils)

CA

32 ● Protecting the Nation’s Groundwater From Contamination

ment is not easily linked to substances found ingroundwater. Adverse effects and toxicity are dis-cussed below. With respect to exposure, five pos-sible pathways of human exposure have been iden-tified (Environ Corp., 1983):

1. direct ingestion through drinking;2. inhalation of contaminants (e. g., during show-

ering);3. skin absorption from water;4. ingestion of contaminated food; and5. skin absorption from contaminated soil.

Except for drinking water containing known levelsof substances, there appear to be no general mod-els available for estimating exposure through theseroutes.

Adverse Impacts of Chemicals

Many of the chemicals detected in groundwaterare known or suspected to cause a variety of adversehealth effects, including depression of central ner-vous system functions, liver and kidney damage,and eye and skin irritation. Some of these chemi-cals are known or suspected human carcinogens.The discussion below summarizes the known ad-verse effects of individual chemicals found ingroundwater; the data upon which the summaryis based are shown in appendix A.2.

Much of the data reviewed below concerning theeffects of chemicals is derived from experimentalstudies on laboratory animals, but some informa-tion (e. g., acute effects such as eye and skin irrita-tion, some cancers) is based on studies of humanpopulations. The inference of human health effectsfrom animal studies is controversial and is reviewedelsewhere (Environ Corp., 1983). However, formany chemicals, data from laboratory studies arethe only means available for assessing potential im-pacts upon humans. Although there is usually nodirect, conclusive evidence that these effects are in-duced at the concentrations at which these chemi-cals are detected in groundwater, a variety ofinformation— qualitative human health studies con-ducted at sites of groundwater contamination (e.g.,at Hardeman County, TN; Harris, et al., no date),data on human health impacts of specific chemi-cals (whether studied directly in humans or in-

directly in laboratory animals), and much anecdotalinformation—suggests that the consumption ofgroundwater contaminated with chemicals can re-sult in acute, subchronic, and chronic human healthimpacts. An important recent study shows a sta-tistically significant relationship between two wellscontaminated with chloroform and TCE and ele-vated leukemia and birth defect rates in Woburn,MA (reported in Science News, 1984).

Apart from the controversial nature of labora-tory data, the information in appendix A.2 is alimited data base because:

●

●

●

●

not all chemicals have been tested for allimpacts,documentation is not available for cases inwhich specific impacts were not observed dur-ing studies of specific chemicals,chemicals that dominate the list of potentialhealth effects are the ones that have been mostthoroughly studied, andthe data were obtained from secondary sources.

Thus the purpose of appendix A.2 is not to estab-lish either that effects will be realized with certaintyin exposed human populations or the probabilityof their occurrence. Rather, the information shownshould be viewed as an indication of the nature ofpotential human health impacts from substances ingroundwater.

A given effect can be caused by numerous chem-icals (see app. A. 2). The effects associated with thelargest numbers of chemicals include (in decreas-ing order of the number of chemicals known tocause these effects): eye and skin irritation, effectson the central nervous system, liver damage, lungand respiratory tract effects, kidney damage, can-cers, and genetic mutation. Of these effects, anddepending on dosage, central nervous system(CNS) damage, liver and kidney damage, andcancers may be the most commonly expected seri-ous forms of adverse health impacts associated withknown groundwater chemical contaminants (En-viron Corp. , 1983). More specifically:

1. Liver, kidney, and CNS toxicants includeethylbenzene and toluene (alkyl-substitutedbenzenes); carbon tetrachloride, chloroform,and TCE (halogenated aliphatic hydrocar-bons); bromobenzene, PBBs, and PCBs (halo-

Ch. 2—Groundwater Contamination and Its Impacts ● 3 3

genated aromatic hydrocarbons); chlordane,DDT, and toxaphene (chlorinated hydrocar-bon pesticides); and some heavy metals.

2. Known or suspected carcinogens listed in table1 include 32 of the organic chemicals-chlori-nated aliphatic hydrocarbons and chlorinatedhydrocarbon pesticides—and 5 of the heavymetals (3 of which may be active only via in-halation). The evidence for human carcino-genicity of some substances has been obtainedfrom human studies and is quite strong. Thereis very little doubt that benzene, benzidine,inorganic arsenic, vinyl chloride, chromium,and nickel are human carcinogens (the lattertwo, however, are not likely to be present ingroundwater in their carcinogenic forms).

Studies of experimental animals where thepredominant effect is on the rodent liver pro-vide the main evidence for carcinogenicity ofchlorinated aliphatic hydrocarbons (e. g., car-bon tetrachloride, chloroform, TCE, PCE,and others; note from above that vinyl chlor-ide is an exception) and chlorinated hydrocar-bon pesticides (e. g., aldrin, chlordane, DDT,dieldrin, heptachlor, toxaphene, and others).It is also possible that nitrates are transformedinto nitrosamines, which are carcinogenic inlaboratory animals (NAS, 1977).

In a review of 31 substances commonlyfound in groundwater (Crump, et al., 1980,cited in Harris, 1983), two compounds withknown human carcinogenic effects were docu-mented. In addition, 12 compounds (includ-ing six chlorinated aliphatic hydrocarbons andfour chlorinated hydrocarbon pesticides) hadcarcinogenic effects in at least one laboratoryanimal species and two compounds had effects

suggestive of carcinogenicity. Despite somescientific debate on the biological relevance ofthese findings for humans (Environ Corp.,1983), Federal regulatory agencies considermany of these substances potential human car-cinogens. One compound had no observableeffects in preliminary tests, and 14 chemicalshad not even been tested in animal exper-iments.

3. Only a few compounds are known to be ca-pable of damaging the reproductive system orcausing birth defects, but some of them arewidely used throughout society. The major

4.

In

substances in this category are DBCP, vinylchloride, EDB, benzene, toluene, and xylene(Harris, 1983) and selected chlorinated eth-anes and phthalate esters, PCBs, and thechlorinated dibenzo-p-dioxins (Environ Corp.,1983).Skin and eye irritation, particularly duringshowering and bathing, might be expectedwhen chemicals are found in groundwater.Data suggest that these effects are reversibleupon cessation of exposure.

Potential Toxicity orPotency of Chemicals

addition to requiring information on the gen-eral adverse effects of groundwater contammants,a standard risk assessment analysis requires infor-mation on the non-carcinogenic toxicity and car-cinogenic potency of the chemicals. That is, adverseeffects are associated with certain chemicals, butthey are elicited at only certain dosages and/or ex-posure levels —and different chemicals have differ-ent abilities to elicit those effects. As part of OTA’sstudy, chemicals found in groundwater were rankedaccording to their relative degree of non-carcino-genic toxicity and carcinogenic potency using dose-response data when available (see table 1; EnvironCorp., 1983).2 Three broad categories are defined:‘ ‘high, ‘‘ ‘‘moderate, and ‘ ‘low’; note that thedefinitions shown in table 1 are different for non-carcinogenic toxicity and carcinogenic potency.

Based on these broad rankings, the followinggeneral conclusions are drawn (Environ Corp.,1983):

1.

2.

Some chemicals are of high toxicity and canelicit non-carcinogenic responses (e. g., liver,kidney, and CNS damage) at relatively lowdoses and/or exposure levels. These chemicalsinclude endosulfan, endrin, and kepone (pes-ticides), and heavy metals (see table 1).Many other chemicals with potential to affectthe liver, kidney, and CNS are of low to mod-erate toxicity and thus require higher dosesand/or exposure levels to elicit these effects.

‘The susceptibility of humans to various substances is also variableamong individuals and is affected by factors such as age, general health,and genetic background.

34 “ Protecting the Nation’s Groundwater From Contamination

3.

These chemicals include trichlorofluorometh-ane, bromochloromethane, chloromethane,and 1,1 -dichloroethane (halogenated aliphatichydrocarbons), bromobenzene and dichloro-benzene (halogenated aromatic hydrocar-bons), and ethylbenzene and toluene (alkyl-substituted benzenes).Substances with high to moderate carcinogen-ic potency can elicit carcinogenic responses atrelatively low doses and/or exposure levels.These chemicals include aldrin, DDT, diel-drin, and chlordane (pesticides), carbon tetra-chloride, chloroform, and 1,1 -dichloroethy -lene (halogenated aliphatic hydrocarbons),benzidine (an aromatic amine), and PCBs(halogenated aromatic hydrocarbons).

There are substantial numbers of chemicalsknown to occur in groundwater for which no tox-icity or potency data are available (beyond someacute effects). Approximately two-thirds of theorganic chemicals and one-half of the inorganicchemicals listed in table 1 may not have associatedtoxicity or potency data. 3 In addition, substancesnot generally thought of in terms of toxicity orpotency (e. g., salt water, micro-organisms, or ni-trates) can also contaminate aquifers, causing bothhealth and non-health impacts.

3Data may be available for these substances in sources not reviewedby OTA.

Photo credit: State of Florida Department of Environmental Regulation

Research on health impacts will provide informationnow lacking about many groundwater contaminants.

Interactions Among MultipleChemicals

One of the potentially most important, and asyet relatively unexplored, health issues of ground-water contamination is that contaminated aquifersusually contain more than one substance. Knowl-edge is almost totally lacking about possible inter-actions among combinations of substances. Suchinteractions, in which subsequent impacts are quali-tatively and quantitatively different than expected(and usually greater—i.e., synergistic), are com-mon in many chemical and biological processes(Odum, 1971).

At least one type of synergistic interaction hasbeen identified that is of potential importance ingroundwater: the liver toxicity of carbon tetrachlor-ide, TCE, and 1 ,1,1 -trichloroethane (halogenatedaliphatic hydrocarbons) is known from animal ex-periments to increase greatly in the presence ofalcohol. This effect has been confirmed in humancase studies for carbon tetrachloride and TCE(Radike, et al., 1977; EPA, 1980a and b). Livertoxicity of TCE and PCE is also affected by Aroclor1254, a polychlorinated biphenyl (PCB) (seeNRDC, 1982; EPA, 1980c).

Biological Substances

Pathogenic biological organisms that have beenfound in groundwater include:

1. bacteria (e. g., typhoid, bacillary dysentery,cholera, gastroenteritis, and tuberculosis);

2. viruses (e. g., enteroviruses and hepatitis); and3. parasites (e. g., protozoa, worms, and fungi).

The micro-organisms most frequently found ingroundwater are bacteria that inhabit the gastro-intestinal tract, and the most common category ofdisease resulting from micro-organisms in ground-water is gastrointestinal. Contaminated ground-water was identified as the cause of approximatelyone-half of all outbreaks of acute waterborne dis-ease occurring in the United States from 1971 to1977, and bacterial contamination has been themost frequently identified source of groundwater-related disease outbreaks (e. g., EPA cites 94 suchoutbreaks between 1945 and 1980; see EnvironCorp., 1983). The potential for bacterial contami-

Ch. 2—Groundwater Contamination and Its Impacts • 35

nation of groundwater depends on both the survivalrate of the species and characteristics of the sub-surface (e. g., moisture content, pH, and temper-ature). Bacterial contamination most commonlyresults from the introduction of human (or animal)fecal material, usually when septic tanks or cess-pools leak or overflow (Environ Corp., 1983).

Viruses and parasites have been implicated ingroundwater contamination incidents in relativelyfew instances. The low rate for viruses may be at-tributed to limitations in detection methods (En-viron Corp. , 1983). The analytical limitations re-garding detection of viruses, coupled with estimatesby the World Health Organization that about 60percent of the cases of waterborne disease reportedin the United States are caused by unrecognizedor unknown agents, suggest that viral contamina-

tion of drinking water (including groundwatersources) may be of greater significance than hasbeen recognized (Environ Corp., 1983). The prin-cipal sources of viruses in groundwater are sewageeffluent (e. g., from septic tanks, cesspools, and landapplication practices), animal feedlots, and dairies.The factors that affect the occurrence of viruses ingroundwater are complex and poorly understood;it is likely that they are similar to those for bacteria.

Radioactive Substances

Most groundwater contains trace levels of natu-rally occurring radioactive substances or their by-products. The types and levels vary from area toarea, depending principally on subsurface materi-als. In addition to natural radiation, radioactive

A , - - - - A - L , -

Credit: Southeast Michigan Council of Governments, 1982

Septic systems can cause both biological and chemical contamination of groundwater and surface water.

36 . Protecting the Nation’s Groundwater From Contamination

substances in groundwater can result from humanactivities. These sources include radioactive wastedisposal sites, waste tailings and piles, and minedrainage related to uranium mining.

Health protection from radiation is a highly de-veloped science, and data accumulated over manyyears link adverse health effects and exposure. Im-portantly, health effects are generally understoodonly at high exposure levels; only in isolated cir-cumstances are these levels of radioactivity likelyto occur in groundwater. The National Academyof Sciences, in its discussion of the health risks ofradioactive drinking water (NAS, 1977), estimatedtotal average body exposure from drinking contam-inated water at less than 1 percent of total averageyearly background radiation exposure received bythe population (total exposure is approximately 100mrem/year). The risk of cancer from total averagenatural background radiation is estimated at 4.5to 45 fatalities per million persons per year (esti-mates depend on particular assumptions; NAS,1977), including 0.6 fatal cases of bone cancer permillion persons per year.

Because radioactive content can vary from aver-age conditions, there can be situations in which

doses are significantly greater than average. For ex-ample, in areas with high groundwater radium lev-els (e. g., 25 pCi/liter of Ra226 and 12.5 pCi/literof Ra228), exposure of the human skeleton couldbe as much as a sixfold increase (up to 600 mrem/year) over that from all natural background sources.Radiation in groundwater could thus be a seriousproblem in localized areas, e.g., parts of NewEngland (Harris, 1984; Duncan, et al., 1976, citedin Prichard et al., 1983). Under the “high”groundwater radium levels mentioned above, therisk of fatal bone cancer could increase to an esti-

mated 4.2 fatalities per million persons per year.

Radiation exposure can also cause developmentalor teratogenic effects; the lowest dose at which anydevelopmental or teratogenic effect has been re-ported is 1,100 mrem/year. Under ‘ ‘average’ con-ditions, doses received by the population are sosmall that no measurable developmental or tera-togenic effects from drinking radioactive ground-water would be found, even during the sensitiveperiod of gestation (NAS, 1977).

NON-HEALTH IMPACTS

There is a general absence of both methodologi-cal experience and data on evaluating the non-health impacts—economic, environmental, andsocial—of groundwater contamination. Examplesof these impacts are shown in table 2. Because avail-able data are insufficient for quantifying or other-wise comparing most of these impacts, this sectionfocuses on the nature of non-health impacts andthe difficulties in their assessment.

Economic Impacts

Data about various types of economic impactsassociated with groundwater contamination aregenerally not available (University of Oklahoma,1983). The data that are available tend to be thedirect costs of corrective action; and they either en-compass such a broad range that they are difficult

to interpret apart from site-specific conditions (e. g.,Corrective actions can cost tens of millions of dollarsor more depending on site conditions), or they lacksufficient documentation (e. g., in terms of describ-ing site conditions) for subsequent comparison andanalysis. Some data may also be unobtainable be-cause of their proprietary nature or use in litigation.

In addition to empirical difficulties, there aremethodological difficulties in assessing the value ofgroundwater quality in terms of both the costs ofcontamination and the benefits of protection. Fewstudies are available that systematically approachan assessment of economic impacts (see Raucher,1983; Sharefkin, et al., 1983; Reitman, 1982).These conceptual difficulties, some of them com-mon to the assessment of impacts on other envi-ronmental media (e. g., surface water and air),include:

Ch. 2—Groundwater Contamination and Its Impacts ● 3 7

Table 2.—Examples of Economic, Environmental, and Social ImpactsResulting from Groundwater Contamination

Agriculture

Households

Municipalities

Economic impactsIndustry Higher operation/maintenance or capital costs (e.g., for accelerated repair or replacement of

damaged equipment or materials)Lost output from downtime during repairs, during the search for alternative water supplies, and

during relocationRelocation costsDecreases in property valueDecreases in revenue if quantity of products sold or their prices fall as a result of lower product

qualitySecondary costs (e.g., incurred by suppliers to inputs to the industry or by receivers of the output

such as by processors or marketing agents)Legal and administrative costsCosts of detection, correction, and prevention activitiesHigher operation/maintenance or capital costs (e.g., for accelerated repair or replacement of

damaged equipment or materials)Loss of output due to damage to productivity of land (also reflected in decreases in property value)Lost revenue from discarding of food products unsuitable for consumptionLoss of output due to injury or death to perennial plants and treesDecreases in livestock productivity, including illness and deathSecondary costs (e.g., incurred by suppliers of inputs to agriculture or by receivers of output)Legal and administrative costsCosts of detection, correction, and prevention activitiesHigher operation/maintenance or capital costs (e.g., for cleaning, replacement, and/or rehabilitation of

damaged pipes, plumbing, appliances)Decreased value of residential propertyRelocation expenses, including search costs, higher purchase prices, higher interest rates and fees,

and moving costsSecondary costs (e.g., contraction or expansion of commercial activities)Loss of income due to sicknessLegal costsCosts of detection, correction, and prevention activities (e.g., pre-treatment and purchase of bottled

water)Lost receipts from property, sales, or income taxesRe-allocation of additional resources to provide emergency servicesCosts of procuring alternative suppliesLegal and administrative costsDetection, correction, and prevention activities

Environmental impactsAesthetics Odor

TasteAppearance

Surface watercontamination bygroundwater

Biota

Air pollutionSoil contamination

Social impactsPsychological stressInconvenience

Damage to vegetation, waterfowl, and aquatic lifeContamination of fish

Social disruption

SOURCE Off Ice of Technology Assessment

Ž determination of the effects of various activi- . selection of an appropriate time horizon forties and practices on groundwater quality; the analysis and an appropriate discount rate

● determination of the effects of changes in for the time value of money; andgroundwater quality on groundwater use; ● assessment of the cost and effectiveness of

● lack of a perfectly competitive economic mar- various approaches to detection, correction,ketplace for valuing groundwater quality; and prevention of groundwater contamination.

38 Protecting the Nation’s Groundwater From Contamination

The economic damages resulting from ground-water contamination shown in table 3 illustrate thetypes and magnitude of documented costs. Dataare easiest to obtain for perceptible, short-term ef-fects on users that are reflected in the marketplace.Importantly, although the real value lost to the Na-tion from any one incident may not be significantcompared to, say the gross national product, theeconomic costs of groundwater contamination aresignificant if the costs for all incidents are com-bined and if the time over which these costs willbe incurred is considered. In addition, the coststo the Nation associated with the contamination ofmany aquifers may well exceed the sum of the costsassociated with individual aquifers—e. g., if thereis widespread loss of potable drinking water or ofagricultural produce. Further, the economic dam-ages from any one incident may be significantfrom the perspective of the populations and usersaffected. For example, cash-flow imbalances orother dislocations (e. g., layoffs) can result, espe-cially during emergencies when impacts may notbe anticipated or planned for.

Environmental and Social Impacts

Contaminated groundwater causes diverse envi-ronmental and social impacts; they are generallynot quantifiable and little documentation isavailable.

Because groundwater provides a significant por-tion of baseflow to streams, the potential for adverseimpacts on surface water quality may be large, espe-cially during periods of low rainfall when dilutionis minimal. Changes in the quantity of groundwateralso influence the quality of groundwater (e. g., thepumping of groundwater can induce the migrationof contaminants). The extent of other environmen-tal impacts is unknown; some cases document dam-age to fish, vegetation, and wildlife. The potentialfor groundwater contaminants (e. g., volatile organ-ics) to enter the atmosphere in the vicinity of cer-tain sources (e. g., landfills) or from volatilizationduring showering has now been recognized.

Social impacts are related largely to the anxietycaused by fear and uncertainty about exposure tocontaminants. Exposure can occur unknowingly be-cause many contaminants are odorless, colorless,and tasteless. Exposure to contaminants occurs overmany years and via many pathways, includingdrinking contaminated water, eating foods thathave been in contact with contaminated ground-water, bathing in contaminated water, and breath-ing contaminants when they volatilize in the show-er. Social impacts also arise from decreasedproperty values, and from lost income because ofillness, relocation, and inconvenience (e. g., in pro-curing alternative water supplies).

CONCENTRATION AND FREQUENCY OFSUBSTANCES FOUND IN GROUNDWATER

Concentration of Substancesin Groundwater

A substance is ‘ ‘detected’ or ‘ ‘reported” if itsconcentration sufficiently exceeds the detection lim-its of sampling and measurement equipment so thatits presence is verifiable. Detection limits (typicallyreferred to as ‘‘trace levels’ imply that valuesbelow the measurement threshold will not bereported as positive even if substances are in factpresent at lower concentrations.

A wide range of concentrations of various sub-stances has been found in groundwater (table 1).The most important conclusions about the concen-tration data are:

. concentrations of substances in groundwaterare site-specific and thus are highly variablespatially;

. concentrations are highly variable temporal-ly—they may fluctuate at a particular site bya factor of 10 during the course of a year (Har-

Location Contaminants Nature of costs Direct costs incurred DocumentationCanton, CT Well closings; extension

of water lines toaffected areas

$145,000-379,000 CRS, 1980a

Oscoda Ml

South Brunswick, NJ

Cohansey Aquifer, NJ

Well closings; provision ofnew source of water

Well closings; extension ofmunicipal water lines to af-fected area

Well closings (148); removalof drums; interimemergency water supply(via tanker trucks); drillingof new wells; extension ofpublic water supply (60°/0

of total monetary costs)Loss of irrigation wellPartial rice crop lossEstimated loss in profits

for changing from irrigatedto nonirrigated crops

Reduced service lives of house.hold plumbing andappliances

$140,000

300,000

CRS, 1980a

CRS, 1980aChloroform, toluene,xylene, trichloroethane,trichloroethylene

Wastes from manufac-ture of organic chem-icals, plastics, resin

$417,000(Residential cost ofwater increased froman average of $45/yearto $75/year)

U.S. EPA, 1976CRS, 1980b

Miller County, AR Brine contaminationfrom oil and gasactivities

$4,000$36,000$150/acre/year for rice$35/acre/year for cotton$20/acre/year for soybeansIncreased annual capital

cost per household of40% as total dissolvedsolids increase from250 ppm to 1,750 ppm

$2 million

Fryberger, 1972

38 communities in 11Midwestern Statesc

Mineral content Patterson, et al., 1968

As reported in Sharefkin,et al., 1983

Atlantic City, NJ Chemical wastes(Price’s Landfill)

Estimated cost of new wellfield to replace contaminatedwells

Cost of alternative water supplyto 35 private residences

Estimated cost of reducedservice lives of householdplumbing and appliances

Estimated average annual costof water softeners or in-creased cost of cleaningproducts

Estimated average costs ofusing bottled water

Loss of farm incomeLoss of farm incomeAlternative water supply for

affected areaPurchase of water by residentsConnection to district water

supply

$250,000

$6.5 million total annualcapital cost

$12.3 million

Orange County, CAd Mineral content Orange County Water District,1982

$2.2 million

$5 million per year$31.2 million per year$180,000

$3-5 per 5 gallons$150 per connection,

monthly operatingcosts of $4-1o

$1.2 million

MontanaSan Joaquin Valley, CAAuburn, MA

Lathrop, CA

Miller, 1980Sheridan, 1981U.S. House of Representatives,

1980CRS, 1980b

SalinitySalinityUnspecified chemicals

Pesticides

Jackson Township, NJ Chloroform, methyl Costs of planned water systemto replace closing of 100wells

CRS, 1980achloride benzenetoluene, trichloro-ethylene, ethyl-benzene, acetone

40 • Protecting the Nation’s Groundwater From Contamination

ris, et al. , no date), and they may vary fromday to day (Harris, 1984);

● concentrations of substances are often manytimes higher in groundwater than in surfacewater; and

● higher concentrations of substances are typi-call y found near the site of their release(Westerhoff, et al., 1982), especially if that sitecontains concentrated amounts of the sub-stance, sources are numerous, and/or the siteis characterized by relatively permeable soils.

A number of surveys focusing on public drink-ing water wells have been conducted by the Statesand the Federal Government in the last 10 years—including the early Environmental Protection Agen-cy (EPA) National Organics Reconnaissance Sur-vey (NORS) and National Organics MonitoringSurvey (NOMS) and, more recently, the Commu-nity Water Supply Survey (CWSS) and GroundWater Supply Survey (GWSS).4 Efforts in thesestudies were oriented toward detection of volatileorganic chemicals (VOCs), as opposed to non-VOCs (NAS, 1977). These studies show that vola-

tile organic compounds are frequently present atdetectable concentrations in public drinking waterwells.5 The studies also reveal that concentrationsof compounds in groundwater are often muchhigher than in surface water; for example, TCE,toluene, and 1,1,1-trichloroethane are up to 1,000times more concentrated in groundwater than insurface water (Burmaster, et al. , 1982).6

The National Inorganic and Radionuclides Sur-vey (NIRS) is an ongoing EPA study of ground-

water-supplied community water systems; 38 in-organic (26 of which have already been detectedin groundwater), 4 radionuclides (all previouslydetected in groundwater), and 2 common measuresof radioactivity are the focus of this investigation.

Because of the site-specific nature of groundwatercontamination, it is not possible to draw more de-tailed conclusions about or to predict typical con-taminant concentrations. At best, concentrationdata indicate the severity of site-specific contamina-tion problems and immediate local risks to publichealth and the environment (see the sections onStandards and Health Impacts). Such data are alsoessential to determine the suitability of alternativecorrective actions (see ch. 8).

Generalizations about concentration data at anylevel more aggregated than at an individual siteare highly tentative. Systematic collection of datain space or time can show how concentrations varyin an area and can provide historical information,thus establishing contamination trends for a par-ticular source and/or type of hydrogeologic setting.In all cases, however, the concentration data aresnapshots at one point in time and thus do not takeinto account the dynamics of system behavior.

Frequency of Occurrence ofSubstances in Groundwater

Frequency of occurrence generally refers to thenumber of positive samples (i. e., number for whichthe substance of concern is detected) in the totalnumber of samples tested. Like concentration data,frequency data can be biased by sampling proce-dures and analytical detection limits (University ofOklahoma, 1983; Westrick, et al., 1983). In addi-tion, data are not usually collected with sufficientdetail for frequency analysis (e. g., detection limitsof the measuring instrumentation are often notspecified), and there may be no information avail-able on frequency distributions. Most importantly,there is often no attempt to link frequency data withconcentration data; thus a ‘ ‘positive’ sample im-plies that the substance is detectable, but it doesnot indicate the concentration.

Interpretation of frequency data is more mean-ingful if information is also available about suchfactors as historical land uses and sources. At least

Ch.2—Groundwater Contamination and Its Impacts ● 41

at the site-specific level, frequency data can givean impression of the pervasiveness of substancesin groundwater. From a regional or national per-spective, however, interpretation of frequency databecomes much more difficult. Nationwide frequen-c}’ studies would require extensive sampling (hun-dreds to thousands of sites) and, like concentrationstudies, would provide only snapshots.

With these limitations in mind, data concerningthe frequency of occurrence for specific chemicalsare summarized in appendix A.3. The national sur-veys listed in the section on Concentration of Sub-stances in Groundwater (NORS, NOMS, CWSS,GWSS), the National Screening Program for Or-ganics in Drinking Water (NSP), and some Statesurveys have all yielded data on the frequency oforganic chemicals in groundwater-supplied drink-ing water. Information on the percentage of totalgroundwater samples in Federal surveys which con-tained detectable levels of VOCs is summarized byConiglio (1982).

General conclusions about the frequency dataare:

c

●

●

several organic chemicals associated withchlorinated solvents, especially TCE and PCE,have frequently been detected in groundwatercontamination incidents;public drinking water systems relying ongroundwater are frequently contaminated withVOCs; andtwo or more VOCs are frequently detected si-multaneously in groundwater supplies.

In studies of drinking water wells conducted by18 States, frequencies of detection of various VOCswere compiled for both random and non-randomsamples (CEQ 1981). For the most common chem-icals in the random samples, frequency of detec-tion ranged among the States from 1 .7-11.3 per-cent for TCE and from 3.6-4.5 percent for 1,1-dichloroethane. Random samples both are more in-dicative of general conditions and generate moreconservative estimates than non-random samples.

The two most recent Federal studies (CWSS andGWSS) provide much information regarding fre-quency of VOCs in groundwater. Information fromthe CWSS indicated that 15 percent of public watersystems relying on groundwater contained at least

one VOC; VOCs were detected in 45 percent ofthe public water systems serving more than 10,000people and in 12 percent of the more numerouspublic water systems serving fewer than 10,000 peo-ple. Because the samples were 1-2 years old at thetime of analysis, some VOCs may have degraded;thus, these percentages are regarded as minimumestimates (Brass, et al. , 1981, cited in NRDC,1982).

The GWSS (Westrick, et al., 1983) provides in-formation on the frequency with which one or moreVOCs were detected in groundwater samples. Inthe GWSS, random samples of groundwater sup-plies from public water systems were collected from466 randomly selected communities. The percent-age of random samples with one or more VOCsdetected was 16.8 percent for small systems (serv-ing fewer than 10,000 people) and 27.9 percent forlarge systems (serving more than 10,000 people).TCE and PCE were detected in 3.2 percent and4.6 percent of the random samples from small sys-tems, respectively, and both were detected in 11.3percent of the random samples from large systems.More importantly, the percentage of random sam-ples with two or more VOCs present was 6.8 per-cent for small systems and 13.4 percent for largesystems. An additional part of the survey focusedon non-random supplies selected by State agencies.

Concentration and Frequency Data inRelation to Governmental Standards

Evaluation of health risks associated with ground-water contamination requires, among other things,information concerning both frequency and con-centration of substances—specifically, the frequencywith which groundwater contains one or more sub-stances at concentrations exceeding levels that areconsidered unsafe. Standards promulgated by gov-ernment agencies specify those limits above whichthe presence of a substance is considered unsafe;they thus serve as a gauge of the potential impactsof contamination. Concentration data alone can re-veal potential problems, but only if they can becompared with standards or health impact data re-lated to those specific concentrations.

No Federal standards have been developed spe-cifically for substances found in groundwater. But

42 ● Protecting the Nation’s Groundwater From Contamination

various Federal standards and guidelines-some de-veloped for drinking water-have been applied togroundwater. These include National InterimDrinking Water Regulations (Primary and Second-ary), Health Advisories, and Ambient Water Qual-ity Criteria. In addition, individual States have de-veloped standards which they are applying togroundwater, including State drinking water stand-ards and State groundwater standards (see chs. 3and 4 and app. C. 3 for additional information re-lated to standards).

Standards or guidelines of some type (State orFederal) have been promulgated for less than one-half the substances that have been detected ingroundwater (refer to table 1). Although Federalstandards or guidelines exist for over 60 substances,there are only 22 enforceable standards (establishedby the National Interim Primary Drinking WaterRegulations) and of these, 18 are for individualsubstances. An additional six Federal standards arenon-enforceable under the Secondary Relations;remaining standards or guidelines are Health Ad-visories or Ambient Water Quality Criteria. Over150 substances and other quality indicators haveState standards; less than one-half of them also havesome type of Federal standard or guideline.

Because there is no consistent approach to thedevelopment of standards, because different stand-ards are used by different Federal and State agen-cies, and because standards do not exist for manysubstances, people in different States do not re-ceive a uniform level of health protection againstgroundwater contaminants. For example, someStates (especially in the Northeast, but also in otherparts of the country) have closed contaminateddrinking water wells in order to prevent human ex-posure to specific chemicals (e. g., TCE, PCE, di-chloroethane, benzene, chloroform, toluene, andvinyl chloride; Environ Corp. , 1983). Concentra-tions of the chemicals in the closed wells almostalways exceeded Ambient Water Quality Criteria,but the levels at which the wells were closed variedgreatly from State to State. For example, wells inNew York, Rhode Island, and Massachusetts wereclosed at levels of tetrachloroethylene ranging from1-61 parts per billion (Ambient Water Quality Cri-terion = 0.8 ppb); and wells in New York andRhode Island were closed at levels of 1,1,1-trichlor-oethane ranging from 3-1400 ppb (Ambient Water

Photo credit: State of Florida Department of Environmental Regulation

About one-half of the Nation’s population depends ongroundwater for drinking, and the level of health protectionagainst groundwater contaminants varies from State to State.

Quality Criterion = 18.4 ppb). Although these dataindicate the levels at which wells were closed, theydo not indicate the minimum threshold concentra-tions that would have elicited well-closing decisions(Environ Corp., 1983).

Theoretically, frequency data could be linkedwith concentration data and various standards toascertain the percentage of contamination incidentsin which some type of standard is exceeded. If thestandard reflects an exposure level that could re-sult in adverse health effects, then this type of analy-sis would yield information on the frequency withwhich the public is exposed to unsafe concentra-tions of contaminants in groundwater. In general,both concentration and frequency data are usuallynot reported in enough detail for such an analysis.

OTA’s study attempted such an analysis, as afirst approximation, for examples with sufficientdata. Documentation showed 38 organic chemicals,25 inorganic chemicals, and two radionuclides forwhich concentrations in at least one groundwatersample are known to have exceeded one or moreof the above types of standards or guidelines (seeapp. A.4 for details of which standards or guide-lines have been exceeded). Of these 65 substances,14 (3 organics, 10 inorganics, and 1 radionuclide)involve National Interim Primary Drinking WaterRegulations, and an additional 5 inorganic chem-icals involve Secondary Regulations. In most caseswhere standards or guidelines were exceeded, State

Ch. 2—Groundwater Contamination and Its Impacts ● 43

standards or Ambient Water Quality Criteria wereinvolved.

Frequency and concentration data are availablefor 13 of the 38 organic chemicals known to exceedsome standard or guideline in at least one sample;for none of these 13 compounds have the NationalInterim Primary or Secondary Drinking WaterRegulations been promulgated. Calculations in-dicate that 4 of the 13 compounds are known toexceed at least one type of standard or guidelinein .5-10 percent of groundwater contamination in-cidents (the type of standard or guideline exceededis shown in parentheses in the following list):

1.

2.3.

4.

carbon tetrachloride (State groundwater andAmbient Water Quality);1,1-dichloroethylene (Ambient Water Quality);tetrachloroethylene (Ambient Water Quality);andtrichloroethylene (Ambient Water Quality).

This list is not intended to be exhaustive; rather,it documents situations where substances are knownto exceed specified standards or guidelines fre-quently.

POTENTIAL BUT AS YET UNDETECTEDSUBSTANCES IN GROUNDWATER

Many substances have the potential to entergroundwater because of their molecular propertiesand association with sources (see the section onAssociation of Substances Found in GroundwaterWith Sources, which follows); they may alreadybe present in groundwater but have not yet beendetected. This study has been unable to determinewhether these substances have not yet been detectedbecause they are not being looked for, or are be-ing looked for but have not been found. A num-

ber of them are known or are suspected to exhibittoxic properties. Table 4 presents some generaliza-tions about potential groundwater contaminantsthat could have serious health effects; these gener-alizations are derived primarily from animal ex-periments. Table 4 should not be viewed as eitherexhaustive or definitive. It appears that some, butnot all, of the contaminants of potential concerncan be detected with standardized analytical meth-ods (Environ Corp., 1983).

TYPES OF SOURCES AND ASSOCIATED SUBSTANCES

Types of Sources

The quality of groundwater is altered by a widevariety of human activities and naturally occurringsituations. Sources are points along the pathwaysthat substances travel as they flow through society,where the substances can be released into ground-water. To illustrate, substances can be stored in orflow through sources in a variety of ways, from thestorage of raw materials (e. g., materials stockpiles)to manufacturing (e. g., product storage) to distri-bution (c. s., pipelines) to use (e. g., pesticide appli-cations) to disposal (which can take place almostan?’where in the process).

OTA’s study has identified 33 sources known tohave contaminated groundwater and has catego-rized them based on the nature of their release ofsubstances to groundwater (table 5). It is impor-tant to note that these categories are for the con-venience of discussion. Depending on emphasis, asource could be categorized in another way. Forexample, non-waste injection wells (for enhancedrecovery and artificial recharge) could be placed inCategories I or V. In addition, sources interact witheach other— a leak from an above ground storagetank could result in substances entering ground-water directly (Category II) or entering urban run-off and, subsequently, groundwater (Category IV).

44 . Protecting the Nation’s Groundwater From Contamination

Table 4.—Potential Groundwater ContaminantsDisplaying Serious Adverse Health Effectsa

Compound or class Potential effects

AcrylonitrileAlkyl lead compounds

Alkylamines and alkanol-amines (alkyl polyamides,secondary amines)

Carbon disulfideDimethyl sulfate

n-HexaneMercaptans

N-NitrosaminesPesticides which are not in-

cluded in Table 1.1Phenols which are not in-

cluded in Table 1.1Propylene oxide

CarcinogenicityNeurotoxicity; damage to

kidneys and hemato-poietic system

Allergic sensitization; liverand kidney injury; poten-tial to form carcino-genic N-nitrosomines

NeurotoxicityCarcinogenicity; mutagen-

icityNeurotoxicityCNS depression; liver and

kidney damageCarcinogenicityNeurotoxicity; enzyme

inhibitionNeurotoxicity; variety of

systemic effectsSuspect carcinogenicity;

mutagenicityadditional details in Environ Corp., 1983.

SOURCE: Off Ice of Technology Assessment

Other categorization schemes are also possible(e.g., according to the nature of the user: agricul-tural, industrial, domestic, and municipal; or thephysical location of the source: above the land sur-face, below the land surface and above the ground-water table, and below the groundwater table).However, classification based on discharge char-acteristics has the advantage of identifying andcharacterizing the entry of substances into thegroundwater system. The points-of-entry, in turn,are places where actions can be taken to discoverand alter the entry— i.e., to detect, correct, and pre-vent contamination.

Three general conclusions can be reached fromthis categorization:

1. There is a great diversity of sources, and theyare associated with a broad range of indus-trial, agricultural, commercial, and domesticactivities. Both wastes and non-wastes are po-tential contaminants of groundwater. How-ever, most attention has been focused onwastes, particularly hazardous wastes, frompoint sources or clusters of point sources. (A‘‘point’ source is an easily identified facility,such as a landfill or impoundment. )

2

3.

Only a few source types (Category I) are spe-cifically designed to discharge substances (i. e.,wastes) into the subsurface.Non-waste releases result from some sourcesdesigned to retain non-waste products (Cate-gories II and III) and as a consequence ofother activities (Category IV) or altered flowpatterns (Category V).

Association of Substances Found inGroundwater With Sources

The occurrence of substances in groundwaterand an understanding of how, why, and where theyare present are directly related to their use and/ordisposition. One way of approaching this topic isto examine the association of various substanceswith specific sources.

Rather than examine all substances shown intable 1 individually, this study relates nine generalclasses of substances to specific sources7 (table 6).Classes of substances with the potential to be foundin association with a source are also indicated.Table 6 does not represent a comprehensive surveyof the literature, even though one was attempted.New information about actual contamination in-cidents is being obtained continually, especially asthe States survey their groundwater resources or

ings in the hierarchy. The groupings shown deviate from convention-al approaches to contaminant categorization: these groupings are basedon molecular properties as well as detectability; conventional catego-ries are based strictly on molecular properties (and thus tend to bemore detailed).

Ch. 2—Groundwater Contamination and its Impacts ● 4 5

Table 5.—Sources of Groundwater Contamination

Category l—Sources designed to discharge substancesSubsurface percolation (e.g., septic tanks and cesspools)Injection wells

Hazardous wasteNon-hazardous waste (e.g., brine disposal and drainage)Non-waste (e.g., enhanced recovery, artificial recharge,

solution mining, and in-situ mining)Land application

Wastewater (e.g., spray irrigation)Wastewater byproducts (e.g., sludge)Hazardous wasteNon-hazardous waste

Category 11—Sources designed to store, treat, and/ordispose of substances; discharge through unplannedrelease

LandfillsIndustrial hazardous wasteIndustrial non-hazardous wasteMunicipal sanitary

Open dumps, including illegal dumping (waste)Residential (or local) disposal (waste)Surface impoundments

Hazardous wasteNon-hazardous waste

Waste tailingsWaste piles

Hazardous wasteNon-hazardous waste

Materials stockpiles (non-waste)GraveyardsAnimal burial Aboveground storage tanks

Hazardous wasteNon-hazardous wasteNon-waste

Underground storage tanksHazardous wasteNon-hazardous wasteNon-waste

ContainersHazardous wasteNon-hazardous wasteNon-waste

Open burning and detonation sitesRadioactive disposal sites

Category Ill–Sources designed to retain substances duringtransport or transmission

PipelinesHazardous wasteNon-hazardous wasteNon-waste

Materials transport and transfer operationsHazardous wasteNon-hazardous wasteNon-waste

Category IV—Sources discharging substances asconsequence of other planned activities

Irrigation practices (e.g., return flow)Pesticide applicationsFertilizer applicationsAnimal feeding operationsDe-icing salts applicationsUrban runoffPercolation of atmospheric pollutantsMining and mine drainage

Surface mine-relatedUnderground mine-related

Category V—Sources providing conduit or inducingdischarge through altered flow patterns

Production wellsOil (and gas) wellsGeothermal and heat recovery wellsWater supply wells

Other wells (non-waste)Monitoring wellsExploration wells

Construction excavation

Category Vi—Naturally occurring sources whose dischargeis created and/or exacerbated by human activity

Groundwater—surface water interactionsNatural leachingSalt-water intrusion/brackish water upconing (or intrusion of

other poor-quality natural water)

SOURCE Office of Technology Assessment.

respond to contamination incidents, inventorysources, and monitor supplies, and as efforts areundertaken to recover and/or remove substances 2.prior to their entry into the groundwater.

Four general conclusions can be drawn from thistable:

1. A diversity of classes of substances is associ-ated with known sources of contamination.The most common are the metals/cations andnon-metals/anions, followed by hydrocarbonswith specific elements (e. g., pesticides and

chlorinated solvents), miscellaneous hydrocar-bons (e. g., fuels), and radionuclides.The association of substances with specificsources often varies according to the natureof the use and disposal of substances by dif-ferent segments of society. For example, pes-ticides may enter groundwater from the stor-age tanks of manufacturers, from aerialspraying during agricultural operations, andfrom residential disposal in backyards. In con-trast, because of their design and operatingconstraints (see app. A.5), radioactive disposal

46 ● Protecting the Nation’s Groundwater From Contamination

Photo cradlt: State of Florfda Department of Environmental Regulation

Wafer supply well

~ ~ 1 Unsaturated zone

Saturated zone

Credit: USGS, 14

3,

4.

sites are not likely to contain many organicchemicals. In addition, substances associatedwith a source are not necessarily found atevery facility of a given source type, and theycan vary from facility to facility and over timeat a given facility. The essential conclusion isthat generalizations about the association ofsubstances with sources are not possible —specific substances associated with a singlesource depend on past and present uses, andthus the association of substances with sourcesis highly site-specific.Almost all sources are likely to release simul-taneously a number of substances with verydifferent properties. Eight sources (subsurfacepercolation, disposal wells, land application,landfills, open dumps, residential disposal,surface impoundments, and undergroundstorage tanks) have already been associatedwith substances from five or more classes, andan additional nine sources have a similar po-tential (table 6). Even if only one class of sub-stances is involved in a particular situation,many individual substances within that classcould be present, and their properties (e. g.,toxicity) could vary.For sources associated with particular activi-ties (e. g., agricultural practices and materialsstorage), fewer classes of substances are likelyto be found combined. Even then, however,a broad range of substances may be presentin groundwater, depending on past and pres-ent land uses.

Poorly constructed and maintained or abandoned wellscan provide a conduit for the introduction ofcontaminants into groundwater because of, forexample, the migration of water through corrodedcasings. In this case, uncontrolled discharge from an

artesian well is causing brackish water upconing.

Ch. 2—Groundwater Contamination and Its Impacts ● 4 7

Photo credit: U.S. .Environmenta/ Protection Agency

Residential disposal as a source of groundwater contamination involves theindiscriminant disposal of household products.

FACTORSTO

INFLUENCING A SOURCE’S POTENTIALCONTAMINATE GROUNDWATER

The extent to which a source has the potentialto contribute to groundwater contamination de-pends on factors that characterize both the generaltype of facility or activity (e. g., all landfills) andthe particular facility or activity of concern (e. g.,a specific landfill). These factors include:

● design, operation, and maintenance charac-teristics;

● release characteristics;● geographic location (pervasiveness and re-

gionality);. number of sources and amounts of material

flowing through or stored in sources; and● hydrogeology.

Design, operation, and maintenance can influ-ence a source potential to contribute substancesto groundwater through faulty operation and main-tenance procedures or through mechanical failureor deterioration; these factors are relatively random.Release characteristics, pervasiveness and region-ality, and the number of sources and amounts of

material are described in this section. (For generaldescriptions of sources and details of calculations,see app. A.5. )

Hydrogeology is site-specific, and it influencesthe potential contribution of individual facilities oractivities primarily by affecting the movement ofsubstances into and within groundwater. (See ch.5 for a discussion of hydrogeologic factors and in-vestigative techniques. )

Release Characteristics

Potential sources of groundwater contaminationare highly variable in the spatial (areal) pattern oftheir releases (table 7). These releases can be: 1)discrete releases, where substances emanate froma single identifiable unit; 2) diffuse releases overa large area, so that substances cannot be tracedto a single identifiable source; or 3) frontal orboundary releases, which may or may not emanate

48 ● Protecting the Nation’s Groundwater From contamination

Table 6.—Sources and Classes of Associated Substancesa

Organic chemicals Inorganic chemicals Biological Radionuclides

ICategory I

Subsurface percolation

Injection wells

Land applicationb

a Wastewater

b Wastewater byproducts

c. Hazardous waste

Category II

Landfills

Open dumps

Residential disposal

Surface impoundments

Waste tailings

Waste piles

Materials stockpiles

Graveyards

Animal burial

Above-ground storage tanks

Underground storage tanks

Containers

Open burning anddetonation sites

Radiooactlve disposal sites

Category I I I

Pipelines

Materials transport andtransfer operations

Category IV

Irrigation practices

Pesticide applications

Fertilizer applications

Animal feeding operations

De-icing salts applications

Urban runoff

Percolation ofatmospheric pollutants

Mining and mine drainage

Potential exists for contaminant in class to be found in groundwater associated with source.

Ch. 2—Groundwater Contamination and Its Impacts ● 4 9

Table 6.—Sources and Classes of Associated Substances—Continued

Category V

Production wells

a 011

b Geothermal and heat recovery

c Water supply

Other wells

Construction excavation

Category VI

Ground Water surface waterI Interactions

Natura l leaching

Salt water Intrusion

from a single source but which generally impactgroundwater along a front or boundary.

The first pattern, discrete releases, is typical ofpoint sources; diffuse and frontal release describenon-point sources. But there are exceptions. Forexample, point sources may be so densely situated(e. g., oil production fields) that substances are re-leased in an essentially diffuse pattern, and no singlesource can be identified. If numerous different typesof point sources are located in an area (e. g., ur-ban area), the specific source of the substancesfound in groundwater may also be obscured. Forthese reasons, the categorization of a source accord-ing to spatial release patterns is often site-specificand thus not rigid.

Sources also vary in the temporal pattern of po-tential releases (table 7). Some sources that are ac-tive year-round are influenced by seasonal patternsof rainfall and recharge (e. g., subsurface percola-tion, materials stockpile runoff, and natural leach-ing). Other year-round sources are not affected bythe elements because their associated materials areenclosed or otherwise protected from climate (e. g.,storage tanks and containers); in these cases, re-leases are random with respect to season. Somesources are active only at certain times of the year

(e. g., agricultural activities and de-icing salts ap-plications).

The age of an individual facility may also influ-ence temporal release patterns. For example, moreconcentrated levels of substances may be releasedduring the active years of a facility’s operations,or if there is increasing mechanical failure or de-terioration over time. Salinity from irrigation flow(a Category IV source, which is seasonal in inten-sity) may also be age-dependent in salts built upin the soil over time.

Geographic Location: Pervasivenessand Regionality

Sources of groundwater contamination are eitherwidespread throughout the Nation, located in a fewconcentrated areas or regions, or extremely local-ized (table 7). The majority of widespread sourcesare point sources; they are numerous but also tendto be concentrated in heavily populated areas. Mostpoint sources are Category II sources and are waste-related (e.g., landfills and surface impoundments).Some non-waste point sources (e. g., storage tanksand water supply wells) and, importantly, somenon-point sources (e. g., pesticide applications and

50 ● Protecting the Nation’s Groundwater From Contamination

Table 7.—Summary of Source Characteristics

Individual facility/activity Aggregate of facilities/activities

Spatial Temporal Diversityrelease release of known Amounts of

Purposea patternb patternc Pervasivenessd contaminantse Numbers f materialg

Category ISubsurface percolation .Injection wells . . . . . . .Land application . . . . . .Category IILandfills. . . . . . . . . . . . .

Open dumps . . . . . . . . .Residential disposal . . .Surface

impoundments . . . . .Waste tailings . . . . . . . .Waste piles . . . . . . . . . .Materials stockpiles . .Graveyards . . . . . . . . . . .Animal burial. . . . . . . . .Aboveground storage

tanks . . . . . . . . . . . . . .Underground storage

tanks . . . . . . . . . . . . . .Containers. . . . . . . . . . .Open burning and

detonation sites. . . . .Radioactive disposal

sites . . . . . . . . . . . . . . .

Category IllPipelines . . . . . . . . . . . .Materials transport and

transfer operations . . .

Category IVIrrigation practices . . . .Pesticide

applications . . . . . . . .Fertilizer applications . . .Animal feeding

operations . . . . . . . . . .De-icing salts

applications . . . . . . . .Urban runoff . . . . . . . . .Percolation of

atmosphericpollutants . . . . . . . . .

Mining and minedrainage. . . . . . . . . . .

Category VProduction wells. . . . . .Other wells . . . . . . . . . .Construction

excavation . . . . . . . . .Category VIGroundwater-surface

water interactions. . . .Natural leaching . . . . . .Salt-water intrusion. . . .

NW

NWNW

w

NWw

w

w

NW

w

wNW

HighModerateModerate

High

HighHigh

HighModerateModerate

LowModerate

Low

Low

ModerateLow

Low

Low

Low

Moderate

Low

LowModerate

Low

LowModerate

Low

Moderate

ModerateLow

Low

LowModerate

NW D,F s Moderate

HighHigh

Moderate

High

Moderate?

High?

HighModerate (?)

Low (?)

Low

Moderate

Moderate

Moderate

HighHigh

Moderate

?Moderate

?

High

High?

?

NANANA

HighHighLow

Moderate(High?)

Moderate7

HighHighHighHigh

?7

7

ModerateModerate

Low

Low

High

Moderate

Moderate

LowModerate

LOW

Moderate?

?

Low (?)

Moderate?

Moderate

???

Ch. 2—Groundwater Contamination and Its Impacts ● 5 1

urban runoff) are also widespread. But widespreadpoint sources may be of greater concern in someregions than in others because of variations in hy -drogeology or the level of dependence on ground-water.

Regional sources tend to be associated with heav-ily populated areas or major economic activities;often they are numerous or have large amounts ofmaterial associated with them. They include sourcesin Categories I, II, V, and VI. For example, sep-tic tanks are relatively more concentrated in Califor-nia and the Northeast, fertilizers and pesticides areapplied primarily in the West and Midwest, brinedisposal wells are located primarily in the South-west, and mine drainage is found mostly in theEast, Midwest, and Southwest. A regional sourcesuch as salt-water intrusion is naturally limited tocertain coastal areas. In addition, because the dis-tribution of sources is dynamic (e. g., industrializa-tion is increasing in the South, and energy devel-opment is increasing in Appalachia and in theMidwest), sources related to previous land uses,rather than present-day activities, may be respon-sible for the contamination.

The regional nature of some activities does notpreclude their associated substances from becom-ing widespread. For example, only a few manu-facturers are primary producers of the active in-gredients in pesticides, but their products are usedby intermediate manufacturers, small industries,residential households, and agricultural operationsthroughout the country.

Maps could be used to show the predominanceof sources on a regional scale as well as the perva-siveness of sources nationwide. Maps are not in-cluded in this report for two major reasons:

1. Available maps generally refer to one sourceor to several related sources. Because the in-formation contained on different maps in-volves different assumptions and levels of de-tail, the relative importance of differentsources is difficult to ascertain.

2. Most importantly, site-specific conditions (in-cluding hydrogeology), which are essential forany conclusions or predictions about ground-water contamination, are not included onthese maps. Relationships would need to beestablished between source locations and hy -

drogeologic areas most vulnerable to the en-trance and subsequent movement of sub-stances in groundwater and source locations.

Numbers of Sources and Amountsof Material Flowing Through

or Stored in Sources

Current estimates of the number of sources andthe amounts of materials flowing through or storedin these sources are presented in table 8. As canbe seen, many of the estimates in the 1977 Reportto Congress (EPA, 1977; Miller, 1980) are updated,and initial estimates for many additional sourceshave been developed in OTA’s analysis. Details ofthe calculations are in appendix A.5.

At least four limitations are inherent in theseestimates:

1.

2.

3,

The estimates are specifically for the amountsof material flowing through or stored in thesource and are not estimates of the amountsof material actually reaching the groundwater(unless otherwise indicated). Thus the esti-mates suggest only the maximum potential forgroundwater contamination.An estimate of the amount reveals nothingabout the nature and concentration of sub-stances in that material. Industrial and mu-nicipal sludge provides an example. Theamount of industrial sludge used in land ap-plications is roughly 7 percent of that usedfrom municipal systems, yet often the chem-ical compounds or their concentrations in in-dustrial sludge (e. g., inorganic acids andhigher concentrations of hydrocarbons) posegreater health threats than the chemical com-pounds found in municipal sludge.Accuracy of the quantitative estimates variesconsiderably from source to source, dependingon the underlying assumptions and complete-ness of the data. This study has attempted toaddress this problem by indicating the rangeof values within which the true value proba-bly falls (see app. A.5 for details), but eventhis approach is arbitrary. It is important toremember that there is a high degree of un-certainty underlying the estimates and that

52 ● Protecting the Nation’s Groundwater From Contamination

Table 8.—Numbers of Sources and Amounts of Material Flowing Through or Stored in Sourcesa

OTA Update 1977 Report

Possible PossibleApproximate Approximate uncertainty uncertainty Approximatenumber of amount of in number in amount amount of

Source facilities material b estimate c estimate c material

Category ISubsurface percolation

Domestic. ... , . . . . . . . . . . .

Industrial . . . . . . . . . . . . . . . .Injection wells

Hazardous waste . . . . . . . . .Drainage, etc. . . . . . . . . . . . .Brine . . . . . . . . . . . . . . . . . . .

Non-waste (enhancedoil recovery) . . . . . . . . . . . I

Non-waste (solution,in-situ) . . . . . . . . . . . . . . . .

Land applicationMunicipal sludge . . . . . . . . .

Industrial hazardous waste .Spray irrigation . . . . . . . . . . .

Category IILandfills

Industrial hazardouswaste. . . . . . . . . . . . . . . . .

Industrial non-hazardous waste. . . . . . . .

Utility. . . . . . . . . . . . . . . . . . .Municipal . . . . . . . . . . . . . . .

Open dumps. . . . . . . . . . . . . . .Residential disposal sites . . . .Surface impoundments. , . . .

Hazardous waste . . . . . . . . .Non-hazardous waste. . . . . .

Waste tailings. . . . . . . . . . . . . .Waste piles

Hazardous waste . . . . . . . . .Non-hazardous waste. ... , .

Materials stockpiles . . . . . . . . .Graveyards. . . . . . . . . . . . . . . . .Animal burial . . . . . . . . . . . . . .Aboveground storage

tanks . . . . . . . . . . . . . . . . . .Underground storage

tanks . . . . . . . . . . . . . . . . . .Hazardous waste . . . . . . . . .Non-hazardous waste. . . . . .Non-waste . . . . . . . . . . . . . . .

ContainersHazardous waste . . . . . . . . .Non-hazardous waste. . . . . .Non-waste . . . . . . . . . . . . . . .

Open burning and detonationsites . . . . . . . . . . . . . . . . . . .

Radioactive disposal sites . . . .

Category IllPipelines

Hazardous waste . . . . . . . . .Non-hazardous waste. . . . . .

16.6 -19.5million25,000

350,000

140,000

12,000

2,500

70485

199

75,700?

15-20,0002,400

?

1,078180,000

?

174????

?

2,0312.5 million

?

3,577??

‘?31’

?700,000miles

820-1,460bgy

1-2 bgy

< 2 x < 2 x 800 bgy

1.2 bgy>10 x > 10x

8.6 bgyd

?525 bgy

<10 x< 10x<10 x

< 10x?

<10 x 460 bgy

24.5 bgy < 10x

<10 x 0.3 mt

4 mty3-4 mty(dry)

0.10 bgyd

?

< 10x < 10x

<10 x>10 x

< 10x?

< 10x >10 x 50 bgy0.81 bgyd

40-140 mty (wet)30 mty (wet)

138 mty

<10 x?

< 2 X>10 x

‘?

>10 x> 10x< 2 x>10 x

?

90 bgy10 bgy

‘?

35.8 bgyd

1,800 bgye

580 mty

< 10x< 2 x

?

< 10x<10 x< 2 X

161 bgy—

0.4 bgy1,730 mty700 mty

??

> 10x< 2 x< 10x

?‘?

?

13.8 bgy25 bg

7

< 10x< 2 x

?

<10 x<10 x

?

>10 x??

>10 x?‘?

?3.7 millioncubic yards

?< 2 x

?< 2 X

?280 bgye

?

< 10x?

>10 x 250 bgy

Ch. 2—Groundwater Contamination and Its Impacts ● 5 3

Table 8.—Numbers of Sources and Amounts of Material Flowing Through or Stored in Sourcesa—continued

OTA Update 1977 Report

Possible PossibleApproximate Approximate uncertainty uncertainty Approximatenumber of amount of in number in amount

Sourceamount of

facilities materialb estimate c estimate c material

Category Ill—continuedNon-waste . . . . . . . . . . . . . . . 175,000 10 billion ? ? —

miles barrelsMaterials transport and

transfer operationsHazardous waste . . . . . . . .

16,000spills

?

14 mty <10 x >10 x

50-60million acres280 million

acre-treatments229 million

acre-treatments

169 million < 2 x < 2 xacre-feet0.26 mty < 2 x < 2 X

activeingredients

42 mty < 2 x < 2 x

Pesticide applications. . . . . .

Fertilizer applications. . . . . . . .

Animal feedingoperations . . . . . . . . . . . . .

De-icing saltsapplications . . . . . . . . . . . .

Urban runoff . . . . . . . . . . . . . . .

8 mty < 2 x

?< 2 x

< 10x

< 2 x?

1,935

?21.2-32.6

million acres

10-12 mty‘?

Percolation ofatmospheric pollutants . . . .

Mining and mine drainageSurface . . . . . . . . . . . . . . . . .

NA

4 millionacres; \

? ?

15,000 active< 10x < 10x 108 billion

gallonsUnderground . . . . . . . . . . . . . 67,000inactive

0.36-1.0mty acid \

Category VProduction wells

Oil wells . . . . . . . . . . . . . . . . 548,000 activity2 million

abandoned

< 10x<10 xg

Geothermal, heatrecovery. . . . . . . . . . . . . . .

Water supply. . . . . . . . . . . . .Other wells (non-waste)

Monitoring . . . . . . . . . . . . . .Exploration . . . . . . . . . . . . . .

Construction excavation . . . . .

Category VIGroundwater-surface

water interactions . . . . . . .Natural leaching . . . . . . . . . . . .Salt-water intrusion . . . . . . . . .

32 ? ? ? —350,000 ? ? ? —

54 Ž Protecting the Nation’s Groundwater From Contamination

4.

they are best used to indicate the most nu-merous and most material-intensive sources.Comparing estimates is difficult because theyare expressed in different units of measure-ment. The units cannot be converted into acommon base unit; thus only simple categor-izations of large versus small numbers oramounts can be made. (See the section onIdentifying Sources With “Significant” Po-tential To Contribute Substances to Ground-water, where this problem is encounteredagain, for more details, )

Given these caveats, table 8 is still useful in atleast two ways:

1. It indicates sources which are numerous and/or have large amounts of associated materials.

2. Table 8 shows that non-point sources (e.g.,Category IV, including fertilizer and pesti-cide applications) and sources dealing withnon-waste products (e. g., Category II, in-cluding underground storage tanks) and withnon-hazardous wastes (e. g., Category 1, in-cluding brine disposal wells) are often asimportant—in terms of numbers or amountsof material as defined in table 7—as pointsources or hazardous waste sources. Many ofthe non-point sources have associated withthem chemicals that are highly toxic (e. g.,pesticide applications) or very diverse (e. g.,underground storage tanks); see the previoussection on Association of Substances Foundin Groundwater With Sources).

Quantitative estimates of the numbers of sourcesare available at least in part for 19 sources. Thecontribution of some sources to groundwater con-tamination is difficult to measure (e. g., salt-waterintrusion), and data are incomplete for others. Ofequal importance, estimates of amounts do not existfor 11 sources and are incomplete for seven others.For some sources, amounts are technically difficultto measure (e. g., drainage wells and residential dis-posal); for others, local information is available butis difficult to compile on a national level (e. g., non-waste containers and water supply wells). With in-creased time and effort, investigators can proba-

bly improve estimates for some sources (e. g., in-dustrial subsurface percolation and hazardous wastecontainers) and possibly obtain sufficient informa-tion to generate first estimates for some of thesources for which there are no estimates (e. g., sprayirrigation).

The most numerous sources include: subsurfacepercolation (domestic), injection wells (brine dis-posal and drainage), industrial landfills, surface im-poundments, underground storage tanks, pipelines,irrigation practices, pesticide applications, fertilizerapplications, mine drainage, and oil wells.

The largest amounts of material apparently flowthrough or are stored in the following sources: sub-surface percolation (domestic), brine disposal wells,industrial and municipal landfills, surface impound-ments, waste tailings and piles, materials stockpiles,and pipelines. Much of the material that entersgroundwater comes from non-point sources, suchas applications of pesticides and fertilizers, espe-cially in particular regions of the country. Non-waste sources such as injection wells, storage tanks,and many agricultural activities, and non-haz-ardous waste, and/or non-waste sources contrib-ute large amounts of material.

Photo credit: Paula Stone, Office of Technology Assessment

Of an estimated 2.4 million steel underground storagetanks in the United States, as many as one-fourth maybe used by farmers; other important users includeservice stations (using an estimated 50 percent) andgovernment agencies (using an estimated 5-6 percent)

(see app. A.5).

Ch. 2—Groundwater Contamination and Its Impacts ● 5 5

POTENTIAL FOR SOURCES TO CONTRIBUTESUBSTANCES TO GROUNDWATER

Determining the contribution of any source togroundwater contamination depends on under-standing a broad range of technical, economic, andsocial factors. Economic and social factors affectwhere sources are located, how they are used, andwhat they are used for. The actual contribution ofsubstances by any source will depend on such tech-nical factors as biodegradation rates, surface andsubsurface hydrology (e. g., percolation and adsorp-tion rates), the amount and type of wastes, releasepatterns, number of sources, and source charac-teristics (condition, maintenance, and operationprocedures).

Two basic approaches are discussed below foridentifying which sources have the potential for con-tributing significant amounts of substances togroundwater. One approach involves the use ofphysical and mathematical models to predict whenand which sources release substances to ground-water and what happens to the substances once theyenter groundwater. This approach can also involverecord-keeping at individual facilities. In the sec-ond approach, descriptive criteria are developed inorder to generate lists of important sources (ascl(’fined on the basis of those criteria).

Modeling the Potential of SourcesTo Contaminate Groundwater

Efforts m protect groundwater would be aidedby a priori information on when an individual fa-cility or activity will release substances with the po-tential to enter groundwater, and by estimates ofwhat portion of these substances will actually en-ter groundwater.

Little work has been done to develop measuresof the potential for sources to contribute substancesto groundwater-. In general, the site-specific natureof hydrogeology and the varying characteristics ofindividual sources have precluded development ofpredictive models. One existing model for steelunderground storage tanks uses tank age and localsoil condition data to generate predictions aboutthe’ situations in which tanks will develop leaks(Rogers, no date). If an inventory of underground

storage tanks (including specific age data) wereavailable, at-risk situations identified by the modelcould be investigated. Apparently this type of mod-eling has not been developed for other sources andis limited by data availability.

Physical and mathematical models are availablethat predict the behavior and movement of sub-stances once they enter groundwater. (See app. A.5for references. ) Most of the models yield a tem-porally varying description of the spatial distribu-tion of a substance in an aquifer (see ch. 5). Inputrequirements generally relate to underlying soilsand other hydrogeologic features and the amountor rate at which the aquifer is receiving the sub-stance. If existing contamination and aquifer char-acteristics are known, some models can be run inreverse to determine the amount of the substancethat must have been released from its source to pro-duce the given conditions. These models rely onempirical measurements for input; the value of theiroutput, therefore, is highly dependent on both theunderlying assumptions and the quality of the in-put data.

Measuring contamination potential thus also in-volves record-keeping at individual facilities. Lossescaused by leakage or infiltration of leachate can beestimated via water balance, injected waste leakage,or back-calculation procedures (University of Okla-homa, 1983). However, these procedures are ba-sically empirical or bookkeeping for an individualfacility, and the information gained is used to esti-mate leachate generation or the amount of contam-inated recharge at that particular facility. Appli-cability of these prediction methods to other similarfacilities is limited. Historic flow records could con-tribute to crude predictions, but the records are gen-erally not available.

Identifying Sources With‘‘Significant” Potential To Contribute

Substances to Groundwater

OTA’s analysis attempted to develop objectivecriteria that could be used to identify and list im-

56 ● Protecting the Nation’s Groundwater From Contamination

portant sources, i.e., sources with a ‘‘significantpotential to contaminate groundwater. However,in the course of developing these lists, a numberof problems became apparent that severely limitedthe usefulness of the lists.

Developing a single unambiguous set of objec-tive criteria is not a simple task. One investigatormight believe that amounts of material are a suffi-cient indicator of importance, and others mightbe concerned with the diversity of substances as-sociated with various sources. Groups of criteriamight be used, but the lists of important sourceswill differ depending on which sets of criteria areselected, as shown below.

An additional problem concerns comparisons ofdifferent units of measurement for a single criterion.For example, suppose that the amount of materialhandled by a source is the criterion under consid-eration. In table 7, amounts of material are meas-ured in gallons, tons, cubic yards, barrels, acres,and acre-feet. Definition of a “large” versus‘‘small” amount is arbitrary because of the inabil-it y to make comparisons among different units ofmeasurement. In addition, documentation or esti-mation of large amounts of material (using any def-inition of large) does not necessarily mean that largeamounts of substances will be released into thegroundwater; estimates of large amounts should beviewed only as upper bound indicators of the po-tential for contaminant release.

To illustrate some of the above problems and toindicate the context in which such lists could beused, listing is examined in detail. As an example,one set of criteria was selected, comprised of fourcharacteristics described in the section on FactorsInfluencing a Source’s Potential To ContaminateGroundwater: number, amounts of material, diver-sity of substances, and pervasiveness. Althoughthese criteria might seem to be relatively objective,all entail arbitrary definitions of low (or small),moderate, and high (or large), The definitions thusdetermine the evaluations made in any list.

Information is even more subjective or sparse forother possible criteria, such as the degree to whichsource control (of operating and maintenance pro-cedures) is required to prevent the release ofsubstances, the potential of the source to introducenew substances into groundwater, the toxicity of

associated substances, and the nature of releasecharacteristics. These criteria are useful in char-acterizing sources, but they are more difficult tointerpret when considering the question of the po-tential of any particular source to contaminategroundwater. For example, the release of sub-stances with any of the spatial or temporal releasepatterns discussed above could result in little to sig-nificant contamination.

Using the above four criteria, several lists ofsources were generated by using different group-ings of the criteria and different levels of impor-tance for particular criteria (e. g., use of high num-bers in one list, moderate to high numbers inanother list). A selection of these lists is presentedin table 9. Although some sources fit into many ofthese lists, a major conclusion is that the exact listingchanges as different criteria are selected. For ex-ample, if regulatory authorities are interested ingroundwater contaminated by a high diversity ofsubstances, there are five important sources (sub-surface percolation, landfills, open dumps, residen-tial disposal, and surface impoundments) and, ofthese, the most important source would be surfaceimpoundments (based on table 6). If the numberof facilities alone is important (e. g., as a gauge ofregulatory efforts required for control), nine sourcesare of primary interest and, of these, the most im-portant source would be subsurface percolation(based on table 8).

Among the first nine lists in table 9, seven sourcesappear on more than one-half the lists: subsurfacepercolation, injection wells, landfills, open dumps,surface impoundments, underground storage tanks,and fertilizer application. Of all sources, only thesurface impoundment source is widespread and hasa ‘ ‘high” ranking for the other three criteria (seetable 7). Additional criteria could justify the inclu-sion of specific sources. For example, it is knownthat a high percentage of underground storage tanksare leaking gasoline and causing a number of con-tamination incidents (see app. A. 5). Location overvulnerable aquifers (e. g., sole-source aquifers)would be another reason for including surface im-poundments and other sources on a list.

The first nine lists are based exclusively on theabove four criteria, which tend to be quantitative;quantitative criteria will generally bias a list toward

Ch. 2—Groundwater Contamination and Its Impacts ● 5 7

I

x x

x x

x x

x

x

x

xx x

x x

x

x

x

x

x X x x x x x

x

x

x

x

x

x

x

x

x

x

x

x

58 ● Protecting the Nation’s Groundwater From Contamination

point sources, because point sources are relativelyeasy to identify and count or measure (note thatof the above seven sources, only fertilizer applica-tions is a non-point source). In contrast, supposetoxicity, a criterion that is more descriptive of thepotential health effects of substances and is notbiased toward point sources, is selected. Then thelist (see the toxicity column in table 9) would in-clude pesticide applications, open dumps, residen-tial disposal (e. g., TCE and other halogenatedaliphatic hydrocarbons), open dumps, and the fa-cilities/activities of each source type that deal withhazardous wastes. Although this list does focus onhazardous waste sources, it also includes severalnon-point sources (pesticide applications, residen-tial disposal, land application, pipelines, and ma-terials transport). Other criteria that could be used

in this manner include economic impacts and envi-ronmental impacts.

This exercise illustrates the difficulty in identi-fying one single list of sources that would satisfyall sets of criteria— the list of sources generated de-pends on the criteria selected for identifying” im-portant” sources. In addition, groundwater con-tamination problems differ from region to regionand from site to site, thereby making national listssomewhat tenuous. Listing the sources is not as im-portant as recognizing that materials flow throughsociety; that problems involve non-point, non-haz-ardous, and non-waste sources; that problems varyfrom region to region; and that groundwater con-tamination is highly site-specific.

CHAPTER 2 REFERENCES

Congressional Research Service, Six Case Studies ofCompensation for Toxic Substances Pollution: Ala-bama, California, Michigan, Missouri, NewJersey,and Texas, prepared for the Committee on Environ-ment and Public Works, U.S. Senate, 1980b.

Coniglio, W., ‘‘Criteria and Standards Division Brief-ing on Occurrence/Exposure to Volatile OrganicChemicals, ” Office of Drinking Water, U.S. Envi-ronmental Protection Agency, 1982.

Considine, D. M., and G. D. Considine (eds. ), VanNostrand’s Scientific Encyclopedia, 6th ed. (NewYork: Van Nostrand Reinhold, 1983)

Council on Environmental Quality, “Contamination ofGround Water by Toxic Organic Chemicals, ”Washington, DC, 1981.

Environ Corp., “Approaches to the Assessment ofHealth Impacts of Groundwater Contaminants, ”draft report prepared for the Office of TechnologyAssessment, August 1983.

Fryberger, J., “Rehabilitation of a Brine-PollutedAquifer, ” Office of Research and Monitoring, U.S.Environmental Protection Agency, 1972.

Geraghty & Miller, Inc., “The Fundamentals ofGround-water Quality Protection, ” New York,1983.

Harris, R. H., ‘ ‘The Health Risks of Toxic OrganicChemicals Found in Groundwater, ” PrincetonUniversity/Center for Energy and EnvironmentalStudies, Report No. 153, 1983.

Ch. 2—Groundwater Contamination and Its Impacts ● 5 9

Harris, R. H., Center for Energy and EnvironmentalStudies, Princeton University, personal communi-cation, January 1984.

Harris, R. H., J. V. Rodricks, R. K. Rhamy, and S.S. Papadopulos, ‘ ‘Adverse Health Effects at a Ten-nessee Hazardous Waste Disposal Site, draft man-uscript, Fourth Annual Symposium on Environmen-tal Epidemiology, University of Pittsburgh, no date.

Hawley, G. G., The Condensed Chemical Dictionary,9th ed. (New York: Van Nostrand Reinhold, 1977).

Kaplan, E. M. G., B. Royce, E. F. Riedel, and J.Sathaye, ‘ ‘Assessment of Environmental ProblemsAssociated With Increased Enhanced Oil Recoveryin the United States: 1980 -2000,” BrookhavenNational Laboratory 51528 UC-92a, under U.S.Department of Energy contract No. DE-AC02-76CH00016, 1983.

Lewis, R. J., and R. L. Tatken (eds. ), Registry of ToxicEffects of Chemical Substances, 1979 ed., U.S. De-partment of Health and Human Services (Washing-ton, DC: U.S. Government Printing Office, Septem-ber 1980).

Metropolitan Area Planning Council, “A Guide to theSafe Use and Disposal of Hazardous HouseholdProducts, Boston, MA, 1982.

Miller, D. W. (cd.), Waste Disposal Effects on GroundWater (Berkeley, CA: Premier Press, 1980).

National Academy of Sciences, Drinking Water andHealth (Washington, DC: National Academy Press,1977).

National Academy of Sciences, Risk Assessment in theFederal Government: Managing the Process (Wash-ington, DC: National Academy Press, 1983).

Natural Resources Defense Council, “Comments of theNatural Resources Defense Council, Inc. on NationalRevised Primary Water Regulations, Volatile Syn-thetic Organic Chemicals in Drinking Water, Ad-vanced Notice of Proposed Rulemaking, 47 FederalRegister, 9350-9358 (Mar. 4, 1982), ” Sept. 30, 1982.

O’Brien, R. P., and J. L. Fisher, ‘ ‘There is an Answerto Groundwater Contamination," WATER\Engi-neering and Management, p. 30ff, May 1983.

Odum, E. P., Fundamentals of Ecology, 3d ed. (Phila-delphia: W. B. Saunders Co., 1971).

Orange County Water District, “Water Quality andConsumer Costs, ” 1972.

Patterson, W. L., and R. F. Banker, “Effects of HighlyMineralized Water on Household Plumbing and Ap-pliances, ’ paper presented at the Annual Confer-ence, American Water Works Association, June1968.

Prichard, H. M., and T. F. Gesell, “Radon-222 inMunicipal Water Supplies in the Central UnitedStates, Health Physics 45:991-993, 1983.

Radike, M. J., K. L. Stemmer, P. G. Grown, E. Lar-son, and E. Bingham, ‘ ‘Effect of Ethanol and VinylChloride on the Induction of Liver Tumors: Prelimi-nary Report, Environmental Health Perspectives21:153-155, 1977.

Raucher, R. L., ‘‘A Conceptual Framework for Meas-uring Benefits of Groundwater Protection, WaterResources Research 19:320-326, 1983.

Reitman, F., “Costs and Benefits in Aquifer Protec-tion, New England Journal, Business and Econom-ics 19(1), 1982.

Ridgley, S. M., and D. V. Galvin, ‘ ‘Summary Reportof the Household Hazardous Waste Disposal Proj-e c t , Toxicant Control Planning Section, WaterQuality Division, Municipality of Metropolitan Seat-tle, WA, 1982.

Rogers, W., ‘‘Tank Integrity Program, Warren Rog-ers Associates, Inc., Newport, RI, no date.

San Francisco Bay Regional Water Quality ControlBoard, “Underground Tank Leak Detection Pro-gram Status Report, ’ 1983.

Science News, vol. 125, No. 104, Feb. 18, 1984.Sharefkin, M. F., M. Schecter, and A. V. Kneese, “Im-

pacts, Costs, and Techniques for Mitigation of Con-taminated Groundwater, pp. 93-126 in Papers forand a Summary of a Workshop on Groundwater Re-sources and Contamination in the United States(Washington, DC: National Science Foundation,PRA Report 83-12, August 1983).

Sheridan, D., “Desertification of the United States’(Washington, DC: Council on Environmental Qual-ity, 1981).

Southeast Michigan Council of Governments, “PublicReview Summary Draft: Genoa Township PolicyPlan for Groundwater Protection, March 1982.

Tucker, R. K., ‘‘Groundwater Quality in New Jersey:An Investigation of Toxic Contaminants, New Jer-sey Office of Cancer and Toxic Substances Research,1981.

U.S. Environmental Protection Agency, “HazardousWaste Disposal Damage Reports, ” No. 3, 1976.

U.S. Environmental Protection Agency, ‘ ‘The Reportto Congress; Waste Disposal Practices and Their Ef-fects on Ground Water, ” 1977.

U.S. Environmental Protection Agency, “AmbientWater Quality Criteria for Carbon Tetrachloride,NTIS PB81-117376, 1980a.

U.S. Environmental Protection Agency, “Ambient

60 ● Protecting the Nation’s Groundwater From Contamination

Water Quality Criteria for Trichloroethylene," NTIS PB81-117871, 1980b.

U.S. Environmental Protection Agency, "Ambient Water Quality Criteria for Tetrachloroethylene," NTIS PB81-117830, 1980c.

U.S. Environmental Protection Agency, "National Sta­tistical Assessment of Rural Water Conditions," june 1984.

U.S. Geological Survey, "Estimated Use of Water in the United States in 1980," USGS Circular 1001, 1983a.

U.S. Geological Survey, "National Water Summary 1983-Hydrologic Events and Issues," Water-Supply Paper 2250, 1983b.

U.S. House of Representatives, 96th Cong., 2d sess., Hearing before a Subcommittee of the Committee on Government Operations, Toxic Chemical Con­tamination of Groundwater: EPA Oversight, 1980.

University of Oklahoma, "Groundwater Contaminants

and Their Sources," draft report prepared for the Office of Technology Assessment, August 1983.

Westerhoff, G. P., and V. W. Uhl,jr., "Control Meas­ures for Groundwater VOCs," WA TERlEngineer­ing and Management, pp. 30-33, july 1982.

Westrick,j.j.,j. W. Mello, and R. F. Thomas, "The Ground Water Supply Survey: Summary of Volatile Organic Contaminant Occurrence Data," Techni­cal Support Division, Office of Drinking Water, U.S. Environmental Protection Agency, Cincinnati, OH, 1983.

Windholz, M., S. Budavari, R. F. Blumetti, E. S. Ot­terbein (eds.), The Merck Index-An Encyclopedia of Chemicals, Drugs, and Biologicals, 10th ed. (Rahway, Nj: Merck & Co., Inc., 1983).

Woodward-Clyde Consultants, Inc., "Groundwater Contaminants and Their Measurement," draft re­port prepared for the Office of Technology Assess­ment, October 1983.

Chapter 3

Federal Institutional FrameworkTo Protect Groundwater

From Contamination

contents

Chapter Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Relevance of Federal Statutes to Groundwater Protection . . . . . . . . . . . . . . . . . . . . . . .

Summary of Federal Statutes and Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Federal Legislation Passed Prior to the 1970s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Environmental Legislation: 1969 to the Present . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Sources Addressed by Federal Statutes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Types of Programs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Water Quality Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Mechanisms for Interagency Coordination. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .USGS Coordinating Committees . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Program-Related Agreements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Water Data Coordination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Efforts To Improve Capabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Financial Assistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Technical Assistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Federal Research and Development Concerning Groundwater Quality . . . . . . . . . . . . . . . . .

Chapter 3 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

TABLESTable No.10. Summary of Federal Programs and Ac

Groundwater Quality . . . . . . . . . . . . . .11. Descriptions of Major Federal Statutes

ivities Related to the Protection of. . . . . . . . . . . . . . . . . . . . . . ,. . . . . . . . . . . .Relevant to the Protection of

Groundwater Quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12. Groundwater-Related Activities of Federal Agencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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13. Relationship Between Sources of Contamination and Federal Statutes . . . . . . . . . . . . . . 7614. Committees for Program Coordination Between USGS and Other Federal Agencies . 8215. Federal Involvement in Groundwater Quality Research and Development . . . . . . . . . . 85

Chapter 3

Federal Institutional Framework ToProtect Groundwater From Contamination

CHAPTER OVERVIEWOTA’s assessment of Federal activities regard-

ing groundwater contamination involved examina-tion of 16 Federal statutes and discussions with rep-resentatives of 11 Federal agencies. The laws andprograms selected for review relate to sources ofcontamination, the regulation of potential con-taminants, and the use of groundwater for drink-ing water supplies. This chapter provides a sum-mary of the existing Federal laws and programs thatprotect groundwater quality. In addition, aspectsof the laws and programs are analyzed that defineor support—and are thus shared in common by—detection, correction, and prevention activities.

The following topics are included:

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relevance of Federal laws to the protection ofgroundwater;summary of Federal laws and programs;sources of contamination addressed by Fed-eral laws;water quality standards;existing mechanisms for interagency coordi-nation with respect to implementation of leg-islative mandates; andefforts of the Federal Government to improveits own capabilities and those of the States toprotect groundwater.

Federal detection, correction, and prevention activ-ities are discussed in greater detail in chapters 6,9, and 11, respectively.

The general conclusions drawn from this infor-mation follow.

There is no explicit, comprehensive nationallegislative mandate to protect groundwater from

contamination. Federal laws and programs do notaddress all sources known to contaminate ground-water, the vast majority of substances that havealready been found or have the potential to be foundin groundwater, or all uses of groundwater,

Specifically with respect to sources, different Fed-eral laws and programs address different sourcesof groundwater contamination in different ways.The differences often have little relation to the po-tential for a source to cause contamination. In gen-eral, more stringent requirements are applied toselected point sources (especially those associatedwith hazardous wastes), rather than non-hazardouswaste, non-waste, and non-point sources.

The Federal approach to contaminants, in termsof standards, is neither complete nor consistent.(The Federal regulation of potential contaminantsfor prevention is discussed in ch. 11.) Althoughdrinking is the principal use addressed by Federalstatutes, not all drinking water supplies are cov-ered (see ch. 6).

There are many Federal laws and programs di-rected toward assisting the States and Federal agen-cies with groundwater contamination problems.These generally provide for financial and techni-cal assistance and research and development. Sev-eral laws also authorize the States to implement fed-erally mandated programs and establish minimumrequirements for such programs. However, Fed-eral efforts to protect groundwater quality are frag-mented, and there is no single agency or organi-zation responsible for all groundwater programsand activities; several coordination mechanisms areused.

63

64 . Protecting the Nation’s Groundwater From Contamination

RELEVANCE OF FEDERAL STATUTES TOGROUNDWATER PROTECTION

Protection of groundwater is not covered com-prehensively by any one Federal law; nor is oneFederal agency or office responsible for overseeingor coordinating all groundwater programs and ac-tivities. 1 Although the groundwater protection strat-egy of the U.S. Environmental Protection Agencyacknowledges the need for comprehensive resourcemanagement, the details of the strategy do not fullyprovide for it (EPA, 1984).2

OTA’s analysis has identified 16 principal piecesof Federal legislation that authorize numerous pro-grams and activities relevant to groundwater pro-tection, and it develops a framework for determin-ing how current laws and programs contribute tothe detection, correction, and prevention of con-tamination. Groundwater protection per se isnot, however, the primary objective of any of thestatutes.

Table 10 summarizes the relationship betweenFederal legislation and groundwater protectionactivities including: detection/investigatory activ-ities; corrective actions for contaminated ground-water; measures to prevent contamination; andstandards for contaminants used in detection, cor-rection, and prevention activities. Although table10 presents an extensive array of programs andactivities, Federal efforts overall are not fully pro-tecting groundwater resources. For example, notall sources of groundwater contamination are in-cluded, and for the general source types that are,not all related facilities and/or activities may be cov-ered; not all drinking water supplies are monitoredroutinely; and standards have not been developedfor most contaminants that have already been de-tected in groundwater.

SUMMARY OF FEDERAL STATUTES AND PROGRAMS

Table 11 summarizes the objectives and majorprovisions of the statutes examined in this study,lists the Federal agencies responsible for their im-plementation, and indicates the relationship be-tween the Federal laws and the States. (State pro-grams are discussed in chs. 4, 7, 10, and 12. )Additional Federal activities undertaken to supportor comply with these laws are summarized in table12. Note that Federal statutes have not been rankedin terms of their relative importance to groundwaterprotection for many of the same reasons that sourceswere not prioritized in chapter 2—i.e., ‘‘impor-

tance’ depends on the ranking criteria chosen andsite conditions.

Federal Legislation Passed Priorto the 1970s

Early Federal legislation regarding water qualityin the United States focused primarily on surfacewaters. These statutes were the precursors of themore comprehensive water quality legislationpassed in the 1970s.

Ch. 3—Federal Institutional Framework To Protect Groundwater From Contamination ● 65

x x x x

x

x

x x x

x x x

. aj- : . . .. . .

x

x

UC

x

x

x x x x x

x

x

x

x x x x

x x

x

x

))

Table ll.— Descriptions of Major Federal Statutes Relevant to the Protection of Groundwater Quality

Objectives and provisions relevantStatute to groundwater protection Responsible Federal agencies Relationship to the States

Atomic Energy Actof 1954, 42 U.S.C.2011a

Clean Water Actof 1977, 33 U.S.C.1251 -1378b

Coastal ZoneManagement Actof 1976, 16 U.S.C.1451

One purpose of the act is to encourage thedevelopment and use of atomic energyfor peaceful purposes consistent with thecommon defense and security and thehealth and safety of the public.

The act authorizes the regulation of thedevelopment and utilization of atomicenergy, including the storage and dis-posal of radioactive wastes.

The objective of the statute is to restoreand maintain the physical, chemical, andbiological integrity of the Nation’s waters.

Activities authorized by the act include:— the construction of sewage treatment

works and the use of alternative wastemanagement techniques (Section 201);

— the establishment of effluent standardsand the regulation of point discharges ofpollutants (Sections 302, 306, 307, and402);

— the development of ambient water qualitycriteria (Section 304);

— regulation of the disposal of dredged orfill materials (Section 404);

— establishment of State or regional waterquality management plans, and theestablishment of a program to developBest Management Practices to controlnon-point source pollution in rural areas(Section 208);

— responses to oil discharges into navigablewater (Section 311).

One policy specified in the statute is topreserve, protect, develop, and wherepossible, restore or enhance theresources of the Nation’s coastal zonefor this and succeeding generations.

The act authorizes funding to encourage andassist the States in the development and

Department of EnergyNuclear Regulatory CommissionEnvironmental Protection

Agency—Office of RadiationPrograms

Environmental ProtectionAgency—Office of Water Pro-grams Operations, Office ofWater Regulations and Stan-dards, and Office of WaterEnforcement and Permits

Department of Agriculture—SoilConservation Service and Agri-cultural Stabilization and Con-servation Service (Section 208)

Department of Transportation—U.S. Coast Guard (Section 311)

Department of Commerce—National Oceanic andAtmospheric Administration

Regulation of certain radioactive mate-rials is delegated by NRC to the Statesthat participate in the AgreementStates Program. Pursuant to the Low-Level Radioactive Waste Policy Act of1980, States are currently engaged inregional and individual planning effortsto site new disposal facilities.

States (or local planning agencies) wererequired by Section 208 to submit area-wide water quality management plansto EPA that identified and proposedsolutions to water quality problems (in-cluding point and non-point sourcesaffecting surface water and ground-water). Funding for Section 208 activi-ties was terminated in 1981. Grantsunder Sections 106 and 205(j) are nowbeing used to support planningactivities.

State (or interstate agency) grants areauthorized (Section 106) to assist withthe administration of water pollutioncontrol activities required by the act.Funds are also available from Sections205(g) and (j) which are reserves fromState construction grant allotments.While Section 205(g) funds are usedprimarily to support construction grantprograms (for sewage treatment works),Section 205(j) funds are authorized tosupport State water quality manage-ment planning.

Regulatory authority for Section 402 isdelegated to States for the point dis-charges of pollutants into navigablewaters. c Section 303 requires Statesto adopt water quality effluent stan-dards for such discharges consistentwith Federal standards.

States are eligible to receive grants if acoastal zone management program isdeveloped that meets minimum Federalrequirements.

Table 11 .—Descriptions of Major Federal Statutes Relevant to the Protection of Groundwater Quality—continued

Statute

ComprehensiveEnvironmentalResponse,Compensation,and Liability Actof 1980, 42 U.S.C.9601

Federal Insecticide,Fungicide, andRodent icicle Act,as amended 7U.S.C. 136e

Federal Land Policyand ManagementAct of 1976, 43U.S.C. 1701, andassociated min-ing Iaws.g

implementation of management programswith respect to the use of land and waterresources in the coastal zone, includingefforts to mitigate salt-water intrusion.

The statute does not contain an explicitpolicy statement.

The act authorizes the Federal Governmentto respond whenever there is a release orthreat of release of hazardous substances,pollutants, or contaminants into the envi-ronment which may present an imminentand substantial danger to public healthor welfare. Responses are financed byexcise taxes levied on petroleum andchemical feedstocks. The act also estab-lishes liability for the cost of responseactions on responsible parties and pro-vides for compensation of expensesincurred by the government.d

The statute does not contain an explicitpolicy statement.

The act requires the registration of allpesticides based on the submission ofspecified data (Section 3), the classifi-cation of pesticides for general orrestricted uses (Section 3), and suspen-sion and cancellation of pesticidescausing unreasonable adverse effects onthe environment (includes water, air, land,plants, man and other animals, and theirinterrelationships) (Section 6). The act alsorequires the establishment of proceduresfor the storage and disposal of pesticidecontainers and excess pesticides (Section19), as well as formulation of a NationalMonitoring Plan for pesticides(Section 20).

The statute specifies that it is the policy ofthe United States that public lands bemanaged in a manner that will protect thequality of scientific, scenic, historical,ecological, environmental, air and atmo-spheric, water resource, and archaeo-logical values.

The act authorizes the regulation of theuse of public lands, including miningoperations.

Environmental ProtectionAgency—Office of Emergencyand Remedial Response

Department of Transportation —U.S. Coast Guard

Department of the Interior

Environmental ProtectionAgency—Office ofPesticide Programs

States may enter into a CooperativeAgreement with EPA and assume leadresponsibiIity for remedial actions, orStates may enter into a contract withEPA whereby EPA assumes leadresponsibility. In either case, States arerequired to assure payment of 10 per-cent of the costs (or 50 percent if thesite is publicly owned), assumeresponsibiIity for all future operationand maintenance required at the site,and assure the availability of an author-ized hazardous waste disposal facility inecessary for the disposal of wastesremoved during remedial activities.

Authority is delegated to States forenforcement of FIFRA provisions (e.g.,ensuring that pesticides are used incompliance with any Federal restric-tions) if States adopt and implementadequate pesticide laws, regulations,and enforcement procedures.f

States may also assume responsibility forthe training and certification of pesti-cide applicators if Federal approval of aplan for such activities is obtained.

Federal funding of State programs isavailable to those States that enter intocooperative agreements with EPA.

Mining regulations may not preempt Statelaws and regulations regarding theconduct of mining operations orreclamation on Federal lands. Statesmay enter into agreements with BLMto provide for joint administration andenforcement of regulatory programs

Table 11.- Descriptions of Major Federal Statutes Relevant to the Protection of Groundwater Quality—continued

Objectives and provisions relevantStatute to groundwater protection Responsible Federal agencies Relationship to the States

Hazardous LiquidPipeline SafetyAct of 1979, 49U.S.C. 2001

HazardousMaterials Trans-portation Act of1974, 49 U.S.C.1801h

National Environ-mental PolicyAct of 1969, 42U.S.C. 4371

Reclamation Actof 1902, 43 U.S.C.390(b)

The statute does not contain an explicitpolicy statement.

The act requires the establishment ofFederal regulations for the movement ofhazardous liquids by pipeline (and theirstorage incidental to such movement) andpipeline facilities in or affecting interstateor foreign commerce; such regulationsmust consider the extent to which theycontribute to public safety.

The policy underlying the statute is toprotect the Nation adequately againstthe risks to life and property which areinherent in the transportation of hazard-ous materials in commerce.

The act requires the establishment ofFederal regulations for the transporta-tion of hazardous materials (includinghazardous wastes in commerce.

The purposes of the statute include: thedeclaration of a national policy to encour-age productive and enjoyable harmonybetween people and the environment, andthe promotion of efforts to preventor eliminate damage to the environmentand biosphere and to stimulate humanhealth and welfare.

The act directs Federal agencies to utilize asystematic, interdisciplinary approach inplanning and decisionmaking that mayhave an impact on the environment and toprepare environmental impact statementsfor major Federal actions significantlyaffecting the quality of the human environ-ment.

The policy underlying the statute supportsthe participation and cooperation of theFederal Government with States and localinterests in developing water supplies fordomestic, municipal, industrial, and otherpurposes.

Some projects funded under the act are forthe development of underground watersupplies that are contaminated due tonatural leaching (e.g., high salt concentra-tions) or human activities and thus requiretreatment prior to use.

Department of Transportation—Office of Pipeline SafetyRegulation

Department of Transportation—Office of Hazardous MaterialsRegulation

All Federal agenciesi

Department of the lnterior—Bureau of Reclamation

Federal regulations do not apply to intra-state pipelines and associated facilitiesfor which there are applicable Stateregulations, provided that the Stateagency is certified annually by DOT.

State regulations that are inconsistentwith Federal requirements are pre-empted. Although there is not a formaldelegation of authority, States mayenter into cooperative agreements withDOT to obtain technical and financialassistance. States may also establishrequirements for certain activities notaddressed by Federal regulations (e.g.,routing the transport of hazardousmaterials).

States have opportunity to review andcomment on Federal actions underthis and other programs under inter-governmental review provisionsauthorized by Executive Order 12372.

Water rights for reclamation projectsmust be obtained through States’ waterrights systems.

States are involved in project planningactivities.

Table 11.— Descriptions of Major Federal Statutes Relevant to the Protection of Groundwater Quality—continued

Objectives and provisions relevantStatute to groundwater protection Responsible Federal agencies Relationship to the States

Resource Conser- The objective of the statute is to promotevation and the protection of health and the environ-Recovery Act of ment and to conserve valuable material1976, 42 U.S.C. and energy resources.690 Subtitle C of the act requires the estab-

lishment of regulations for hazardouswaste generators, transporters, and ownersor operators of facilities who treat, store,or dispose of such wastes.

Subtitle D requires the establishment ofFederal guidelines for State solid wastemanagement plans.

Environmental Protection Regulatory authority for Subtitle C isAgency—Office of Solid delegated to States that establishWaste programs that incorporate minimum

Federal requirements. Programs may bemore stringent than Federal require-ments. Financial assistance is author-ized to the States for developmentand implementation of suchprograms.

Although Subtitle D of the act does notmandate the development of State solidwaste plans, States are required tomeet certain minimum requirements to

Safe Drinking The statute does not contain an explicit Environmental ProtectionWater Act of objective but is designed to assure that Agency—Office of1974, 42 U.S.C. public water systems meet minimum Drinking Water300f standards for the protection of public

health.The act requires the establishment of con-

taminant standards for drinking water(Part B), the establishment of regulationsfor underground injection (Part C), and theprotection of sole source aquifers (Part C).

obtain EPA approval and qualify for -

Federal financial assistance. (Subtitle DState grants have not been available in1982 and 1983.)

States may assume primary enforcementresponsibility for public water systems(PWS) to ensure compliance withnational drinking water regulations ifminimum Federal requirements are met.States may establish standards that aremore stringent than Federal standardsand may also set standards forsubstances not addressed by theFederal regulations.

Regulatory authority for the UndergroundInjection Control (UIC) Program is alsodelegated to those States that establishprograms that incorporate minimumFederal requirements. Programs may bemore stringent than Federalrequirements.

Financial assistance is authorized toStates for the development and imple-mentation of both the PWS and UICprograms.

States, municipalities, partnerships, asso-ciations, companies, corporations, orindividuals may petition EPA to des-ignate a sole source aquifer. Once anaquifer is so designated, any of theseparties may petition EPA to review thepotential of a project to contaminatethe aquifer and create a significanthazard to public health.

Table 11 .—Descriptions of Major Federal Statutes Relevant to the Protection of Groundwater Quality-continued

Objectives and provisions relevantStatute to groundwater protection Responsible Federal agencies Relationship to the States

Surface MiningControl andReclamation Actof 1977, 30 U.S.C.1201

Toxic SubstancesControl Act of1976, 15 U.S.C.2601

Toxic SubstancesControl Act of1976, 15 U.S.C.2601 (continued)

Water Researchand DevelopmentAct of 1978, 42U.S.C. 7801

One purpose of the statute is to establisha nationwide program to protect societyand the environment from the adverseeffects of surface coal mining operations.

The act requires the establishment of regula-tions for surface mining of coal (and thesurface effects of underground coal min-ing) and authorizes reclamation ofabandoned mine lands.

The primary purpose of the act is to assurethat chemical substances and mixtures donot present an unreasonable risk of injuryto health or the environment.

The purpose of the statute is to stabilize andcontrol both inactive mill tailings in a safeand environmentally sound manner and tominimize or eliminate radiation hazards tothe public.

The act requires the establishment of regula-tions for mill tailings at uranium orthorium processing mills and authorizesremedial actions at inactive sites.

The purpose of the statute is to assist theNation and the States through waterresources science and technology toaddress a variety of water quality andquantity concerns.

The act authorizes the establishmentof a water resources research and tech-

Department of the lnterior—Office of Surface Mining

Department of Agriculture—Soil Conservation Service

Environmental ProtectionAgency—Office of ToxicSubstances

Department of EnergyNuclear Regulatory CommissionEnvironmental Protection

Agency—Office of RadiationPrograms

Department of the Interior

Regulatory authority is delegated toStates that establish programs thatincorporate minimum Federal require-ments. Financial assistance is author-ized to States for the development andimplementation of such programs.

Grants are available for States toestablish programs to prevent or elimi-nate unreasonable risks to health or theenvironment in association withchemicals for which EPA is eitherunable or unlikely to take action underTSCA.

States may not establish or continuerequirements (e.g., testing requirementsor other regulatory actions) forchemicals for which EPA has pre-scribed rules or orders unless they areidentical to the Federal requirements,prohibit the use of the chemical, or areadopted under the authority of otherFederal laws. Exemptions may beapproved by EPA under specifiedcircumstances.

Regulatory authority for active uraniummills is delegated by NRC to the Statesthat participate in the AgreementStates Program.

States may enter into cooperative agree-ments with DOE for remedial actionprojects; the agreements define theresponsibilities of the parties. Statesare required to pay 10 percent of thecosts, concur with the remedial actionplan, and acquire private lands, asnecessary, to be used as a permanentdisposal site for residual radioactivematerials.

States are required to designate thecollege or university at which the insti-tute is established if there is more thanone land grant college within a State.Two or more States may cooperate inthe establishment of a regionalinstitute.

Table 11 .—Descriptions of Major Federal Statutes Relevant to the Protection of Groundwater Quality—continued

I

72 • Protecting the Nation’s Groundwater From Contamination

Table 12.—Groundwater-Related Activities of Federal Agencies

Department of Agriculture—Agriculture Research Service:ARS is conducting a limited number of research projectsrelated to groundwater recharge and the impacts ofagricultural activities on groundwater quality.

Department of Agriculture—Forest Service: The ForestService is conducting environmental research projectson the fate and transport of pesticides (under theNational Agricultural Pesticide Impact AssessmentProgram).

Department of Commerce— National Bureau of Standards:NBS is responsible for projects regarding thedevelopment of quality assurance standards that areused by other Federal agencies (e.g., EPA and DOE) tomonitor the analytical performance of laboratories.

Department of Defense: The Army, Navy, and Air Force areparticipating in a program to identify and evaluatehazardous waste disposal sites on military installationsand to undertake remedial actions at certain sites tocontrol the migration of wastes (Installation RestorationProgram).

The Army Toxic and Hazardous Materials Agency(USATHAMA), Air Force Occupational EnvironmentalHealth Laboratory, Air Force Engineering and ServiceCenter, and Navy Energy and Environmental SupportActivity provide technical support for the InstallationRestoration Program and conduct research related tothese efforts.

The Army Medical Bioengineering Research andDevelopment Laboratory develops water quality criteriafor certain munitions compounds.

The Army Corps of Engineers is working with EPA(under an interagency agreement) on design andconst ruct ion o f remedia l ac t ion pro jec ts forCERCLA-designated sites. Research projects are alsobeing conducted to support these activities.

Environmental Protection Agency-Office of Research andDevelopment: EPA’s Environmental PhotographicInterpretation Center in Warrenton, VA, is responsible foracquiring and interpreting overhead imagery to supportprograms of EPA as well as other Federal agencies.Activities include conducting inventories of abandonedwells, mines, and hazardous waste sites, identifyingfailures in septic tank systems, and supportingemergency (e.g., oil spills) response activities.

EPA’s Environmental Monitoring Systems Lab-oratory in Las Vegas, NV, the Robert S. Kerr En-vironmental Research Laboratory in Ada, OK, and theEnvironmental Research Laboratory in Athens, GA areconducting studies related to prediction (e.g., studies ofthose characterist ics of aquifers that influencecontaminant behavior) and monitoring (e.g., protocols for

designing groundwater sampling programs). Otherresearch activities related to source control, healtheffects, and treatment technologies are also beingconducted at other EPA facilities.a

Department of Energy: Programs have been established foridentifying and decommissioning nuclear materialsstorage and processing facilities that have becomecontaminated. Hydrogeologic investigations are beingconducted at some of these sites. These programsinclude the Formally Utilized Sites Remedial ActionProgram and the Surplus Facilities ManagementProgram.

Department of Housing and Urban Development:Environmental assessments are conducted related tohousing projects; groundwater impacts are con-sidered.

Department of the Interior—Bureau of Land Manage”ment: BLM is conducting inventories of hazardous wastesites on public lands.

Department of the Interior—National Park Service:Groundwater monitoring studies are conducted atvarious national parks to develop baseline data and todetermine the extent and impacts of groundwatercontamination from sources such as septic tanks andagricultural activities.

Department of the Interior—U.S. Geological Survey: TheWater Resources Division of USGS is responsible forcollection and analysis of hydrogeologic information(including groundwater data), maintaining computerizeddata bases, conducting research, and coordinatingFederal activities with respect to the use and acquisitionof water data.

Department of the lnterior— Fish and Wildlife Service: FWSis conducting inventories of hazardous waste sites forall FWS lands and facilities.

Department of the lnterior— Bureau of Indian Affairs: BIAis planning to conduct inventories of hazardous wastesites on or near Indian reservations.

National Science Foundation: The Division of Civil andEnvironmental Engineering, Directorate for Engineering(the Hydraulics, Hydrology, and Water ResourcesProgram, and the Environmental and Water QualityEngineering Program) supports research projects ontopics such as subsurface transport and wastewatertreatment. Policy-related research is conducted by theDivision of Research and Analysis, Directorate forScientific, Technological and International Affairs.

Nuclear Regulatory Commission: Research projects areconducted related to the fate and transport of radioactivesubstances in support of regulatory activities.

aEPA also supports several other types of activities related to groundwater. For example, EPA established a consortium called the National Center for Ground WaterResearch in September 1979. The consortium consists of the University of Oklahoma, Oklahoma State University, and Rice University; and the Ground Water ResearchBranch of the Kerr Laboratory serves as the center’s immediate technical liaison. The primary objective of the center is to identify long-term problems and needsrelated to groundwater quality protection (e. g., transport and fate of contaminants and subsurface characterization) (Canter, 1982). EPA also provides funding to theGroundWater Clearinghouse at the Holcomb Research institute. The clearinghouse contains an extensive file of groundwater models and assists the States in modelselection and application (see OTA, 1982).

SOURCE Office of Technology Assessment.

Ch. 3—Federal Institutional Framework To Protect Groundwater From Contamination ● 7 3

past 10 years for storage and disposal of radioac-tive substances.

Environmental Legislation:1969 to the Present

The National Environmental Policy Act of 1969(NEPA) was the first of many laws specifically en-acted to protect the environment. It establishes anational policy on environmental quality and directsFederal agencies to use a systematic and interdis-ciplinary approach in decisionmaking and planningto ensure that environmental concerns are suffi-ciently considered. The act also requires Federalagencies to prepare environmental impact state-ments (EISs) for major Federal actions significantlyaffecting the environment. Although NEPA doesnot directly address groundwater, the EIS processprovides a mechanism for evaluating the impactsof proposed projects (e. g., construction of a sewagetreatment plant) and regulatory programs ongroundwater.

Other environmental legislation passed in theearly 1970s contains explicit wording for the pro-tection of air, water, and oceans. G The objectiveof the Federal Water Pollution Control Act Amend-ments of 1972 (referred to as the Clean Water Act,CWA) is “to restore and maintain the chemical,physical, and biological integrity of the Nation’swaters. 7 However, because of ambiguous lan-guage contained in key regulatory provisions of thestatute and conflicting judicial interpretations,8 its

%ee the Federal Water Pollution Control Act Amendments of 1972,33 U,S.C. 1251 et seq., as amended by the Clean Water Act of 1977;the Clean Air Act of 1970, 42 U. S.C. 1857 et seq., as amended; andthe Marine Protection Research and Sanctuaries Act of 1972, 33U.S.C. 1401 et seq., as amended.

‘Section 10 1(a).8Section 402 of the act establishes the National Pollutant Discharge

Elimination System (NPDES), which requires that all point dischargesinto ‘‘navigable waters’ be permitted. The legislative history of thestatute suggests that the NPDES program is limited to surface waterdischarges. The permit program established by EPA is limited to sur-face water discharges. Federal courts have complicated the interpreta-tion of the applicability of Section 402 to groundwater. The SeventhCircuit upheld EPA’s authority to regulate underground discharges(United States Steel Corp. v. Train, 556 F. 2d 822, 7th Cir., 1977);two other courts denied EPA such authority (United States v. GAFCorp., 389 F. Supp. 1379, S, D, Tex., 1975, and Exxon Corp. v,Train, 554 F. 2d 1310, 5th Cir., 1977).

Section 303 of the act authorizes establishment of State water qualitystandards. Although the language used in Section 303 does not men-tion groundwater standards explicitly, one court has upheld the author-

74 ● Protecting the Nation’s Groundwater From Contamination

application to groundwater has been limited. None-theless, provisions of the act are directly relevantto groundwater: Sections 208, 205(j), and 106 pro-vide authorization and funding for State and re-gional monitoring and planning activities directedat both surface water and groundwater; Sections201 and 311 authorize programs related to poten-tial sources of groundwater contamination (land ap-plication of sewage treatment wastes and facilitiesused to store large quantities of oil, respectively);and Section 304 provides for development of waterquality criteria.

In 1974, Congress enacted the Safe DrinkingWater Act (SDWA) to “assure that water supplysystems serving the public meet minimum nationalstandards for protection of public health’ (U.S.House of Representatives, 1974). To accomplishthis goal, the act authorizes development and en-forcement of drinking water standards for contam-inants that may adversely affect human health, es-tablishment of a program to regulate undergroundinjection activities to protect drinking water sup-. — - — —ity of EPA to require States to develop such standards in cases wherea ‘ ‘clear hydrologic nexus’ can be shown between surface water andgroundwater (Kentucky ex rel. Hancock v. Train, 6 ELR 20689, E.D. Ky,, 1976). For a more detailed discussion, see Wilson, 1976; Com-ments, 1978; and Tripp, et al. , 1979.

plies, and designation of sole-source aquifers to pro-tect aquifer recharge areas. The act does not estab-lish a comprehensive program for protection of allgroundwater resources.

Subsequent legislation, enacted between 1976and 1980, authorizes preventive measures (e. g., de-sign and operating requirements) and federallyfunded remedial action programs for specificsources of groundwater contamination. These stat-utes include: the Resource Conservation and Re-covery Act (RCRA), the Surface Mining Controland Reclamation Act (SMCRA), the Uranium MillTailings Radiation Control Act (UMTRCA),the Hazardous Materials Transportation Act(HMTA), the Hazardous Liquid Pipeline SafetyAct (HLPSA), and the Comprehensive Environ-mental Response, Compensation, and Liability Act(CERCLA, commonly known as “Superfund”).The objectives or purposes of these statutes focusmore generally on protection of public health andthe environment than on protection of groundwaterper se; and the regulatory programs that followedare inconsistent regarding groundwater protection(see chs. 6, 9, and 11).

In addition to source-oriented statutes, two othersregulate the production and use of pesticides and

Photo credit:

FIFRA addresses the improper storage and disposal of pesticides and

State of Florida Department of Environmental Regulation

pesticide containers and residues.

Ch. 3—Federal Institutional Framework To Protect Groundwater From Contamination ● 75

other chemical substances. The Federal Insecticide,Fungicide, and Rodenticide Act (FIFRA) providesfor registration and classification of pesticides (e. g.,pesticides that may have unreasonable adverse envi-ronmental effects can be classified for ‘ ‘restricteduse’ in specified areas) and authorizes developmentof procedures for storage and disposal of pesticidesand pesticide containers and residues. The ToxicSubstances Control Act (TSCA) authorizes the reg-ulation of chemical substances or mixtures that maypresent an unreasonable risk of injury to humanhealth and the environment. Regulations regard-ing the manufacture, processing, distribution incommerce, use, or disposal can be promulgated.To date, however, the application of these twostatutes to groundwater has been limited.

Three additional statutes relate to groundwaterprotection. Two of them focus on natural resourcesmanagement. The Coastal Zone Management Actof 1972 (CZMA) provides Federal funds to Statesfor development and implementation of manage-ment programs for coastal areas. Some State man-agement programs are concerned with salt-waterintrusion, a source of groundwater contamination.

The Federal Land Policy and Management Actof 1976 (FLPMA) authorizes the Bureau of LandManagement (BLM) to manage public lands onthe basis of multiple use and sustained yield prin-ciples. Although the act does not discuss ground-water explicitly, it does authorize the managementof public lands in a manner that protects the qualityof ecological, environmental, and water resourcevalues. The statute provides BLM with explicit au-thority to regulate the use and development of pub-lic lands through permits, leases, licenses, published

rules, and other instruments. g One use of publiclands with the potential to contaminate ground-water is mining.

The Water Research and Development Act of1978 (WRDA)11 authorizes the establishment ofState Water Resources Research Institutes to con-duct research and development relating to waterresources, to disseminate information about theseefforts, and to train scientists and engineers. Nu-merous projects funded under this program relateto groundwater quality.

943 U. S.C. 1732.Ioprior t. the passage of FLPMA, BLM had established or pro-

posed regulations governing certain activities on Federal lands underthe authority of several mining laws, including the U. S, Mining Lawsof the 1860s and 1870s, the Mineral Leasing Act of 1920, and theMaterials Act of 1947. With the enactment of FLPMA and the realloca-tion of responsibilities for mining operations (among DOI’S BLM,USGS, Minerals Management Service, and Conservation Division),BLM initiated efforts to revise the existing regulations so that theymore clearly conformed with the objectives of the new legislation. Re-quirements for mining activities on Federal lands discussed in subse-quent chapters reflect these changes; note that regulations for theGeothermal Steam Act were redesignated, with minor revisions, in43 CFR 3260 on Sept. 30, 1983.

The U.S Mining Laws (see 30 U.S.C. 22 et seq. ) include the LodeLaw of July 26, 1866 (14 Stat. 251), the Placer Law of July 9, 1870(16 Stat. 217), and the Mining Law of May 10, 1872 (17 Stat. 91),as amended. These laws address all ‘ ‘locatable’ mineral deposits suchas gold, silver, uranium, lead, iron, and copper. The Mineral Leas-ing Act of 1920 (30 U.S. C. 181) and the Materials Act of 1947 (30U.S. C. 601) address “leasable” minerals, including coal, phosphate,sodium, potassium, sand, gravel, and clay,

The Minerals Leasing Act and 16 other laws, Attorney General’sOpinions, and Secretary’s Orders address onshore oil and gas opera-tions. Regulations for oil and gas production have been undergoingsubstantive revisions and were not analyzed in detail as part of thisstudy. See table 11, footnote g, for a brief description of the relation-sip between the revised regulations and ground water.

1 I section 410 of the act repe~ed the Water Resources Research Actof 1964 (Public Law 88-379, 78 Stat. 329, 42 U. S.C. 1961 et seq.),as amended, and the Saline Water Conversion Act of 1971 (PublicLaw 92-60, 85 Stat. 159, 42 U.S. C. 1959 et seq.), as amended.

SOURCES ADDRESSED BY FEDERAL STATUTES

This section focuses on current Federal programsand activities to address specific sources of ground-water contamination. It reviews the sources cov-ered by each statute and the types of programs thateach authorizes. Subsequent chapters describe indetail Federal investigatory activities (includingmonitoring), corrective actions, and preventivemeasures for specific sources.

Sources

Table 13 summarizes the relationship betweensources known to contaminate groundwater and theFederal statutes, (The table is organized accord-ing to the OTA source categories described in ch.2; see table 5.) Two significant points about sourcesand types of programs. based on table 13, are:

.——..——————

76 ● Protecting the Nation’s Groundwater From Contamination

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Ch. 3—Federal Institutional Framework To Protect Groundwater From Contamination ● 7 7

1.

2.

existing Federal statutes do not cover allknown sources of contamination discussed inthis study; andsources are not treated in a uniform mannerby the programs authorized by Federal leg-islation.

Table 13 indicates that most sources (all but 4)are covered by at least one statute and that 18sources are covered by more than one statute. 12 Butthe coverage is not as comprehensive as it appearsin the table. Most Federal statutes limit coverageby defining only subsets of facilities and/or activi-ties of a given source type that are subject to theirrespective requirements. These definitions arebased on various criteria, such as the presence ofcertain contaminants (e. g., hazardous wastes).Moreover, the statutory definition of sources issometimes narrowed further by the regulationsissued by the Federal agencies responsible for im-plementing the statutes.13 Descriptions of thesources covered by Federal programs is compiledin appendix B. 1, which also indicates whether de-tection, correction, or prevention provisions havebeen established for each source. These provisionsare discussed in chapters 6, 9, and 11, respectively.

Based on the information in appendix B. 1 andthe data on sources presented in chapter 2, a pre-

Illt is impomant to point out that the applicability of CERCLA tosources of contamination as presented in table 13 is based on the typesof sources currently on the National Priorities List. It is certainly pos-sible to use CERCLA to cleat with other sources that release any haz-ardous substance, pollutant, or contaminant. Under CERCLA, haz-ardous substances are those designated by CWA (Sections 31 l(b)(2)(A)and 307(a)); RCRA (Section 3001); CERCLA (Section 102); the CleanAir Act (Section 112); and TSCA (Section 7). A pollutant or con-taminant includes ‘ ‘any element, substance, compound, or mix-ture that will, or may reasonably be anticipated to cause death,disease, behavioral abnormalities, cancer, genetic mutation,physiological malfunctions, or physical deformations in organisms ortheir offspring’ (Section lo). Petroleum (including crude oiland any fraction thereo~ and natural gas, natural gas liquids, liquefiednatural gas, and synthetic gas usable for fuel are explicitly excludedfrom the definition of hazardous wastes.

13 For example, Section 3001 of RCRA requires EPA to promulgate

regulations identifying the characteristics of hazardous wastes and list-ing particular wastes. The statute explicitly defines hazardous wastesas solid wastes which may: ‘ ‘(A) cause, or significantly contribute toan increase in mortality or an increase in serious irreversible, or in-capacitating reversible illness; or (B) pose a substantial present or po-tential hazard to human health or the environment when improperlytreated, stored, transported, or disposed of, or otherwise managed[42 U,S. C. 6903( S)].” The listing criteria developed by EPA (see 40CFR 261) have been subject to much discussion and criticism in thatthey limit the universe of hazardous wastes currently being regulated,See OTA, 1983.

liminary list of sources of groundwater contamina-tion which are not currently being addressed byFederal statutes would include:

●

●

●

●

●

surface impoundments used to contain non-hazardous wastes (e. g., impoundments usedin agriculture);waste piles and materials stockpiles used tostore non-hazardous wastes (except pesticides);tanks (aboveground and underground) usedto contain non-hazardous wastes;non-coal mining activities on private lands;andpipelines not regulated by the Hazardous Liq-uid Pipeline Safety Act.

Given the limitations of OTA’s information onsources, this list should not be viewed as either ex-haustive or rigid. Further, some States are address-ing some of these sources. Thus, a thorough assess-ment of source coverage necessitates examinationof both Federal and State activities. (See ch. 4 fora discussion of State coverage of sources. )

Types of Programs

In addition to the sources that are covered byFederal statutes, it is also important to look at thetypes of programs authorized by the laws (table 13).These range from mandatory permit or licensingprograms to such voluntary programs as develop-ment of Best Management Practices for new or ex-isting sources of contamination. Other programsdirect the Federal Government to undertake reme-dial action at inactive or abandoned sites that eitherhave contaminated or have the potential to contam-inate groundwater.

The Federal Government’s general approach toprevention and control of contamination fromsources with hazardous wastes and other toxic ma-terials (e.g., mining operations and injection wells)differs from the one used for most non-hazardouswaste sources (e. g., sanitary landfills in CategoryH) and non-waste sources (e. g., agriculture-relatedsources in Category IV and all sources in Category

14Five more sources not covered by Federal statute are: percola-tion of atmospheric pollutants, graveyards, animal burial grounds,deicing salts, and household disposal. The OTA analysis in ch. 2 didnot identify these sources as major contributors to groundwater con-tamination nationwide.

VI). The major distinction is that the types of pro-grams applicable to non-hazardous waste and non-waste sources rely on use of voluntary design oroperating procedures (e. g., Best Management Prac-tices), and those associated with hazardous or toxicsubstances establish mandatory requirements (e. g.,permit programs). Significantly, programs withmandatory requirements focus on point sources ofcontamination, and voluntary approaches are gen-erally used with non-point sources.

The types of programs authorized by Federalstatutes that are relevant to sources of contamina-tion can generally be described as follows (refer totable 13):

●

●

●

Programs that establish mandatory require-ments (e.g., design, operation, monitoring,and/or corrective action requirements) for

sources of groundwater contamination: T a b l e13 indicates that 11 statutes authorize devel-opment and enforcement of such require-ments. Site-specific permits or licenses are re-quired by several of these laws (i.e., SubtitleC of the Resource Conservation and RecoveryAct, the Safe Drinking Water Act, the Sur-face Mining Control and Reclamation Act, theAtomic Energy Act, and the Uranium MillTailings Radiation Control Act). In addition,some statutes specify that regulatory author-ity may be delegated to States that meet cer-tain Federal criteria and/or enter into specif-ic agreements with Federal agencies (table 10).Programs that authorize Federal funding ofoptional State programs for specific sources:Subtitle D of the Resource Conservation andRecovery Act is in this category. States areawarded grants to develop solid waste man-agement plans if the plans meet specified cri-teria for sanitary landfills.Programs that establish Best ManagementPractices (BMPs) or recommended proceduresfor design and operation of certain sources:Best Management Practices for certain non-point sources have been developed under theClean Water Act (e. g., agriculture-relatedsources in Category IV). Procedures are rec-ommended for the storage of pesticides anddisposal of pesticide residues under FIFRA(e.g., some Category II sources).

Photo credit: U.S. Geological Survey

The storage and disposal of radioactive substancesis regulated under the Atomic Energy Act. Thisphotograph shows vaults used to contain low-level

radioactive wastes in shallow land burial sites.

Programs that establish Federal design andoperating criteria that must be met by ownersor operators in order to receive funds for spe-cific projects (orproject components) that arepotential sources of contamination: This cat-egory includes the Innovative and AlternativeTechnology provisions of Section 201 of theClean Water Act for land application of sludgeand wastewater from sewage treatment.Programs that establish grant programs toStates for water planning and management ac-tivities: Under the Coastal Zone ManagementAct, grants are awarded to States for devel-opment and implementation of coastal zonemanagement plans. Plans may provide for

Ch. 3—Federal Institutional Framework To Protect Groundwater From Contamination ● 7 9

minimizing impacts of salt-water intrusion bycontrolling land and water uses. Section 208of the Clean Water Act also provides for Statewater planning and management activities.Funds may be used at the State or local levelon non-point sources that cause groundwaterquality problems.

● programs that fund Federal remedial actionsfor sources of groundwater contamination:These statutes include the ComprehensiveEnvironmental Response, Compensation, andLiability Act, the Surface Mining Control andReclamation Act, and the Uranium Mill Tail-ings Radiation Control Act. Some water de-velopment projects funded under the Recla-

mation Act also involvecontaminated groundwater.

Two statutes not included above

treatment of

are the NationalEnvironmental Policy Act (NEPA) and the WaterResources Development Act (WRDA). AlthoughNEPA is not directed at particular sources, envi-ronmental impact statements may be required forfederally funded projects that are potential sourcesof groundwater contamination (e. g, constructionof a highway or housing development). WRDA alsodoes not address specific sources, but research proj-ects funded under the act may relate to sources ofcontamination.

—

80 ● Protecting the Nation’s Groundwater From Contamination

WATER QUALITY STANDARDS

Water quality standards specify the limits beyondwhich substances in the environment may cause ad-verse impacts. Standards may be developed strictlyto protect public health, the environment, or usesof groundwater, or to balance the benefits and costsof achieving different levels of protection.

Water quality standards may be applied in pro-grams to detect, correct, or prevent groundwatercontamination. Detection programs may use waterquality standards to determine whether there is aproblem that warrants action. For example, underthe Safe Drinking Water Act, public water suppliesare monitored for contaminants specified by theNational Interim Primary Drinking Water Regu-lations (NIPDWR); if concentrations exceed speci-fied levels, certain steps must be taken, includingpublic notification. Under the Resource Conser-vation and Recovery Act, hazardous waste land-fills must be monitored for particular substances;if concentrations exceed specified levels, more in-tensive monitoring is required, possibly leading tocorrective action. Correction programs may usewater quality standards in determining cleanupgoals (e. g., under RCRA, the NIPDWR may beused to set cleanup requirements; in the absenceof drinking water standards, background levels oran alternative concentration limit may be used ona case-by-case basis). Prevention programs may usewater quality standards in defining unacceptablelevels of contamination (e. g., under the CleanWater Act, NIPDWR may be used to limit dis-charges to groundwater from the land applicationof wastewater, depending on the use of the ground-water).

In addition to standards that relate correction orprevention programs to the actual quality of waterthat may result from a particular activity, technol-ogy-based approaches such as design and operat-ing requirements are also often used. In 1972, withpassage of new water quality legislation, the Fed-eral Government de-emphasized quality-based pol-lution control, given the difficulties in linkingallowable releases of pollutants from point sourcesto the quality of surface waters.15

~~For a more detailed discussion of the legislative history of the Fed-eral transition to technology-based standards with respect to surfacewater, see Copeland, 1983; and Davis, et al., 1976.

Federal statutes require standards for drinkingand surface water quality, but not specifically forgroundwater (see also the section Concentrationand Frequency Data in Relation to GovernmentStandards, ch. 2). For drinking water, there are22 Federal mandatory minimum standards for pub-lic drinking water supplies under the Safe Drink-ing Water Act National Interim Primary DrinkingWater Regulations (Maximum Contaminant Lev-els, MCLs). Federal minimum standards are notset for surface water quality; rather, the FederalGovernment provides general guidance to theStates on setting standards for specific water usesthrough Ambient Water Quality Criteria under theClean Water Act. These criteria include numericand narrative water quality standards to protectpublic health and welfare, aquatic life, and recrea-tional use. If a State does not adopt as a minimumthe NIPDWR or federally approved surface waterquality standards, the the Federal Government isauthorized to assume responsibilities for standardsin the State.

The Federal Government also provides guidanceon standards for selected substances in drinkingwater through National Secondary Drinking WaterRegulations and Recommended Maximum Con-taminant levels (RMCLs) under the Safe Drink-ing Water Act and Health Advisories (formerly,Suggested No Adverse Response Levels, SNARLS).National Secondary Drinking Water Regulationscover selected contaminants and concentrations thatmay adversely affect either odor, appearance, orthe public welfare. RMCLs are non-enforceablehealth goals for public water supplies and are setat levels that would result in no known or an-ticipated health effects, including an adequatemargin of safety.

16 Health Advisories cover selectedcontaminants found in drinking water for whichthere are no Federal requirements.

As shown in appendix C.3, which lists the spe-cific substances covered by Federal and/or State

l~Th e first RMCLS were proposed for nine volatfle synthetic organicchemicals (VOCS) in the Federal Register on June 12, 1984. MCLSfor these chemicals will be proposed when the RMCLS are finalized.MCLS are to be set as close to the RMCLS as feasible but will alsobe based on a balancing of health protection with other factors in-cluding the availability and costs of treatment technologies.

Ch. 3—Federal Institutional Framework To Protect Groundwater From Contamination ● 8 1

Photo credits” State of Florida Department of Environmental Regulation

An underground source of drinking water is in part defined under the Safe Drinking Water Act as containing fewer than10,000 milligrams per liter (mg/1) of total dissolved solids (TDS) (left). Good tasting water has less than 1,500 mg/1 of TDS (right).

water quality programs, different programs gen- concerns as well as technology-related and economicerally apply to different substances. When a factors, while Ambient Water Quality Criteria con-substance is covered by more than one program, sider only health or environmental impacts. Fur-minimum requirements or suggested concentra- ther, health information from Ambient Watertions differ from program to program. Such dif- Quality Criteria includes the ingestion of aquaticferences arise because concentrations developed life and not just adverse impacts from drinkingunder the Safe Drinking Water Act reflect health water.

MECHANISMS FOR INTERAGENCY COORDINATION

The multiplicity of both groundwater-related coordinating all groundwater programs and activ-laws and the agencies responsible for their imple- ities, three mechanisms for interagency coordina-mentation has fragmented Federal protection of tion are used and are described below. Activitiesgroundwater quality. Further, within certain agen- to be coordinated are both regulatory, primarilycies, numerous offices are responsible for ground- focusing on sources of contamination, and non-reg-water activities (refer to tables 11 and 12). Because ulatory, including data collection, technical assist-no single agency or organization is responsible for ance, and research and development.

82 Ž Protecting the Nation’s Groundwater From Contamination

USGS Coordinating Committees

The U.S. Geological Survey and other Federalagencies have entered into Interagency Agreements(IAGs) or Memoranda of Understanding (MOUs),which establish coordinating committees comprisedof representatives of each agency. The committeescoordinate plans and activities of mutual interest,including water-related issues (e. g., hydrologic in-vestigations), and exchange data and information.Table 14 lists the agencies with which USGS hasestablished committees, their effective dates, andtheir purposes. As table 14 indicates, the scope ofthese committees extends beyond groundwater-re-lated issues. Nonetheless, the committees providea forum for raising groundwater concerns and haveled to additional agreements that focus on ground-water quality.

Program-Related Agreements

IAGs and MOUs established between Federalagencies also relate to implementation of statute-specific programs or activities concerning ground-water protection, such as provision of technical as-sistance for hydrogeologic investigations (e. g.,groundwater monitoring) or for corrective actions.Several agreements described below are examplesof the types of programs that have been arranged:

● The Environmental Protection Agency and theArmy Corps of Engineers have entered intoan agreement whereby the Corps providesboth management and technical assistance toEPA with respect to implementation of theComprehensive Environmental Response,Compensation, and Liability Act (CERCLA).

Table 14.—Committees for Program Coordination Between USGS and Other Federal Agencies

Federal agency Effective date Purpose

Department of Agriculture—Soil Conservation Service

Department of Commerce—National Oceanic andAtmospheric Administration

Department of Energy—Office of Energy Research

Department of the lnterior—Bureau of Land Management

Department of the lnterior—Bureau of Mines

Department of the lnterior—Bureau of Reclamation

Department of the lnterior–Office of Surface Mining

Environmental ProtectionAgency

5/12/73, revised1/21/76

2/20/72

11/8/78

3/6/74, revised9/9/82

12/9/77

4/15/83

7/26/78

8/5/81

To exchange data and information, to cooperate in programs, and tocoordinate fields of operation such as geologic, soil, chemistry,mineralogic erosion, watershed, river basin, flood, land resources,wetland, hydrologic, sediment, snow, topographic surveys, andmapping and resource analysis.

To coordinate related programs including seismology, marine geologyand geophysics, hydrology, mapping, and earth resource surveys fromspace.

To develop an exchange of information on research, to resolve issues ofpolicy and responsibilities, to arrange cooperation in operation ofprograms, and to exchange budget information for cooperativeprograms.

To coordinate related programs including lease management,environmental studies, land and resource classification, mapping andsurveys, and water resource investigations.

To clarify the primary roles of the agencies and to establish mechanismsfor coordination, including resource classification, data storage, anddata standards.

To coordinate related programs including mapping, land and waterresource planning, water resources investigations and research,geologic investigations and research, and information systems.

To coordinate data exchanges and related programs, includingmonitoring, hydrologic studies, land use, geologic mapping, datasystems, and programs and budgets.

To provide a mechanism to coordinate programs and plans, provide fortechnology transfer and data exchanges, arrange for cooperation andsupport of programs of mutual interest, arrange exchange of budgetand planning information, act as a clearinghouse for EPA/USGScontacts, and provide information on existing and future MOUs andIAGs between the agencies.

SOURCE: USGS, 1983

Ch. 3—Federal Institutional Framework To Protect Groundwater From Contamination ● 83

Under the agreement, the Corps is responsi-ble for managing the design, construction, andoperation of remedial actions at hazardouswaste sites for which EPA (as opposed to aState) assumes lead responsibility.

● An agreement between EPA and USGS speci-fies the cooperation and extent of assistancethat USGS will provide EPA’s Office of WastePrograms Enforcement in gathering informa-tion and assessing the hydrology and geologyof hazardous waste sites. The types of assist-ance that USGS can provide include but arenot limited to: provision of data from USGSfiles on groundwater systems near a hazard-ous waste site; technical assistance on the de-sign or review of investigative studies; andcomments on remedial action designs and thepredicted effectiveness of such actions.

● Another agreement between EPA and USGSis for USGS assistance to EPA in fulfilling itsresponsibility to designate sole source aquifersunder Section 1424(e) of the Safe DrinkingWater Act. USGS provides EPA with the fol-

lowing: aquifer descriptions, evaluations ofaquifer vulnerability to contamination, back-ground information on drinking water sourcesand alternative water supply sources, and pro-jections of water consumption,

Water Data Coordination

A 1964 directive issued by the Office of Man-agement and Budget, Circular No. A-67, prescribesguidelines for ‘‘coordination of Federal activitiesin acquiring water data from streams, lakes, reser-voirs, estuaries, and groundwater. The Depart-ment of the Interior was assigned lead responsibil-ity. In October 1964, the Office of Water DataCoordination was established within the Water Re-sources Division of USGS to implement provisionsof the directive. Two advisory committees, the In-teragency Advisory Committee on Water Data andthe Advisory Committee on Water Data for Pub-lic Use, were also established to assist USGS.

EFFORTS TO IMPROVE CAPABILITIES

Improving Federal and State capabilities to pro-tect groundwater quality requires a variety of activ-ities, including financial assistance, technical assist-ance, and research and development. The followingdiscussions generally describe Federal activities andprograms in these areas.

Financial

A number of Federal

Assistance

statutes examined in thisstudy authorize grant programs for the States. Noneof the provisions, however, is earmarked exclusivelyfor groundwater activities.

As indicated in table 11, the States maybe dele-gated authority to implement certain regulatoryprograms, and grants are provided for these pur-poses. For example, Subtitle C of the ResourceConservation and Recovery Act, the Surface Min-ing Control and Reclamation Act, and the Under-ground Injection Control (UIC) Program of theSafe Drinking Water Act have such provisions.

Funds under these programs are not limited togroundwater-related activities.

Under other statutes, the States are awardedgrants for planning and other water-related activi-ties. For example, Section 208 of the Clean WaterAct authorizes the States or regional planning agen-cies to prepare water quality management plans toidentify and propose solutions to water qualityproblems; the plans, however, are not legally bind-ing. Section 208 was designed explicitly to addressnon-point sources such as agriculturally and silvi-culturally related sources (e. g., irrigation returnflows), mine-related sources, construction activi-ties, and salt-water intrusion.

17 Funding for Sec-

tion 208 activities ended in 1981, but additionalfunding for State water quality activities is nowavailable through Sections 106 and 205(j) of theClean Water Act. Funding for other programs(e.g., the Coastal Zone Management Act, RCRA

17sectirjn 208(b)(2)(F)—(K)

84 ● protecting the Nation’s Groundwater From Contamination

Subtitle D, and the Rural Abandoned Mine Pro-gram) has either been reduced or eliminated in re-cent years.

Technical Assistance

Programs within EPA, USGS, and the Soil Con-servation Service (SCS) provide technical assistanceon groundwater quality to the States, individuals,and other Federal agencies. For example, EPA’sOffice of Drinking Water advises the States andother authorities in determining the types of re-sponse appropriate to contamination incidents,Health Advisories for 22 contaminants have beendeveloped; they suggest the level of a potential con-taminant in drinking water at which adverse healtheffects would not be anticipated for the most sen-sitive members of the population. Other kinds oftechnical assistance activities at EPA include prep-aration of special guidance manuals for EPA pro-gram implementation (e. g., RCRA permit writermanuals) and guidance on laboratory testing.

USGS technical assistance to the States and otherFederal agencies includes a variety of programs(e. g., the Hazardous-Waste Hydrology Program,the Assistance to Other Federal Agencies Program,and the State Cooperative Program) (Chase, et al.,1983). USGS assists in the development of bothFederal and State regulations and standards formanaging disposal of hazardous wastes and assistsFederal agencies on toxic waste cleanup underRCRA and CERCLA programs. Through the Na-tional Water-Data Storage and Retrieval System(WATSTORE) and National Water Data Ex-change (NAWDEX), USGS maintains and pro-vides access to data on surface water and ground-water quality and quantity and to meteorologicaldata. USGS study and research results are dissem-inated through numerous publications. USGS alsoprovides training programs for Federal, State, andlocal agencies on hydrologic investigations. (Ch.6 describes selected USGS activities in more detail.)

Although SCS programs are not directed specif-ically at groundwater, technical assistance to theStates, counties, and individuals is providedthrough the Rural Clean Water Program and thedevelopment of Best Management Practices to min-imize adverse impacts on water quality. Financialassistance to individuals may be provided through

the Agricultural Stabilization and ConservationService (ASCS) to implement some Best Manage-ment Practices.

In compliance with Section 104 of CERCLA, theAgency for Toxic Substances and Disease Registrywas established as part of the Centers for DiseaseControl (CDC) in April 1983.18 CDC is currentlyworking with the National Governors’ Association(NGA) to implement Section 104(i)(3). Under thesection, the Agency for Toxic Substances and Dis-ease Registry is required to maintain a completelist of areas closed to the public or otherwise re-stricted in use because of toxic substance contami-nation. A Memorandum of Understanding is cur-rently being negotiated between CDC and EPA onthe responsibilities of each for administering pro-visions of Section 104. CDC has also designatedpublic health advisors in EPA’s regional offices toassist in assessing health impacts at uncontrolledhazardous waste sites.

Other Federal agencies also have designated re-sponsibilities under Section 104:

1.

2.

3.

The Food and Drug Administration conductsfield investigations and analyses of food chaincrops affected by CERCLA sites (Sectionl o ) .The National Library of Medicine is conduct-ing an inventory of literature, research, andstudies on health effects of toxic substances( S e c t i o n l o ) .The National Institute of EnvironmentalHealth Sciences analyzes compounds foundat CERCLA sites (Section lo).

Federal Research and DevelopmentConcerning Groundwater Quality

At least 26 Federal organizations are conduct-ing or are planning to conduct research and devel-opment (R&D) studies on groundwater quality.Table 15 lists the organizations and categorizes theirmajor groundwater quality R&D activities. Mostof the work that is done requires an understand-ing of groundwater flow systems.

1848 FR 17651-17652. The agency was established fOllOwing settle-ment of a lawsuit brought by the Environmental Defense Fund (EDF)against the Department of Health and Human Services for their fail-ure to comply with Section 104 of CERCLA. See Reisch, 1983.

Ch. 3—Federal Institutional Framework To Protect Groundwater From Contamination ● 85

Table 15.—Federal Involvement in Groundwater Quality Research and Development’

Categories of groundwater quality R&Db

Federal organization 1 2 3 4 5 6 7 8 9 10

National Science Foundation. . . . . . . . . . . . . . . . . . . .Department of Agriculture

Agricultural Research Service. . . . . . . . . . . . . . . . .Forest Service. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Soil Conservation Service. . . . . . . . . . . . . . . . . . . . .

Department of CommerceNational Bureau of Standards. . . . . . . . . . . . . . . . .

Department of DefenseArmy Corps of Engineers. . . . . . . . . . . . . . . . . . . . .Army Medical Bioengineering R&D Laboratory. . .Army Toxic and Hazardous Materials Agency. . . . .

Department of Energy. . . . . . . . . . . . . . . . . . . . . . . . . .Department of the Interior

Bureau of Indian Affairs. . . . . . . . . . . . . . . . . . . . . .Bureau of Land Management. . . . . . . . . . . . . . . . . .Bureau of Reclamation. . . . . . . . . . . . . . . . . . . . . . .Fish and Wildlife Service. . . . . . . . . . . . . . . . . . . . .Geological Survey. . . . . . . . . . . . . . . . . . . . . . . . . . .National Park Service. . . . . . . . . . . . . . . . . . . . . . . .Office of Surface Mining. . . . . . . . . . . . . . . . . . . . .Office of Water Policy. . . . . . . . . . . . . . . . . . . . . . . .

Environmental Protection AgencyEnvironmental Monitoring Systems Laboratory. . .R.S. Kerr Environmental Research Laboratory. . . . .Environmental Research Laboratory. . . . . . . . . . . .Office of Pesticide Programs. . . . . . . . . . . . . . . . . .Office of Radiation Programs. . . . . . . . . . . . . . . . . .Office of Research and Development. . . . . . . . . . .Office of Solid Waste. . . . . . . . . . . . . . . . . . . . . . . .Office of Water. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Nuclear Regulatory Commission. . . . . . . . . . . . . . . . .

x x x

x xx

x x

x

x x xxx

x

xxx xx

X x x x x xx x

x xx x x x

x xxxx

x xx x x x x

xx

x x

x

x x

x

The most diverse research programs—in termsof the number of R&D categories involved—arethose of the Environmental Protection Agency (theOffice of Research and Development is most ac-tive), the U.S. Geological Survey, and the ArmyCorps of Engineers. Information made availablefor this study does not allow a detailed breakdownof projects within all the agencies.

Institutional involvement is highest—in terms ofthe number of organizations conducting researchin a particular category—in the detection ofgroundwater contamination and in subsurface fate

and transport of contaminants. Detection effortsgenerally involve point sources (e. g., waste piles,landfills, mine drainage, underground injectionwells, surface impoundments, and septic tanks), butsome efforts are also being directed toward non-point sources (e. g., salt-water intrusion, farm run-off, and pesticide applications). Several organiza-tions are also involved in standards certification andquality assurance, hydrogeologic investigations,and treatment technologies.

As of 1978, the Federal budget for all water re-search was approximately $225 million but only $10

86 • Protecting the Nation’s Groundwater From Contamination

million to $12 million was spent on groundwaterR&D (U.S. House of Representatives, 1978). Dataavailable for this study are not sufficient for esti-mating current Federal expenditures either ongroundwater quality R&D overall or on specific cat-

egories of R&D. In general, groundwater R&D ex-penditures are not identified as such, and withoutdetailed budget information, the extent and focusof Federal groundwater R&D activities cannot beassessed.

CHAPTER 3 REFERENCES

Canter, L. W., "Groundwater Quality Management," Journal of the American Water Works Association, October 1982, pp. 521-527.

Chase, E. G.,]. E. Moore, and D. A. Rickert, "Water Resources Division in the 1980's-A Summary of Activities and Programs of the U. S. Geological Survey's Water Resources Division," USGS Circular 893, 1983.

Comments in "Groundwater Pollution in South Dakota: A Survey of Federal and State Law," South Dakota Law Review, vol. 23, No.2, pp. 734-798, summer 1978.

Copeland, C., "Water Quality: Implementing the Ciean Water Act, " Congressional Research Service Issue Brief IB83030, 1983.

Davis,]. C., and B. S. Davis, The Politics of Pollution (Indianapolis, IN: Pegasus-Bobbs-Merrill Co., 1976).

Feliciano, D., "Comparison of the U.S. Environmental Protection Agency's Groundwater Protection Strat­egies," Congressional Research Service 84-528 ENR, Feb. 8, 1984.

Miller, D. W. (ed.), Waste Disposal Effects on Ground Water, pp. 445-446 (Berkeley, CA: Premier Press, 1980).

Office of Technology Assessment, Technologies and Management Strategies for Hazardous Waste Con­trol, OTA-M-196 (Washington, DC: U.S. Govern­ment Printing Office, March 1983).

Office of Technology Assessment, Use of Models for Water Resources Management, Planning, and Pol­icy, OTA-0-159 (Washington, DC: U.S. Govern­ment Printing Office, August 1982).

Reisch, M. E. A., "Superfund: Hazardous Waste Cleanup," Congressional Research Service Issue Brief IB 83064, 1983.

Spector, S., Branch of Technical Support, Bureau of Land Management, personal communication, Sept. 11, 1984.

Tripp,]. T. B., and A.]affe, "Preventing Groundwater Pollution: Towards a Coordinated Strategy To Pro­tect Critical Recharge Zones," Harvard Environ­mental Law Review, vol. 3:1, pp. 364-410, 1979.

U.S. Environmental Protection Agency, "Proposed Ground Water Protection Strategy," Office of Drink­ing Water, Nov. 1980.

U.S. Environmental Protection Agency, "Proposed Ground Water Policy-Draft," Office of Drinking Water, Feb. 2, 1983.

U.S. Environmental Protection Agency, "Ground­Water Protection Strategy," Office of Ground-Water Protection , August 1984.

U.S. Geological Survey, "Annotated Bibliography of Water-Related MOUs and lAGs," Office of Water Data Coordination, December 1983.

U.S. House of Representatives, Committee on Public Works, "Federal Water Pollution Control Act Amend­mentsof1972," Report No. 92-911. Mar. 11,1972.

U.S. House of Representatives, Committee on Inter­state and Foreign Commerce, Report No. 93- 1185, pp.1, July to, 1974.

U.S. House of Representatives, 95th Cong., 2d sess., "Groundwater Quality Research and Development," hearing ( including report) before the Subcommittee on the Environment and the Atmosphere, Commit-.. ____ ~_: ______ ~ 'T' __ t.. __ l_~. A ~_ 0 C)t::. __ ~ C)'7 lCC UU >JLICULC c1UU ~ CLUUUIUt:;y, "'pI. u, .:.U, c1JJU ':'1,

1978. U.S. Senate Committee on Public Works, "Federal

Water Pollution Control Act Amendments of 1971 , " Report No. 92-414, Oct. 28, 1971.

Wilson, V. P., "Groundwaters: Are They Beneath the Reach of the Federal Water Pollution Control Act Amendments," Environmental Affairs, vol. 5, pp. 545-566, 1976.

Chapter 4

State Institutional FrameworkTo Protect Groundwater

From Contamination

Contents

Chapter 4 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107

TABLES-/:1/)1(. ,\”() l’aqc’16. OTA Sta:c Sur\cy Responses: State Activities To Improve Capabilities To Deal

W’ith Grcundwater Contamination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9517. Orl’A Sta e Survey Responses: Examples of Special Studies To Irnpro\e

State Ca~abilitics To Deal With Groundwater Contamination . . . . . . . . . . . . . . . . . . . . 9618. OTA Sta e Sur\cy Responses: Distribution of State Special Studies Among

.Source Cfitegories . . . . . . . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . 971{), O’1’A Stzll c surl.~y Responses: Types of’ Useful Information From Other States . . . . . 97z(). OTA Stal e Su r~’ey Responses: Number of Statrs Reporting Positive and/or

Negative Effects of Selected Federal Laws and Programs on Effbrts To Deal W’ithGroundwiter Contamination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

21. l’ypes of State Groundwater Quality Standards Programs in 1981 and 1983 . . . . . . . . 101zz. <)’I’A Sta[ e Survey Responses: Strengths and Problems in Programs To Deal With

C~roundw:lter Contamination and Desired Federal Assistance , . . . . . . . . . . . . . . . . . . . . 10323. OTA State Sur\ey Responses: Types of Sources for Which States Experience

Variati(>ny; in Their .Ability “lo Deal Effectively \\’ith Groundwater Contamination . . 105

FIGURE! ;F’i,yurc ,1’[~. i’,!,ye

1. Number 01 States With Programs To Detect, Correct, or Pre\entGroundwater Contamination From Selected Sources in 1981 and 1983 . . . . . . . . . . . . . . 93

‘2. O-l’A State Sur\q’ Responses: Number of States With No Programs 1’o Detect,Corrt’et, or Prtx’ent Groundwater Contamination From Selected Sources . . . . . . . . . . . . 94

Chapter 4

State Institutional Framework To ProtectGroundwater From Contamination

—— . — —— — — — -— — — -—— — . -CHAPTER OVERVIEW

OTA State Survey

Information on the States presented in this re-port is based primarily on a survey of all the Statesconducted by OTA from June to September 1983.The objectives of the questionnaire, which was sentto the State Governors, were to obtain a commoninformation base for assessing the extent to whichindividual States use avaiIable techniques for handl-ing existing groundwater contamination problemsand to learn the status of State efforts concerninggroundwater quality protection. All 50 States re-sponded. Summary information derived from Stateresponses is discussed in this chapter regarding theinstitutional framework; technically oriented issuesrelated to specific detection, correction, and pre-vention activities are covered in chapters 7, 10, and12, respectively.

State responses to the OTA survey reflect theviews of State personnel involved in groundwaterquality programs. Questionnaires received by theGovernors’ offices were forwarded to the Stateagencies with groundwater quality responsibilities.Responses were prepared by a single agency in 36States, although several programs within the agencyoften participated. Fourteen States coordinatedtheir responses with more than one agency. Theextent to which the response of a single agencyreflects State activities is highly variable, depen-ding on the relative role of that agency in dealingwith groundwater contamination. In view of thefact that many States are actively developing orrevising their contamination programs, responsesreflect program status only as of the date of thequestionnaire, i.e., summer 1983.

Survey questions were divided into eight cate-gories: sources, detection, corrective actions, pre-vention, improving capabilities, State policies,Federal-State relations, and impacts. Emphasis was

on the detection and correction of existing contam-ination. Thus, further investigation would be re-quired for a detailed analysis of prevention.

A list of the State agencies that responded anda copy of the questionnaire are presented in appen-dixes C. 1 and C.2, respectively. Because many ofthe questions asked in the survey are open-ended,the fact that only a few States commented on a par-ticular issue does not necessarily imply that the issueis not of concern to other States. Issues raised bythe State responses should thus be interpreted aspotentially important to additional States as well.

State questionnaire responses discuss most, butnot all, of the sources of contamination, techniquesfor hydrogeologic investigations, and correctionalternatives presented in the technical chapters ofthis report. The technical chapters have additionalcoverage because they continued to evolve after thequestionnaire was distributed. Nevertheless, Stateresponses provide a factual and comprehensive basisfor analysis of State activities and concerns.

State Institutional Framework

In this chapter, State perceptions of groundwatercontamination problems and a general descriptionand assessment of their efforts to handle these prob-lems are presented. ’ The following topics are dis-cussed:

. State perceptions of groundwater contamina-tion problems;

. Overview of State activities to protect ground-water quality from contamination by selectedsources;

1 For more detailed accounts of selected State programs see GAO,1984; Pye, et al., 1983; Henderson, et al., 1984; National Confer-ence of State Legislatures, 1983; and Magnuson, 1981.

89

38-799 0 - 84 - 4 : QL 3

90 Ž Protecting the Nation’s Groundwater From Contamination

●

●

●

State efforts to improve capabilities to deal withgroundwater contamination;State perspectives on Federal programs, in-cluding Federal water quality standards andguidance; andState strengths, problems with their programsto protect groundwater quality, and types ofdesired Federal assistance.

Conclusions drawn from this information are sum-marized below.

Problems with groundwater quality have beenidentified in every State, and all the States are work-ing to improve their efforts to deal with contamina-tion. State efforts to protect groundwater qualityhave increased markedly in the past 2 years; forexample, the States are beginning to look at moretypes of activities and facilities that are potentialsources of groundwater contamination than previ-ously. However, there are differences in the waysthe States perceive and address contamination prob-lems—different States have different problems, pri-orities, capabilities, and approaches. Some sourcesof contamination are receiving more attention thanothers. Some potential sources are not being ad-dressed by most of the States. The States are alsoat different stages in developing and implement-ing programs, and generally, are at the very earlystages.

The States have been more successful address-ing some types of sources of contamination thanwith others: new v. old, active v. inactive, largev. small, concentrated v. widespread, point v. non-point, non-agricultural v. agricultural, and indus-trial wastes v. residential wastes. They have alsobeen generally more successful with sources forwhich there is a Federal mandate for action or forwhich they have explicit authority. In general, thefocus of State programs is on point sources ofwastes, rather than on non-point sources and non-waste sources. More States give priority to, andhave developed programs for, prevention ratherthan detection or correction.

All the States recognize problems with their ef-forts to protect groundwater from contamination.The problems relate primarily to resources (e. g.,funding, technical expertise, and information anddata) and authority to develop and implement pro-grams. Lack of authority to deal with some sources

is considered a serious problem by almost 40 per-cent of the States. Although there is a general lackof uniformity among the States about the sourcesfor which they do not have authority, at least twosources—underground storage tanks and agricul-tural practices—were highlighted by one-half theStates noting problems with authority. z

Current Federal laws and programs are gener-ally helpful to the States. But the level of supportis not perceived as adequate by most States, noris support directed at all the specific areas wherethe States have identified problems (e. g., Federalguidance on water quality standards is perceivedas insufficient by many States). In some cases, theStates feel that Federal initiatives have actuallyhindered State efforts.

Problems have been created for some States bysome Federal programs. For example:

● programs have resulted in the transferring ofsurface water quality problems to ground-water;

. resources have been shifted from groundwaterissues to other Federal priorities;

● programs have failed to provide explicit

2The States obtain authority to address sources of groundwater con-tamination through a variety of mechanisms. For example, a Statemay establish authority through legislation specifically addressing asource (e. g., regulating solid waste landfills); legislation specificallyaddressing groundwater quality (e. g., m+y-dating discharges to ground-water); or more general water quality legislation that enables a Stateto protect the quality of State waters (delined to include groundwaterin many States). State legislation may be passed in response to Fed-eral laws or programs, or legislation may be developed by the Stateindependently of any Federal activities. For example, Federal lawsmay require that States establish a program (or the Federal Govern-ment will develop a program for the State, as in the Safe DrinkingWater Act) or a Federal law or program may offer a State financialassistance if the State establishes a program meeting Federal criteria,as in the Coastal Zone Management Act.

Once a State has established authority to address groundwater con-tamination, specific programs are developed (unless they are specifi-cally described in the legislation) and implemented. Program devel-opment may involve approval of administrative regulations andguidelines that describe the scope of the program in greater detail thanthe enabling legislation. For example, a State may have a law thatauthorizes the establishment of standards for groundwater quality,but the specific standards and the exact circumstances in which theyare applied are established in administrative rules or regulations. Suchadministrative rules and regulations may require some type of ap-proval by the State legislature, or they may be up to the discretionof the implementing agency. State program implementation may re-quire that the legislature appropriate special funds for that purpose,or program funding may depend on the implementing agency’s makingallocations from its general operation budget.

Ch. 4—State Institutional Framework To Protect Groundwater From Contamination ● 9 1

●

●

●

authority to the States to deal with ground-water quality problems;programs have not provided adequate and sus-tained funding for both development and im-plementation;programs have not been applicable to thehydrogeologic conditions in all States; andprograms have had technical deficiencies.

and the differences in State hydrogeologic condi-tions and institutional arrangements.

The States generally want Federal assistance inthe form of funding, technical assistance, researchand development, information management, ad-ministrative improvements, and policy develop-ment. Different States want different combinationsof these kinds of assistance and would like assist-

These problems are related to the lack of Fed- ance directed toward detection, correction, preven-eral goals for groundwater protection and the fail- tion, standards, or, more generally, improvementure of Federal programs to recognize both the in- of State capabilities to handle contamination.terrelationships among all environmental media

STATE PERCEPTIONS ABOUT GROUNDWATERCONTAMINATION PROBLEMS

Incidents of groundwater contamination havebeen identified in all 50 States (USGS, 1984), butperceptions about what constitutes a problem vary.For example, some States consider small areas ofcontamination or several incidents of contamina-tion a statewide problem; others do not. The ex-tent to which an isolated site-specific problem is ofstatewide concern is partly a function of the avail-ability of alternative high-quality water supplies,the number of further incidents expected from vari-ous sources of contamination, and the capabilityof a State to detect and correct contamination from

existing sources and to prevent contamination fromnew sources.

Several States commented on the future of ground-water protection, Some are pessimistic about con-trolling contamination, given the complexity of theproblems and the politics and emotions involved.Other States are optimistic that contamination willbe controlled if they are able to establish and/or im-plement programs to: 1) prevent groundwater qual-ity degradation from a variety of sources; 2) obtaina better understanding of hydrogeology, sources,

Photo credits: State of F/orida Department of .Environrnenta/ Regulation

Contaminated groundwater has been detected in every State.

92 Ž Protecting the Nation’s Groundwater From Contamination

and groundwater quality; and 3) detect and cor- ity. Overall, the States are devoting more atten-rect contamination from existing sources. tion to preventing contamination than to detect-

Regardless of their perceptions of contamination ing or correcting it. This pattern is consistent withState comments on present and future priorities.problems, all the States are working to improveMost States give highest priority to prevention.their capabilities for protecting groundwater qual-

OVERVIEW OF STATE ACTIVITIES TO PROTECTGROUNDWATER FROM CONTAMINATION

Historical Perspective

State efforts regarding contamination have beenchanging rapidly in the past few years. The num-ber of States working to address particular sourceshas increased substantially in the past 2 years.Some States that have only recently recognized par-ticular sources as problems (e. g., underground stor-age tanks) are beginning to address them. Figure1 compares the number of States with programseither to detect, correct, or prevent groundwatercontamination from selected sources in 1981 withthe number in 1983. Information in the figure doesnot imply that all types of facilities and activitiesfor any given source are included, that the samefacilities and activities are covered consistently fromState to State, or that details of programs for sourceshave remained the same over time.

As discussed in chapter 3, the Federal Govern-ment has some type of program for nearly all thesesources. The extent to which State activities are aresponse to Federal initiatives is not evident fromavailable information. However, some State re-quirements are more stringent than available Fed-eral guidance for some sources; other States areconstrained from addressing certain sources by alack of Federal initiatives. Further, some Statescommented that they can more easily address con-tamination from sources for which there is a Fed-eral mandate.

Current State Programs

The OTA State survey asked the States whetherthey had programs to detect, correct, or preventcontamination from various sources. Figure 2 shows

the number of States with no program to detect,correct, or prevent contamination from varioussources. The fact that a State program is directedat a particular source does not necessarily implythat all aspects of contamination from that sourceare being addressed. A program may be limited topreventing further contamination from a particu-lar source rather than focusing on detecting and/orcorrecting existing contamination. In addition,State programs may deal only with a subset of fa-cilities and activities of any particular source type.

Two major points are apparent from figure 2:1) some sources of groundwater contamination arereceiving attention from more States than others.In general, sources in OTA Category I (sources de-signed to discharge substances) and Category II(sources designed to store, treat, and/or dispose ofsubstances) are receiving the attention of moreStates than sources in Category IV (sources thatdischarge substances as a consequence of otherplanned activities); and 2) not all States are ad-dressing all potential sources. The reasons givenwere: 1) the source is not commonly found or doesnot occur in the State; or 2) no problems with thesource have been encountered. With respect to thefirst reason, sources that are most commonly foundin particular regions include de-icing salts (north-ern States), salt-water intrusion/brackish water up-coning (coastal and western States), and irrigationreturn flow (western agricultural lands). With re-spect to the reason that problems have not yet beenfound, it is possible that some problems will notbe recognized until they are looked for. This pointis especially true for the groundwater contaminantsthat are often not directly observable by taste, odor,color, or acute illness.

Ch. 4—State Institutional Framework To Protect Groundwater From Contamination • 93

Figure I.—Number of

S O U R C Ea

States With Programs to Detect, Correct, or Prevent Groundwater ContaminationFrom Selected Sources in 1981 and 1983

Subsurface percolation (1)

Injection wells (1)

Land application (1)Wastewater

Wastewater byproducts

Landfills (II)

Surface impoundments (II)

Leaks from storage, pipelines,etc. (II, Ill)

Agricultural runoff (IV)

Urban runoff (IV)

Mining and mine drainage (IV)

Salt-water intrusion/brackishwater upconing (VI)

Spills and accidents

I 1 1 1 I !o 10 20 30 40 50

Number of StatesKey:

w Based on OTA State SurveyResponses, 1983.

■ Based on WRC, 1981.

a The ~ ource~ included are those listed on both the OTA and wRc surveys, Roman numerals refer to OTA source Categories (see table 5). See also the footnOtes to

fig. 2 for a description of the sources included.

SOURCE: Water Resources Council (WRC), 10S1; and the Off Ice of Technology Asaeaament.

STATE EFFORTS TO IMPROVE CAPABILITIES TODEAL WITH GROUNDWATER CONTAMINATION

States are undertaking a variety of activities to ●

improve their capabilities to deal with groundwatercontamination and are developing institutionalframeworks to support their efforts. In this section,information provided in State survey responsesabout these activities is described. It demonstratesthe general points which follow:

●

● The States are approaching the need to im-prove their efforts in many different ways.

Most activity to improve capabilities is at anearly stage of development. Training staff anddeveloping their capabilities, detecting con-tamination, collecting data on particularsources or aquifers, and developing manage-ment strategies and programs are among themost commonly reported activities.All potential sources of contamination, as iden-tified by OTA’s study, are not being consid-ered by all the States.

94 ● Protecting the Nation’s Groundwater From Contamination

Figure 2.—OTA State Survey Responses: Number of States With No Programs To Detect, Correct, or PreventGroundwater Contamination From Seiected Sources

aThe sources Included are those listed on the OTA survey. Roman numerals refer to OTA source categories (see table 5).

bL.ndflll •• Some States did not specify whether programs were for hazardous or sanitary landfills. Thus information on the number of States without hazardous or sanitary landfill programs is uncertain. However, one State explicitly noted that it did not have any programs for hazardous waste landfills. All States have some kind of landfill program.

cL •• ks from .tor.gelplpell ..... The States were not specifically asked about storage tanks and containers (category II) and pipelines and materials transport and transter operations (category \II). These sources are combined into the general category 01 leaks from storage/pipelines about which the States were questioned.

More specific information on the status of State programs to address leakage of underground storage of petroleum products is available from (API, 1983b). State and local governments have been regulating underground storage at an increasing rate over the last several years.

Provisions of State underground leak laws are variable and may Include one or more of the following basic elements: coverage of new or existing tanks; equipment or installation requirements exceeding those of the National Fire Protection Association or the Uniform Fire Code; secondary containment; replacement; inventory control; testing; monitoring; or abandonment provisions. Of the 18 States that have enacted statewide regulations, five States' programs Include monitoring reo quirements, and two States had proposed monitoring requirements as of June 1983.

The Congressional Research Service (Feliciano, 1984) indicates that few Slate laws or regulations are directed toward prevention 01 leakage and groundwater con­tamination by underground storage tanks. And In several cases, the laws or regulations refer mainly to the need for preventing fire or explosion hazards caused by tank contents.

dAgricultUnt end egriculturel runoff. Some States referenced general programs for agriculture and agricultural runoff rather than reporting on programs for irrigation practices, pesticide and fertilizer applications, and animal feeding Operations.

eo.·lclng Hit •. The States were not asked to distinguish between the application of de-icing salts (IV) and the stockpiling of de-icing salts (II).

f Abandoned .. lla. The States were not asked to distinguish among the various types of production and other wells (V). Improper abandonment of any type of well can result In groundwater contamination.

gSpllla encl.cc!dent •. These have not been classified in a particular source category in OTA's assessment because a spill or accident can result in groundwater con­tamination Irom almost any type 01 source (e.g., rupture of storage tanks, spill in transport, and flooding 01 a surface impoundment) due to operational or management problems.

SOURCE: Office of Technology Assessment.

Ch. 4—State Institutional Framework To Protect Groundwater From Contamination ● 9 5

As shown in table 16, the highest number ofStates are working to improve staff capabilities,undertaking special studies, and improving coordi-nation among programs. A large number of Statesis also involved in public education, facility devel-opment, and agency reorganization. Many Statescommented that their efforts—especially as relatedto staff development and training, public educa-tion, and facility development—were limited by in-sufficient funding. There is a wide variety of Stateactivities, as shown in tables 17 and 18 and dis-cussed below.

Staff Development and Training. Forty-fiveStates reported staff development and trainingactivities to improve their capabilities. Twenty-twoStates provided examples of activities, which canbe classified as: classes and conferences (e. g, shortcourses, hands-on training, workshops, seminars,and safety training); benefits (e.g.,, improved sal-ary structures, career ladders, continuing educa-tion funding, and management programs); and ad-ditional staff. Some States are engaging in morethan one type of activity.

Special Studies. Forty-three States reported con-ducting special studies to improve their capabilities.All but two of these States provided examples oftheir studies, which cover five major areas: detec-tion, sources and/or contaminants, aquifer char-acteristics, groundwater management and protec-tion strategy development, and regulatory programdevelopment. The number of States reporting eachtype of activity and examples of their studies arepresented in table 17. Some detail is provided aboutthe types of sources being studied in table 18.Sources that discharge substances as a consequenceof other planned activities (Category IV) are re-ceiving the most attention.

Table 16.—OTA State Sunrey Responses: StateActivities To Improve Capabilities To Deal With

Groundwater Contamination

Number of States Activity

45 . . . . . . . . . . . . . . . . . . . . . Staff development and training43 . . . . . . . . . . . . . . . . . . . . . Special studies42 . . . . . . . . . . . . . . . . . . . . . Coordination programs36 . . . . . . . . . . . . . . . . . . . . . Public education29 . . . . . . . . . . . . . . . . . . . . . Facility development24 . . . . . . . . . . . . . . . . . . . . . Agency reorganization10 . . . . . . . . . . . . . . . . . . . . . Other

SOURCE Office of Technology Assessment.

Coordination Programs. Forty-two Statesreported special coordination programs. All but twoof these States provided examples of their coordi-nation activities, which may be classified as: in-teragency coordination (e. g., with Federal agen-cies, among State agencies, and with regionalagencies); program coordination; and other activ-ities (e. g., formation of special groundwater com-mittees, designation of special staff for coordina-tion, management program strategy development,written agreements, and data base improvements).The most commonly reported activity was inter-agency coordination. Of the eight States noting co-ordination with Federal agencies, seven specifiedthe agencies; the U.S. Geological Survey (USGS)was listed by all seven.

Forty-two States also reported benefiting frominformation provided by other States. Most infor-mation exchange among States occurs informallythrough: personal contacts (e,g., direct inquiry,visits, and informal discussions); attendance atevents (e. g., conferences, seminars, special train-ing sessions, and workshops); written materials(e. g., publications, newsletters, rules, regulations,and guidelines); associations (e. g., Association ofState and Interstate Water Pollution Control Ad-ministrators, National Governors’ Association, andinterstate commissions); and contact with consult-ants and experts. Contact through Federal agen-cies (e. g., Environmental Protection Agency andUSGS) was reported by relatively few States.

Table 19 summarizes major categories of infor-mation that the States want from each other. Theyare primarily interested in learning about pro-grams—types of approaches, successes, and fail-ures —rather than about the details of individualsites.

Thirty-two States reported a need to change someof their own practices to facilitate the exchange ofinformation among States. Two types of changeswere reported by the majority of States: 1 ) improv-ing data management, such as by establishing aninformation clearinghouse, and 2) preparing reportson State experiences. Several States expressed in-terest in sharing their experiences through a cen-tralized, national data base, recognizing that muchof the information would have to be keyed to spe-cific hydrogeologic conditions. Several States alsonoted that to write, print, and distribute reports

96 • Protecting the Nation’s Groundwater From Contamination

Table 17.—OTA State Survey Responses: Examples of Special Studies To Improve State Capabilities To DealWith Groundwater Contamination

Number of:

Type of study States Studies Examples

A. Detection studies . . . . . . . . . . . . . . . . . . . . . . . . . .Problem areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Program development. . . . . . . . . . . . . . . . . . . . . . . . .

Source-related . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Use-related. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

B. Source and contaminant studies . . . . . . . . . . . . .Assessments/inventories . . . . . . . . . . . . . . . . . . . . . .

Program development. . . . . . . . . . . . . . . . . . . . . . . . .

Impacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

C. Aquifer studies . . . . . . . . . . . . . . . . . . . . . . . . . . . .Baseline data... . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Modeling studies . . . . . . . . . . . . . . . . . . . . . . . . . . . .Contamination potential . . . . . . . . . . . . . . . . . . . . . . .

D. Groundwater management protection strategy . .Program development

Contamination response . . . . . . . . . . . . . . . . . . . . . .

Staff development . . . . . . . . . . . . . . . . . . . . . . . . . . . .Data management improvement . . . . . . . . . . . . . . . .

E. Regulatory program development . . . . . . . . . . . . .Standard development . . . . . . . . . . . . . . . . . . . . . . . .

Enforcement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2418

5

3

1

1913

6

6

1714

22

1210

4

11

2

3325

5

5

1

3416

7

8

2116

23

2014

4

11

53

2

Coal mining area studies—UT;TCE studies—AZ.

Groundwater quality monitoring assessment—PA; Study of techniques for detection ofpollutants-CT.

Monitoring coal-fired electric generating plantsludge and ash pits, selected municipalIagoons, and selected oil and gas drillingand production facilities—ND.

Investigating water quality at non-municipalpublic supply wells-AR.

Surface impoundment assessment and injec-tion well inventories-AL; Statewide toxicsubstances assessment—NM; behavior oforganic contaminants in groundwater—FL;pesticide studies-CA, Wl.

Bulk storage program development—NY; rulesneeded for drilling oil and gas in hydrogensulfide areas—OK; irrigation disposalwell alternatives study—lD; Statewideassessment of magnitude of groundwatercontamination—Ml.

Coal mining impact studies—UT; effects ofsalt-water disposal associated with oil fieldactivities—MS; impact of pesticides ongroundwater–FL, AZ, HI.

Near-surface permeability—FL; recharge areamaps—WV; hydrogeologic studies—GA, DE,IL, KY, NE, NJ, SC, SD.

Solute transport studies–MS.Potential for contamination of shallow acqui-

fers from land disposal of municipalwastes—lL.

Prevention strategies for particular region—WA, NY; statewide management/protectionstrategy—AR, Ml, NE, NY, ND, OK.

Point/non-point tradeoff project—NY; evaluateaquifer restoration/cleanup schemes—MA;incident response—NY, VT; HydrogeologicInvestigation Team—NH.

Staff evaluations—DE.Groundwater management information system

project—NY.

Develop standards for hazardous chemicals ingroundwater—FL; develop and adoptgroundwater quality standards–OR.

Coordinated UIC program—AR; permittee orresponsibility party studies—DE.

SOURCE: Off Ice of Technology Assessment.

Ch. 4—State Institutional Framework To Protect Groundwater from Contamination ● 9 7

Table 18.—OTA State Survey Responses: Distribution of State Special StudiesAmong Source Categories

Totalnumber of Assessments/ Program

Sources studies inventories development Impacts

a Wasteb Non-wastec Note that the totals do not add up to the totals in table 17 because some of the contaminant-related studies indicated in

that table (sources and contaminant studies) are not linked to specific source categories.SOURCE Off Ice of Technology Assessment

Table 19.—OTA State Survey Responses: Types of Useful Information From Other States

Information Number of States a Major topics of interest

Corrective . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Experience with techniques; case histories; cleanupstandards.

Detection activities. . . . . . . . . . . . . . . . . . . . . . . . 28 Experience with techniques; case histories;behavior of specific contaminants in particularhydrogeologic environments; monitoringprograms.

Prevention activities . . . . . . . . . . . . . . . . . . . . . . 14 Experience with techniques, design criteria andsiting requirements for some types of facilities;Best Management Practices.

Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 General water quality standards; maximum con-taminant levels; discharge standards; treatmentor technology based standards.

Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Groundwater contamination problems associatedwith different sources.

Other . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Groundwater quality management/protectionstrategies; risk assessment information; impactsof groundwater contamination; research results;legislation; interstate groundwater flow andquality; public education.

aFortY.eight states described the types of lnfOrmatlOn that would be useful.

SOURCE Off Ice of Technology Assessment

and studies on their experiences requires increasedstaff and support budgets.

Public Education. Thirty-six States reportedpublic education activities, and 16 listed examples:written materials (e. g., pamphlets, magazine arti-cles, and use of the news media) and personal con-tacts (e. g., workshops with consultants, seminars,and speaker bureaus). Some States noted that theyhave public information programs; the programsmay be either general or targeted at particularsources or areas where groundwater contamination

Facility Development. Twenty-nine Statesreported facility development activities, with 22States listing examples. The most commonly re-ported activity is related to laboratory improve-ments (e. g., expansion of State water quality lab-oratories, certification and quality assurance checkson private laboratories, upgrading techniques, ad-ditional analysis of particular substances such asorganic chemicals or radionuclides, and purchaseof laboratory equipment). Other activities listed in-clude improving computer capabilities, developingspecial waste disposal facilities (e. g., State hazard-

is of concern. ous waste facilities and agricultural chemical wash-

98 ● Protecting the Nation’s Groundwater From Contamination

ing facilities), and establishing quality assuranceprograms.

Agency Reorganization. Twenty-four Statesreported some type of agency reorganization de-signed at least in part to improve their capabilitiesto deal with groundwater contamination. TwelveStates gave examples, which may be categorizedas: consolidating groundwater expertise in onegroup or establishing a special task force; creating

a single agency for the environment or for waterresources; and establishing a special agency orgroup for special projects or sites of contamination.

Other Activities. The “other” category listed by10 States relates primarily to either general pro-gram development (e. g., specific laws, priorities,or standards for groundwater) or data collection(e.g., improved drilling capability and monitoringand inventory efforts).

STATE PERSPECTIVE ON FEDERAL PROGRAMS

In this section, two major themes are discussed:1) whether selected Federal laws and programs havehelped or hindered State efforts to protect ground-water quality, and 2) how States use Federal wa-ter quality standards and guidance for groundwatercontaminants.

State Responses AboutSelected Federal Laws

In the State survey, the States were askedwhether selected Federal laws and programs havebeen a help to them or hindrance. For the mostpart, Federal laws and programs have helped manyStates address contamination. Several Statespointed out problems with some Federal programs.In general, States have different problems. Theyrelate primarily to Federal programs that: shiftproblems with the quality of another environmentalmedium to groundwater; divert resources to activ-ities other than groundwater; do not explicitlyauthorize consideration of groundwater; lack flex-ibility to address specific conditions in a State;create administrative problems for a State; do notfund activities mandated by the Federal Govern-ment; and have provisions that the States view astechnically unsound or inappropriate,

Table 20 shows the number of States comment-ing positively and/or negatively about the laws andprograms. When a State commented both positivelyand negatively, the comments may apply to a singlesection of a law or to different sections. The ‘‘noimpact comment has several possible meanings:

1) that the law or program does not apply to theState (e. g., the Bureau of Indian Affairs (BIA) isactive only in States with Indian lands and theCoastal Zone Management Act (CZMA) appliesonly to States bordering seacoasts or the GreatLakes); 2) that respondents to the questionnairewere not familiar with the applicability of the lawor program to groundwater issues (e. g., the Na-tional Bureau of Standards (NBS)); or 3) that thelaw or program has no bearing on the efforts of aparticular State (e.g., Surface Mining Control andReclamation Act (SMCRA) and CZMA). Notethat the number of States commenting that a lawor program has no impact on their efforts to dealwith groundwater contamination is relatively large.

In the following discussion, information on thenegative comments is presented in detail. Thesecomments provide a basis for determining neededchanges in existing laws and programs, or ap-proaches to avoid in establishing new programs,to help the States with their groundwater con-tamination problems.

The positive comments, not discussed in detailhere, indicate the types of Federal laws, programs,and services that the States view as helpful. In gen-eral, the positive comments include many of thepoints made by the States in their response to ques-tions about how the Federal Government can bestassist them (see the next major section, e.g., tech-nical assistance, funding, research and develop-ment, and information management). Positivecomments were also made for Federal programsthat, for example, are flexible and can be tailoredto individual State needs and conditions.

Ch. 4—State Institutional Framework To Protect Groundwater From Contamination ● 9 9

Table 20.—OTA State Survey Responses: Number of States Reporting Positiveand/or Negative Effects of Selected Federal Laws and Programs on Efforts

To Deal With Groundwater Contaminationa

State response

Both positivePositive Negative and negative No impact

LawsCWA . . . . . . . . . . . . . . . . . . . 33 2 12 3SDWA . . . . . . . . . . . . . . . . . . 36 1 10 3RCRA . . . . . . . . . . . . . . . . . . 33 2 10 5CERCLA . . . . . . . . . . . . . . . . 31 0 4 15TSCA . . . . . . . . . . . . . . . . . . . 12 0 0 38UMTRCA . . . . . . . . . . . . . . . . 7 0 2 41FIFRA . . . . . . . . . . . . . . . . . . 11 1 37CZMA . . . . . . . . . . . . . . . . . . 6 0 1 43SMCRA . . . . . . . . . . . . . . . . . 15 2 1 32ProgramsSCS . . . . . . . . . . . . . . . . . . . . 26 2 1 21ASCS . . . . . . . . . . . . . . . . . . . 16 0 0 34NBS . . . . . . . . . . . . . . . . . . . . 4 0 0 46BIA . . . . . . . . . . . . . . . . . . . . 2 0 1 47BLM . . . . . . . . . . . . . . . . . . . 7 0 1 42BuRec . . . . . . . . . . . . . . . . . . 8 0 0 42USGS . . . . . . . . . . . . . . . . . . 43 0 1 6WRDA . . . . . . . . . . . . . . . . . . 14 0 1 35asee text and ch 3 for abbrewatlons.

SOURCE’ Off Ice of Technology Assessment

Federal laws and programs that have influencedthe most States include: the Clean Water Act(CWA), the Safe Drinking Water Act (SDWA), theR e s o u r c e C o n s e r v a t i o n a n d R e c o v e r y A c t(RCRA), the Comprehensive EnvironmentalResponse, Compensation, and Liability Act(CERCLA), and programs of USGS. Most Statesview favorably the contribution these laws and pro-grams have made to their handling of contamina-tion programs. But, with the exception of USGSprograms and CERCLA, a relatively large num-ber of States noted that these Federal programs havealso had negative (or both positive and negative)effects on their efforts.

It is important to recognize that although oneState may view a particular section of a law aslimited in its application to groundwater, anotherState may be using that same provision very effec-tively. Such discrepancies may reflect differencesamong States’ groundwater problems as well as in-stitutional differences (e. g., authority and priorities)which affect the use of a State’s resources. Nega-tive aspects of these laws and programs mentionedby the States are described below, with emphasison the laws receiving the most negative comments(i.e., CWA, SDWA, and RCRA).

Clean Water Act. The States were asked to com-ment on Sections 104 (Research, Investigation,Training, and Information); 106 (Grants for Pol-lution Control); 201 (Grants for Construction ofTreatment Works); 205j (Grants for Water QualityManagement Planning); 208 (Areawide WasteTreatment); 303 (Water Quality Standards and Im-plementation Plans); and 402 (National PollutantDischarge Elimination System, NPDES). FourteenStates made negative comments about the varioussections. Two major issues were raised about howthe act has hindered State efforts to deal withgroundwater contamination:

1.

2.

Ten States noted that the act has promotedsurface water quality protection efforts to thedetriment of groundwater quality (e. g., landdisposal practices, increased wastewater treat-ment, and point source discharges in normallydry streambeds) and has diverted resourcesaway from groundwater issues.One State noted that the lack of explicitauthority in the law to address discharges togroundwater has prevented the State from do-ing so.

It should be noted that many States are activelyusing their discharge elimination permit systems

100 ● Protecting the Nation’s Groundwater From Contamination

to regulate discharges to groundwater (20 Statescommented only positively on Section 402).

Safe Drinking Water Act. The States were askedto comment on the following portions of this law:Part B—Section 1412 (National Drinking WaterRegulations); Part C—the Underground InjectionControl Program and the Sole Source Aquifer Pro-gram; and Part E—Sections 1442 (Research, Tech-nical Assistance, Information, and Training of Per-sonnel) and 1443 (Grants for State Programs). Thenegative comments from 11 States about one ormore of these provisions raised two major issues:

1, Six States noted that the provisions of the SoleSource Aquifer Program and the Under-ground Injection Control Program were notapplicable to or were of little value for con-ditions in their States.

2. Six States noted administrative problems withimplementation of the Underground InjectionProgram and Sections 1442 and 1443.

Resource Conservation and Recovery Act. TheStates were asked to comment on Subtitles C (Haz-ardous Waste Management) and D (State or Re-gional Solid Waste Plans) of the act. Twelve Statesmade negative comments about one or both pro-visions, with three major points of concern:

1.

2.

3.

Eight States cited problems with administra-tion or implementation of program require-ments (e. g., difficulties with requirements forauthorization of State programs or conflictsbetween Federal requirements and ongoingState programs; difficulties in dealing withEPA staff and coordinating with other EPAprograms; inflexibility of certain rules; andlack of Federal support for enforcement ofSubtitle D).Five States noted funding problems, particu-larly for Subtitle D, but also for monitoring,laboratory facilities, and staff to implementSubtitle C.Three States cited technical shortcomingswithin the law: the emphasis on land disposal,mandated use of liners, and inadequate per-formance standards that, according to oneState, hinder proper disposal; the lack of in-formation about the adverse effects of variousconcentrations of contaminants; the omissionof some known toxic or carcinogenic chemi-

cals from RCRA’s hazardous waste list; andquestions about the applicability of statisticalmethods used to evaluate concentrations ofsynthetic chemicals.

Other Laws and Programs. The negative com-ments made by a relatively few States about otherFederal laws and programs generally relate to thesame kinds of problems and concerns discussedabove for the Clean Water Act, the Safe DrinkingWater Act, and the Resource Conservation andRecovery Act.

That the law or program shifts surface waterquality problems to groundwater was mentionedby three States with respect to the Soil Conserva-tion Service, by one State with respect to studiessupported by its Water Resources Research Insti-tute, and by one State with respect to the Bureauof Land Management and the Bureau of IndianAffairs.

The lack of explicit authority to deal withgroundwater quality problems has been a problemfor one State with respect to the Surface MiningControl and Reclamation Act (SMCRA). Threeother States noted that SMCRA has little impacton groundwater quality.

Administrative problems with the UraniumMill Tailings Radiation Control Act (UMTRCA),noted by two States, relate to coordination betweenState and Federal agencies; with the Comprehen-sive Environmental Response, Compensation, andLiability Act (CERCLA), noted by three States,relate to problems with coordination and the slowrate of progress in program implementation; withSMCRA, noted by one State, relate to retainingState primacy; and with the Coastal Zone Man-agement Act, noted by one State, relate to coordi-nation problems among State agencies.

Funding problems with the USGS CooperativeProgram were indicated by one State. The Statewas unable to participate in the Program becauseof the cash payments required for matching funds.One State mentioned the lack of funding to com-ply with Federal requirements under CERCLA toevaluate sites,

Technical shortcomings were noted by two Stateswith respect to the Federal Insecticide, Fungicide,and Rodenticide Act (FIFRA); some registeredpesticides have contaminated groundwater.

Ch. 4—State Institutional Framework To Protect Groundwater From Contamination . 101

State Use of Federal Guidance onQuality Standards for Groundwater

Water quality standards provide a baseline fordetection, correction, and prevention activities, TheStates apply standards to groundwater through theirdrinking water quality programs and/or ground-water quality programs.

As mentioned in chapter 3, the Federal statutesrequire the establishment of quality standards fordrinking water and surface water. The FederalGovernment establishes minimum standards forselected substances in drinking water and providesguidance for additional substances in drinking wa-ter and surface water. Although the Federal Gov-ernment does not require the States to set qualitystandards for groundwater, many States have doneso, especially in the past 2 years, as shown in table21. States have either established explicit author-ity for groundwater quality standards or have usedtheir general authority over water quality (oftenbased on Federal mandates to control surface wa-ter pollution) to address groundwater. Some Stateshave not developed groundwater quality standardsin the absence of explicit Federal guidance.

Also shown in table 21 are the types of Stategroundwater quality standards—i.e., whetherstandards are numerical, narrative, or both. Nu-merical standards specify concentration limits (e. g.,parts per million of a substance). Narrative stand-ards describe limits but do not specify concentra-tions (e. g., a non-degradation standard requiringthat concentrations be at or below natural back-

ground levels) or even necessarily individual con-taminants (e. g., a standard prohibiting the dis-charge of toxic, carcinogenic, teratogenic, ormutagenic substances into groundwater). Numer-ical standards are generally preferable to narrativestandards because the substances that are coveredand the concentrations that are acceptable areclearly stated. Because of difficulties in obtainingtoxicological and risk-related information (discussedin ch. 2 and app. A. 1), there are many problemsin developing numerical water quality standards.

State standards are based on available literature;the States have not conducted their own researchto determine toxicological, risk, and impact infor-mation. Some standards are based on the detec-tion limits of instrumentation, for practical pur-poses, rather than on the appraisal of risksassociated with different concentrations of individ-ual substances.

Major conclusions about State water qualitystandards applied to groundwater, compared withavailable Federal water quality standards andguidelines, are discussed below.

Federal drinking water standards and guidanceon acceptable concentrations of substances in wa-ter are not adequate for State needs. When Fed-eral standards or guidance are available, the Statesoften do not rely on them. Although it is not re-quired by Federal law, most States have developedor are developing groundwater quality standards.Some States have established drinking water stand-ards for substances in addition to, and/or appliedmore stringent standards to, those substances cov-

Table 21.-Types of State Groundwater Quality Standards Programs in 1981 and 1983

Types of standards/number of States

1983 1981

State groundwater quality Notstandards programs Numerical Narrative Both specified Total TotalPrograms exist specific to

groundwater. . . . . . . . . . . . . . . . . . . 6 3 10 1 20 8Programs exist based on

general water quality standardsthat apply to both surface waterand groundwater. , . . . . . . . . . . . . . 2 2 1 6 11 1

Developing programs specific togroundwater . . . . . . . . . . . . . . . . . . . 1 4 1 6 12 9

No program development . . . . . . . . . . — — — — 7 32

SOURCE” Office of Technology Assessment; American Petroleum Institute (API), 1983; and WRC, 1981

102 ● Protecting the Nation’s Grourtdwater from Contamination

ered by Federal regulations. State standards includenumerical limits for many substances for which theFederal Government has provided no guidance.

The standards States apply to groundwater areextremely diverse. They have developed standardsfor different substances, and when different Stateshave standards for the same substance, the valuesare usually not the same. It is not clear, however,how different standards affect the level of ground-water quality protection, given the varying behaviorof contaminants in different hydrogeologic environ-ments and the many uses of groundwater.

Appendix C .3, a table on Federal and State wa-ter quality standards, indicates the range of drink-ing water and groundwater quality standards estab-lished by the States, the States with these standards,the standards established by the Federal NationalInterim Primary and Secondary Drinking WaterRegulations, and Federal guidance provided byHealth Advisories and Ambient Water Quality Cri-teria. A summary of comments, drawn from ap-pendix C.3, follows:

●

●

States have developed water quality standardsfor numerous substances for which the Fed-eral Government has not established standardsor provided guidance. The States have estab-lished drinking water or groundwater qualitystandards or other indicators of quality for over150 substances. The Federal Government hasestablished standards or provided guidance fordeveloping water quality standards for lessthan half of this number. The Federal Govern-ment has provided guidelines for fewer than20 substances for which no State has standards.Apart from the substances covered by the Na-tional Interim Primary Drinking Water Reg-ulations, few States have developed standardsfor the same substances (i. e., different States

●

●

●

have generally developed standards for dif-ferent substances).Even when States have standards for the samesubstances, the standards are usually not thesame.State water quality standards differ in strin-gency from Federal standards or guidelines forthe same substances. In general, State drink-ing water standards are more stringent thanNational Secondary Drinking Water Regula-tions and Ambient Water Quality Criteria. Ingeneral, State groundwater quality standardsare also more stringent than Federal guide-lines, but there are substantial numbers ofsubstances for which the State groundwaterquality standards are less stringent than Am-bient Water Quality Criteria.Overall, the States have established ground-water quality standards for many more sub-stances than they have established drinkingwater standards;3 this may reflect the States’orientation to the prevention of groundwatercontamination. The substances for which aState has established groundwater qualitystandards are usually different than the onesfor which it has established drinking waterstandards. If a State has established drink-ing water standards and groundwater qualitystandards for the same substance, the ground-water quality standard is usually more strin-gent than the drinking water standard.

3In New York, the State with groundwater quality standards forthe highest number of substances, groundwater quality standards serveas guidelines for drinking water quality. Reconnaissance studies con-ducted by the State arc used to identify water supplies that have thepotential to be contaminated from these substances. More detailedinvestigations are undertaken if a potential problem is identified. TheState has found that water suppliers are responsive to the use ofguidelines and has not felt the need to establish formal regulations(Markusen, 1984).

Ch. 4—State Institutional Framework To Protect Groundwater From Contamination • 103

STATE STRENGTHS AND PROBLEMS IN PROGRAMSTO DEAL WITH GROUNDWATER CONTAMINATION

AND DESIRED FEDERAL ASSISTANCE

In response to survey questions about strengthsand problems in State groundwater protection pro-grams (e. g., program weaknesses, needed changes,and limiting factors) and how the Federal Govern-ment can be of most assistance, the States broughtup a number of issues related to six topics: 1 )sources of contamination, 2) general capabilities todeal with contamination, 3) standards for ground-water quality, 4) detection, 5) correction, and/or6) prevention. Table 22 summarizes the State re-sponses. Individual responses are presented in ap-pendix C .4; and examples of issues for which eachState appears to be particularly articulate are pre-sented in appendix C.5. Major findings, presentedbelow, are followed by details on each topic:

• Because the questions were basically open-ended (i. e., the States were not asked directlyabout strengths, problems, and the desire forFederal assistance with respect to detection,correction, and prevention), table 22 reflectsthe issues that questionnaire respondentsvoluntarily raised, perhaps feeling they wereof the greatest concern to their groundwaterprograms. The fact that a State did not com-ment about a particular issue does not neces-sarily reflect a lack of strengths, problems, ordesire for Federal assistance with respect tothat topic.

●

●

●

The fact that the highest number of Statescommented about improving capabilities anddetection probably reflects the early stage ofdevelopment of most State programs. Thatthese issues dominate many States’ concernsdoes not mean that they do not need assist-ance in other areas.Many States did not highlight any strengths,all the States noted problems, and nearly allwant some change in Federal assistance efforts.Comments on strengths relate primarily to theexistence of institutional mechanisms (e. g.,authority and program regulations) to addressvarious components of the problems in a State.Comments on problems relate primarily toresources (e. g., financial, staff, and informa-tion) or authority. Comments on desired Fed-eral assistance address six major categories: 1)funding, 2) technical assistance, 3) researchand development, 4) new policy development,5) information management, and 6) admin-istrative improvements. Funding, technicalassistance, and R&D were suggested by thehighest number of States. Six States mentionedthe need for a national policy on protectionof groundwater in order to overcome Stateprogram constraints in handling groundwatercontamination; at least 14 other States want

Table 22.—OTA State Survey Responses: Strengths and Problems in Programs ToDeal With Groundwater Contamination and Desired Federal Assistance

Number of States

DesiredFederal

Issues Strengths Problems assistance Total

Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 20 — 33Improving capabilities . . . . . . . . . . . . . . . . . . . . . . . . 12 48 41 50Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 19 19 28Detection, ., , ., ... , . . . . . . . . . . . . . . . . . . . . . . . . . 15 38 29Correction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 19 23 35Prevention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 12 10 18

Total States ... , . . . . . . . . . . . . . . . . . . . . . . . . . . 38 50 48 50

SOURCE’ Office of Technology Assessment

104 • Protecting the Nation’s Groundwater From Contamination

Federal funds for development of State pol-icies and programs.

● The States do not want Federal assistance onall the problems that they identified. In par-ticular, they do not desire Federal assistancewith problems related to water rights.

● Survey responses reveal a great deal ofvariability. One State’s strengths may beanother’s problems. Different States highlightproblems with different sources and differentaspects of programs for improving capabilities,standards, detection, correction, and preven-tion. Some States are concerned about estab-lishing authority, and others about either de-veloping or implementing programs. A Statemay have different needs for different sourcesor for detection, correction, or prevention. Inaddition, the States seek different kinds of Fed-eral assistance.

Sources

Strengths and Problems

Thirty-three States commented on the adequacyof their authority to deal with sources of contamina-tion. Some States listed either strengths or prob-lems with respect to authority for sources, and somelisted both. When both strengths and problems werenoted, they relate to different categories of sources,different sources within a single category, or differ-ent characteristics of facilities or sites of a particu-lar source type. Other comments on sources are re-

lated to strengths and problems with detection,correction, prevention, or improving capabilities.They are discussed in that context below.

Although the States did not use the same ter-minology, apparently many sources for which someStates reported having adequate authority are thesame sources for which other States reported in-adequate authority. These responses highlight thefact that the States have different capabilities fordealing with different sources of contamination andmay indicate that individual States are most con-cerned about different sources of contamination.In addition, relatively few States commented on theadequacy of their authority for specific sources.However, a relatively large number of States com-mented on the inadequacy of their authority to dealwith agriculturally related sources (including agri-cultural wastes, non-point source control, and pes-ticide and fertilizer use) and underground storagetanks. No States commented specifically on hav-ing adequate authority to deal with these sources.

A State may have adequate authority with re-gard to some facilities associated with a particularsource but not regarding others. Table 23 lists char-acteristics of sources for which States reported theirrelative success in establishing and/or implement-ing programs to control groundwater contamina-tion. The relative success of controlling contamina-tion may reflect the ease with which States are ableto acquire authority to regulate different types ofoperations (which may in turn relate to public sup-port, available resources, number of facilities, and

Photo credits: Office of Technology Assessment (left) and State of Florida Department of Environmental Regulation (right)

Many States lack adequate authority to deal with agriculturally related activities that are potential sources ofgroundwater contamination including fertilizer applications and animal feedlot operations.

Ch. 4—State Institutional Framework To Protect Groundwater From Contamination • 105

Table 23.—OTA State Survey Responses: Types ofSources for Which States Experience Variations in

Their Ability To Deal Effectively WithGroundwater Contamination

More success Less success

New facilitiesActive sitesLarge operators, facilities,

sitesRegulation federally

mandatedConcentrated sourcesNonagriculturePoint sourcesIndustrial wastes

Old facilitiesInactive sitesSmall operators,

facilities, sitesRegulation not federally

mandatedWidespread sourcesAgricultureNon-point sourcesHousehold wastes

SOURCE: Off Ice of Technology Assessment

other factors). Success may also reflect the kindsof options that are available for controlling con-tamination from different sources (e. g., it may beeasier and less expensive to design new facilitiesthan to retrofit old ones to prevent contamination).

Federal Assistance

Sources of contamination were not mentionedspecifically when the States listed desired Federalassistance. Rather, desired assistance related to im-proving capabilities, standards, detection, correc-tion, and prevention, as described in the follow-ing sections.

Improving Capabilities

Strengths and Problems

All of the States commented on their strengths,problems, and/or desire for Federal assistance toimprove their handling of contamination. Com-ments on strengths relate primarily to institutionalmechanisms that provide flexibility for respondingto newly recognized problems (e. g., coordinationamong State programs, staff training opportunities,and legislative support). Other strengths includeavailability of information on aquifer characteris-tics as an aid to decisionmaking.

Comments on problems relate primarily to hav-ing sufficient resources and support to establish orimplement institutional mechanisms. Almost all ofthe States are concerned with having sufficientfunds and staff. Funding problems were reportedby the highest number of States. With staff, the

problems relate to having, attracting, and retain-ing sufficient numbers of adequately trained per-sonnel.

The States also noted that a number of changesare required in their programs. Several States rec-ognize problems with their institutional framework,including lack of authority to deal with contamina-tion, and inability to develop and implement a co-ordinated strategy (e. g., because of factors relatedto regulations and their enforcement). Resolutionof these institutional problems is complicated insome States by the lack of support of various inter-est groups, policy conflicts or coordination prob-lems among State agencies and between State andFederal programs, and the low priority of ground-water relative to surface water.

Federal Assistance

Forty-one States expressed a desire for Federalassistance to improve their capabilities—apart fromFederal assistance related to standards, detection,correction, and prevention. Desired types of Fed-eral assistance to improve capabilities, indicated bythe highest number of States, include: general tech-nical assistance for groundwater quality programs;funding for development of groundwater policiesand programs, State research and development,and staff training; and Federal activities related toinformation management and information/technol-ogy transfer. Suggested improvements to Federalregulatory programs include more flexible regula-tions to meet individual States’ needs, coordina-tion among Federal laws and among Federal andState agencies, and adequate funding for federallymandated programs.

Standards

Strengths and Problems

Twenty-eight States commented about theirstrengths and problems with quality standards forgroundwater or drinking water and desire Federalassistance in this area. Strengths relate primarilyto the existence of standards for groundwaterquality. The most frequently reported problems arethe lack of groundwater quality standards in gen-eral and the lack of numerical standards or toxico-logical or risk information for particular substances

106 . Protecting the Nation’s Groundwater From Contamination

(e.g., volatile or synthetic organics and radiologicalsubstances).

Federal Assistance

Nineteen States reported a desire for Federalassistance related to quality standards (two of themalso commented on strengths in their own efforts).Research and development was most frequentlycited (e. g., information on toxicology, impacts, andrisk assessment). Other suggestions are for techni-cal assistance and additional Federal drinking wa-ter standards.

Detection

Strengths and Problems

Forty-six States commented about the strengthsand problems with their efforts, and about their de-sire for Federal assistance, to detect contamination.Strengths relate primarily to institutional resourcesand mechanisms (e. g., staff expertise and coordi-nation among State agencies) to detect contamina-tion, at least from some sources. More States notedstrengths with respect to their detection efforts thanthey did with respect to any other category of activ-

ity related to dealing with contamination.

Nearly all the States commenting on the strengthsof their detection programs also noted problems.Problems relate primarily to institutional concerns,particularly funding and other resource (e. g., staff)constraints that prevent a State from obtaining dataon groundwater contamination. Not having theauthority to obtain data on particular sources is aproblem for many States. Many noted the need tomodify and increase monitoring activities, althoughthey differed on focus—whether the emphasisshould be sources of contamination, aquifer char-acteristics, or ambient quality.

Federal Assistance

Twenty-nine States expressed a desire for Fed-eral assistance specifically related to detection.Funding for data collection was the most commonlyreported. Research and development for monitor-ing and technical assistance for hydrogeologic anal-ysis and interpretation were also listed. In addition,funding, technical support, and R&D for labora-tory analysis were noted.

Correction

Strengths and Problems

Thirty-five States commented about strengthsand problems and their desire for Federal assist-ance with corrective action. In general, theirstrengths relate to the existence of institutionalmechanisms (e. g., authority, funding, and priorityranking systems) to undertake corrective action forat least some sources. Their problems relate pri-marily to insufficient funding and other resources(e. g., staff). Other problems relate to inadequateinstitutional mechanisms (e. g., authority, includingwater rights, coordination, and enforcement) andto the lack of technology for correcting contamina-tion in some environments (e. g., karst).

Federal Assistance

Twenty-three States expressed a desire for Feder-al assistance related specifically to corrective action,12 of them noting neither strengths nor problemsin this area. The highest number of States speci-fied technical assistance (e. g., to implement cor-rective action, to train staff on safety and on theuse of corrective action techniques, and to deal withthe public when groundwater contamination is dis-covered); improvements through research anddevelopment (e. g., low-cost corrective action tech-niques for treating specific contaminants, for par-ticular sources like on-site waste disposal or oil fieldwastes, or for aquifers in general; and cleanupstandards); and funding assistance (e. g., to dealwith contamination in general, existing problems,large problems, and sources for which Federal fund-ing is not available). Other areas cited by a fewStates include: Federal program administration(e. g., continued support or improvements to theFederal “Superfund” program); Federal policy de-velopment (e. g., establishing a national ground-water policy for prevention and correction); anddevelopment of an information clearinghouse re-lated to experience with corrective action.

Prevention

Strengths and Problems

Eighteen States commented about problems ordesired Federal assistance for prevention of con-

Ch. 4—State Institutional Framework To Protect Groundwater From Contamination ● 107

lamination. No States commented specifically aboutstrengths in their prevention programs.

Comments on problems were institutional innature and relate either primarily to the absenceof or deficiencies in some types of programs for pre-vention (e. g., classification systems, well-drillingstandards, environmental impairment liability in-surance, recharge area protection, and hazardouswaste disposal facilities) or to the lack of resourcesto implement existing institutional mechanisms(e. g., funds for existing prevention programs tohandle more potential sources of contamination).The technical adequacy of some prevention mech-anisms was questioned by one State.

Federal Assistance

search and development activities (e. g., developingcontrol technologies or Best Management Practices(BMPs) for additional sources or contaminants anddetermining which substances should never be dis-charged to groundwater) and to funding (e. g., toimplement BMPs and federally mandated pro-grams). Additional Federal assistance is also desiredfor information management (e.g., a clearinghousefor information on State approaches and regula-tions to prevent groundwater contamination) andfor changes to existing Federal programs (e. g.,change in the emphasis of RCRA from land dis-posal to recycling and chemical destruction of toxicmaterials and improvements in FIFRA pesticideregistration requirements to increase success inidentifying contamination potential prior to mar-keting).

Ten States desire Federal assistance for preven-tion activities. Comments relate primarily to re-

CHAPTER 4 REFERENCES

American Petroleum Institute (API), “Guide to GroundWater Standards of the United States, ” 1983a.

American Petroleum Institute, ‘ ‘Underground LeakL a w s , May 6, 1983b.

Feliciano, D., ‘‘ Leaking Underground Storage Tanks:A Potential Environmental Problem, ” CongressionalResearch Service 84-508 ENR, Jan. 11, 1984.

General Accounting Office, ‘ ‘Federal and State EffortsTo Protect Ground Water, 1984.

Henderson, T. R., J. Traubman, and T. Gallagher,‘‘Groundwater: Strategies for State Action’ (Wash-ington, DC: Environmental Law Institute, 1984).

Magnuson, P., ‘‘Groundwater Classification, Septem-ber 1981 (copyright by Geraghty & Miller, Inc.,Svosset. NY. 1982).

Markusen, K., Department of Health, State of NewYork, personal communication, Mar. 3, 1984.

National Conference of State Legislatures, ‘ ‘Ground-water Management and Protection: A MidwesternState’s Policy Agenda, ” June 1983.

Pye, V. I., R. Patrick, and J. Quarles, Gz-oundwaterContamination in the United States (Philadelphia:University of Pennsylvania Press, 1983).

U.S. Geological Survey, National Water Summary1983—Hydrogeologic Events and Issues, U S G SWater-Supply Paper 2250 (Washington, DC: U.S.Government Printing Office, 1984).

U.S. Water Resources Council (WRC), “State of theStates, Water Resources Planning and Management,Groundwater Muddlement. ” Mav 1981./ , L 1 ,

Chapter 5

Hydrogeologic Investigations ofGroundwater Contamination

Contents

Page

Chapter Overview.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

Approaches for Minimizing Difficulties With GroundwaterContamination Investigations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135

Ensuring the Reliability of Hydrogeologic Investigations .....,. . . . . . . . . . . . . . . . . . . . . . . 135Approaches f’or Minimizing Difficulties in Measuring Substances . . . . . . . . . . . . . . . . . . . . . 137

Chapter 5 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138

TABLESTable No, Page

24.

25.26.

27.

28.

29.

Groundwater Contaminants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Costs and Detection Limits of Methods for Measuring the MolecuProperties of Contaminants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Techniques Commonly Used To Measure Media-BasedProperties of Contaminants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . 129ar-13ased. . . . . . . . . . . . . . . . 130

. . . . . . . . . . . . . . . . 133

Chapter 5

Hydrogeologic Investigations ofGroundwater Contamination

CHAPTER OVERVIEW

This chapter describes the current status of hy -drogeologic investigations. The first section, TheConduct of Hydrogeologic Investigations, sum-marizes the general approach used for investiga-tions, describes the two primary driving forces ofinvestigations (i. e., site conditions and objectives),and discusses the design of investigations in termsof information requirements, techniques, and mon-itoring networks. (This section is based onGeoTrans, Inc., 1983a, unless otherwise indicated.)The second section, Approaches for MinimizingDifficulties With Groundwater Contamination In-vestigations, discusses reliability of data collectionand interpretation.

The conclusions that follow are based on thisinformation.

Hydrogeologic investigations play an integralrole in understanding and evaluating groundwatercontamination regardless of the policy objective(i.e., whether to detect, correct, or prevent con-tamination). The techniques for obtaining infor-mation on hydrogeologic conditions and ground-water quality are now generally available.

Because of the inherent difficulties in dealing withthe subsurface (e. g., its inaccessibility to directobservation), there will always be some degree ofuncertainty about contaminants—which substancesare present and at what concentrations, where theyare going, and how fast they are moving. The na-ture and degree of the uncertainty vary accordingto such factors as the hydrogeologic environment,types of contaminants, the number and history ofthe sources involved, and the type of techniquesused. Under most circumstances, the uncertaintiescan be reduced, although not eliminated, to obtain

reliable results. The uncertainties are most oftenreduced by combining complementary techniquesand/or collecting increasingly detailed site informat-ion. These strategies, however, usually increasethe costs of and/or time for an investigation. Theimpacts of uncertainties on decisionmaking can beminimized by making conservative assumptionsand conducting sensitivity analyses.

Design and implementation of investigations arehighly dependent both on site-specific conditionsand on the specific objective to be achieved at a site(i.e., detection, correction, or prevention). The site-and objective-specific nature of groundwater con-tamination problems requires that investigations betailored to each individual problem. It is thus im-practical to standardize requirements for hydrogeo-logic investigations (e. g., with respect to the num-ber or location of monitoring wells). The burdenof performing reliable hydrogeologic investigationsfalls on those responsible for obtaining, interpret-ing, and applying results; and the required skilledpersonnel are in short supply.

Many techniques are available for analyzing con-taminants once a groundwater sample has been ob-tained. Generally, the techniques identify contam-inants and quantify their concentrations, but theyalso introduce a bias in terms of which of the con-taminants present are detected. Behavioral prop-erties of contaminants (e. g., mobility and toxicity),on the other hand, cannot be measured directly andthus must be deduced from indirect information,experience, and judgment. Understanding the be-havior of contaminants is important for detection,correction, and prevention of problems.

117

112 ● Protecting the Nation’s Groundwater From Contamination

THE CONDUCT OF HYDROGEOLOGICINVESTIGATIONS

General Approach of Investigations

Hydrogeologic investigations are the process forcollecting and analyzing information on the pres-ence and behavior of contaminants in the subsur-face. This knowledge is obtained primarily by col-lecting and analyzing data on the hydrogeologicenvironment (to ascertain the rate and direction ofgroundwater flow and help predict contaminantbehavior) and on groundwater quality (to ascertainthe presence and concentrations of contaminants).Investigations are simplified if information aboutthe nature and location of sources of contamina-tion is known and if information is available on theproperties of contaminants likely to be found.Knowledge of contaminant properties is helpful,for example, in determining how fast contaminantsmove relative to groundwater flow or if they moveindependently of flow.

Hydrogeologic investigations usually involve thedesign and operation of a groundwater qualitymonitoring network to collect data on the behaviorof contaminants in the subsurface in order to satisfydetection, correction, or prevention objectives.1 Forexample, to detect contamination from a potentialsource, understanding the behavior of expectedcontaminants is required to determine where con-tamination is most likely to be found. To correcta problem, understanding contaminant behavioris necessary to determine the nature and extent ofthe problem and to predict responses to alternativecorrective measures. To prevent contamination,understanding contaminant behavior is necessaryto select, design, and evaluate preventive measures.

Key issues in the design of monitoring systemsare: what information is required, what techniquesare applicable for obtaining this information, whatshould be the number and location of measuringpoints, and how frequently should samples be col-lected. Answers to these questions depend on con-ditions at the site and the objectives to be achieved.

‘For sample discussions of methodologies for hydrogeologic in-vestigations, see Todd, et al., 1976; Wood, et al., 1984; and GeoTrans,Inc., 1983b.

Hydrogeologic investigations of groundwatercontamination problems rely on many of the sametechniques (e. g., groundwater exploration, aquifertesting, geochemistry, and mathematical modelingof groundwater flow) developed in the past 60 yearsto evaluate groundwater resources for supply pur-poses. These hydrogeologic techniques were devel-oped primarily to evaluate permeable and saturatedgeologic units (e. g., aquifers) covering extensiveareas, most often at the county or regional scale.For investigations of contamination, the scale isusually much smaller; and low permeability units,which can act as a barrier to contaminant migra-tion, and the unsaturated zone, which can retaincontaminants for long periods, can be very signif-icant. Data that were historically collected and ana-lyzed only in special research studies must be ob-tained routinely in investigations of contamination.

Many simplifying assumptions often used ingroundwater supply investigations (e. g., that thevertical component of flow is not significant; thatflow in fractured media can be approximated byan equivalent porous media; and that the unsatu-rated zone is of minor importance) are often notapplicable in groundwater contamination investiga-tions. As a result, the costs and time required forthese hydrogeologic investigations are higher thanthose for water supply investigations. In addition,the investigation of contamination requires moreprecise well drilling and water quality sampling.

Site Conditions

There are inherent difficulties in obtaining in-formation on an environment that not only ismostly inaccessible to direct observation but is alsoextremely variable in both space (i. e., thehydrogeology at a single site may be complex andnon-uniform) and time (i. e., the rate and directionof groundwater flow and groundwater quality arenot constant). Each site will have a unique com-bination of characteristics including:2

‘Listing is based on discussion by Keith, et al., 1982a.

Ch. 5—Hydrogeologic Investigations of Groundwater Contamination • 113

Regionaldischarge

area

Localrecharge Local

Monitoring w*

area;

Credit: Geraghty & Miller, 1983

Regional groundwater flow is of primary interest in evaluating the water supply potential of an aquifer;local groundwater flow is of primary concern in investigations of contamination.

sources of contaminants (e. g., associated typesof contaminants and release patterns);the hydrogeologic environment (e. g., topog-raphy, vegetation, climate, geology, surfaceand subsurface hydrology, unsaturated zone,and contaminant transport parameters); andgroundwater use (e. g., effects of pumping ratesand schedules on groundwater flow).

To have confidence that the interpretation of in-formation in hydrogeologic investigations reflectsactual conditions in the subsurface, some investiga-tions require more detailed information than otherson the hydrogeologic environment and ground-water quality, More detailed information is re-quired at sites where: the hydrogeologic environ-ment is very complex (e. g., heterogeneous or

fractured aquifers v. uniform or simple aquifers),the contaminants present do not move with ground-water flow (e. g., the presence of immiscible v. mis-cible contaminants), and information is limitedabout which contaminants are present, contami-nant properties, and sources and their contaminantrelease characteristics.

Objectives

The different purposes of hydrogeologic inves-tigations—detection, correction, and prevention—are presented in table 24. As shown, the design andoperation of a monitoring effort will vary accord-ing to the objective to be achieved, the steps to betaken to meet the objective, and the type of pro-

114 • Protecting the Nation’s Groundwater From Contamination

Table 24.—Elements of Groundwater Protection and Topics for Hydrogeologic Investigations

Detection Correct ion Prevention

ObjectivesIdentify/quantify existing

contaminationCharacterize nature and

extent of contamination

Assess impacts

Steps in meeting objectivesEvaluate detection options—assess

their applicability and potentialimpacts

Select detection measures and designsystem

Implement detection system

Evaluate performance

ProgramsMonitor sources

Monitor supplies

Monitor groundwater resources (e.g.,ambient quality)

Inventory sources

Characterize nature andextent of contamination

Reduce/eliminate existinggroundwater contamination

Assess/reduce/eliminateimpacts of groundwatercontamination

Evaluate both technology-and management-basedcorrective action options— assess their applicabilityand potential impacts

Select and design correctiveaction measures

Implement corrective actionstragtegy

Evaluate performance

Correct sources that arecausing contamination

Correct supplies (uses) thatare contaminated

Correct groundwater re-sources that are con-taminated

Identify potential forfuture contamination

Hinder/prohibit con-taminants from enteringsubsurface

Assess/reduce/eliminateimpacts of futurecontamination

Evaluate preventive actionmeasures — assesstheir applicability andpotential impacts

Select and designpreventive measures

Implement preventivemeasures

Evaluate performance

Prevent sources fromcausing contamination

Prevent supplies frombecoming contaminated

Prevent groundwaterresources from be-coming contaminated

SOURCE: Office of Technology Assessment

gram to be implemented.3 Examples of how thesethree elements influence the need for informationabout the hydrogeologic environment and waterquality in a hydrogeologic investigation is describedbelow.

Objective. At a given site, an objective to detectcontamination will generally require less detailedwater quality information than an investigation tocorrect contamination. For example, in a detectioninvestigation it may be sufficient to define theboundaries of a contaminated area; in a correctioninvestigation, more detailed information about vari-ations in contaminant concentrations within thearea may be necessary to evaluate correction alter-natives.

Steps. Steps in meeting an objective also influ-ence the level of detail to be obtained about water

30ther factors, such as different motivations for conducting investiga-tions (e. g., a State environmental program investigating threats topublic health; an industry complying with regulatory requirements;and an industry investigating potential liabilities associated with knowncontamination), also influence the nature of the investigation in termsof funds, time, and expertise that are devoted to the task.

quality and the hydrogeologic environment. Inves-tigations to evaluate the feasibility of options gen-erally require less detailed information than in-vestigations to select and design the action.

Program. Different kinds of programs may re-quire different kinds of information. A detectionprogram for water supplies may be limited to iden-tification and quantification of contaminants inpublic water supplies, as required under the SafeDrinking Water Act. Monitoring under such a pro-gram is relatively straightforward because the meas-uring points are defined as the existing water supplywells, and the type of information required is wa-ter quality data. There is no need to evaluate thehydrogeologic environment to determine where tocollect samples. However, samples taken withoutinformation about the hydrogeologic environmentand associated flow system provide only a singlesnapshot of water quality-at the place and at thetime the sample is collected; they cannot be usedeither to predict whether water quality is likely tochange or to indicate the location of the source ofcontamination. Alternatively, a detection program

Ch. 5—Hydrogeologic Investigations of Groundwater Contamination ● 115

to determine whether a source is in fact contam-inating groundwater requires information on thehydrogeologic environment near the source—in ad-dition to the collection and analysis of water qualitysamples —in order to identify areas that are mostlikely to show evidence of contamination.

Design of HydrogeologicInvestigations of Groundwater

Contamination

Information Requirements

Contamination investigations require informa-tion on the hydrogeologic environment, waterquality, sources of contamination, and propertiesof contaminants, as shown in table 25.4 The im-portance of this information in understanding thebehavior of subsurface contaminants is also pre-sented in table 25. The major points of the tableare summarized below:

● The primary purposes for collecting hydrogeo-logic data are to determine the rate and direc-tion of groundwater flow, evaluate the typesof contaminants likely to be found, and de-termine whether the contaminants and thegroundwater are likely to be moving at thesame rate and direction.

● Information on the hydrogeologic environ-ment (i. e., surface conditions—topography,vegetation, climate and surface water hydrol-ogy; geology; and subsurface hydrology—unsaturated zone, groundwater hydrology,contaminant transport parameters, and ground-water use) is obtained primarily to describe theflow of groundwater. Evaluating flow involvesthe collection of data on the quantity, timing,rate, direction, and pathways of water mov-ing from the surface through the unsaturatedzone and into and through the saturated zone.

Information about the hydrogeologic envi-ronment is important in understanding wheth-er contaminants will move at the same rate asgroundwater or if physical, chemical, and/orbiological processes are likely to occur that willcause them to move at different rates.5 Anal-

— .4Hydrogeologic terms are defined in app. D.5Chemical and biological processes can alter the rate of contain i-

nant movement, change contaminant concentrations, and transformthe contaminants that are present. These processes are a function of

ysis of the physical, chemical, and biologicalproperties of the hydrogeologic environment,along with information on the properties ofcontaminants, is needed to evaluate the behav-ior of contaminants in the subsurface.

The hydrogeologic environment is dynamic,and information on spatial and temporal varia-tions is also important to assess contaminationproblems accurately. Some human activitiescan influence the flow of groundwater (e. g.,pumping groundwater for use can alter the di-rection of flow, and modifications to the landsurface can alter the amount of water infiltrat-ing to the groundwater system).

● Information on water quality is collected pri-marily to determine the nature and/or verifythe extent of contamination. Water quality in-formation also contributes to knowledge of thenature and rate of chemical and biologicalreactions that influence contaminant behavior.

● Information on sources of contamination isuseful in predicting the types of contaminantslikely to be present, their locations, and theirconcentrations. When interpreted along withdata on groundwater flow and associated con-taminant behavior, source data can be usedto predict the location, rate, and directionof contaminant movement. Knowledge ofsources aids in determining the area to be in-

both the properties and concentrations of the contaminants presentand the properties of the hydrogeologic environment (i. e., the un-saturated and saturated zones). Chemical processes include: adsorp-tion-desorption, oxidation-reduction, acid-base, solution-precipitation,ion pairing or complexation reactions; and radioactive decay. Chemicalprocesses are least significant in clean sand aquifers and some crystallineenvironments. Biological processes may be direct (e. g., enzyme activ-ity) or indirect (e. g., production of metabolizes; alteration of pH andEh conditions; and provision of a surface for the accumulation andconcentration of contaminants). Biological processes may result in theuptake, decay, or transformation of organic materials or the genera-tion of additional contaminants. These processes can be particularlyconfusing in investigations of a source when information is availableon the original contaminants but not on their altered states. For ex-ample, biological processes can transform trichloroethylene (TCE) io

vinyl chloride, tetrachloroethylene to trichloroethylene, and heptachlorto heptachlor epoxide (McCarty, 1984). Biological processes are mostsignificant in zones of higher oxygen availability and larger pore spaces,such as the unsaturated zone.

Physical processes include dispersion, whereby dissolved con-taminants spread in ways that would not be predicted if the con-taminants were moving only with the groundwater. Dispersion is afunction of the hydrogeologic environment. It is independent of theproperties of the contaminant. Dispersion results in an apparent fastermovement of contaminants, relative to the average groundwater flow,at lower concentrations. Dispersion is especially important in frac-tured systems.

116 . Protecting the Nation’s Groundwater From Contamination

Table 25.—importance of Information Used in Hydrogeologic Investigationsa

B. Vegetative data

C. Climatic data (precipitation;evapotranspiration; site temperature)

D. Geologic data (surficial deposits;subsurface stratigraphy; Iithology;structural geology)

E. Surface hydrology data (overland flow;stream discharge; stage; recurrenceinterval; baseflow discharge)

Information obtained for Importance of information forhydrogeologic investigationsb understanding contaminant behavior in subsurface

L information on the hydrogeologicenvironment

A. Topographic data Provide partial information on flow (i.e., rate, directions, andpathways of unsaturated zone and groundwater flow and re-lationship of groundwater to surface water including: relativeposition of water levels in wells, locations of possible dis-charge and recharge areas, rates of infiltration and surfacerunoff, and general direction of groundwater flow).

Provide partial information on flow (i.e., rate and pathways ofwater movement into and out of the subsurface). Alsovegetation type and condition may reflect the quality ofgroundwater and be used to identify areas of contamination.Used to estimate depth to water table and identify possibledischarge and recharge areas.

Provide partial information on flow (i.e., the quantity, timing,and rate of movement of water and contaminants into thesubsurface). Provide basic information to assess rate ofreactions and biodegradation of contaminants.

Provide partial information on flow (i.e., location and volumesof potential groundwater supplies, pathways for water andcontaminant movement into and out of underlyingformations, and direction and rate of groundwatermovement) and are used to identify possible recharge anddischarge areas. Also, provide partial information onmechanical dispersion (mixing) and attenuation reactions ofcontaminants.

Provide partial information on flow (i.e., quantity, rate, andtiming of water movement into and out of subsurface). Usedto identify and quantify possible discharge and rechargeareas, and to identify potential conduits for contamination.Surface water may affect concentrations of contamination atdischarge points.

Provide partial information on flow (i.e., on the flow regimewhich influences the rate, direction, and quantity of waterand contaminants moving from the surface intothe saturated zone). Usually relatively unimportant in thehumid areas such as the Eastern United States.

Provide partial information on flow (i.e., the rate, direction, andquantity, of groundwater and contaminant flow). Also,provide partial information on recharge anddischarge characteristics.

F. Unsaturated zone data (water table;geometry; hydraulic properties: effectiveporosity, effective permeability, relativepermeability, permeability, specificstorage; flow parameters: pressure head,hydraulic gradient, fluid saturation;recharge/discharge: surface watercharacteristics, precipitation/evapotranspiration)

G. Groundwater hydrology (Saturated Zone)data (aquifer characterization: confinedaquifers, unconfined aquifers, leakyaquifers; hydraulic parameters of aquifers:storativity, transmissivity, primarypermeability, secondary permeability, pri-mary porosity, secondary porosity;confining unit geometry; hydraulicparameters of confining units: hydraulicconductivity, specific storage; flowparameters: water levels, hydraulicgradient, flow velocity; recharge/discharge: surface water characteristics,precipitation contributions, confining layerleakage, fracture/matrix flux)

H. Contaminant transport parameters Provide partial information on properties of the hydrogeologic(distribution coefficient; dispersivity co- environment that influence the potential for physical,efficient; flow velocities; relative chemical, and biological reactions that result insaturations; cation exchange capacity; contaminants moving at different rates than water throughsubsurface mineralogy; ambient water the groundwater flow system.chemistry; microbiology)

Ch. 5—Hydrogeologic Investigations of Groundwater Contamination • 117

Table 25.—importance of Information Used in Hydrogeologic Investigationsa—continued

Information obtained for Importance of information forhydrogeologic investigationsb understanding contaminant behavior in subsurface1.

Il.

Ill.

Iv.A.

B.

Groundwater use (current usage;projected usage)

Information on water quality(contaminants present; concentrations)

Information on sources of contamination(location; contaminants; releasecharacteristics: location, volumes,contaminants, concentrations, timing)timing)

Information on properties of contaminantsMolecular-based properties

Media-based properties

Provides partial information on flow (i.e., the influence ofgroundwater pumping on the rate and direction ofgroundwater and contaminant flow). Also providesinformation on impacts of contamination.

Provides data on concentrations and distribution ofcontaminants.

Provides data on types of contaminants that are likely to bepresent, requirements for collecting and analyzing samples,and suitability of different types of corrective action. Alsoprovides data on flow (i.e., used to describe and predict therate and direction of contaminant movement and thelocation of contaminants).

Provide information to identify which contaminants arepresent and at what concentrations.

Provide information used as a basis for deducing contaminantbehavior (e.g., persistence and mobility). -

a Based on GeoTrans. Inc., 1983bb Hydrogeologlc terms are defined In app D 1

SOURCE Off Ice of Technology Assessment

●

vestigated, the sites for collecting water qualitysamples, and sampling and analysis pro-cedures.Information on properties of contaminants isimportant in understanding the rate and direc-tion of contaminant movement, the locationof contaminants relative to the water table andless permeable units, the persistence of the con-taminants in the subsurface, and the types oftechniques that can be used to detect, correct,and prevent contamination.

The properties of contaminants that aremost important for their detection in the sub-surface relate to volubility. Hydrogeologic in-vestigations of contaminants that are onlyslightly soluble (immiscible) require more in-formation on the hydrogeologic environmentand water quality than may be needed to de-scribe contaminants that move with ground-water flow, Immiscible fluids that are alsomore dense than groundwater (e. g., many in-dustrial solvents) may move in a differentdirection than groundwater flow. Immisciblefluids that are less dense than water (e. g.,many petroleum products) tend to float on topof the water table and may require waterquality sampling in the unsaturated zone.

Although all the hydrogeologic informationshown in table 25 is useful for accomplishing in-vestigation objectives for most site conditions, the

amount and types of information collected in prac-tice is limited because of the time and costs of ob-taining and analyzing data. The information col-lected varies, depending on site conditions andstudy objectives. Examples of different informa-tion needs according to objectives were discussedin the preceding section on Objectives. The majorsite conditions that determine the information tobe collected relate to the complexity of the hydro-geologic environment, the climate, the number ofpotential contamination sources, and knowledge ofthe behavior of the contaminants. G

cExamples of variations in information collected under different siteconditions are described below:

●

●

●

●

In fractured (as opposed to unfractured) aquifers, informationis needed on fracture patterns, joint patterns and spacings, andpossibly dual porosity properties (i. e., primary and secondarypermeability and porosity).In semi-arid (as opposed to humid) climates where the water tableis deep, information on the properties of the unsaturated zone(e. g., moisture content and relationships between relativepermeabilities and capillary pressure) is very important for defin-ing groundwater flow and determining the potential for con-tamination.Where multiple sources (rather than a single source) of contamina-tion are suspected, water quality sampling and analysis may bedirected more to contaminants that are unique to a particularsource, perhaps at very low concentrations, than to contaminantsthat are likely to be found at the highest concentrations.Where the behavior of contaminants can be readily described-forexample, by having knowledge that the contaminant is quicklydegraded or strongly retarded in groundwater—collection of dataon water quality can be concentrated in areas near the sourcerather than over a wider area.

118 ● Protecting the Nation’s Groundwater from Contamination

Source of product Source of product

t -(Greater density than water) ( L e s s e r d e n s i t y t h a n w a t e r )

Unsaturatedzone

ISaturated Direction of

zone g r o u n d w a t e r f l o w

Product flow

.Flow of dissolved product

Credit: Geraghty & Miller, 1983

Immiscible contaminants that are more dense than water may not move in the same direction as groundwater flow.Immiscible contaminants that are less dense than water tend to float on top of the water table.

Techniques for Obtaining InformationAbout the Hydrogeologic Environment

The presence and concentrations of most con-taminants are determined from groundwater qual-ity samples. Techniques for sample collection arediscussed in this section on the hydrogeologic envi-ronment, and the analytical techniques for meas-uring the contaminants in a water quality sampleare discussed in the next section on contaminants.

Techniques used to describe the hydrogeologicenvironment and to collect groundwater qualitysamples are organized into 12 major categories intable 26. The table outlines the general types of in-formation obtained from the techniques and thelimitations of the techniques under different con-ditions.

In general, some information on the behaviorof subsurface contaminants can be obtained andinterpreted with greater reliability than others.

Groundwater flow can be readily described in mostenvironments; however, information cannot bereadily obtained on the physical, chemical, andbiological processes that may cause contaminant at-tenuation. This difference reflects both the stateof scientific understanding and available technol-ogy. For example, groundwater flow is better un-derstood and mathematical modeling of flow ismore highly developed than for contaminant be-havior; thus data can be interpreted more reliably,and more accurate predictions can be made forgroundwater flow than for contaminant behavior. 7

Summary points and findings from table 26 arehighlighted below:

● Techniques. There are many techniques forobtaining information about groundwater flowand the movement of contaminants.

7For a more detailed discussion of differences in models for ground-water flow and contaminant behavior, see OTA, 1982.

Table 26.—Techniques for Hydrogeologic Investigations: Information Obtained and Principal Constraints on Applicationa

Major site constraints

Techniques Information Subsurface geology Subsurface hydrology Water quality Surface conditions Other constraints 10 identity geologic, ny- type of geologic Complexity of subsurface con- Not a constraint. Not a constraint.

published informa- drologic, hydrogeologic, formation: May not ditions: Usually data are un-tion water-quality, topo- -

graphic, and climaticconditions.

2. Mapping To delineate surfacegeologic, soil, ortopographic con-ditions.

3. Remote sensing To assess indirectly(aerial photography geologic, hydrologic,and thermal, infra- hydrogeologic, orred, and radar water qualitysatellite imagery) characteristics of the

earth’s surface. Areconnaissance toolto optimize surfacefield studies.

4. Excavations and To access directly thedrilling subsurface environ-

ment for the purposeof geologic sampling,geophysical logging,water quality sam-pling, and fluid po-

be sufficiently detailed available for specific sites,for complex geologic but some regional hydrogeo-settings. logic information may be use-

ful, particularly in simple,uniform hydrogeologic set-tings.

Not a constraint. Not a constraint. Not a constraint. Site access: Inacces-sible terrain may beproblematic duringground surveys.

Depth: Techniques Saturation conditions: Somegenerally provide techniques (e.g., radar) toinformation on only detect presence of contamina-face features but some tion are applicable only intechniques may provide unsaturated areas where theresome information on is a moisture difference be-shallow groundwater tween contaminated andflow and/or con- uncontaminated areas.taminant seepage Flow system: Detectable con-within 10 feet of the lamination limited to dis-Iand surface. charge areas with techniques

Type of geologic formation: other than radar.Some techniques canpenetrate the surfaceand provide informationon contaminants ifunder thin alluvium orsand.

Depth: Excavations Not a constraint.generally only done atless than 20 feet.Applicability ofdifferent drilling tech-niques varies withdepth; however, with

tential measurements. use of proper equip-ment, holes can bedrilled to virtually anydepth.

Type of geologic forma-tion: Some drillingtechniques can beused in only certaintypes of materials (soilversus rock, consoli-dated versus unconsoli-dated, prone to cavingversus non-caving).

Nature of Chemical Com- Climate: Some techniquespounds: Contaminant are weather dependent;distribution can be cloud cover interferesdetected by various tech- with all techniquesniques if chemicals except radar.stress vegetation, Timing: Some techniquescause tonal changes are accomplished bestin surface water, or at different times ofthermal anomalies. day (e.g., predawn or

midday) and seasons.

Nature of chemical Scale: Excavations cancompounds: Presence of cover larger areas thancertain contaminants drilling.may limit use of some Site access: H may be dif-

Proprietary data maylimit availability.

Nonsite-specificinformation oftenadequate; re-presents separatecost. May require arelatively long timeto complete (daysto months).

Nonsite-specificinformation oftenadequate; repre-sents separatecost.

Property access: Mayrequire a relativelylong time tocomplete (days to

drilling fluids to avoid ficult to reach some sites months). Relativelysample contamination. (e.g., steep or marshy) with high cost to im-Variations in contamina- steep or marshy) with plement.tion with depth may some types of equip-Iimit use of certain ment.techniques to avoidcross-contamination.

Table 26.-Techniques for Hydrogeologic Investigations: Information Obtained and Principal Constraints on Applicationa—continued

Major site constraints

Techniques Information Subsurface geology Subsurface hydrology Water quality Surface conditions Other constraints

5. Geologic sampling To identify directly Depth: Type of sample Not a constraint. Not a constraint.stratigraphy and that can be obtainedgeologic structure depends on the depthand to obtain and penetration cap-geologic samples for ability of drill rig and/laboratory testing of or sampling equipment. - . hydraulic and soil Depth is not a limitingcharacteristics. factor for obtaining

either undisturbedsamples from someunconsolidatedmaterials, or rep-resentative andnon-representativesamples from anytype of materials.b

Type of geologic forma-tion: Some limitationsdepending on whetherconsolidated or uncon-solidated. See Depth.

6. Hydrometeorolog- To quantify temperature, Not a constraint. Not a constraint.ical measurements precipitation, evapo-

transpiration, andinfiltration at theearth’s surface.

7. Surface hydrology To identify flow and(hydraulic measure- water qualityments; surface characteristics ofwater sampling) surface water.

8. Subsurface Hydro- To measure subsurfacelogy water level or pres-a. Potential sure for evaluating

measurements direction of flow and

Not a constraint. Not a constraint.

Depth: Depth is a limit- Saturation conditions: Choiceing factor for some of techniques depends ontechniques (e.g., some whether measurement is re-tensiometers and drill quired for the saturated or

to calculate flow rates.

stem tests). However, unsaturated zone.within and between techniques are avail-hydrologic units in able to obtain measure-both the unsaturated ments at any depth,and saturated zones. provided specially de-

signed wells are drilled.Type of geologic forma-

tion: Fine-grained, lowpermeability materiallimits the use of cer-tain techniques (e.g.,standpipes). However,

Not a constraint.

Nature of chemical com-pounds: Difficult to ob-

Not a constraint. May require arelatively long timeto complete (daysto months).

Not a constraint. Field techniques tomeasure transpira-tion are difficultto apply, so esti-mates are usuallymade. Nonsite-specific informationoften adequate; rep-resents separatecost.

Not a constraint. Nonsite-specific infor-mation often ade-

tain samples of many or. quate; representsganic compounds that separate cost.are only slightlywater-soluble.

Not a constraint. Not a constraint. Not a constraint.

w

I

oI

I-l.

w

Table 26.--Techniques for Hydrogeologic Investigations: Information Obtained and Principal Constraints on Applicationa—continued

Major site contraints

Techniques Information Subsurface geology Subsurface hydrology Water quality Surface conditions Other constraints

a. Potentialmeasurements(cent’d)

b. Hydraulic testing To determine thehydraulic propertiesof in-situ subsurfacematerials needed forcalculations of flowrates in the unsatu-rated zones ordirectly measuregroundwater flowvelocities and to de-termine contaminanttransport parameters.

c. Laboratory test-ing (hydraulic,geologic)

d. Water qualitysampling

To measure the hydrau-lic properties of sam-ples of subsurfacematerials needed forgroundwater flow cal-culations of variablysaturated materials(e.g., porosity) andselected contaminanttransport parameters(e.g., adsorption).

To obtain a subsurfacewater sample repre-sentative of in-situwater quality foranalyses of the pre-

techniques are avail-able to obtain measure-ments in any type offormation providedspecially designedwells are drilled.

Type of geologic forma- Complexity of subsurface con- Not a constraint.tion: Some unsaturated ditions: Some techniqueszone techniques (e.g., (e.g., slug tests and flowinfiltration tests) are meters) measure conditionsimpractical in coarse- only at or near the point ofgrained soils due to measurement, and do notthe amount of water re- account for spatial heteroge-quired. Choice of tech- neities.niques (e.g., slug test, Saturation conditions: Somepressure injection test, t echn iques a re app l i cab le i nand pump test) for either saturated or unsaturatedsaturated zone depen- zones.dent on permeabilityof formation.

Depth: Testing dependent Complexity of subsurface con- Not a constraint.on obtaining appropri- ditions: Superior to fieldate type of sample (i.e., measurements of vertical per-undisturbed, repre- meability of fine-grained un-sentative, or non- consolidated materials. Majorrepresentative). limitation is small sample

Type of geologic formation: size and the applicability ofDepends on whether extrapolating point informationconsolidated or uncon- to the three-dimensionalsolidated. See Depth. space being assessed.Provides good methodof measuring perme-ability of fine-grainedunconsolidated mate-erials. Choice ofgeologic samplingtechnique (hydrometerv. sieve tests) dependson grain size.

Depth: Some pumps to Complexity of subsurface con-evacuate wells and ob- ditions: Multiple completiontain samples have wells to characterize verticaldepth limitations. distribution of water quality

Type of geologic formation: are limited due to concernssence and concentra- In high permeability about the effectiveness oftions of chemicals formations, evacuation sealing to prevent hydraulicand other substances of sampling wells to connections and the abilityin unsaturated and ensure sample is not to obtain representativesaturated zones. affected by the well samples from different

is problematic. sampling zones. SaturationHowever, techniques conditions: Different tech-

Nature of chemical com-pounds: Casing, well ma-terials, and pumps mustbe selected both toresist deterioration fromlong-term exposure tonatural chemicals orcontaminants and tominimize interferencewith the measurement ofspecific constituents.Current knowledge of

Not a constraint. Relatively highequipment cost; in-tensive manpowerrequirements; andneed for skilled per-sonnel. May causeshort-term changesin water levels.Tracers may haveadverse environ-mental effects.

Not a constraint. Not a constraint.

Not a constraint. Not a constraint

are available to min- niques are used to obtain sam - sampling interferences isimize the amount of pies in the unsaturated zone limited for most wellpumpage required materials.

Table 26.—Techniques for Hydrogeologic Investigations: Information Obtained and Principal Constraints on Applicationa—continued

Major site contraints

Techniques Information Subsurface geology Subsurface hydrology Water quality Surface conditions Other constraints

d. Water quality before sample collection, Design constraints of mul-sampling which may in turn limit tiple completion wells(cent’d) selection of the most (e.g., small diameter) may

effective sampling may limit use of mostequipment for parti- effective sampling equip-cular constituents. ment for some chemical

parameters. Proper disposalof evacuation water priorto sampling is depend-ent on its quality.Techniques used toevacuate wells and ob-tain samples may resultin incorrect measures ofsome compounds(especially dissolvedgases and volatileorganics). Also, thepresence of someconstituents (e.g.,sediment) may damagesome types ofequipment. Sometechniques allow exces-sive exposure to theatmosphere or othergases that might in-fluence the measurementof specific parameters.

Complexity of subsurface con- Not a constraint. Not a constraint.ditions: choice of modelingtechnique (i.e., analytic ornumeric) depends on com-plexity of problem. Modelingcomplex systems limited bycost of obtaining data. Mostgeostatistical methods requirethat the sample population benormally distributed; thus ifdata represent complex sub-surface conditions, geo-statistical methods may bedifficult or impossible toapply.

10. Surface geophysics To assess indirectly Depth: Depth limitations Complexity of subsurface condi- Nature of chemical com-(electrical resistivity

Climate: Some techniquesstratigraphy and ex- are dependent on tech- tions: Techniques applicable pounds: Chemicals of in- requiring electrode con-

and electromagnetic tent of subsurface nique. Generally, tech- only in relatively simple strati- terest must be capable of tact not applicable inconductivity; ground- contamination to aid niques cannot be ap- graphic conditions. Natural both inducing a change frozen soils or in drypenetrating radar; in placement of plied at depths greater subsurface properties must be in the subsurface param- sandy areas (e.g., electri-seismic refraction; monitoring well sand than 500 feet. sufficiently uniform so as not eter measured by the cal conductivity). How-shallow geothermic to reduce number of Type of geologic forma- to confuse or mask the ef- method and showing a ever, other techniques

9. Hydrogeologic To simulate or predict Not a constraintsystem analysis the behavior of sub-(modeling; geo- surface hydrogeologicstatistics) units, including

groundwater flowand solute transport;or to estimate thevalues of hydrogeo-Iogic phenomena atunmeasured points.

Relatively high costto implement. Mayrequire a relativelylong time tocomplete (weeks tomonths). Special-ized skills required.Requires a clear de-finition of thehydrogeologic par-ameters used, in-cluding their vari-ability in time andspace.

Relatively high equip-ment cost; need forskilled personnel;may require a rela-tively long time tocomplete (weeks tomonths).

method) - wells. tion: Minimum detecta- fects of chemicals. Natural different response than are applicable in these

Table 26.—Techniques for Hydrogeologic Investigations: Information Obtained and principal Constraints on Applicationa—continued

Major site contraints

Techniques Information Subsurface geology- Subsurface hydrology Water quality Surface conditions Other constraints

10 Surface geophysics ble concentration conditions that may be surrounding subsurface conditions (e.g., elec-(cent’d) -

11. Subsurface (bore-hole) geophysics(acoustical; elec-trical-magnetic; nu-clear; flow; thermal;geochemical)

strongly Influenced by responsible for false detection conditions, -Many tech- tromagnetic conduc-properties of subsur- or nondetection Include: dis- niques (e.g., resistivity tivity).face materials. Condi- continous, thick layers of clay; and conductivity Nature of surface: Conductions that may prevent hydrogeologic heterogeneity; methods) generally are tors (e.g., metal fences,good results include: variations in natural ground- ineffective for defining overhead power lines,naturally conductive water chemistry due to organic contaminant paved areas, buildings,brackish water, steep changes in geologic materials; plumes. However, the storage tanks, and bu -water table, crystalline and variations in surfacerock, and karst or other topography.environs where ground- Some methods are more effec-water flow IS concen - tive than others for detectingtrated along lntercon- small fracture zones contain-nected fractures in ing high contaminant concen-massive bedrock. trations (e.g., electromagnetic

conductivity iS better thanelectrical resistivity).Homogeneous subsurface en-vironments having layers of in-creasing densities present in-terpretative difficulties forsome techniques (e.g., seismicrefraction). All techniquesgenerally require subsurfacedrilling or monitoring for verifi-cation of results.

Saturation conditions: Sometechniques can be used to ob-tain some types of informa-tion only in the unsaturatedzone (e.g., electrical resistivitycan track contaminant move-ment in only the unsaturatedzone).

presence of organic ried pipelines or wires)chemicals and petroleum may impair use of someproducts may be techniques.delineated in sand or Sensitivity of differentgravel aquifers at depthsgenerally less than 25feet with groundpenetrating radar.

Relatively high concentra-tions required by tech-niques for detection ofcontaminants. Tech-niques only providegross information onconcentrations of someindividual constituents.Some techniques can beeffective in delineatingextent of high concentra-tions of inorganic con-tamination in suitablegeologic environments.

techniques to these fea-tures is variable. Barerock, wetlands, shallowlakes, and dry sandyareas prevent use oftechniques requiringelectrode contact.

To measure direct physi- Depth: Not a Iimiting fac- Saturation conditions: Some Nature of chemical com- Not a constraint. Relatively high costcal properties of sub- tor for most tech--

surface materials to niques provided an un-evaluated Iithology, ge- cased borehole can beologic structure, hy- drilled.draulic properties, wa- Type of geologic forma-ter quality, and flow. tion: Most techniques

can be used only inuncased boreholes,and thus cannot beused in geologic for-mations that cave inwhen drilled. Excep-tions include nuclearlogs which can beused in cased bore-holes. Some tech-

techniques (e.g., electrical-magnetic logging techniques)are applicable only in satu-rated zone. Some techniquescan be used to provide certaintypes of information in the un-saturated zone, and othertypes of information in thesaturated zone (e.g., neutronlogs).

pounds: Some tech- to implement.niques applicable only ifconstituents in ground-water have propertiesthat will induce responsefrom instruments (e.g.,spontaneous potentiallogs). Some techniquescan be used to detectparticular contaminants(e.g., Draeger tubes candetect over 140 in-situsoil gases).

Table 26.—Techniques for Hydrogeologic Investigations: Information Obtained and Principal Constraints on Applicationa-continued

Major site constraints

Techniques Information Subsurface geology Subsurface hydrology Water quality Surface conditions Other constraints

11.

12.

Subsurface(cent’d)

Hydrogeochemistry To perform field testingof water samples todetermine need forfurther laboratorychemical analysis andto analyze for unsta-ble constituents.

niques more suitablefor obtaining informa-tion on particular typesof geologic materials(e.g., natural gammalogs for obtaining clayunit properties).

Not a constraint. Not a constraint. Nature of chemical com- Not a constraint.pounds: Field techniquesavailable to obtain infor-mation on conductance,organic vapors, alkalinity,pH, Eh, DO, iron, andhydrocarbons. (See Sub-surface Hydrology —Groundwater qualitysampling, for additionalconstraints.)

Not a constraint.

Ch. 5—Hydrogeologic Investigations of Groundwater Contamination ● 125

. .

Photo credit: U.S. Geologic

Techniques are available for the direct sampling of groundwater quality.

al Survey

● Information Obtained. Regardless of whattechniques are used, which parameters aremeasured, and whether the measurements aretaken directly or indirectly, all measurementsmust be interpreted in conjunction with otherdata to determine groundwater flow and thebehavior of contaminants. Interpretation ofdata is uncertain because of factors relating to:the precision, accuracy, or detection limits ofthe equipment; lack of a unique measurement(e.g., geophysical response) for particular sub-surface conditions; the degree to which averag-ing of conditions masks actual conditions; andthe degree to which the sample or the meas-urement represents in-situ phenomena.

Some techniques are useful in obtaininggeneral information; others are used to obtainsite-specific information. Some techniques(e.g., excavation and drilling) are not used to

provide information per se, but their use is anecessary step before other techniques can beapplied. Other techniques (e. g., mathematicalmodeling) are not used to measure propertiesof the hydrogeologic environment but can beused to simulate conditions and predict ground-water flow and movement of contaminants.

Techniques are generally available to col-lect data on the unsaturated zone, ground-water hydrology, sources, and contaminants;this information is necessary to make reliablepredictions of groundwater flow and estimatecurrent and future water quality in most envi-ronments. However, historic data and datareflecting changes with time (e. g., ground-water use and the contaminant release char-acteristics of sources) are usually not availablefor a specific site, which diminishes the reliabil-ity of some investigations.

126 ● Protecting the Nation’s Groundwater From Contamination

● Constraints. Factors that can limit the use of Some techniques are limited to particular sub-different techniques are related primarily tosite conditions, costs, and the availability ofskilled personnel. Additional constraints in-clude problems with property access and thepotential for adverse effects.

Site conditions that can limit the use ofhydrogeologic techniques include: subsurfacegeology (e. g., depth and type of geologic for-mation); subsurface hydrogeology (e. g., com-plexity of subsurface conditions, saturationconditions, and flow system); water quality(e. g., nature of the contaminants), and sur-face conditions (e. g., presence of buildings,pavement, power lines, vegetative cover, andother features; site accessibility; climatic fac-tors; time of day; and size of the area).

As shown in table 26, site constraints on ob-taining information vary for different catego-ries of hydrogeologic techniques as well as forspecific techniques within each category (e. g.,

surface conditions (e. g., different techniquesare used for the saturated zone than for theunsaturated zone). In addition, the site con-straints that apply to a particular techniquevary, depending on the purpose for which thetechnique is used (e. g., subsurface geologyconstraints on geologic sampling depend onthe type of sample that is needed).

There are a few types of information thatcannot be obtained reliably using any tech-nique including: chemical reactions in fluidscontaining multiple contaminants, propertiescharacterizing in detail groundwater flow andchemical transport in fractured media, certainhydraulic properties of very low permeabilitymedia, in-situ determinations of hydraulicproperties in the unsaturated zone when im-miscible contaminants are present, and historyof the contaminating source.8

climate is a constraint only on certain remote 8See ch. 2 for discussion of the problems associated with determin-sensing and surface geophysical techniques). ing the contribution of a source to groundwater contamination.

Photo credit: U.S. Environmental Protection Agency

Remote sensing equipment can be used to identify, document, and evaluate groundwater quality problems. The dataacquisition system, which is mounted on the aircraft and operates 500-10,000 ft above ground level, includes

(from left to right): an instrument logger for recording location, time, and altitude; a control console;a multispectral scanner; and an aerial mapping camera.

Ch. 5—Hydrogeologic Investigations of Groundwater Contamination ● 127

The costs of applying hydrogeologic tech-niques depend primarily on site conditions andthe objectives to be achieved. Costs of hydro-geologic investigations to define contamina-tion problems can range from $25,000 to$250,000, and litigation can double the figure(Miller, D., 1982). Many factors determinecosts: the complexity of surface and subsur-face conditions, areal extent of the study area,number and frequency of measurements, avail-ability and quality of existing information, siteaccess, experience and training of personnel,reliability and capability of equipment, avail-ability of equipment, geology, weather, andthe need for site-specific v. regional data.These same factors also determine the amountof time required, and they affect the choice ofequipment and the number and locations ofmeasurements to be taken.

Equipment costs limit the use of certaintechniques (e. g., hydraulic testing, hydrogeo-logic systems analysis, surface geophysics, andsubsurface geophysics). Either less costly or lesssophisticated techniques are used. The costsof applying certain techniques (e.g. geologicsampling, potential measurements, waterquality sampling, and subsurface geophysics)are reduced if a well or borehole can be usedfor more than one purpose. However, the in-formation required to meet particular objec-tives will influence the decision on whether touse a single well or borehole for several tech-niques. Investigation costs can also be reducedby using indirect or field screening techniquesto provide reconnaissance level information forselection of direct measurement locations.

Availability of reliable equipment capableof operating efficiently under the site condi-tions is an important factor in determiningcosts (e. g., choice of drilling methods andpumping equipment depends on site condi-tions). Capital expenditures for major equip-ment and materials vary, depending on thepurpose and technical sophistication of theequipment. Certain types of equipment aremore readily available in some areas of thecountry than others because of their other uses(e.g., subsurface geophysics equipment is usedextensively for petroleum and mineral ex-ploration).

The experience and training of personnelaffect costs in terms of the level of skills neededto design an investigation and collect and in-terpret data. Highly specialized skills are re-quired for some techniques, and skilled peo-ple are in short supply. The result is relativelyhigh costs to obtain their services.

Property access may limit the use of drillingand associated techniques. Permission to drillwells is often not readily granted on privateproperty because of the inconvenience and dis-ruption created by the drill rig. Interest indrilling beyond property boundaries is oftenquite low because whoever finances the drillingmust usually assume liability for damages.

The potential for short- or long-term adverseeffects limits the use of some techniques. Forexample, short-term changes in water levelsduring hydraulic pump tests may limit theiruse in some environments (e. g., where thereare water supply wells). Use of tracer tests isunacceptable to many regulatory authoritiesbecause tracers (some of which maybe radio-active) may remain as a potential contaminantin the environment.

Techniques for Obtaining InformationAbout Contaminants

Advances during the last decade in techniquesfor analyzing water quality samples—for identify-ing increasing numbers of specific substances, fordetecting substances at progressively smaller con-centrations, and for increasing the automation ofinstrumentation—have been major driving forcesbehind the detection of contaminants in ground-water. Continued improvement is expected; notonly will previously undetected substances be foundbut more will be detected at increasingly small con-centrations.

Not all contaminants, however, can be detectedat low concentrations using routinely available tech-niques. Further, the fact that certain substances can

be measured at increasingly small concentrationsdoes not mean that they need to be. Rather, anal-ysis should be guided by the levels at which sub-stances may cause adverse impacts (Environ Corp. ,1983). Major unresolved issues concern whichsubstances and concentrations to measure, givenlimited resources, in order to evaluate the risks to

128 ● Protecting the Nation’s Groundwater From Contamination

public health and to provide the public with con-fidence that it is being protected.

At present, techniques for measuring substancesin groundwater are not being used consistently, andthey introduce a bias in terms of which of the sub-stances present are detected. In addition, analyti-cal accuracy becomes increasingly difficult toachieve as concentrations become very small andmixtures become more complex (Woodward-ClydeConsultants, 1983; Shifrin, 1984).

Properties of Substances. —Analyzing contam-inants in a groundwater sample is based on the ca-pability of instrumentation to discern certain prop-erties of substances. These properties are importantin contamination studies because they are charac-teristic of either individual substances or groups ofsubstances and because they determine the nature,behavior, and response of substances under variousconditions.

In the context of groundwater contamination, adistinction can be made between two types of prop-erties, molecular-based and media-based (Wood-ward-Clyde Consultants, 1983).9 Measurement ofthese two types of properties is based on differentprinciples. In addition, the two relate to differentobjectives. For example, the detection of contam-inants in a groundwater quality sample (e. g., deter-mining the general presence of substances or iden-tifying and/or quantifying the concentrations ofspecific substances) is based principally on themeasurement of molecular-based properties. Mo-lecular-based properties are derived solely from thebasic construction of the substance: 1) elementalcomposition (i. e., elements and their frequency ofoccurrence in a molecule); 2) structure (i. e., spatialarrangement of elements); and 3) functional group(i.e., arrangement of elements into stable combina-tions). In contrast, media-based properties are theprincipal basis for characterizing the behavior ofcontaminants. Understanding behavior is necessaryfor designing hydrogeologic investigations includ-ing: evaluating the applicability of corrective ac-tions, assessing the vulnerability of an aquifer tocontamination, and assessing health and environ-mental impacts. Media-based properties are derivednot only from the basic construction of a substance

‘For the purposes of this SI udy, substances have been organized intonine groupings (see ch. 2, footnc)te 7 and table 6).

but also from its concentration in solution (in thiscase, in groundwater) and its interaction with thesurrounding (e. g., hydrogeologic) environment. Al-though molecular-based and media-based proper-ties are interrelated by molecular composition, thisinterrelationship is not well understood.

Information examined as part of this study, aboutthe current status of the techniques for analyzingsubstances that are found in groundwater, is sum-marized below.

Measuring Molecular-Based Properties. —Manyanalysis techniques are available for measuring themolecular-based properties of substaces in ground-water, as shown in tables 27 and 28 (Woodward-Clyde Consultants, 1983). Many of these tech-niques are routinely available and have been stand-ardized—i. e., they are ‘ ‘referenced’ and publishedby the scientific community. Many standardizedtechniques have also been sanctioned by EPA—i.e., protocols have been established to ensure thatthe regulated community applies techniques con-sistently and to facilitate enforcement. 10

With general (also known as non-specific, surro-gate, or indicator) methods, it is possible to discernmolecular-based properties that are common to,and hence can be used to determine the presenceof, groups or classes of molecules. The major ad-vantages of general methods are that they are rela-tively inexpensive in terms of both capital costs andcosts per sample, and their use requires neither so-phisticated equipment nor highly skilled technicalpersonnel. The shortcomings include that manygeneral methods can neither measure low concen-tration levels (i. e., several parts per billion or less)

10Standardized methods have been subjected to statistical tests ofprecision (i. e., the reproducibility of results) and accuracy (i, e., theproximity of the measured results to the actual value) when used todetect substances in a representative group of samples. Detection usingstandardized methods therefore is not to depend on the specific natureof the sample.

Development of analytical methods for measuring substances in wa-ter has intensified since the passage of the Federal Water PollutionControl Act Amendments of 1972. The act’s requirements triggeredwidespread analysis of surface water as well as municipal and indus-trial effluents for biochemical oxygen demand (BOD), chemical ox-ygen demand (COD), and other general parameters. Enforcementof regulations developed pursuant to the 1972 Amendments led to theneed for a high degree of uniformity in the conduct of analytical pro-grams to ensure consistency and equity within the regulated commu-nity. EPA first sanctioned the use of methods for measuring both gen-eral parameters and specific parameters in EPA, 1974 (revised 1979).

Ch. 5—Hydrogeologic Investigations of Groundwater Contamination ● 129

Table 27.—Analytical Methods for Measuring the Molecular-Based Properties ofGroundwater Contaminantsa

Contaminants Routinely b

Methods measured Available

substance)

GC (gas chromatography, bothgas-liquid and gas-solid)

HPLC (high performance liquidchromatography)

Detection systemsCD (conventional detectors)MS (mass spectrometry)

Inorgan icGeneral methods

Eh (Oxidation potential)Specific conductancepH/acidity

Contaminant-specific methodsAA (atomic absorption spectrometry)ICAP (induction-coupled argon plasma)Wet chemistry

ColorimetryGravimetryTitr imetry

RadionuclidesGeneral methods

Gross emissionContaminant-specific methods

Concentration/i dentification

MicroorganismsGeneral methods

Standard plate count

Multitube fermentationMembrane filtration

Contaminant-specific methodsCulturingMorphologyConcentration/Identification

Organics

Polynuclear aromatics

OrganicsOrganics

Oxidizing metalsIonized speciesMineral acids

Metals/cat ionsMetals

Non-metals/anionsMetalsAcids

YesNoNoNo

YesYesYesYesYesYes

Yesd

Yes

YesYes

YesYesYes

YesYesYes

Yes

Yese

YesAerobic and facultative

anaeorbic, heterotrophicbacteria

Coliform bacteriaColiform bacteria, pathogens,

parasitesYese

PathogensParasites, fungi

130 ● Protecting the Nation’s Groundwater From Contamination

Table 28.—Costs and Detection Limits of Methods for Measuring the Molecular-Based Propertiesof Contaminantsa

Costs b ($) Detection Iimitsc

Method Per sample Capital (ppm) (ppb)

15-3030-6020-4010-3030-6020-3020-40

60-10020-3030-70

30-500100-1,500

40-500

10-153-53-5

10-15

150125-200

10-35

75/group1,000/strain

40-751,000-1,500

9,000-15,00012,000-30,0005,000-16,0005,000-12,0004,000-6,0004,000-6,0001000-2,000

8,000-10,000500-1,500

1,000-2,500

8,000-30,00055,000-220,000

8,000-40,000

1,000-1,5001,000-1,5001,000-1,500

500-1,000

12,000-20,000125,000-175,000

2,000-5,000

2,500-4,0002,500-4,000

5,000-7,00030,000-60,000

1(O.1)d

(1)

0.0020.0020.0250.010.20.01

<0.001-01<0.001-0.01

0.000001

N/AN/A

±0.1 pH unit±0.1 mg CaC03/l

<0.001–0.2<0.001-0.2

01-1

N/AN/A

l-2pCi/ll-loo pCi/l f

0.05-1 pCi/lg

1,000(loo)

(1,000)—

22

2510

20010

<1-1oo< l – l o

0.001

<1-200<1-200

100-1,000

Ch. 5—Hydrogeologic Investigations of Groundwater Contamination ● 131

nor identify individual substances of a group orclass. Individual substances would be of concernif they were expected to vary in terms of their po-tential impacts. In addition, data from generalmethods can be difficult to interpret, especiallywhen interferences arise from the presence of sev-eral different types of substances in the sample.These interferences are known to give misleadingresults (‘false positives’ (Davis, 1984).

With contaminant-specific methods, it is possi-ble both to identify individual substances and toquantify their concentrations at extremely lowlevels. The disadvantages of contaminant-specificmethods are that they are more costly than gen-eral methods, and they require the use of relativelysophisticated equipment. These methods, as wellas general methods, are also subject to quality con-trol problems with analysis procedures, and datacan be difficult to interpret (e. g,, there will alwaysbe some degree of uncertainty about how well datarepresent in-situ conditions).

Three important points about measuring molec-ular-based properties are discussed below relatedto: 1) which substances can be measured, 2) theextensive use of gas chromatography/mass spec-trometry (GC/MS), and 3) the ‘ ‘standardized’concept as it relates to groundwater contamination(see Woodward-C1yde Consultants, 1983).

Substances Measured. —Not all known or poten-tial substances can be detected at trace levels usingroutinely available standardized methods. Someof these substances have been, or may be, associ-ated with toxic effects in either clinical or labora-tory studies.

Organic chemicals:

● There are no routinely available generalmethods for measuring trace levels of someorganic chemicals known to occur in ground-water, including aromatic and polynuclearhydrocarbons. There are no general methodsfor measuring trace levels of some substancesthat have the potential to be found in ground-water— e. g, glycols and oxygenated hydrocar-bons such as aldehydes, ethers, esters, ketones,and alcohols,

● Standardized contaminant-specific methods—namely gas chromatography/mass spectrom-etry, GC/MS—tend to be available for only

●

selected organics (i. e., 129 ‘‘Priority Pollut-ants’ and pesticides regulated under CWA).11

There are no cost-effective methods for meas-

132 . Protecting the Nation’s Groundwater From Contamination

Photo credit: U.S. Environmental Protec(/on Agency

Gas chromatography/mass spectrometry equipment isused for the qualitative identification and quantitative

measurement of individual organic chemicals.

2.

3.

molecular weight, substances that are unstableat high temperatures, and substances that arehighly soluble in water. In many of thesecases, relatively simple, modified versions ofsome standardized GC/MS procedures areadequate (e. g., for malathion); in other cases,entirely different methods, such as High Per-formance Liquid Chromatography (HPLC),may be required (Davis, 1984). Specializedmodifications of standardized GC/MS meth-ods may also be possible for additionalsubstances such as dioxin (2,3,7,8 -TCDD);dioxin is difficult to detect because it is rela-tively insoluble in water and often present atconcentrations of only parts per trillion. Ingeneral, none of these other techniques havebeen standardized and used routinely.Standardized GC/MS methods could be ap-plied directly (i. e., without modification) tosubstances in addition to the Priority Pollut-ants (e. g., xylenes and aniline). AlthoughEPA has made significant research and devel-opment commitments to improve the basic in-strumentation of GC/MS and associated dataprocessing systems, less attention has beengiven to widening the routine use of stand-ardized GC/MS methods for additional sub-stances (e. g., by expanding the list of PriorityPollutant organics).While contaminant-specific techniques, suchas standardized GC/MS methods, are cost-effective for identifying substances in a sam-

ple of unknown composition if the substancesare amenable to analysis by the methods, themethods may be otherwise inefficient (i. e.,very costly) for unknown samples. Little re-search attention has been given to develop-ing techniques for substances not amenableto analysis by GC/MS or to developing reli-able and inexpensive screening techniques(e.g., alternative types of analytical and phys-ical/chemical testing methods) for narrowingthe universe of potential substances that mightbe present in a sample and therefore for effi-ciently determining which contaminant-specif-ic techniques are most applicable (Davis,1984; Woodward-Clyde Consultants, 1983). 12

Standardized Methods. -Central to the stand-ardization of methods is the concept of a represent-ative sample (refer to footnote 10). This is a diffi-cult concept to apply to groundwater samplesbecause groundwater contamination is site-specific,and the ‘ ‘representative samples’ used to stand-ardize a method may not represent the universe ofgroundwater samples to which the method mightbe applied. Thus the use of a standardized, rou-tinely available method does not guarantee that sub-stances in groundwater can be detected with theprecision and accuracy indicated by following thestandard procedures.

Measuring Media-Based Properties. —Oncesubstances in groundwater have been identified bymeasuring their molecular-based properties, it isoften essential to understand their behavior.Behavioral characteristics—e. g., persistence andmobility-determine, for example, the extent of thecontamination problem and likely impacts. How-ever, with present techniques, behavioral charac-teristics of a substance cannot be measured directly.Rather, the characteristics are deduced from themedia-based properties of the substance. Theseproperties are determined by the nature of the sub-

Ch. 5—Hydrogeologic Investigations of Groundwater Contamination ● 133

then deduced using this information together withprofessional judgment and experience (e. g., to per-form correlation analyses).

Approaches for the Measurement of Substancesin Groundwater. —Techniques for measuring sub-stances in groundwater are not now being selectedand used consistently to ensure that all potentialcontaminants at a given site are being addressed,that substances are being detected efficiently giventime and financial constraints, and that informa-tion obtained can be meaningfully interpreted,

consuming and costly; high-quality data required for correlations areoften not available; and published data are often incomplete, incon-sistent, or imprecise. For example, published data are found in suchreferences as Weast, 1978-1979; Perry, et al., 1973; EPA, 1981; Wind-holz, et al., 1983; and Sax, 1979. Data tend to be limited to such prop-erties as density, viscosity, ignitability, corrosivity, miscibility,volubility, and vapor pressure. Information is not available for all sub-stances and is often not sufficiently accurate for analysis of tram levels.Moreover, while some of these properties, such as ignitability and cor-rosiveness, are used for classifying wastes as hazardous (under RCRA),they contribute little information about the behavior of such substancesin groundwater. Other properties that are of interest to groundwatercontamination studies, such as adsorption, bioaccumulation, and thepartition coefficient (i. e., the tendency of a substance to partition be-tween soil and water) are not generally available and must bc meas-ured using groundwater samples.

Table 29.—Techniques Commonly Used To Measure Media-Based Propertiesof Contaminants

Media-based property Techniques employed

Density Measure forces transmitted by a mass of the substance beinganalyzed as in viscous-drag, gas-density meter.

Viscosity Measure fluid friction by either mechanical drag between drivenand free members immersed in the sample or resistance toflow.

Adsorption Use batch test or leaching columns.Volubility Dissolve measured amount of contaminant in a given volume of

water at room temperature.Volatility Estimate quantity of contaminant vaporized from water by use

of an Organic Vapor Analyzer (OVA).Immiscibility Shake contaminants in water and observe if there is complete

mixing.Bioaccumulation Determine concentration of contaminant in sample (e.g., via fish)

and compare with background level.Reactivity Observe violent reaction of contaminant and/or generation of

toxic gases, vapors or fumes when mixed with water.Degradability Measure CO2 evolution, or determine rate of disappearance of

parent compound over time.Stability Observe disappearance of parent compounds or generation of

daughter products.Oxygen uptake Determine biochemical oxygen demand (600) or chemical

oxygen demand (COD).Partition coefficient Measure concentration of contaminant in soil relative to

concentration of contaminant in water.

SOURCE: Woodward-Clyde Consultants, Inc., 1983.

134 • Protecting the Nation’s Groundwater From Contamination

given the objective (detection, correction, or pre-vention) of the measurement program. A coherentapproach would consider measuring molecular-based properties with both general methods (e. g.,as screening tools to narrow the choice of possiblesubstances present) and contaminant-specific meth-ods (e. g., to identify individual substances and de-termine their concentrations). 15

EPA has made efforts in the direction of a mas-ter scheme for measuring substances (e. g., EPAMethod 8600 is being developed as a comprehen-sive analytical scheme to determine the presenceof chemicals listed in Appendix VIII of RCRA,Part 261). Agency efforts are not yet coordinatedin a way that responds fully to the spectrum ofsubstances found in groundwater and possibly atextremely low concentrations.

For example, the groundwater indicator param-eters to be measured at both interim status facil-ities (40 CFR 265) and permitted facilities underthe detection monitoring system (40 CFR 264) aredelineated as pH, Specific Conductance, TotalOrganic Carbon (TOC), and Total Organic Halo-gens (TOX). Some substances known to cause ad-verse health impacts are not detectable using theindicator parameters. TOC and TOX measure-ments have the disadvantages of general methodsdiscussed above (e. g., subject to interference ef-fects). In addition, there are categories of con-taminants that are neither halogenated, acidic, norconducting and that may be toxic at less than 1 partper million (ppm, the detection limit of TOC) in-cluding pesticides and pesticide byproducts (e. g.,dioxin and 2,4,5-T, both of which are known to

occur in groundwater; see ch. 2) (Woodward-ClydeConsultants, 1983). “To a great extent, becauseof an overreliance on indicator parameters, wedon’t know much more now about which sites are‘clean’ or ‘potentially dirty’ than we did before EPAstarted using the indicator monitoring approach 3years ago” (Davis, 1984).

Monitoring Networks

Hydrogeologic investigations involve collectinginformation about the hydrogeologic environmentand water quality at selected locations and thenmaking assumptions about what is likely to beoccurring between sampling points. In general, themore the sampling points, the less uncertainty isassociated with interpretation of what is taking placein the subsurface. But practical considerations limitthe number of measurements taken. The numberof measuring points (for direct techniques), the den-sity of measurements (for indirect techniques), andthe verification that is required to obtain a satisfac-tory level of confidence in the results depend onsite conditions and the objective of the investigation.

To account for horizontal and vertical variationsin the hydrogeologic environment and in waterquality, both the location of sampling points andsampling frequency will vary depending on site con-ditions and objectives. For example, measuringpoints could be located at random or in an evenlyspaced pattern, or in relation either to the pathwaysof substances (i. e., measuring points are locatedwhere substances are either expected and/or not ex-pected to be found) or to concentrations (i.e., meas-uring points are located where concentrations arehighest and/or lowest). Sampling could be con-ducted once, annually, seasonally, or more fre-quently, depending, for example, on whethergroundwater flow patterns change periodically.

Ch. 5—Hydrogeologic lnvestigations of Groundwater Contamination ● 135

Source of contamination

Monitoringwells

. . * . “ * .

n

i

● ✍ ✎ “ . . & .“ ” “ 1 1 ’ . 1

.● ● *

. ● ●

Unsaturated zone

Unconfined aquifer

Confining unit

Confined aquifer

Confined aquiferwith fractures

● . Contaminated groundwater● . ● *

●

G r o u n d w a t e r f l o w

In order to detect contamination, sampling wells need to be located at varying depths and

Credit: Geraghty & Miller, 1983

distances from the source.

APPROACHES FOR MINIMIZING DIFFICULTIES WITHGROUNDWATER CONTAMINATION INVESTIGATIONS

Ensuring the Reliability ofHydrogeologic Investigations

As described in the previous sections, investiga-tions of groundwater contamination are very com-plex and uncertain because the hydrogeologic envi-ronment is not easily observed, and hydrogeologyvaries both spatially and temporally. Hydrogeolo-gists cannot describe and predict with absolute con-

fidence the rate, direction, and pathways of con-taminant movement in groundwater. Estimates canbe made and ranges of values given but there willalways be some degree of uncertainty about whichcontaminants are present, where they are moving,how fast they are moving, and their concentrationsas they move.

Despite these uncertainties, investigations areunder way, and they are used as a basis for mak-

136 ● Protecting the Nation’s Groundwater From Contamination

ing decisions about I he need for and usefulness ofalternative corrective and preventive actions. Giventhe nature of such decisions— e.g., regarding publichealth and the dollars involved-decisionmakersand the public need some assurance that certainelements of uncertainty are minimized and thathydrogeologic investigations provide reliableresults.

Factors that tend to increase uncertainty in in-vestigations of groundwater contamination include:complex hydrogeologic environments; lack of his-toric information about sources of contamination;substances that do not move with groundwater (be-cause they are immiscible, or due to physical, chem-ical, and biological processes that alter their natureor retard their movement); changing patterns ofgroundwater use; and inexperienced or untrainedindividuals designing investigations and collectingand analyzing hydrogeologic information.

All of these factors reflect conditions at the siteand are beyond the direct control of decisionmak-ers, except the choice of personnel. Most of the site-related factors that contribute to uncertainty canbe overcome by an experienced hydrogeologist,provided sufficient time and funds are available.That is, steps can be taken such that the uncertain-ties do not undermine ability to make reliable pre-dictions about the response of contamination to

Photo (<redIt: U.S. Environmental Protection Agency

Special precautions must be taken to ensure thatsamp les a re no t con tam ina ted by t he samp l i ngequipment. This photo shows aquifer material b e i n gextruded from a core sampling tube while a sterileshaving device removes material that has been in

contact with the inside of the sampler.

various corrective or preventive measures. For ex-ample, by collecting more information over a longerperiod on the presence of substances and the rateand direction of groundwater flow, investigators canreduce many uncertainties about complex hydro-geologic environments, sources of contamination,and changing patterns of water use. The one ma-jor exception, where reliable predictions are unlike-ly, is in fractured environments (e. g., karst regionsof the southeastern United States).

Uncertainties about immiscible substances thatdo not move with groundwater can be reduced withthe collection of more information, especially aboutthe hydrogeologic factors that control the movementof such substances. The uncertainty associated withthe behavior of substances that do not move withgroundwater flow due to physical, chemical, andbiological processes cannot be reduced significantly,given technical limitations in understanding theseprocesses. However, precautionary steps can betaken to minimize the impact of this and any otherremaining uncertainties, including: using sensitivityanalyses to test the significance of varying assump-tions about groundwater flow and the behavior ofsubstances; using conservative or worst-case as-sumptions about groundwater flow as the basis fordesigning corrective or preventive measures; andcontinuing the monitoring of groundwater flow andwater quality as part of the implementation of anyprogram to corrector prevent contamination so thatany errors in predictions about the response of con-taminants can be recognized early and compensat-ing actions can be undertaken.

These precautionary steps may lead to over-design and higher costs for corrective or preven-tive measures. However, overdesign may be theonly way to limit risks associated with the lack ofprecise knowledge about the concentration andlocation of substances and the rate and directionof their movement.

An additional step that can be taken to improvereliability, and perhaps to reduce future costs andtime required, is to keep records on the use ofgroundwater and the location of potential sourcesand their associated substances, With these recordsthe hydrogeologist will have a better idea aboutwhich substances are of concern at a site and whereto look for them.

Ch. 5—Hydrogeologic Investigations of Groundwater Contamination ● 137

Approaches for MinimizingDifficulties in Measuring Substances

Analysis of water quality samples is a technicallycomplex process, and the difficulties associated withaccurate measurement and interpretation of dataare discussed in the literature (e. g., Keith, et al.,1982b, 1983; Miller, S., 1982). Uncertainties canbe introduced at many steps—including when thesample is collected, handled, transferred, stored,prepared for analysis, as well as analyzed (Shifrin,1984). Thus, detection limits (as presented in table28) are not absolute; they depend on many factors,including the skill and experience of the analyst,the combinations and concentrations of the sub-stances present, and the equipment used. For ex-ample, acceptable ranges for precision and accu-racy, used for EPA-sanctioned methods by contractlaboratories, range from 15 to 50 percent and 15to 200 percent, respectively, depending on theorganic classes measured (Keith, et al., 1983).16

In all cases, uncertainties in the analytical resultsneed to be defined if the data are to be correctlyinterpreted. This need is especially important forthe types of groundwater samples for which a highdegree of accuracy is not now attainable—samples

in which there are complex mixtures of substances,samples in which substances are present at traceconcentrations, and samples being analyzed withrelatively new analytical methods.

Some uncertainties can at least be defined, if notreduced, through quality assurance/quality controlprograms. QA/QC programs, which are part ofEPA’s contract analysis program, need to considersample handling and storage procedures, samplepreparation, care of equipment, methods for assess-ing data for completeness, and record-keeping anddocumentation (ACS, 1980, 1982). Analysis of sev-eral samples is also important for obtaining statis-tically significant results. Other factors importantfor obtaining meaningful analytical results ingroundwater contamination studies concern: thelaboratory certification process,l7 laboratory selec-tion, availability of background information (e.g.about sources and users), availability of informa-tion about the nature and history of the sample,independent confirmation of the quality of 1abora-tory data, and guidance on the selection of appro-priate measurement methods (Woodward-ClydeConsultants, 1983; Keith, et al., 1983).

38-799 0 - 84 - 6 : QL 3

138 ● Protecting the Nation’s Groundwater From Contamination

Photo credit: U.S. Environment/ ProtectIon Agency

Standard reference materials are provided by EPA’s Environmental Monitoring Laboratory to laboratories for instrumentcalibration and internal checks in order to evaluate performance.

CHAPTER 5 REFERENCES

American Chemical Society (ACS), “Data Acquisitionand Data Quality Evaluation in EnvironmentalChemistry, Analytical Chemistry 52:2242, 1980.

American Chemical Society, “Improving the Reliabilityof and Acceptability of Analytical Chemical DataUsed for Public Purposes, ” Chemical EngineeringNews 60(23):44, 1982.

Brass, H. J., “Procedures for Analyzing Organic Con-taminants in Drinking Water, Journal AmericanWater Works Association, pp. 107-112, February1982.

Chapman, P. M., G. P. Romberg, and G. A. Vigers,“Design of Monitoring Studies for Priority Pollut-ants, ’’Journal of the Water Pollution Control Fed-eration, vol. 54, No. 3, pp. 292-297, March 1982.

Davis, S., Environment Testing and CertificationCorp., personal communication, May 1984.

Environ Corp., “Approaches to the Assessment ofHealth Impacts of Groundwater Contaminants, ”draft report prepared for the Office of TechnologyAssessment, Aug. 15, 1983.

Environmental Science and Technology, vol. 15, No,6, 1982.

GeoTrans, Inc., “Technologies for a HydrogeologicAnalysis-Interim Draft Report, ” draft report pre-pared for the Office of Technology Assessment,1983a.

GeoTrans, Inc., ‘‘RCRA Draft Permit Writer’s Man-ual, Groundwater Protection, 40 CFR Part 264 Sub-part F, ‘‘ U.S. EPA contract No. 68-01-6464, draft,1983b.

Geraghty & Miller, Inc., “The Fundamentals ofGroundwater Quality Protection, ” New York, 1983.

Keith, S. J., L. G. Wilson, and H. R. Fitch, “Sources

Ch. 5—Hydrogeologic Investigations of Groundwater Contamination ● 139

of Spatial and Temporal Variability in Ground -Wa-ter Quality Data and Methods of Control: CaseStudy of the Cortaro Monitoring Program, Ari-z o n a , in Second National Symposium on AquiferRestoration and Groundwater Monitoring, NationalWatcr Well Association, Columbus, OH, pp. 217-228, May 26-28, 1982a.

Keith, S.J., and 1,. G. Wilson, ‘‘ Stacking the Deck inGround-Water Quality Data, Proceedings of theArizona Section of the American Water ResourcesAssociation Ground Water Quality ManagementSymposium, Tucson, AZ, pp. 27-34, Oct. 29, 1982b.

Keith, S.J., M. T. Frank, G. McCarty, and G. Moss-man, ‘ ‘Dealing With the Problem of Obtaining Ac-curate Ground-Water Quality Analytical Results,Proceedings of the Third National Symposium onAquifer Restoration and Ground-Water Monitoring,Columbus, OH, pp. 272-283, May 25-27, 1983.

McCarty, P., Stanford University, personal communi-cation, July 17, 1984.

Miller, D., Testimony before the Toxic Substances andEnvironmental Oversight, Committee on Environ-ment and Public Works, U. S. Senate, July 28, 1982.

Miller, S.. “Quality Assurance, Analytical Methods,and Hazardous Wastes, Environmental Science andTechnology, vol 16, No. 6, pp. 332A-336,4, 1982.

Neal, R. A., ‘‘ Drinking Water Contamination: Priori-ties for Analysis of Organics, Guest Editorial, vol.17, No. 3, p. 11 3A, 1983.

Office of’ Technology Assessment, Use of Models forW a t e r R e s o u r c e s M a n a g e m e n t , P l a n n i n g , a n d P o l -icy, OTA-O - 159 Washington, DC: U.S. Govern -ment Printing Office, August 1982).

Perry, R. H., and C. H. Chilton (eds. ), Chemical Engi-neers' Handbook, .5th cd. (New York: McGraw-HillBook Co., 1973).

Sax, N. 1., Dangerous Properties of IndustrialMaterials, .5th cd. ( New York: Van Nostrand Rein-hold, 1979).

Shifrin, N., Cambridge Analytical Associates, personalcommunicant ion, Apr. 16, 1984.

Todd, D. K.. R. Al. Tinlin, K. D. Schmidt, and L.G. Everett, ‘‘A Groundwater Quality Monitoring

Methodology, Journal American Water WorksAssociation, pp. 586-593, 1976.

U.S. Environmental Protection Agency, ‘‘Methods forChemical Analysis of Water and Waste," Environ-mental Monitoring and Support Laboratory (EMSL),Cincinnati, OH, EPA-600/4-79-020, 1974, revisedMarch 1979.

U.S. Environmental Protection Agency, ‘‘TreatabilityManual , Office of Research and Development,Washington, DC, EPA 600/2-82-001 (3 vols. ), Sep-tember 1981.

U.S. Environmental Protection Agency, ‘ ‘Test Meth-ods for Evaluating Solid Waste, Physical/ChemicalMethods (SW-846 ),” July 1982.

U.S. Environmental Protection Agency, ‘ ‘Methods forNonconventional Pesticides Chemicals Analysis ofIndustrial and Municipal Wastewater," EffluentGuidelines Division, Washington, DC, EPA 440/1 -83/079-C, January 1983.

U.S. Geological Survey, ‘ ‘Laboratory Analysis, Book5, Section A, Techniques of Water-Resources In-vestigations of the United States Geological Survey"(Washington, DC: U.S. Government Printing Of-fice, 1979).

Vicory, A. H., Jr., and J. F. Malina, Jr., ‘ ‘ApparatusNeeds and Costs for Monitoring Priority Pollutants,

Journal of the Water Pollution Control Federation,vol. 54, No. 2, pp. 125-128, February 1982.

Weast, R. C. (cd.), Handbook of Chemistry and Phys-ics, 59th ed. (West Palm Beach, FL: CRC Press,Inc., 1978-79).

Windholz, M., S. Budavari, R. F. Blumetti, and E. S.Otterbein (eds. ), The Merck Index—An Encyclo-pedia of Chemicals, Drugs, and Biological, 10th ed.(Rahway, NJ: Merck & Co., Inc.l 1983).

Wood, E. F., R. A. Ferrara, W. G. Gray, and G. F.Pinder, Groundwater Contamination From Hazard-ous Wastes (Englewood Cliffs, NJ: Prentice Hall,Inc., 1984).

Woodward-Clyde Consultants, Inc., ‘ ‘GroundwaterContaminants and Their Measurement, draft re-port prepared for the Office of Technology’ Assess-ment, October 1983.

Detection

Chapter 6

Federal Efforts To DetectGroundwater Contamination

Contents

P a g e

Chapter Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , 14.5

Chapter 6 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161

Groundwatc:r Adivities of the U.S. Geological Survey .......................... 145 Federal PJ'OgraIJI". .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 Fccieral-Stat(· Cooperative Program. . . . . . . . . . . . . . . . . . . . . . . . . . . 146 Activities f(»)' Other Federal Agencies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 146

Investigations of Aquifer Systems and Ambient Groundwater Quality. . . . . . . . . . . .. 146 Regional Aquifer-System Analysis Program. . . 147 Ambient Grl>undvvater Quality Appraisal. . . . . . . . . . 147

Monitoring Drinking 'Vater Supplies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 147 Public \Natc' Sy~tcrns . . . . . . . . . . 147 EPA Drinking VVatel" Survey!' .. 149

Source Inventories ....................................................... 150 Formal Studics . . . . . . . . . . . . . . . . . . . . . . . . . . . 150 Reporting Requirements. . . . . . . . . . . . 152 Regulatory Requirements Related t() I l1\Tntories . 1 Y1

Groundwater Monitoring and Sources ........... . . . . . . . . . . . . . . . . . . . . . . . . . . .. 155 l\fol1itoring Provisions of Fednal Programs. . . . . . . 155 Monitoring and Remedial Action Programs 1 ()() Other J\efonitoring Acti\'it ic!' 16()

TABLE "/"ah/(' No

:30. Federal Groundwater j\I()nitol"ing Provisions and Objcctives . 15(j

FIC;URE /·'iglll"(" No. Pag('

:>. Stat us of the USGS Regional Aquifer-System Analysis Prograrn ................... . 148

Chapter 6

Federal Efforts To DetectGroundwater Contamination

CHAPTER OVERVIEW

This chapter describes the investigatory activi-ties of the Federal Government related to ground-water contamination. Some of these activities areexplicitly mandated by Federal legislation. Othershave been undertaken by Federal agencies eitherto support regulatory programs or as special studies.The techniques used for detection activities are dis-cussed in chapter 5.

Four major types of Federal investigatory pro-grams are discussed:

1.

2.3.

4.

conducting hydrogeologic investigations ofaquifer systems, including ambient ground-water quality;monitoring drinking water supply systems;conducting inventories of potential sources ofcontamination; andmonitoring groundwater in the vicinity of spe-cific sources of contamination (includes:monitoring conducted by Federal agencieswith respect to federally financed remedial ac-tion programs, hydrogeologic investigations,special studies, and monitoring required

under regulatory programs that apply to facil-ity owners or operators).

These programs are providing significant informa-tion on the Nation’s groundwater problems. How-ever, their coverage is generally limited relative tothe sources of contamination and substances dis-cussed in chapter 2. For example, only recently arehydrogeologic investigations starting to look fororganic chemicals; monitoring provisions for drink-ing water supplies address only selected substancesfound in public systems; inventories are conductedfor only particular sources; and monitoring require-ments are specified for only particular sources andtheir coverage is inconsistent.

The chapter begins with an overview of U.S.Geological Survey (USGS) activities. AlthoughUSGS does not have regulatory authority with re-spect to groundwater contamination, hydrogeologicinformation developed by its Water Resources Divi-sion supports the programs of other Federal agen-cies as well as State and local governments.

GROUNDWATER ACTIVITIES OF THEU.S. GEOLOGICAL SURVEY

Principal responsibility in the Federal Govern- Program, and 3) activities for other Federalment for-providing hydrogeologic information and agencies.appraising the Nation’s water resources lies withinthe Water Resources Division of the USGS. 1 Thedivision conducts three types of programs: 1) Fed- Federal Programseral programs, 2) the Federal-State Cooperative

Congressional appropriations for USGS support‘USGS was established by legislation passed in 1879 (see 43 U.S. C.

31 et seq ). Subsequent legislation specifically authorized USGS toactivities on research, data collection, high-priority

gaug-c streams and dcterm ine the Nation water supply. For an over- special topics, and coordination of Federal use and. .view of all L’SGS activit ics sec Chase, ct al., 1983. acquisition of water data.

145

146 ● Protecting the Nation’s Groundwater From Contamination

Examples of programs related to groundwaterquality include the Regional Aquifer-SystemAnalysis Program, the Toxic Wastes-Groundwa-ter Contamination Program, the Radioactive WasteProgram, and the Coal Hydrology and Oil ShaleHydrology Programs. In addition, USGS maintainsthe National Water-Data Exchange (NAWDEX)and is involved in research efforts related to ground-water contamination (see ch. 3).

Federal-State Cooperative Program

The Federal-State (Inoperative Program encom-passes hydrologic data collection and water re-sources investigations relevant to State and localneeds and issues. Congressional appropriations sup-port the program, and the States are required tomatch Federal funds on a 50-50 basis. USGS con-siders this program ‘‘the foundation of much of thewater-resources management and planning activ-ity in the Nation and it serves as an early warningsystem for the detection of emerging water prob-lems’ (USGS, 1982). The program is active in all

50 States, Puerto Rico, Virgin Islands, Guam,and the Trust Territories; and during 1982, USGShad agreements with more than 800 State and localagencies (at a total funding of more than $80 mil-lion). Of these projects, 414 were at least partlyrelated to either groundwater quality or quantity.The total budget for the groundwater portions ofthe investigations was $25 million (USGS, 1982;Chase, et al., 1983).

Activities for Other Federal Agencies

USGS also provides hydrologic expertise and re-lated information to other Federal agencies uponrequest. The agencies are generally required toreimburse USGS. Programs established throughInteragency Agreements and Memoranda of Un-derstanding are included in this category (see ch.3). In 1982, USGS undertook 115 projects at leastpartly related to groundwater for other Federalagencies. The total budget for the groundwater por-tion of these projects was $5,5 million (USGS,1982).

INVESTIGATIONS OF AQUIFER SYSTEMS ANDAMBIENT GROUNDWATER QUALITY

Section 104(a)(5) of the Clean Water Act specifiesthat EPA shall,

. . . in cooperation with the States, and their po-litical subdivisions, and other Federal agenciesestablish, equip, and maintain a water quality sur-veillance system for the purpose of monitoring thequality of the navigable waters and groundwa-ters . . . [emphasis added].

As noted above, USGS is responsible for collect-ing most of the Nation’s water quality data. It oper-ates two nationwide surface water monitoring pro-grams: the National Stream Quality AccountingNetwork (NASQAN) and the National HydrologicBenchmark Network.2 Fundamental differences be-

zrI’he NASQAN pr~rarn is cornpr]sed of 504 operating stations de-signed to monitor the quantity and quality of water in major U.S.rivers. The National Hydrologic Benchmark Network monitors hy-drologic characteristics of 52 small drainage basins that are relati~”elyunaffected by human activities. Data collected from these programsare stored in computer systerls maintained by USGS and EPA.

tween surface water and groundwater have pre-cluded the establishment of a similar nationwideprogram for the collection of groundwater data. Forexample, there is no single point in an aquifer fromwhich ‘ ‘upstream’ water quality can be deduced,as in river basins.

Although there is no nationwide groundwaterdata collection program, groundwater studies havebeen conducted by numerous Federal, State, andlocal agencies. 3 The data collected relate to site-specific conditions and the characterization of cer-tain aquifers. Historically, the studies have focusedon certain inorganic compounds; only recently havehydrogeologic investigations of specific instances of

3Therc were 28,964 active obser~’ations by Federal agencies atgroundwater stations in 1968 (see Langford, 1977). In 1982, ground-water quality data were collected at more than 7,000 stations throughthe Federal-State Cooperative Program and other L’SGS activities (seeChase, et al,, 1983, p. 34).

Ch. 6—Federal Efforts To Detect Groundwater Contamination ● 147

contamination started to provide some informationon organic chemicals in groundwater. In recogni-tion of these data gaps, USGS is currently involvedin a program to characterize the Nations majoraquifer systems and will begin to monitor ambientgroundwater in selected areas of the United Statesin 1984.

Regional Aquifer-System AnalysisProgram

In 1978, USGS began a series of studies to pro-vide basic information about certain regionalgroundwater systems that comprise a significantportion of the Nation’s water supply. The RegionalAquifer-System Analysis (RASA) Program hasidentified 28 systems for possible study. Types ofinformation being developed include: characteris-tics of the flow system; general water quality; re-gional utilization patterns; and response of aquifersystems to stress. Computer simulation models arebeing developed for each system to assist in under-standing the natural flow regime and changes re-

sulting from human activities and in predicting theeffects of future stresses (e. g., waste disposal, arti-ficial recharge, and pumping). The status of RASAstudies as of September 1984 is shown in figure 3.

The RASA studies are conducted on a very largescale and contribute only indirectly to site investiga-tions of groundwater contamination by providinga framework for model selection and analysis. Stud-ies conducted as part of the Federal-State Cooper-ative program provide more detailed informationabout local areas within the regional systems.

Ambient Groundwater QualityAppraisal

USGS is initiating an ambient groundwater qual-ity study that will emphasize detection of organicchemicals and trace metals. Representative areasof the United States will be selected on the basisof climate, hydrogeology, land use, and other fac-tors. A sampling network will be designed for eacharea, both with samples taken first at a reconnais-sance level and then at a more detailed level(Cohen, 1983).

MONITORING DRINKING WATER SUPPLIES

Public Water Systems

Part B of the Safe Drinking Water Act (SDWA)establishes a program to ensure that public drink-ing water supply systems comply with minimumnational standards for substances that may ad-versely affect human health. The requirements ap-ply to both surface water and groundwater. Sec-tion 141 requires the Environmental ProtectionAgency (EPA) to promulgate National DrinkingWater Regulations that specify either MaximumContaminant Levels (MCLs) or treatment tech-niques for such substances. (See app. C. 3 for alisting of standards for specific substances and otherquality indicators. )

The act also provides for the establishment of anenforcement program for public water systems. Un-

der Section 1413, a State may assume primary en-forcement responsibility if it:

1.

2.

3.

4.

5.

adopts drinking water regulations at least asstringent as the Federal regulations;adopts and implements adequate enforcementprocedures;complies with EPA record-keeping and report-ing requirements;permits variances or exemptions based on con-ditions at least as stringent as the Federal re-quirements (Sections 1415 and 1416 of SDWAallow for variances and exemptions, respec-tively, from the drinking water regulations ifsuch action would not pose an unreasonablerisk to health); andadopts and implements an adequate plan forprovision of safe drinking water under emer-gency circumstances.

Figure 3.-Status of the USGS Regional Aquifer-System Analysis Program

• Studies completed (1)

~ Phase I Studies completed ~ Phase II Studies underway, fiscal year 1984 (5)

o Studies underway, fiscal year 1984 (10)

~!~ Studies initiated, fiscal year 1984 (3)

o Studies planned, fiscal year 1985 (1)

SOURCE: Uses, 1984.

lo0'b I Oahu, Hawaii

1982-86

I~~~I Carribbean Islands Aquifer

1984-87

Atlantic Coastal Plain

1980-85

Floridan Aquifer System 1979-82

& • ~ o (b Q. 5'

CC)

i\ ~ ~ ~ o· :'l f/)~

Ch. 6—Federal Efforts To Detect Groundwater Contamination ● 149

As of September 1984, 52 out of the 57 States andTerritories covered by the program had acceptedprimacy for public water supply systems (Baltay,1984). 4 EPA is responsible for enforcing the regu-lations when a State does not assume primacy.

The Safe Drinking Water Act defines a publicwater system as ‘‘a system for the provision to thepublic of piped water for human consumption, ifsuch system has at least 15 service connections orregularly serves at least 25 individuals. The SafeDrinking Water Act does not address individualdrinking water supplies (e.g., private domesticwells). EPA estimates that there are approximately12-14 million individual private wells in the UnitedStates supplied by groundwater (EPA, 1983a).

Public water systems are further divided into‘‘community’ and ‘ ‘non-community’ systems by

4 l)ri m.ic y has not ken a( ccpted b} the Ilist ri( t of (;olurnbia, I nd i-

,ina, P(, nnsyl\an ia, Orcgmn, or W’yorning ( Pcnns~l\ania is expcctcd[() [I(I s() in 1 98.5) (13altay, 1984) ‘1’erri[orie\ under EPA jurisdictionarc Ameri( arl Samoa, (;uam, ?J(Jrt hem hlarianas, Puerto RICO, Trust‘1’crrit[)rics, ,int] L’. S. \’ir~in Jslar](l\.

‘Section 1 401(4), $2 U .S C; 300(f)(4).

EPA regulations. G ‘ ‘Community’ systems serve atleast 15 connections year-round or regularly serveat least 25 people. ‘‘ Non-community’ systemsserve transient users, such as at highway rest stopsor campgrounds, and are not required to complywith the standards for organic chemicals. 7 TheStates may also decide that non-community systemsnot be required to meet the nitrate standard; none-theless, concentrations may not exceed a specifiedlevel.8 A recent EPA inventory indicates that thereare 59,660 community systems and approximately160,000 non-community water supplies (Kimm,1983).

EPA Drinking Water Surveys

EPA’s Office of Drinking Water and Office ofResearch and Development have conducted a num-

640 CFR 141 .2(c).740 CFR 141.12.840 CFR 141.1 1(d). The water supplier must demonstrate that the

water will not be a~’ailable to children under the age of 6; that useof the water will not ~’suit in adl’crse health effects; that there willbe public notification of the levels; and that the local and State offi-cials will be notifrcd of levels exceeding the national standard.

Photo credit: State of Florida Department of Environmental t3egu/atiorr

There are 12-14 million individual private wells in the United States used for drinking water; these wells are not coveredby SDWA. Shown here are the pump and storage tank for a private well.

150 ● Protecting the Nation’s Groundwater From Contamination

ber of surveys of drinking water supplies to providedata to support regulatory actions under SDWA(e. g., development of MCLs). These surveys in-clude: the National Organic Reconnaissance Sur-vey (1975, focused primarily on surface water); theNational Organics Monitoring Survey (conducted1976-77); the Rural Water Survey (conducted1978-79); the Community Water Supply Survey

(1978); and the Groundwater Supply Survey (con-ducted 1980-81) (see ch. 2 for additional informa-tion), EPA initiated a survey in July 1984 to col-lect necessary information about the nationwideoccurrence of selected inorganic contaminants andradionuclides in community drinking water sup-plies (EPA, 1983b); results are not expected to beavailable before 1986 (Westrick, 1984).

SOURCE INVENTORIES

The Federal Government is also involved in in-vestigatory efforts concerning specific sources ofknown or potential groundwater contamination.Activities related to the compilation of informationon locations and characteristics of actual or poten-tial sources are generally referred to as inventories.Inventories provide one indication of the extent towhich particular sources are or may be contributorsto contamination problems.

Federal inventory activities are of three types:

1.

2.

3.

Federal statutes authorize the use of funds tosupport formal studies or projects involvingthe collection of information from, for exam-ple, Federal, State, and local government filesand records, field investigations, and aerialphotography;Federal statutes or regulatory programs estab-lish requirements for the submission of infor-mation on spills, accidents, or other releasesof contaminants that have the potential toenter groundwater; andFederal regulations require responsible par-ties to submit information about particularsources.

These inventories focus on selected sources in OTACategories I, II, and 111 (namely, sources designedto discharge substances; sources designed to store,treat, and/or dispose of substances; and sources thattransport or transmit substances; see ch. 2, table5). There are no explicit inventory provisions forsources in OTA Categories IV, V, and VI (namely,sources discharging substances as a consequenceof other planned activities; sources that provide con-duits for or induce discharges of substances; andnaturally occurring sources).

Formal

The Resource Conservation and Recovery Act(RCRA) and the Safe Drinking Water Act(SDWA) contain provisions authorizing the use ofFederal funds to conduct formal studies that involvethe collection of information about particularsources —open dumps, hazardous waste sites, andsurface impoundments.

Open Dumps

Section 4005(b) of RCRA requires EPA to pub-lish an inventory of all open dumps in the UnitedStates. The States were to conduct the inventoryon the basis of specific criteria developed by EPAfor classifying solid waste facilities as sanitary land-fills or open dumps, and the inventory was to becompleted no later than 1 year after promulgationof the criteria. The criteria were published in 1979(with subsequent amendments in 1981), almost 2years later than the date specified by the statute. g

EPA first published its inventory in 1981. It listed1,209 open dumps; 80 of them were cited as hav-ing violated the groundwater requirements speci-fied in the criteria. However, a General Account-ing Office (GAO) study indicated that the 1981inventory was based on incomplete reports fromthe States (GAO, 1981).

‘RCRA specifies that a facility may be classified as a sanitary landfill‘ ‘only if there is no reasonable probability of adverse effects on healthor the environment from disposal of solid waste at such facility’ [42~’. S.C. 6944(a)]. Criteria established by EPA specify eight conditionsthat must be met by a facility in order to be classified as a sanitarylandfill; onc of the criteria requires that a facility not contaminate anunderground drinking water source beyond the facility boundary oran alternatiic boundary (set on a case-b}’-case basis). See 40 CFR257.3,

Ch. 6—Federal Efforts To Detect Groundwater Contamination ● 151

. ..

●

✌

= . .

Open

Photo credit: u.S. Environmental Protection Agency

dumps and their potential for groundwater contamination have been partially inventoried by the Statesbut inventories have not been completed due to inadequate funding from EPA.

The inventory was published a second time in1982, to reflect State efforts during 1981. The thirdedition of the inventory, published in 1983, incor-porated both additions and deletions submitted by18 States during 1982 (EPA, 1983c). The third edi-tion contains 2,081 facilities; 130 violations ofEPA’s groundwater criteria were reported. EPAestimates that these figures are based on evalua-tion of only 3 percent of the more than 300,000 solidwaste facilities in the United States (Absher, 1983).

A major problem encountered by the States withrespect to completion of the inventory has been thelack of financial assistance from EPA. No Federalfunds for Subtitle D programs were made availableduring 1982 and 1983, although funding was orig-inally planned to extend through 1984 (EPA,1983c).

Hazardous Waste Sites

The 1980 amendments to RCRA added Section3012, which requires each State to, “as expeditious-ly as practicable, undertake a continuing programto compile, publish, and submit . . . an inventorydescribing the location of each site within such Stateat which hazardous waste has at any time beenstored or disposed of."10 Although Section 3012 alsoprovides for Federal financial assistance to theStates, funds were not appropriated until Septem-ber 1982, when $10 million was appropriated fromthe Hazardous Substance Response Trust Fundunder the Comprehensive Environmental Resource,Compensation, and Liability Act (CERCLA).11

1042 U S.C 69:12,L 1 &,c public 1,al$. 97.272, Appmprl~t ionj .Act for the Eni’ironmc’ntd

Protection Agency, Sept. 30, 1982

152 Ž Protecting the Nation’s Groundwater From Contamination

Funds were allocated to the States in proportionto the number of sites listed in EPA’s hazardouswaste site inventory as of January 17, 1983.

In addition to State inventories, some Federalagencies have undertaken or have proposed inven-tories on Federal lands. For example, the Depart-ment of Defense conducted record searches of itsinstallations to identify hazardous waste sites. Asof August 10, 1983, 781 (out of911 ) searches werecompleted (Daley, 1983). The Fish and WildlifeService recently requested all field stations to in-ventory all lands and facilities (Hester, 1983); andthe Bureau of Land Management is developing astrategy to conduct hazardous waste site inventories(Lawton, 1983).

Surface Impoundments

Section 1442(b)(3)(C) of the Safe Drinking Wa-ter Act allows EPA to award grants and enter intocontracts with any public agency, educational in-stitution, or other organization to develop and ex-pand the capability of States and municipalities tocarry out the purposes of the statute. In 1978, EPAmade $5 million available to the States to conductstudies to assess the magnitude and potential ef-fects of surface impoundments on groundwaterquality. Although a draft report was issued in 1982on the results of the assessment, a final report hasnot yet been issued by 13 PA. Subsequent drafts havebeen issued; the most recent is dated July 1983.

The objectives of the studies were: to locate andcount the number of surface impoundments in theUnited States and its Territories; to provide a firstapproximation of the groundwater pollution poten-tial of the impoundments; to assist the States andEPA in developing a better understanding of theproblems caused by surface impoundments; and toprovide a data base upon which Federal (e.g., EPA)and State authorities could develop a strategy tocontrol or regulate pollution from these sources, in-cluding to recommend legislative programs, if nec-essary (EPA, 1983d).

The States located 180,973 surface impound-ments used for industrial, municipal, agricultural,mining, and oil and gas extraction purposes. 13 EPA

“48 FR 5686.i +S{lnlc . S[att.s ~ls[) ~ eportcd (In other types of impoundments such

as septic systetns, farm ponds used for stock watering, and safety im-poundments around bulk sto~ ge tanks.

concluded from the studies that fewer than 10 per-cent of all sites are located in a manner that poseslittle threat of groundwater contamination, and ap-proximately 85 percent of all sites are located within1 mile of a potential surface or groundwater source(EPA, 1983d). (See ch. 2 and app. A.5 for furtherinformation on surface impoundments. )

Reporting Requirements

Four Federal statutes and their associated regu-latory programs require notification of EPA or theDepartment of Transportation (DOT) in the eventof a spill, accident, or other release of specified con-taminants. The relevant statutes are the Clean Wa-ter Act and CERCLA for EPA; and the Hazard-ous Liquid Pipeline Safety Act (HLPSA) and theHazardous Materials Transportation Act (HMTA)for DOT. Although reporting activities are notinventories in the strict sense, they do providedocumentation on releases of substances from vari-ous sources. But, with the exception of CERCLA,the emphasis of reporting requirements is on sur-face water discharges, not groundwater. In addi-tion, the programs address different substances; al-though there is some overlap, each agency hasdeveloped its own list of contaminants that it con-siders hazardous.

EPA Regulations: CWA and CERCLA

Section 311 of the Clean Water Act (CWA) re-quires individuals in charge of facilities or vesselsto notify the National Response Center in the eventof any discharge of oil or a hazardous substanceinto navigable waters, along adjoining shorelines,or into waters of the contiguous zone. The Na-tional Response Center is operated by the U.S.Coast Guard in Washington, DC. Its function isto convey information about releases of oil and haz-ardous substances to the appropriate governmentagencies so that they, in turn, can determinewhether and how response action should be taken.15

Although Section 311 relates to surface water dis-

14Section 3 I I@)(2)(A) requires EPA to promulgate regulations listing

the hazardous substances that are subject to this section. These sub-stances are listed in 40 CFR 116. Section 31 l(b)(4) requires the de-termination of quantities of oil and hazardous substances, dischargeof which may be harmful to public health or welfare. 40 CFR 117specifies the quantities.

1540 CFR 300.36.

Ch. 6—Federal Efforts To Detect Groundwater Contamination ● 153

charges, it is significant here to the extent that theremay be a connection between surface water andgroundwater.

CERCLA contains a provision that is similar toSection 311 of CWA, but it is explicitly applicableto groundwater as well as surface water. Section103(a) requires individuals in charge of facilities orvessels to notify the National Response Center inthe event of any release of any hazardous substancesin quantities equal to or greater than specifiedamounts. 16 The definition of the term ‘‘release’encompasses: spilling, leaking, pumping, pouring,emitting, emptying, discharging, injecting, escap-ing, leaching, dumping, or disposing into the envi-ronment.17 In addition, Section 103(c) of CERCLArequired individuals to notify EPA of the existenceof any unauthorized hazardous waste facilities byJune 1981. The sites identified are part of EPA’sinventory of hazardous waste sites.

DOT Regulations: HLPSA and HMTA

Under regulations promulgated by DOT forpipelines and transportation-related sources, all car-riers are required to submit written reports to DOTdescribing any accidents within 15 days of theirdiscovery. DOT prepares annual reports whichsummarize the information reported under theseregulations. (See app. A.5 for data on numbers ofaccidents from these reports. )

DOT regulations under HLPSA specify that anyfailure in a pipeline system must be reported if therelease of a hazardous liquid (defined as petroleum,petroleum products, or anhydrous ammonia) re-sults in: 1) an explosion or fire not intentionallyset by the operator; 2) loss of 50 or more barrelsof liquid; 3) escape to the atmosphere of more than5 barrels a day of highly volatile liquids; 4) the deathof anyone; 5) bodily harm to anyone; or 6) esti-

l’L’nder CERCI,A, the term ‘‘hazmfous substances’ includes thosesubstances ct]~cred h} Se( tions 311 (b)(2)(A) and 307(a) of CWA, Sec-tion 102 of CER[; I.A, Section 3001 of RCRA, Section 112 of theClean Alr Act, and Sm-tion 7 of ‘1’SCA. Se(tion 102(a) of CIERC IAreyu i res F-PA to designate hazardous substances (in add it ion to thosespcclfied abo~x- ) and to establish reportable quant it ics for them, Sec-tion 102(b) specifics that a reportable quantity of 1 pound shall applyto all the haza~iou$ substances includccl in the statutes 1 isted abm’c(ex( ept for differ-ent quantltie~ established under Section 31 l(b)(4) ofCWA) unless and until F,P.A estahlishcs reportahlc quantitt regula-tions pursuant to %ction 1 02(a).

1‘SC( t ion 101 (22)

mated damage to the property of the operator orothers, or both, exceeding $5,000.18 In cases of sig-nificant damage, DOT must be notified immedi-ately by telephone. Criteria for such instances in-clude, but are not limited to, accidents resultingeither in damage exceeding $5,000 (as above) orin the ‘‘pollution of any stream, river, lake, reser-voir, or other similar body of water that violatedapplicable water quality standards, caused discol-oration of the surface of the water or adjoiningshoreline, or deposited a sludge or emulsion beneaththe surface of the water or on adjoining shore-lines. ”19 Similar conditions for groundwater are notspecified,

DOT regulations for HMTA contain similarprovisions. The hazardous materials coverage is ex-tensive.20 DOT must be notified by telephone atthe earliest practicable moment after any incidentin which: 1) a person is killed; 2) a person receivesinjuries requiring hospitalization; 3) estimated dam-age to the carrier or other property exceeds $50,000;4) fire, breakage, spillage, or suspected radioactivecontamination involving shipment of radioactivematerial occurs; 5) fire, breakage, spillage, or sus-pected contamination involving shipment of etio-logic agents occurs; or 6) in the judgment of thecarrier, the situation should be reported .21 In theevent of a discharge of a reportable quantity of ahazardous substance into navigable waters or alongadjacent shorelines, the National Response Cen-ter must be notified (see the discussion under CWAabove). As is true for the pipeline requirements,no reporting requirements are tied to groundwatercontamination other than the propertyvisions.

Regulatory Requirementsto Inventories

damage pro-

Related

Part C of SDWA requires EPA to establish reg-ulations specifying minimum requirements for StateUnderground Injection Control (UIC) Programs.

1849 c FR 195,50. A spe(ial accident reporting form has been d(.-~clop~d b~ DOT (110’1’ Form 7000-1).

1949 c FR 19.5. 52(a).

‘“See 49 C FR 172z 14q c FR 171 15, 1)0”1’ F{)rnl F 5800, 1 must also be submit te(l

within 15 days of disco~ery of the accident (see 4° (~ FR 171. 16).

38-799 0 - 84 - 7 : QL 3

154 • Protecting the Nation’s Groundwater From Contamination

Final Federal regulations were published on Feb- by rule to submit inventory information to theruary 3, 1982, and the States are now in the proc- States or EPA about their operations within oneess of developing UIC programs based on these re- year after they are authorized. The inventory formquirements. The States are required to establish a requires information on the facility name and loca-permitting program for injection wells. Most exist- tion, a legal contact, ownership, the nature and typeing wells are authorized by rule until a State pro- of wells, and the operating status of the wells .22gram is in place and site-specific permits are issued.One section of the Federal regulations requiresowners and operators of injection wells authorized ‘Z40 CFR 144.26.

.

Photo credit: State of Florida Depatiment of Environmental Regulation

Permitting rules developed under State Underground Injection Control Programs typically addressthe const ruc t ion and moni tor ing o f in jec t ion wel ls . - -‘ -

Ch. 6—Federal Efforts To Detect Groundwater Contamination ● 155

GROUNDWATER MONITORING AND SOURCES

This section summarizes Federal efforts relatedto monitoring specific sources of groundwater con-tamination. Three types of monitoring activities arediscussed:

1. monitoring requirements specified by Feder-al regulations that apply to facility owners andoperators;

2. monitoring conducted by Federal agenciesrelative to federally funded remedial pro-grams; and

3. monitoring conducted by Federal agencies aspart of hydrogeologic investigations related tocertain sources.

Table 30 summarizes these groundwater monitor-ing activities as they relate to Federal statutes andindicates the objectives of each program. AppendixE contains more detailed information about theseactivities for each source. In addition to the statu-tory provisions shown in table 30, other Federalgroundwater monitoring activities are also de-scribed below.

In summary, Federal monitoring requirementsare specified for certain sources in OTA Catego-ries 1, II, IV, and V (see ch. 2, table 5). But thereare inconsistencies in the coverage of the monitor-ing provisions for similar sources under differentprograms. Detailed guidance on the design of site-specific monitoring systems is not provided in theregulations. Although guidance manuals have beendeveloped by some agencies, the individuals whodraft and review permits (including exemptions)are responsible for ensuring the adequacy of site-specific systems; adequately trained personnel arein short supply. A detailed discussion of these con-clusions follows.

Monitoring Provisions ofFederal Programs

There are 10 regulatory programs authorized byFederal statutes that establish groundwater moni-toring provisions for sources of contamination.However, these programs address only certainsources in OTA Categories I, 11, IV, and V, and

monitoring is not required for many of them. Forexample, there are no requirements for non-pointsources in Category IV such as irrigation practicesand fertilizer applications. Groundwater monitor-ing requirements are not established for anysources in Categories III and VI.

In addition, monitoring requirements forsources within the same category are not uniform.Under the Toxic Substances Control Act (TSCA),for example, required groundwater monitoring forPCB disposal sites is limited to an initial collectionof background data. In contrast, the regulationspromulgated for radioactive disposal sites under theAtomic Energy Act (AEA) and for hazardous wastesites under the Resource Conservation and Recov-ery Act (RCRA) require monitoring during oper-ation and after closure.

For the most part, final Federal regulations donot contain explicit monitoring requirements (e. g.,numbers and locations of wells) in recognition ofthe site-specific nature of groundwater contamina-tion problems and the technical uncertainties asso-ciated with hydrogeologic investigations (see ch. 5).Because of the variety and complexity of factors thatmust be considered in designing a program to mon-itor (e. g., sample and analyze) groundwater qual-ity, Federal regulations establish monitoring objec-tives and general guidelines rather than detailedrequirements. 23

In the absence of detailed monitoring require-ments, several Federal agencies have developedmanuals to assist both permit (or license) writersand the regulated community. 24 The manuals pro-vide guidance on determining background levels,selecting parameters, designing a monitoring net-work (e. g., number and location of wells), select-ing appropriate sampling frequencies, and othertopics. Because monitoring programs do not specifydetailed requirements, the burden of ensuring that

Z~scC. ~, ~,, Fi~~ N~~ Rcwla[ ions ~Or 1.o\\I Lrvcl Radioact i~’e \$’astt’Disposal Facilities, 47 FR 57452, Dec. 27, 1982; Final OShl Rc’~u-lationj for Surface Coal hlining and Rcrlamat ion Opm-ations, 48 FR43974, Scpt. 26, 1983; and Final EPA Rc~ulations for HazardousJ$’astc I,and Disposal Facilities, 47 FR 32274, July 26, 1982,

24 ~’~~r ~.~amp]~., s{>c FYJ4, 1983c,, 1983f; and NRC, 1983a, 1983t~.

Table W.—Federal Groundwater Monitoring Provisions and Objectives

Statutory authority Monitoring provisionsa Monitoring objectives

Atomic Energy Act

Clean Water Act—Sections 201 and 405

—Section 208

Coastal Zone Management Act

Comprehensive EnvironmentalResponse, Compensation,and Liability Act

Federal Insecticide, Fungicide,and Rodenticide Act—Section 3

Federal Land Policy andManagement Act (andAssociated Mining Laws)

Hazardous Liquid PipelineSafety Act

Hazardous MaterialsTransportation Act

National EnvironmentalPolicy Act

Reclamation Act

Resource Conservation andRecovery Act

Groundwater monitoring is specified in Federal regulations for low-level radioactivewaste disposal sites. The facility license must specify the monitoring requirementsfor the source. The monitoring program must include:—Pre-operational monitoring program conducted over a 12-month period. Param-

eters not specified.—Monitoring during construction and operation to provide early warning of releases

of radionuclides from the site Parameter and sampling frequencies not-

specified.—Post-operational monitoring program to provide early warning of releases of radio-

nuclides from the site. Parameters and sampling frequencies not specified.System design is based on operating history, closure and stabilization of the site.

Groundwater monitoring related to the development of geologic repositories will beconducted. Measurements will include the rate and location of water inflow intosubsurface areas and changes in groundwater conditions.

Groundwater monitoring may be conducted by DOE, as necessary, part of remedialaction programs at storage and disposal facilities for radioactive substances.

Groundwater monitoring requirements are established on a case-by-case basis for theland application of wastewater and sludge from sewage treatment plants.

No explicit requirements are established; however, groundwater monitoring studiesare being conducted by SCS under the Rural Clean Water Program to evaluate theimpacts of agricultural practices and to design and determine the effectivenessof Best Management Practices.

The statute does not authorize development of regulations for sources. Thus, anygroundwater monitoring conducted would be the result of requirements establishedby a State plan (e.g., monitoring with respect to salt-water intrusion) authorized andfunded by CZMA.

Groundwater monitoring may be conducted by EPA (or a State) as necessary torespond to releases of any hazardous substance+ contaminant, or pollutant (asdefined by CERCLA).

No monitoring requirements established for pesticide users. However, monitoring maybe conducted by EPA in instances where certain pesticides are contaminatinggroundwater. b

Groundwater monitoring is specified in Federal regulations for geothermal recoveryoperations on Federal lands for a period of at least one year prior to production.Parameters and monitoring frequency are not specified.

Explicit groundwater monitoring requirements for mineral operations on Federal landsare not established in Federal regulations. Monitoring may be required (as a permitcondition) by BLM.

Although the statute authorizes development of regulations for certain pipelines forpublic safety purposes, the regulatory requirements focus on design and operationand do not provide for groundwater monitoring.

Although the statute authorizes development of regulations for transportation forpublic safety purposes, the regulatory requirements focus on design and operationand do not provide for groundwater monitoring.

The statute does not authorize development of regulations for sources.

No explicit requirements established; however, monitoring may be conducted, asnecessary, as part of water supply development projects.

Groundwater monitoring is specified in Federal regulations for all hazardous wasteland disposal facilities (e.g., landfills, surface impoundments, waste piles, andland treatment units).

to obtain background water quality data and to evaluatewhether groundwater is being contaminated.

To confirm geotechnical and design parameters and toensure that the design of the geologic repositoryaccommodates actual field conditions.

To characterize a contamination problem and to select andevaluate the effectiveness of corrective measures.

To evaluate whether groundwater is being contaminated.

To characterize a contamination problem and to select andevaluate the effectiveness of corrective measures.

To characterize a contamination problem (e.g., to assessthe impacts of the situation, to identify or verify thesource(s), and to select and evaluate the effectiveness ofcorrective measures).

To characterize a contamination problem.

To obtain background water quality data.

Table 30.—Federal Groundwater Monitoring Provisions and Objectives—continued

Statutory authority Monitoring provisions Monitoring objectives

Resource Conservation and I t ’Recovery Act (cent’d) These requirements specify the installation of at least one upgradient well and

–Subtitle C three downgradient wells. Samples must be taken quarterly during the first year andanalyzed for the National Interim Drinking Water Regulations, water quality indicatorparameters (chloride, iron, manganese, phenols, sodium, and sulfate), and indicatorparameters (pH, specific conductance, TOG and TOX). In subsequent years,each well is sampled and analyzed quarterly for the six background water qualityindicator parameters and semiannually for the four indicator parameters.Groundwater monitoring requirements can be waived by an owner/operator if awritten determination indicating that there is low potential for waste migration viathe upper-most aquifer to water supply wells or surface water is made and certifiedby a qualified geologist or engineer. The determination is not submitted to EPAfor verification or approval.

The monitoring requirements for a fully permitted facility are comprised of a three-partprogram:

—Detection Monitoring — Implemented when a permit is issued and there is noindication of leakage from a facility. Parameters are specified in the permit.Samples must be taken and analyzed at least semiannually. Exemptions fromdetection monitoring program may be granted by the regulatory authorityfor landfills, surface impoundments, and waste piles with double liners andleak detection systems.

—Compliance Monitoring — Implemented when groundwater contamination isdetected. Monitoring is conducted to determine whether specified concentrationlevels for certain parameters are being exceeded (levels are based on backgroundconcentrations, maximum contaminant levels specified by the National DrinkingWater Regulations [if higher than background], or an alternative concentrationlimit [established on a site-specific basis]). Samples must be taken and analyzedat least quarterly for parameters specified in the permit. Samples must alsobe analyzed for a specific list of 375 hazardous constituents (Appendix Vlll,40 CFR 261) at least annually.

—Corrective Action Monitoring – Implemented if compliance monitoring indicatesthat specified concentration levels for specified parameters are being exceeded(and corrective measures are required). Monitoring must continue until specifiedconcentration levels are met. Parameters and monitoring frequency not specified.

—Exemption from groundwater monitoring requirements may be granted by theregulatory authority if there is no potential for migration of liquid to theuppermost aquifer during the active life and closure and post-closure periods.

—Subtitle D Groundwater monitoring may be required by State solid waste programs. Federalrequirements for State programs recommend the establishment of monitoringrequirements.

Safe Drinking Water Act—Part C—Underground Groundwater monitoring requirements may be specified in a facility permit for

Injection Control Program injection wells used for in-situ or solution mining of minerals (Class Ill wells) whereinjection is into a formation containing less than 10,000 mg/l TDS. Parameters andmonitoring frequency not specified except in areas subject to subsidence orcollapse where monitoring is required on a quarterly basis.

Groundwater monitoring may also be specified in a permit for wells which injectbeneath the deepest underground source of drinking water (Class I wells).Parameters and monitoring frequency not specified in Federal regulations.

To obtain background water quality data and evaluatewhether groundwater is being contaminated.

To obtain background water quality data or evaluatewhether groundwater is being contaminated (detectionmonitoring), to determine whether groundwater qualitystandards are being met (compliance monitoring), and toevaluate the effectiveness of corrective action measures.

To evaluate whether groundwater is being contaminated.

Table 30.— Federal Groundwater Monitoring provisions and Objectives—continued

Statutory authority Montoring provisions Monitoring objectives

Surface Mining Control and Groundwater monitoring is specified in Federal regulations for surface and under-Reclamation Act ground coal mining operations to determine the impacts on the hydrologic balance

of the mining and adjacent areas. A groundwater monitoring plan must bedeveloped for each mining operation (including reclamation). At a minimum,parameters must include total dissolved solids or specific conductance, pH, totaliron, and total manganese. Samples must be taken and analyzed on a quarterlybasis.

Monitoring of a particular water-bearing stratum may be waived by the regulatoryauthority if it can be demonstrated that it is not a stratum which serves as anaquifer that significantly ensures the hydrologic balance of the cumulativeimpact area.

Toxic Substance Control Act—Section 6 Groundwater monitoring specified in Federal regulations requires monitoring prior to

commencement of disposal operations for PCBs. Only three wells are required ifunderlying earth materials are homogeneous, impermeable and uniformly sloping inone direction. Parameters include (at a minimum) PCBs, pH, specific conductance,and chlorinated organics. Monitoring frequency not specified.

No requirements are established for active life or after closure.Uranium Mill Tailings Federal regulatory requirements for active mill tailings sites are, for the most part, the

Radiation Control Act same as those established under Subtitle C of RCRA.C

Groundwater monitoring for inactive sites may be conducted if necessary to deter-mine the nature of the problem and for the selection of an appropriate remedialaction.

Water Research and The statute does not authorize the development of regulations for sources.Development Act Groundwater monitoring may be conducted as part of projects funded by the act.

To obtain background water quality data and evaluatewhether groundwater is being contaminated.

To obtain background water quality data

To obtain background water quality data, evaluate whethergroundwater is being contaminated, determine whethergroundwater quality standards are being met, andevaluate the effectiveness of corrective action measures.

To obtain background water quality data and to characterizea contamination problem.

a The ~onltoring Provisions presented in this table are either those specified by regulatmns for exlstlng and new sources; or for groundwater monitoring that may be conducted as Part of an lnvesti9atoW study or remedial

b~~~~~i$~o~~n~jacturers may be required by EpA t. subm{t g~oundwater monitoring data as pafi of the registration requirements for a pestlclde product to evaluate the potentlat for a pesticide tO COntaf_Ilinate groundwater.csee app. E.2 for a surnma~ of the differences between UMTRCA and RCFtA rnOnitOrh9 rfWJirernents.SOURCE Office of Technology Assessment,

Ch. 6—Federal Efforts To Detect Groundwater Contamination ● 159

1

-

- - - - - -- - - - - - - - - -

100 feet

Level of contamination ug/l (ppb):

❑ >100,000 10,000-100,000 1,000-10,000 100-1,000n

1-100

Cred/t Tewhey, et al , 7982

The site-specific nature of groundwater contamination problems requires that hydrogeologic investigations be tailoredto site conditions. At this site, the design of the monitoring system provided data that were used for determining

the vertical distribution of volatile organic chemicals.

site-specific monitoring satisfies program objectiveslies with the individuals responsible for drafting andapproving facility permits and licenses.

Although monitoring requirements generallylack specificity, some Federal regulations containmore detailed requirements than others. For ex-ample, the regulations developed under the Sur-face Mining Control and Reclamation Act(SMCRA) and TSCA specify the minimum pa-rameters that must be measured; and RCRA (Sub-title C), the Safe Drinking Water Act, SMCRA,and the Uranium Mill Tailings Radiation ControlAct (UMTRCA) specify monitoring frequencies.In addition, the number of monitoring wells isspecified in both the requirements for PCB disposalsites under TSCA and the interim status require-ments under Subtitle C of RCRA.

OTA’s study did not focus on the implementa-tion of Federal regulations (see OTA, forthcom-ing). A recent General Accounting Office (GAO)stud y of the RCRA interim status program in fourStates indicates a substantial amount of non-com-pliance with the groundwater monitoring require-ments (GAO, 1983). For example, in two of thefour States, 78 percent of the facilities required toconduct groundwater monitoring were not in com-pliance with the regulations (e. g., monitoring wellswere lacking and wells were not sited correctly).

Some of the non-compliance was related to the tech-nical complexities of locating and constructing wellsand the costs of well installation, sampling, andanalysis. The States also cited a number of prob-lems regarding enforcement of the RCRA regula-tions: lack of resources (e. g., staff); lack of techni-cal expertise and guidance; and confusion amongState agencies about jurisdiction over facility in-spections.

As indicated in table 30, the interim status re-quirements (which specify the number of monitor-ing wells) must be met by hazardous waste landdisposal facilities until a final permit is approvedeither by the Environmental Protection Agency(EPA) or a State with an EPA-approved RCRAprogram, EPA estimates that it will take approxi-mately 10 years to review and approve permits foran estimated 1,350 land disposal facilities nation-wide (GAO, 1983).

Certain facilities are exempted from ground-water monitoring requirements. The exemptionor waiver provisions noted below provide varyingdegrees of guidance for making exceptions on a site-by-site basis:

•Under the SMCRA regulations for coal min-ing, monitoring of a water-bearing stratummay be waived by the regulatory authority if

160 . Protecting the Nation’s Groundwater From Contamination

●

●

it is determined that the stratum is not an aqui-fer that significantly ensures the hydrologicbalance of the ‘ ‘cumulative impact area.”25

The waiver determination is based on infor-mation developed as part of an assessment (re-ferred to as a ‘ ‘probable hydrologic conse-quences determination”) regarding whetherthe mining operation will adversely affect thehydrologic balance; cause surface or ground-water contamination; and affect groundwateravailability, water quality, or a variety of otherfactors. 26

Under the RCRA Subtitle C interim statusprogram, owners and operators of land dis-posal facilities can waive groundwater moni-toring requirements if they obtain a writtendetermination, certified by a qualified geologistor geotechnical engineer, that there is low po-tential for water migration from the facility viathe uppermost aquifer to water supply wellsor surface water. The waiver document is re-tained at the facility; it is not submitted to EPAfor review until the facility is called in for finalpermit review, which may be as long as 10years. The evaluation of the potential for mi-gration must be based on an assessment of thewater balance, unsaturated and saturated zonecharacteristics, and proximity of the facility towater supply wells or surface water. 27RCRA Subtitle C regulations for fully per-mitted land disposal facilities also contain ex-emption provisions. Groundwater monitoringmay be waived by the regulatory authority forfacilities if it is determined that there is no po-tential for migration of liquids to the upper-most aquifer during active, closure, and post-closure periods, Any predictions made aboutmigration potential must be based on assump-tions that maximize the rate of liquid migra-tion.28 In addition, at landfills, surface im-poundments, and waste piles where doubleliners and leak detection systems are installed,exemptions from the detection monitoring pro-

ZSTh e cumulative impact ~rea is the area within which the proposedmining operation may interact with all other anticipated mining. (30CFR 701.5, 48 FR 43985, Sept. 26, 1983).

ZGS ee 30 CFR 780,21, 48 FR 43985, Sept. 26, 1983. The regula-tions specify the types of information that must be submitted to sup-port this,

2740 CFR 265.90(c),ZS40 CFR 264.90(b)(4).

gram may be granted. A previous OTA studyof the hazardous waste land disposal technol-ogies specified in the RCRA regulations con-cluded that the lack of groundwater monitor-ing at double-lined facilities does not protectgroundwater because such systems are not fail-safe (OTA, 1983).

Monitoring and Remedial ActionPrograms

In addition to the monitoring requirementsdescribed in the previous section, groundwatermonitoring may also be conducted as part of a fed-erally funded remedial action effort-e. g., to char-acterize a contamination problem and to evaluateand select among alternative corrective measures.

Table 30 indicates that monitoring is addressedby programs authorized by AEA, the Comprehen-sive Environmental Response, Compensation, andLiability Act (CERCLA), and UMTRCA. Likethe requirements discussed above for permitted orlicensed facilities, explicit groundwater monitoringrequirements are not specified under these pro-grams. Such an approach is consistent with the site-specific nature of groundwater contaminationproblems.

Other Monitoring Activities

A number of Federal agencies are undertakingadditional groundwater monitoring programs with

Photo credit: U.S. Environmental Protection Agency

Hydrogeologic investigations, including soil testing asshown, provide important input to the evaluation and

selection of corrective actions.

Ch. 6—Federal Efforts To Detect Groundwater Contamination Ž 161

respect to specific sources of contamination. Someof this work focuses on some of the sources in Cat-egories IV and VI for which no monitoring re-quirements are established (e.g., fertilizer applica-tions, animal feeding operations, and naturalleaching).

Additional monitoring has been undertaken bythe following Federal agencies:

● The Soil Conservation Service (SCS), in con-junction with the States, private institutions,and other Federal agencies such as the Agri-cultural Stabilization and Conservation Serv-ice, is involved with several contamination in-vestigations under the Rural Clean WaterProgram authorized by Section 208(j) of theClean Water Act relating to agricultural oper-ations (table 30). The groundwater data be-ing collected will be used to support the de-velopment of Best Management Practices. 29

● EPAs Office of Pesticide Programs has beeninvolved with several groundwater monitor-ing studies. For example, the office conductedmonitoring studies where contamination frompesticide applications was detected. The stud-ies focused on aldicarb and DBCP. In addi-tion, EPA has been evaluating groundwaterquality and the fate and transport of pesticidesin several States (e. g., Wisconsin, Georgia,and California) in conjunction with the States,local governments, universities, and other Fed-eral agencies (e. g., USGS). The studies focuson those pesticides used in each State that,based on their chemical properties, have thegreatest potential to leach into groundwater

~qcjne s~u~}, ~~ IJ~~CaStcr count ),, PA, is concerned with contamina -

t ion result Ins from w]ur( es such as animal wastes and fertilizer andpcsticidc applic-ations. Groundwater is being monitored to cstahlishbac kgrounc] lmels and to aswss the impacts of the Best !tIanagcmentPractices (USDA, 1982) A similar -xuct>’ is being undertaken in easternSouth Dakota (South I]akota State’ Coordinating Committm. 1982).

●

●

(Severn, et al., 1983). EPA and other Federalagencies have been working together on mon-itoring related to the formulation and imple-mentation of the National Pesticide MonitoringPlan (NPMP) under the Federal Insecticide,Fungicide, and Rodenticide Act.30 A programdirected exclusively at groundwater, however,has not been implemented .31The Bureau of Reclamation, in conjunctionwith SCS and USGS, is participating in mon-itoring efforts as part of the Colorado RiverBasin Salinity Control Program.32 The sourcesof contamination are underlying geologic for-mations containing salts, which are beingleached due to infiltration of excessive amountsof irrigation water. The groundwater data col-lected will be used in the development of ir-rigation water management strategies.USGS has programs devoted to three specificsources of groundwater contamination: 1 ) coaland oil shale development, 2) radioactive wastedisposal, and 3) toxic waste disposal (see pre-ceding section on Federal Programs) Each in-volves groundwater monitoring. For example,as part of the coal and oil shale programs,USGS is collecting data at thousands of min-ing areas. Under the Toxic Wastes-Ground-water Contamination Program, field investiga-tions are being conducted on the mobility andfate of organic substances in groundwater.33

J o . % ction 20(b) and (()s I For add it ion~ d iscusslon ahut the NPM P St>t’ h-at ional Re\earch

Council, 1978.+ZTh<, c:olor~o R i~,er Basin Sal lnlt f, Con[ ml Act Of 1 !] ~ 4 ( I>Ub] i(

I.aw 93-320) authorizes construction, operation, and maintenan~ t,of certain works to cent rol water salinit}, in the (3010rado Ri\er BasinThe program is extensive, cm”cnng se~’en States (California, Arizon,l.-New \fexico, Colorado, Nc\’ada, Utah, and \$’yoming) di~ided int[)numerous units. Othcr Federal agencies such as the ASricultur.dStabilization and Conscr\ation Ser\ice, EPA, the Bureau of LandManagcrncnt, and the Fish and Wildlife Service are involted in varlouiaspects of the projcrt, As an example, see DOI, 1983,

JISC<. ~:hasc.. ct al. , 1 ~8~}.

CHAPTER 6 REFERENCES

Absher, S., Office of Solid Waste, U.S. Environmental Baltay, P. Office of Drinking Water, U.S. Environ-Protection Agency, personal communication, August mental Protection Agency, personal communication,1983. Sept. 13, 1984.

162 ● Protecting the Nation’s Groundwater From Contamination

Chase, E., J. Moore, and D. Rickert, “Water Re-sources Division in the 1980’s—A Summary of Activ-ities and Programs, USGS Circular 893, 1983.

Cohen, P., Chief Hydrologist, U.S. Geological Survey,Testimony before the Subcommittee on Natural Re-sources, Agriculture Research and Environment,Committee on Science and Technology, U.S. Houseof Representatives, May 19, 1983.

Daley, P. S., Director of Environmental Policy, Depart-ment of Defense, Testimony before the Subcommit-tee on Investigations and Oversight, Committee onPublic Works and Transportation, U.S. House ofRepresentatives, Aug. 10, 1983.

General Accounting Office (GAO), “Solid Waste Dis-posal Practices, “ July 23, 1981.

General Accounting Office (GAO), “Interim Report onInspection, Enforcement, and Permitting Activitiesat Hazardous Waste Facilities, GAO/RCED-83-241, Sept. 21, 1983.

Hester, F. E., Deputy Director, Fish and Wildlife Serv-ice, “Hazardous Waste Sites on Service Lands, ”memorandum, Sept. 22, 1983.

Kimm, V. J., Office o ‘Drinking Water, U.S. Environ-mental Protection Agency, Testimony before theSubcommittee on Health and the Environment,Committee on Energy and Commerce, U.S. Houseof Representatives, July 28, 1983.

Langford, R. H., U.S. Geological Survey, Testimonybefore the Subcommittee on the Environment andthe Atmosphere, Committee on Science and Tech-nology, U.S. House of Representatives, September1977.

Lawton, R, H., Deputy Director, Energy and MineralResources, Bureau of Land Management, personalcommunication, Nov. 9, 1983.

National Research Council, Pesticide Decision Making(Washington, DC: National Academy of Sciences,1978).

Nuclear Regulatory Commission (NRC), “Guidelinesfor Groundwater Monitoring at In-Situ UraniumSolution Mines, Office of Nuclear Regulatory Re-search, June 1983a.

Nuclear Regulatory Commission (NRC), “SubsurfaceMonitoring Program for Sites for Disposal of Low-Level Radioactive Waste, ” NUREG/CR-3164,April 1983b.

Office of Technology Assessment, Technologies andManagement Strategies for Hazardous Waste Con-troZ, OTA-M- 196 (\ Washington, DC: U.S. Govern-ment Printing Office, March 1983).

Office of Technology Assessment, “Cleanup of Uncon-trolled Hazardous Waste Sites Under Superfund,forthcoming.

Offutt, C., Office of Pesticide Programs, U.S. Environ-

mental Protection Agency, personal communication,Sept. 30, 1983.

Severn, D. J., C. K. Offutt, S. Z. Cohen, W. L. Bur-nam, and G. J. Burin, ‘‘Assessment of GroundwaterContamination by Pesticides, ” Hazard EvaluationDivision, Office of Pesticide Programs, U.S. Envi-ronmental Protection Agency, June 7, 1983 (pre-pared for the FIFRA Scientific Advisory Panel Meet-ing, June 21-23, 1983, Arlington, VA).

South Dakota State Coordinating Committee, “Oak-wood Lakes—Poinsett, Comprehensive Monitoringand Evaluation Plan, Rural Clean Water Program,July 1982.

Tewhey, J. D., J. E. Sevee, and R. L. Fortin, “Sil-resim: A Hazardous Waste Case Study, The Pro-ceedings of the National Conference on Managementof Uncontrolled Hazardous Waste Sites, 1982.

U.S. Department of Agriculture, “ComprehensiveWater Quality Monitoring and Evaluation of BestManagement Practices in the Conestoga HeadwatersProject, Rural Clean Water Program, ” Soil Conser-vation Service, October 1982.

U.S. Department of the Interior, “Colorado RiverWater Quality Improvement Program, Bureau ofReclamation, Denver, CO, January 1983.

U.S. Environmental Protection Agency, “DraftGroundwater Protection Strategy, ” December1983a.

U.S. Environmental Protection Agency, “SupportingStatement for OMB Clearance Package for NationalInorganic and Radionuclide Survey, ” TechnicalSupport Division, Office of Drinking Water, Nov.11, 1983b.

U.S. Environmental Protection Agency, “Inventory ofOpen Dumps, ” Office of Solid Waste, May 1983c.

U.S. Environmental Protection Agency, “Surface Im-poundment Assessment, National Report, ” draft,Office of Drinking Water, July 1983d.

U.S. Environmental Protection Agency, “GroundwaterMonitoring Guidance for Owners and Operators ofInterim Status Facilities, ” Office of Solid Waste,SW-963, March 1983e.

U.S. Environmental Protection Agency, “RCRA DraftPermit Writer’s Manual-Groundwater Protec-t i o n , Office of Solid Waste, Apr. 29, 1983f.

U.S. Geological Survey, Statement before the Subcom-mittee on Toxic Substances and EnvironmentalOversight, Committee on Environment and PublicWorks, U.S. Senate, July 28, 1982.

U.S. Geological Survey, “Regional Aquifer-SystemAnalysis Program, ” USGS, W-249-84, 1984.

Westrick, J., Office of Drinking Water, U.S. Environ-mental Protection Agency, personal communication,Sept. 7, 1984.

Chapter 7

State Efforts To DetectGroundwater Contamination

Contents

Page

Chapter Overview.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165

State

StateStateState

Detection Programs for Sources of Contamination . . . . . . . . . . . . . . . . . . . . . . . . 165

Inventory and Monitoring Activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166Inventory Activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166Monitoring Activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167

Formal Procedures for Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168Formal Procedures for Obtaining Groundwater Quality Information . . . . . . . . . . . . . . . . . . 168Formal Procedures for Using Monitoring Data.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169

Use, Preferences, and Problems With Techniques forHydrogeologic Investigations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169

Use and Preferences for Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169Problems With Hydrogeologic Investigations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171

Chapter 7 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172

31.

32.

33.

OTA State Survey Responses: Number of States Conducting Inventories andMonitoring Different Categories of Sources of PotentialGround water Contamination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167OTA State Survey Responses: State Use and Preferences for Techniques forHydrogeologic Investigations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170OTA State Survey Responses: State Problems With ImplementingHydrogeologic Analyses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171

FIGUREFigure’ No, Page

4. OTA State Survey Responses: Number of States With Programs To DetectGroundwater Contamination From Selected Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166

Chapter 7

State Efforts To DetectGroundwater Contamination

CHAPTER OVERVIEW

In this chapter, State responses to survey ques-tions about their efforts to detect groundwater con-tamination are presented. (See the section OTAState Survey in ch. 4 for guidance in interpretingsurvey results. ) The following topics are discussed:

●

●

●

●

sources of groundwater contamination forwhich the States have detection programs;State inventory and monitoring activities;formal procedures for monitoring; andState use, preferences, and problems with tech-niques for hydrogeologic investigations.

Additional information on State strengths, prob-lems, and types of desired Federal assistance relatedto detection is found in chapter 4. The techniquesused for detection activities are discussed in chapter 5.

The conclusions drawn in this chapter follow.

The States are working to detect contaminationprincipally through inventories, source monitoring,water supply monitoring, and ambient water qual-ity monitoring. Inventory and monitoring effortsare focused on point sources related to waste dis-posal and large public water supplies. Not all po-tential sources of contamination of water suppliesare being monitored.

Most States are working to improve monitoringand detection but are constrained primarily by in-stitutional or technical factors often related to fund-ing (e. g., technical expertise, manpower, availabili-ty of equipment, and the high cost of applyingavailable technology). The States also experiencetechnical constraints in conducting hydrogeologicanalyses because of the uncertainties inherent ingroundwater contamination investigations (see ch. 5).

State detection programs are, for the most part,in the early stages of development. Some Stateshave made more progress than others. Much of theactivity is handled on an ad hoc case-by-case basis,relying on the best professional judgment of staff.This practice is somewhat troublesome for theStates because many have difficulty attracting andretaining staff with sufficient technical expertise.

All but five States perceive weaknesses with theirdetection programs or opportunities for Federal as-sistance in this area including: funding, technicalassistance, and research and development, as dis-cussed in chapter 4.

STATE DETECTION PROGRAMS FOR SOURCESOF CONTAMINATION

Many States have detection programs for a va- These programs involve primarily inventory activ-riety of sources, as shown in figure 4. The highest ities or actual monitoring of groundwater qualitynumber of States have programs to detect contam- and are discussed in the next section. Other detec-ination from surface impoundments and landfills tion activities would include inventory control (i. e.,(both hazardous and sanitary). Generally, more accounting for all material) and/or testing the in-State programs are associated with OTA source tegrity of facilities.Categories I, II, and 111 than with IV, V, and VI.

165

166 Protecting the Nation’s Groundwater From Contamination

Figure 4.—OTA State Survey Responses: Number of States With Programs To Detect GroundwaterContamination From Selected Sources

— D e t e c t i o n

C o r r e c t i o n

- - - - P r e v e n t i o n

See fig. 2 for footnotes a through g.

SOURCE: Otflce of Technology Assessment.

STATE INVENTORY AND MONITORING ACTIVITIES

State Inventory Activities this information can assist in identifying potentialproblem sources:

Inventories are used primarily to locate sites or ● Forty-seven States conduct inventories of po-facilities with the potential to contaminate ground- tential sources of contamination. As shown inwater. A few States have conducted inventories of table 31, the States have inventoried differentsubstances used in the States that could potentially sources. Most of these efforts have not beencontaminate groundwater (e. g., pesticides, herbi- comprehensive, i.e. , many potential sourcescides, and hazardous substances). Specific contam- of contamination identified by OTA’s analy -ination incidents are also recorded by some States; sis have not been inventoried.

Ch. 7—State Efforts To Detect Groundwater Contamination . 167

Table 31.—OTA State Survey Responses: Number ofStates Conducting Inventories and Monitoring

Different Categories of Sources of PotentialGroundwater Contamination

SourceSource categorya Inventories monitoring

l— Sources designed todischarge substances . . . . . . 26 27

ll— Sources designed to store,treat, and/or dispose ofwastes c . . . . . . . . . . . . . . . . . . . 37 42

ll— Sources designed to storenon-wastes d ... , ., . . . . . . . . . 8 3

Ill— Sources designed to transportor transmit substances . . . . . 1 0

IV— Sources that dischargesubstances as a consequenceof other planned activities . . . 6 10

V— Sources that provide aconduit g . . . . . . . . . . . . . . . . . . 2 0

Vl— Naturally occurring sourcesh . 1 3Not specified . . . . . . . . . . . . . . . . . . 6 4None . . . . . . . . . . . . . . . . . . . . . . . . . 3 1Total number of States . . . . . . . . . . 47 49

‘The states cflci not use consistent terminology In response to questlcms abouttheir Inventory and monltor!ng actlwtles, responses were classified according toOTA source categories (see ch 2). Examples of the various types of Stateresponses included In each category are Ilsted in the respective footnotes,

bunderground Injection wells, surface treatment and disposal systems, waStewaterdisposal, sept!c systems, sludge disposal, and drainage wells

clndustrlal waste management areas, hazardous waste SlteS, mIJfllCIPal waste sites,lagoons, waste treatment systems, open dumps, landfills, waste storage ponds,and RCRA s~tes

dunderground storage tanks, salt storage and Industrial sitese Tr a n s p o f la t l on fac l l l t l esf Urban Clweloprnent, agnculturaf practices, 011 and gas development. related

sources, and mining operationsgWells, springs and active and abandoned wellshNat ural contamination and saltwater lfltruSIOn

SOURCE Off Ice of Technology Assessment

• The highest number of States inventory Cat-egory II sources (designed to store, treat, and/or dispose of substances). Within this category,inventories are concentrated on waste-relatedfacilities. More than one-half the States alsoinventory Category I sources (designed to dis-charge substances). Relatively few States haveconducted inventories of sources in other OTAcategories.

State Monitoring Activities

Having identified potential sources of contamin-ation and, in some cases, substances that are po-tential contaminants, the States may monitor todetermine whether groundwater is actually contam-inated. Monitoring may be directed at variouspoints of concern: potential sources, water supplies,and ambient conditions.

Monitoring Potential Sources of Contamination

●

●

●

Forty-nine States monitor sources for potentialcontamination. Most of these efforts focus onCategory II waste-related facilities or on otherpermitted or licensed activities, including manyCategory I sources, as shown in table 31.

Monitoring potential sources of contaminationis generally not comprehensive. All facilities andactivities of a particular source type are not moni-tored, and some sources are not monitored at all.For example, four States monitor only selectedfacilities within various source categories, andone State monitors only permitted or licensed fa-cilities. Sources that are not monitored by at leastone State include: direct discharges to ground-water through sinkholes, abandoned hazardouswaste sites that are not currently eligible for cor-rective action funding under the ComprehensiveEnvironmental Response, Compensation, andLiability Act (CERCLA), and many abandonedsolid waste sites.

The sources of priority concern vary among theStates. The highest number of States give prior-ity to Category II sources, particularly hazard-ous waste sites and substances and landfills.

Monitoring Water Supplies:

●

●

All public drinking water supplies are monitoredfor compliance with the Safe Drinking WaterAct. Ten States monitor private wells either onrequest or in relation to potential sources of con-tamination. Few States monitor industrial watersupplies (three) or agricultural supplies (two).

In general, priority is given to public drinkingwater supplies. The attention given to monitor-ing private wells and non-drinking water suppliesvaries. One State gives priority to private wellsand one State to supplies other than drinkingwater.

Monitoring Ambient Quality

● In general, 38 States monitor ambient groundwa-ter quality or are in the process of developingsuch programs. These programs include: relyingon U.S. Geological Survey (USGS) monitoringof wells; limited monitoring of new wells; moni-toring for background quality only in relation topermit activities; using a statewide monitoring

168 ● Protecting the Nation’s Groundwater From Contamination

network; or monitoring special sites or regionsof concern. Most State ambient quality monitor-ing to ascertain existing groundwater contamina-tion appears limited.

● Nine States rely on USGS monitoring programsfor information about ambient water quality.However, USGS recognizes that these are inade-quate to detect contamination from organicsubstances and trace metals and to provide in-formation on key chemical parameters such asdissolved oxygen and microbial activity (Cohen,1983). ‘

● Eight States are in the process of developingmonitoring programs to improve their informa-tion on ambient quality. For example, one Stateis planning to expand monitoring for pesticidesand radiological substances, particularly in moredensely populated areas.

● Only one State explicitly reported having a state-wide groundwater monitoring network. OneState has an ambient water quality network forthe most populous part of the State. Anothermonitors selected areas with suspected or knowngroundwater quality problems. Four other Statesfocus on particular sites or regions of concern.

‘ Engerg, 1983, also notes inadequate data collection for pesticides,radionuclidm, and microbial activity in groundwatm in Nebraska. Sim-ilar inadequacies are being found in the seven other States where LTSGSis conducting appraisals of g-oundwater quality data (Ragone, 1983).

FORMAL PROCEDURES FOR MONITORING

Detection programs involving groundwater mon-itoring require the systematic collection and analy-sis of a great deal of technical data, as discussedin chapter 5. The OTA survey asked the Statesabout their use of formal policies, procedures, andguidelines for obtaining groundwater quality infor-mation and using Monitoring data. Survey re-sponses further demonstrate the different approachesthat States are taking to detect contamination.

Many States have not formalized their approachto all activities related to obtaining or using moni-toring data; rather, they rely on case-by-case eval-uations and their best professional judgments.

Others have formalized policies, procedures, orguidelines for these activities, but they are not nec-essarily alike (i. e., different monitoring componentsare included by different States, and even when theStates include the same individual components,they do so in different ways).

Formal Procedures for ObtainingGroundwater Quality Information

Most States have formalized approaches to col-lecting and analyzing groundwater quality samples.At least 17 States rely on Federal guidelines. A few

Ch. 7—State Efforts To Detect Groundwater Contamination ● 169

States prepare their own protocol manuals (e. g.,seven States for collecting samples and eight Statesfor analyzing samples).

To determine which parameters to measure ata particular site, many States also rely on Federalguidance through lists prepared for various regu-latory programs and laws (e. g., the National In-terim Primary Drinking Water Regulations, coalmining regulations, and the list of Priority Pollut-ants). Reliance on Federal lists is a problem for oneState, which commented that routine sampling asrequired in the Safe Drinking Water Act neededto be changed to cover substances more commonlyused in the State.

Formal Procedures for UsingMonitoring Data

Forty-three States make routine comparisons ofmonitoring data with quality standards. Of the 23States that described their efforts, 13 make routinecomparisons only for drinking water; 6 conductroutine comparisons in relation to specific facilitiesor permit programs for activities with the poten-tial to contaminate groundwater; 2 make routinecomparisons for all monitoring wells; and 2 makecomparisons only during special studies (e. g., con-tamination investigations or public health studies).

Twenty-two States have formal policies on theconfidentiality of the groundwater information thatthey collect. State policies on public accessibilityto groundwater information vary. For example, insome States information is confidential only if litiga-tion or a trade secret is involved. Information maybe confidential in some States if requested by land-owners. In one State, information is confidentialonly if pollution is confined to the property of thepolluter. One State noted that essentially nothingis confidential.

All but one State detect groundwater contamina-tion by responding to complaints of suspected con-tamination. About one-half of the States have for-mal policies, guidelines, or procedures for thispurpose. Types of formal policies vary, rangingfrom record-keeping activities to policies that areincorporated in regulatory programs for particu-lar sources. Four States have established, or are inthe process of developing, special groundwater con-tamination response programs.

A few States noted problems in responding tocomplaints about possible contamination. Theproblems primarily reflect limited resources for theeffort. In one State only a fraction of the complaintresponses were timely. Another State noted that itsometimes charges for sample analyses.

USE, PREFERENCES, AND PROBLEMSWITH TECHNIQUES FOR HYDROGEOLOGIC

INVESTIGATIONS

Use and Preferences for Techniques

The use and preferences of the States for varioustechniques to collect hydrogeologic data are shownin table 32. Most States use a variety of techniquesto conduct hydrogeologic analyses. Although someStates use a technique routinely, others may useit only in special circumstances or not at all. Cer-tain techniques are notable for their routine use bymost states (e.g. , unpublished and published stud-ies, mapping, and excavations and drilling). Othertechniques stand out because they are not used

routinely by many States (e. g., remote sensing withsatellites, hydraulic testing tracer tests, contami-nant transport modeling, and ground-penetratingradar), but some States apply these techniques inspecial circumstances.

Only excavations and drilling test wells are pre-ferred by more than one-half the States. Reasonsgiven for preferring particular techniques include:cost, time, availability of equipment, and techni-cal capability (relates to ease of use, staff expertiserequired, reliability and accuracy, value of results,

38-799 n - 84 - 8 : QI, 3

170 . Protecting the Nation’s Groundwater From Contamination

Table 32.—OTA State Survey Responses: State Use and Preferences for Techniquesfor Hydrogeologic Investigations

Number of States:

Using in HavingUsing special preference

Categories of techniques routinely circumstances for use

Unpublished and published information:(Existing studies). . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Remote sensing:

Aerial photography . . . . . . . . . . . . . . . . . . . . . . . . . . .Satellite imagery . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Excavations and drilling:(Test wells) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .(Stratigraphy) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Geologic sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Hydrometeorologic measurements:

(Climate, l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Surface hydrology:

Hydraulic measurements (watershed analysis) . . . .Surface water sampling . . . . . . . . . . . . . . . . . . . . . . .

Subsurface hydrology:Potential measurements. . . . . . . . . . . . . . . . . . . . . . .Hydraulic testing:

(Trace - tests) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .(Aquifer tests) . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Laboratory testing . . . . . . . . . . . . . . . . . . . . . . . . . . . .Water quality sampling. . . . . . . . . . . . . . . . . . . . . . . .

Hydrogeologic systems analysis:Modeling

(Groundwater flow modeling). . . . . . . . . . . . . . . . .(Contaminant transport modeling ) . . . . . . .. . . . .

Geostatistics . . . . . . :........ .Surface geophysics:

Electrical resistivity andelectromagnetic conductivity(Surface potential) . . . . . . . . . .

Ground-penetrating radar(Surface-penetrating radar) . . .

Shallow geothermic method(Temperature). . . . . . . . . . . . . .

Subsurface (borehole) geophysicsHydrogeochemistry-(sniffers)d . . .

-.. . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . .

4442

212

4039

N Qb

28

28NQ

NQ

325

NQNQ

37

2826

16

19NQ

NQ

2420

90

o

0NQ

NQ

419

NQNQ

11 34 53 35 3

NQ NQ NQ

10 32 7

3 24 1

7 18 021 24 13

7 23 1aThe techniques listed are the Same as those presented in ch. 5. The terminology used in the OTA State Suwey iS shown inparentheses, indifferent

%he OTAStatisurvey did not specifically question States about their use and preference for this technique.cThe States Were questioned about subsurface geophysics in general Informationon specific techniques was not requested.dsniffers were ttle only hydrog~tlemistry technique included in the survey. More conventional measurements (e.9., PH) are probably

used by more States with greater frequency,

SOURCE: Of fic~ of Technology Assessment.

Ch. 7—State Efforts To Detect Groundwater Contamination ● 171

Photo credit: ~atiorral Water Well Association

Although many techniques are available for conductinghydrogeologic investigations, some techniques are not

used routinely such as ground-penetrating radar.

and applicability to hydrogeologic conditions).These factors influence both the choice of tech-niques for hydrogeologic investigations that a Stateconducts and the decision on what the State canreasonably require under its regulatory authority.

Problems With HydrogeologicInvestigations

Forty-nine States described problems in conduct-ing hydrogeologic analyses. Table 33 classifies theseproblems with analyses as technical, institutional,or legal. General findings from this table are below:

● The States experience a variety of problemsin conducting hydrogeologic analyses, and dif-ferent States have different problems.

● The most common problems are institutional.Funding for analyses is a problem for the high-est number of States. Other frequently citedinstitutional problems, often related to fund-

Table 33.—OTA State Survey Responses: StateHProblems With ImpIementing ydrogeologic

Analyses

Number of Statesa/Types of problems

Technical problems:13 Intensive data requirements for particular techniques

and lack of data16 Difficulties in interpreting data and with accuracy of

techniques (e.g., for dealing with multiple sourcesand/or complex hydrogeologic environments)

4 Lengthy time required to conduct analyses1 Timing constraints (e.g., seasonal limitations with

some equipment)2 High expense and questionable cost effectiveness4 Limited technology (e.g., most organic contaminant

analyses require collection of water qualitysamples; monitoring techniques are inadequate forkarst environments; and contaminant transportmodels are not well developed)

Institutional problems:19 Lack of manpower36 Lack of funds27 Inadequate technical expertise (e.g., difficulty

attracting and/or retaining qualified professionals)13 Unavailability of equipment2 Over-reliance on consultants1 Inadequate laboratory capabilities2 Difficulties in keeping up with technical

advancements2 Lack of interagency coordination1 Lack of public confidence in the State

Legal problems:2 Water rights conflicts

10 Difficulties in obtaining site access (e.g., permissionto drill off site)

1 Confidentiality of information (e.g., proprietarypumpage records)

1 Difficulties in recovering costs of investigations frompolluters

aForty.nine States responded to this question

SOURCE: Office of Technology Assessment

●

●

ing, include inadequate technical expertise,lack of manpower, and unavailability ofequipment.The most common technical problems include:difficulties in interpretation of data, inaccuracyof techniques, and intensive data requirementsfor particular techniques. Four States noteda lack of technology to investigate particularcontaminants or hydrogeologic environments,and seven others noted a need for advance-ments in detection techniques.Legal problems with the use of hydrogeologictechniques were reported by relatively fewStates. The most common is obtaining accessto areas to drill and investigate possible con-tamination.

172 ● Protecting the Nation's Groundwater From Contamination

CHAPTER 7 REFERENCES

Cohen, P., Chief Hydrologist, U.S. Geological Survey, Quality in Nebraska, ” U.S. Department of the In-Statement before the Subcommittee on Natural Re- terior, U.S. Geological Survey Open-File Report 83-sources, Agriculture Research, and Environment, 128, 1983.Committee on Science and Technology, U.S. House Ragone, S., U.S. Geological Survey, personal commu-of Representatives, May 19, 1983. nication, Mar. 25, 1983.

Engerg, R. A., “Appraisal of Data for Ground Water

Correction

Chapter 8

The Correction of GroundwaterContamination: Technologies and

Other Alternatives

Contents

Page

Chapter Overview.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177

Selecting a Corrective Action Strategy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177Technical and Non-Technical Conditions Determining the Applicability of

Corrective Action Alternatives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179Performance of Corrective Action Alternatives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183

Stage of Development of Corrective Action Alternatives . . . . . . . . . . . . . . . . . . . . . . . . 192

Chapter 8 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193

TABLESTable No. Page

34. Corrective Action Alternatives: Techniques and Descriptions . . . . . . . . . . . . . . . . . . . . . 17835. Corrective Action Techniques: Objectives, Performance, and Status . . . . . . . . . . . . . . . 185

Chapter 8

The Correction of GroundwaterContamination: Technologies and

Other Alternatives

CHAPTER OVERVIEW

Correction is broadly defined in this study to in-clude reducing concentrations of, eliminating, orotherwise controlling contaminants in groundwater.This chapter describes the principal technical andmanagement options available for corrective actionand analyzes them in terms of their applicabilityunder different conditions, performance, and stageof development. Technical options are categorizedunder containment, withdrawal, treatment, and in-situ rehabilitation; management options, whichmay have technical components, are a fifth cate-gory. These categories generally reflect differences

among alternatives in terms of how and wheresubstances are acted upon.

Although there is a wide variety of alternativesfor correcting groundwater contamination, their ef-fectiveness is uncertain. Experience with them islimited, their applicability can be determined onlyin relation to given site conditions, and their per-formance over the long term is an unknown. Sometechnologies are new, but many are commerciallyavailable, having been developed for surface water,industrial, and other purposes.

SELECTING A CORRECTIVE ACTION STRATEGY

The principal options available for corrective ac-tion are shown in table 34. Although there is a widevariety of options, no one alternative is capable ofresponding to all conditions likely to be found ata groundwater contamination site. Rather, optionstend to address specific hydrogeologic components,objectives, or steps (refer to table 24) in a correc-tive action process. For example, options in thetreatment category assume that contaminated wateris already in the treatment system and do not ad-dress how it will be removed from the subsurface(e.g., with withdrawal methods). Thus, in practice,alternatives are combined in a corrective action

strategy to take advantage of their complemen-tarities.

Selecting a combination of alternatives involvesmaking tradeoffs—among time, costs, perform-ance, and other factors—and not all tradeoffs arequantifiable. As yet, there is no standard approach

to formulating corrective action strategies, in largepart because groundwater contamination is site-spe-cific and experience is limited. Experts contactedfor this study stressed the need for a more scientif-ic and less ad hoc approach in applying and tailor-ing combinations of techniques to sites. Such amethodology would systematically consider site con-ditions, resource constraints, and performance ob-jectives in evaluating and selecting among alter-natives.

Experience appears to show that the selection ofa corrective action strategy is not primarily basedon lowest costs. Rather, selection appears to bebased on how quickly methods can be imple-mented, how quickly they are expected to achievedesired results, and the uncertainty associated withtheir performance. Considerations in selecting tech-niques, which have been identified on the basis ofcase histories, include: the potential for a public

177

—

178 ● Protecting the Nation’s Groundwater From Contamination

Table 34.—Corrective Action Alternatives: Techniques and Descriptionsa

I. Containment: This category consists of geotechnical methods that act to limit the mobility and prevent the further spreading of contaminants. Contaminants are not actually removed from the subsurface but are contained or isolated from the rest of the environment-e.g., via physical barriers or hydrodynamic pressures. Techniques are applied in relation to either the contaminants or their source. 1. Slurry Wall: Consi sts of a material (slurry) barrier wall

constructed in-place; is usually located below the wa­ter table and surrounding a site to limit the horizontal migration of cont 3minants in the saturated zone; is also used to reduc ~ hydraulic gradients, facilitate with­drawal, or channelize groundwater flow.

2. Sheet pile: Consists of a material (e.g., concrete, steel, or wood) barrier wall inserted into place by driving or vibration; is usually located below the water table and around a site to lir1it the horizontal migration of con­taminants in the ~;aturated zone.

3. Groutingb: Consists of a material cutoff injected into voids of water-bearing strata either to cover, bottom seal, or bind toge'her the subsurface materials at a site.

4. Geomembrane cU'off: Involves the insertion of syn­thetic sheeting into an open trench (combining aspects of both thf~ slurry wall and sheet pile) to form a barrier wall; is used primarily to limit the horizontal migration of contclminants in the saturated zone.

5. Clay (or other) CUlotte: Clay (or other material, e.g., concrete) barrier ""all; normally is constructed above the water table anc downgradient of a site to limit the horizontal migration of contaminants in the unsatu­rated zone (which is commonly negligible).

6. Linerd: Consists 01 a material (e.g., clay or synthetic) barrier constructecl or emplaced to isolate (e.g., cover or seal) contaminat ng sources in order to limit the ver­tical migration of contaminants; is often a facility de­sign component.

7. Natural containmfmt: Involves limitation of con­taminant mobility by naturally occurring geochemical, geologic, and/or hydrologic conditions; is evaluated by analytical andlor empirical methods.

8. Surface sealingd: Is used as an infiltration control measure to limit the vertical migration of contaminants either by reducing leachate production andlor recharge.

9. Diversion ditch d : 13 used as an infiltration control measure to limit surface runoff into a contamination management area (e.g., a slurry-walled area) by chan­nelizing and diverting surface drainage.

10. Hydrodynamic cont~o/: Limits the horizontal migration of contaminants in the saturated zone through selec­tive pumping and the subsequent creation of pressure troughs or pressum ridges.

II. Withdrawal: Withdrawal options include methods for ei­ther directly removing or faCilitating the removal of con­taminated groundwatN andlor contaminated soils from the subsurface. Techniques are principally applied in di­rect relation to the ccntaminants. 1. Pumping: Involves the removal of contaminated

groundwater by pumping from wells or drains; controls the lateral (and in s)me cases, vertical) migration of

contaminants; can be used for flushing (via artificial recharge).

2. Gravity drainage: Involves the removal of groundwater from the subsurface using the force of gravity (e.g., using sumps of French drains) instead of pumps; con­trols the lateral (and in some cases, vertical migration of contaminants.

3. Withdrawal enhancement: Enhances the ability to withdraw either groundwater or contaminants, typi­cally by increasing contaminant solubility in water (e.g., by injecting steam or heat, bacteria or nutrients, or surfactants).

4. Gas venting: Removes gases associated 'IJith contami" nation (e.g., methane and petroleum-related products).

5. Excavation: Involves the direct removal of contami­nated soil andlor groundwater resulting from source I~~k~n~ '~~"~l::t~.

III. Treatment: This category includes physical and chemi­cal/biological treatment methods for detoxifying con­taminants found in groundwater. These methods presume that contaminants have already been withdrawn from the subsurface (e.g., via withdrawal methods) in the form of contaminated groundwater or contaminated soils. Treatment can be applied at the source, at the site of con­t~min~tion {An in on-~itA trA~tmAnt Itnit~\ nrior to thA

di~t~'ib~ti~'n\~rg'~~~~d~~t~~ -f~'~' ~-~~ (~.·g~~/i'nr-~~·n·i~i P~I wastewater treatment facilities), and at the point of end use (e.g., at the tap).

a. Phvsical treatment 1.' sk-imri?in-g:l-nvolves the removal of floating con­

taminants (e.g., oil, grease, and hydrocarbons) in a multi-layer solution.

2. Filtration: Involves the physical retention and subse­quent removal of contaminants present as suspended solids.

3. Ultrafiltration: Involves the physical filtration, through semi-permeable membranes, of suspended and dis­solved metals, emulsified hydrocarbons, and sub­stances of high molecular weight.

4. Reverse osmosis: Involves the osmotic filtration, through semi-permeable membranes, of contaminants (e.g., metals and radioactive wastes) present as dis­solved solids; operates at high pressures (up to 1,500 psi g).

5. Air stripping: Uses air injection to facilitate the volatili­zation and removai to the atmosphere of contaminants (e.g., volatile organics and hydrogen sulfide) that are present in water as dissolved solids.

6. Steam stripping: Involves the fractional distillation of .._1,...:1 __ .. _ ...... _:_ .... _ .. _ ..... ro_ro ............ _ ........ : __

VUfc:llfft:: UfYc1fllv;:' UI Yc1;:,t::;:, uy fft::c1lfffy.

b. Chemical/biological treatment 7. Precipitation/clarification/coagulation: Removes con­

taminants (e.g., suspended and colloidal solids, phos-nh'!:l+o.~ !:linn ho.-::2.\I\/ rno.+ !:III co\ thp'"".nh +h~ 11~.4!"'\. "f t-"I(;"\J~, QIIU II\J"QYJ III\J"LQlvl "IIIVU~II Ulv U.;Jt;; VI

chemical additives such as coagulants and coagulant aids.

8. Ion exchange: Removes selected ions (primarily inor­ganic) via the exchange of ions between an insoluble solid salt ("ion exchanger") and a solution containing the ion(s) to be removed.

9. Adsorption: Removes contaminants (primarily organics) via their tendency to condense, concentrate,

Ch. 8—The Correction of Groundwater Contamination: Technologies and Other Alternatives • 179

Table 34.—Corrective Action Alternatives: Techniques and Descriptionsa—continued

10.

1.

12.

13.

or adhere on the surface of another substance (e,g.,granular activated carbon and synthetic resins) withwhich they come into contact.Electrodialysis: Separates and removes positive ornegative ions under the action of an electrical field.Chemical transformation: Involves oxidation-reductionreactions for the chemical conversion of contaminantsto less toxic substances (e.g., by ozone treatment,hydrogen peroxide treatment, ultraviolet photolysis,and chlorination).Biological transformation: Involves the transformationand removal by micro-organisms of dissolved and col-loidal biodegradable contaminants; includes both aer-obic and anaerobic processes.Incineration: Involves the high-temperature transfor-mation of contaminants into constituent components;many types of thermal destruction systems are in-cluded.

lV. In-situ rehabilitation: In-situ rehabilitation techniques aredirected at immobilizing or otherwise detoxifying con-taminants in place.1. Biological degradation: Involves either stimulating the

growth of native microflora or injecting specific organ-isms to consume or otherwise alter contaminants.

2. Chemical degradation: Involves the injection ofspecific chemicals that react with or otherwise altercontaminants.

3. Water tab/e adjustment: Involves either the isolationof the contaminated zone (and creation of a detoxify-ing unsaturated environment) by lowering the watertable or the artificial inducement of increased flush-ing action by raising the water table.

v.

4. Rehabilitation via natural processes: Involves the nat-ural degradation, dispersion, or detoxification of con-taminated groundwater; is evaluated by analyticaland/or empirical methods.

Management option: Management options are usuallyapplied either to prevent further contaminant ion or to pro-tect potential exposure points from contaminatedgroundwater. These methods thus focus on sources andexposure points rather than on the contaminants per se.The methods also tend to be institutionally-based ratherthan technology-based.1.

2.

3.

4.

5.

6.

7.

Limit/terminate aquifer use: Limits access or exposureof receptors to contaminated groundwater.Develop alternative water supply: Involves the substi-tution of contaminated groundwater with alternativesupplies (e.g., surface water diversions and/or storage,desalination, and new wells).Purchase alternative water supply: Includes bottledwater and water imports.Source removale: Involves the physical removal of thesource of contamination and includes measures toeliminate, remove, or otherwise terminate source ac-tivities; could also include modification of a source’sfeatures (e.g., operations, location, or product) to re-duce, eliminate, or otherwise prevent contamination.Monitoring: Involves an active evaluation program witha “wait and see” orientation.Health advisories: Involves the issuance of notifica-tions about groundwater contamination to potentialreceptors.Accept increased risk: Involves the decision to acceptincreased risk; is usually a “no action” alternative.

aBa~ed on Woodward.Clyde Consultants, Inc, lg83. See this reference for a detailed bibliography on Spec( flc correct ive actlofl alternativesbean be ~ o ns ld ered a form of chemical lmmoblllzatlon If Injected directly Into the plume of contaminationC p ~y5, c a l barrler5 located above the ~ate~ table WIII not affect the horizontal mlgratlon of contaminants In the saturated z o n ed Most often “Sed ,n the context of either ,~ource removal” or the prevention of recharge to the groundwater System. rather than as a COfltalflmf3flt Optl Ofl per S’‘Modlf, cat, on of a Source ,5 features ,5 often an Important element of corrective action In the context of preventing future ground water contamination (1 e , reducingthe need for future corrective action)

SOURCE Off Ice of Technology Assessment

health or environmental hazard, the potential forany hazard to become more serious over time, thepotential for loss of public confidence, the poten-tial for liability, and fear of the unknown (Wood-ward-Clyde Consultants, 1983).

Technical and Non-TechnicalConditions Determining theApplicability of Corrective

Action Alternatives

The applicability and selection of alternatives fora groundwater contamination problem depend onsite conditions. Conditions are technical (e. g., geo-logic setting, aquifer type, saturation, and type and

concentration of substances) and non-technical(e.g., cost, time, safety, and institutional factors).They are described in detail in appendixes F. 1 andF.2, respectively.

There are site conditions that limit all technolo-gy-based corrective action strategies, assuming astringent criterion for contaminant reduction, elim-ination, or control. Among these conditions are:1) the presence of multiple bodies of contamina-tion at a site and/or complex mixtures of substances;2) heterogeneous, highly complex aquifers; 3)depths of contamination beyond approximately 20meters; and 4) the presence of substances that par-tition (i. e., separate) out of water and are non-bio-degradable. The degree to which these constraintseffectively preclude application of technology de-

180 ● Protecting the Nation’s Groundwater From Contamination

pends to a large extent on whether substances canbe withdrawn and treated.

Often withdrawal and treatment are not possi-ble. For example, the application of some with-drawal methods (e. g., pumping) is limited in uncon-solidated, fine-g-rained materials of low permeabilityand may be impractical (in terms of time and costs)if high water volume handling requirements are in-volved. Individual treatment techniques addressspecific types of substances, and no single techniqueis applicable to the mix of substances often foundin groundwater. Further, sudden temporal changesin the types and/or concentrations of substancespassing through a treatment system can lessen treat-ment effectiveness. Thus, several treatment tech-niques would generally be required to treat con-taminated groundwater, but even then there is noguarantee that all substances will be reduced todesired levels.

Other conditions that determine and often re-strict the applicability of corrective actions to a givensite

●

●

●

include:

hydrogeology, e.g., methods requiring con-struction (many containment methods and ex-cavation) are often technically impractical inhard rock; material barriers depend on thepresence of a horizontal stratum of low per-meability and sufficient thickness for anchor-ing; and highly fractured sedimentary or crys-talline rock precludes the use of most techniquesexcept pumping, treatment (if withdrawal canbe accomplished), and grouting;types and concentrations of contaminants,e.g., special handling and disposal may be re-quired with options involving construction orwithdrawal in the presence of certain sub-stances; high concentrations severely reducethe efficiency of withdrawal; mixtures of sub-stances reduce the efficiency of treatment; andmultiphase flow (as when substances are im-miscible in and denser than water) poses specialdesign and implementation problems for mostmethods;depth, e.g., methods involving constructionequipment are generally limited to depths ofapproximately 20 meters;

●

●

●

environmental and health effects, e.g., healtheffects are associated with containment andmanagement options that allow the continuedpresence and potential for continued migra-tion of substances; environmental effects po-tentially include alterations to existing ground-water flow patterns if construction or pumpingis involved and the introduction of biologicalor chemical agents—and the continued pres-ence of altered substances—with in-situ reha-bilitation; and some treatment options canhave air pollution side-effects (air stripping);cost, e.g., depending on site conditions, costscan be tens of millions of dollars or more; con-tainment tends to be capital-intensive duringconstruction and installation with relativelysmall long-term operation and maintenancecosts, while withdrawal is less capital-intensiveoverall but has significant long-term operationand maintenance costs; and cost considerationshave effectively precluded corrective action inareas larger than about O. 1 km2 and for vol-umes exceeding about 1,000 m3; andperformance objectives in terms of the con-tinued presence of substances—e. g., excava-tion eliminates substances from a site relativelyquickly but depends on the availability ofan alternative site for disposal of excavated ma-terials; pumping may remove high concentra-tions of substances in the near term, but dec-ades of pumping may be required before asignificant additional reduction is achieved;and treatment may also be required over thelong term and removal efficiencies are highlyvariable.

Appendix F.3 summarizes information aboutconditions determining the applicability of correc-tive action alternatives in relation to the OTAsource categories discussed in chapter 2 (refer totable 5). Essentially, no technically based correc-tive action can stop a source from causing contam-ination: 1) if the source is deep, such as manysources in Category I (i. e., sources designed to dis-charge substances) and Category V (i. e., sourcesthat provide a conduit); or 2) the source releasessubstances over a wide area or if large volumes ofwater are involved, as in Category IV (i. e., sourcesthat discharge substances as a consequence of other

Ch. 8—The Correction of Groundwater Contamination: Technologies and Other Alternatives Ž 181

-

. ,,

.,

,

Photo cradt: Geraghb’ & Miller, 198.3

Movement of contaminated groundwater can sometimes be controlled by pumping (i.e., hydrodynamic control) as shownabove. Groundwater that is withdrawn must subsequently be treated and/or disposed of in some way; below, discharge

lines carry recovered water away from the site.

182 ● Protecting the Nation’s Groundwater From Contamination

Credit: Geraghty & Miller, 198.3

Containment options that use material barriers depend on the presence of a horizontal stratum of low permeability andsufficient thickness for anchoring as shown above; some type of pumping scheme (e.g., wells or drains) may also be

needed to prevent the overflow of contaminated water from inside the barrier. Backfill is being pushedinto an almost completed slurry wall in the photograph below.

Photo credit: National Water Well Association

Unsaturated zo 1e

Saturated zone

Elevated water tabie

Ch. 8—The Correction of Groundwater Contamination: Technologies and Other Alternatives . 183

Photo credit: US. Environrnenta/ Protection Agency

Airstripping towers can be used to remove contaminants from groundwater; however, precautionsmust be taken to minimize any associated air pollution problems.

activities including pesticide and fertilizer appli-cations).

Performance of Corrective ActionAlternatives

Corrective actions have been taken to improvegroundwater quality, but how well they performremains uncertain over both the short and the longterm. Inability to characterize performance of cor-rective measures arises because of the following fiveinterrelated factors.

1 ) Performance is relative. Evaluation of per-formance requires the establishment of a bench-mark or a target level for comparison. For exam-

ple, when the desired reduction in contaminantconcentrations is minor, many corrective actionalternatives may qualify as ‘‘effective, but as thelevels of desired or required cleanup increase, manyalternatives may no longer qualify. Performanceis also measured not only against existing condi-tions but in relation to future conditions—i.e., thesuitability of improved quality to satisfy likely futureuses.

2) Performance must be assessed in relation tothe specific conditions at a given site (see the pre-ceding section of this chapter). The site-specificityof groundwater contamination problems and, inturn, of the applicability of corrective action alter-natives precludes a meaningful generalized assess-ment of technology performance.

184 Ž protecting the Nation’s Groundwater From Contamination

3) Even when site information is available, thereis always some degree of uncertainty about the sub-surface environment —e.g., which substances arepresent, at what levels, and where (see ch. 5)—that can limit the effectiveness of alternatives inunforeseen ways. The principal uncertainty factorsthat influence performance are summarized in table35 and relate to materials compatibility, the het-erogeneity of the aquifer, and the types of sub-stances present. Others are related to the qualifica-tions of personnel and the quality of construction,handling, and operation.

4) There is virtually no long-term experienceupon which to base the assessment of correctiveactions. For example, although there have been fed-erally funded cleanup activities under the Compre-hensive Environmental Response, Compensation,and Liability Act (CERCLA) and other Federalstatutes, none has involved groundwater (see ch.9). As a consequence, a then-ough performance eval-uation of individual alternatives under different siteconditions will not be available in the near term.Although many case histories are reported in theliterature, they often do not contain enough detailfor an evaluation of technology performance. In ad-dition, access to information appears limited be-cause it is often proprietary or involved in litigation.

5) The projected performance of technology andthe degree of uncertainty about its performancedepend on the time available to meet cleanup ob-jectives or standards desired (e. g., as specified inpermits, presented in a notice of regulatory com-pliance, and in response to public pressures) andon available funds. For example, in addition tospecifying the levels to which the concentrations ofsubstances must be reduced, a time frame may alsobe specified.1 Time constraints may preclude manycorrective act ion alternatives from consideration,perhaps resulting in a choice among more costlyoptions; or desired cleanup standards may be nei-ther technically nor economically feasible in thetime specified.2

1 In a surx’cy of rcmedial action projects undertaken for EPA (SCSEngineer-s, 1981 ), legal action to identify ‘ ‘responsible” parties forcorrect i~’c action alone varied from 4 to 9 }’ears.

‘For example, if cleanup stan+~ards must be achieved in, say, 5 years,then a time- and capital- inten: i~e method of containment may haveto be chosen (e. g., a slurry wall requiring replacement once etery 50

Although an accurate performance assessmentis not presently possible, it is possible to reducethe uncertainties associated with performanceand/or to improve the likelihood that an alterna-tive will perform well. Examples are describedbelow:

●

●

●

●

The evaluation, selection, design, and imple-mentation of corrective action alternatives arebased on information obtained from hydro-geologic investigations. Thus, improving thereliability of hydrogeologic information (seech. 5) will improve corrective action decision-making.Realistic expectations in terms of objectives,time, and costs are important in ensuring thatfailure is not inevitable.Monitoring can gauge long-term effectivenessand enable modification of the corrective ac-tions chosen if necessary. But measuring per-formance is indirect and varies among thealternatives. Possible indicators of perform-ance are presented in table 35.Quality control and quality assurance proce-dures—e.g., regarding the use of constructionequipment on-site and the handling and place-ment of physical barriers—can also minimizethe likelihood of poor performance.

Importantly, different types of uncertainties areassociated with different alternatives, and the per-formance of some may be more certain (though notnecessarily more desirable) than others, dependingon site conditions. Management options are mostoften selected because their performance is the mostcertain. For example, terminating aquifer use de-pends neither on subsurface hydrogeology nor onthe nature and behavior of substances; over the longterm, however, there may be a risk of public ex-posure to substances remaining in the subsurface.

years), precluding methods that have long-term operational require-ments but smaller capital costs (c. g., hydrodynamic control). A netpresent value criterion would select hydrodynamic control in the ab-scncc of a near-term time constraint. However, a pumping systemma}’ achie~e a 90-percent reduction in contain inant concentration levelsin 5 years, but an additional 50 years may be required to reach a ~oalof 95-percent reduction.

oI

I

to?w

Table 35.—Corrective Action Techniques: Objectives, Performance, and Status

Principal componentsof uncertainty Measuring Development status

Technique Objective affecting performance performance Summary a Remarks

Containment1. Slurry wall To halt the hori-

zontal migrationof contaminantsfrom a contami-nation plume;often used inconjunctionwith surfaceseal, run-on, andrunoff controls.

2. Sheet pile

3. Grouting

Same as slurrywall.

To encapsulatecontaminants(via bottom andlateral grouting).

● Long-term materials compati-bility, particularly with certainorganic solvents such asaromatics and halogenatedspecies.

● Wall consistency and integra-tion with the confining bed.

● Longevity of walI integrity.Ž Quality of design and

installation.

● Occurrence of premature piIefailure, especially in thepresence of highly concen-trated corrosive contaminants.

● Contact between the groutmaterials and all fracture andpore spaces.

● Compatibility of formationfluids and wastes with groutmaterials.

Performance of a slurry wall isis determined by variousmethods. Monitoring well dataoutside of the wall can indi-cate the degree of leakage.Hydraulic head differencesdetermine leakage potential;actual leakage can be cal-culated. Head measurementsin underlying aquifers determinepotential for vertical leakage.Permeability measurementsof confining bed also deter-mine leakage potential.

Same as slurry wall except thatmeasurements are taken atspecific places whereleakage is expected to occur,e.g., at pile joints andwhere piles are integratedwith the confining bed.

Encapsulation processes cannotbe easily monitored or con-trolled (e.g., a barrier wall canbe more easily inspectedduring construction thaninjected grout; and groutinjection is not as easily con-trolled as trenching). interpreta-tion of monitoring well datafor downgradient contami-nants is the principal measureof performance.

2

2

2

Technology for conventional,trenched slurry walls is wellestablished as a constructiondewatering practice; however,allowable leakage for con-struction applications is lesscritical than for contaminationapplications. In general, long-term (30 years) performanceevaluations are not availablebecause the operation require-ments of dewatering areusually short term (less than1 year). Historical records oflong-term performance underexposure to varying contam-inant types is also unavaila-ble. Advanced techniques,such as the vibrating beamemplacement method, have alimited history of applicationto contamination problemsand should be consideredunproven.

This technique is conventionallyused for construction dewat-ering. Its long-term viability incorrosive environments (e.g.,acid wastes) is unproven.Also, the effectiveness withwhich the method can limitcontaminant migration isquestionable for stringentperformance criteria (e.g., iflow or no leakage is desired.)

Grouting is conventionally usedin mine dewatering and damconstruction. Design require-ments in historical uses aregenerally to limit water flow,not to minimize or eliminateflow or to encapsulatecontaminants.

Table 35.—Corrective Action Techniques: Objectives, Performance, and Status-continued

Principal componentsof uncertainty Measuring Development status

Technique Objective affecting performance performance Summary a Remarks

4. Geomembrane Same as slurrywall.

5. Clay cutoff To halt the hori-zontal migrationof contaminants(in the unsat-urated zone).

6. Liner To limit thevertical migra-tion of con-taminants;commonly usedas a facilitydesigncomponent.

7. Natural To contain orcontainment otherwise limit

the migration ofcontaminantsvia retardationin aqueousmedia, in geo-logic forma-tions, or byhydrogeologicconditions.

8. Surface sealing To limit infiltrationinto the con-taminated area;commonly usedin conjunctionwith runoff diver-sion ditchesand material bar-riers (e.g., slurrywall and grout-ing) and with

Compatibility of synthetic - “same as slurry wall.membranes with organicsolvents.Installation of a verticalliner with grout backfill with-out damage.Integration ot the liner withthe confining bed.Compatibility of materials andquality of installation.

Occurrence of punctures dueeither to improper installationor to settling of underlyingmaterials.Impacts of organic solventson synthetic liners or clays—e.g., holes or reduced ef-fective permeability.Quality of materials selectionand installation.

Representativeness of charac-terization of hydrogeologyand contaminant retardation.

● Accuracy and completenessof data, especially concern-ing contaminant retardation.

● Heterogeneity of subsurfaceconditions.

● Quality of management,inspection, and repair.

Monitoring in the vicinity ofthe cutoff can be accom-plished with suction lysi-meters, core samples, andother techniques applicableto the unsaturated zone.

Performance of liners can bemonitored by underdraincollection systems or con-ventional monitoring welltechniques.

Detection of contaminants inmonitoring wells can verifypredicted migration rates.

Visual inspection can locateholes or cracks. IncreasedIeachate production indicatesleakage. Also, increasedpumpage requirements inhead management systemmay indicate leakage.

3

2

1

5,6

1

Contamination applications are

A

are in the R&D phasealthough the technology iscommercially available. Fieldtests are only now being con-ducted; long-term perform-ance data are not available.

clay cutoff is a standardconstruction technique but ithas limited utility in ground-water contamination applica-tions because horizontal mi-gration in the unsaturatedzone is most often negligible.

Liner technology is well estab-lished and has been appliedextensively to ground-water contamination problems.However, long-term perform-ance data for both syntheticliners and compacted claysare limited. The use of under-liners is limited mainly tohazardous-waste facilitydesign.

Techniques are available topredict the general directionand rate of movement ofnatural flow systems. Buttechniques used to pre-dict contaminant migrationrates and concentration levels(e.g., solute transport models)are not well established andsubject to great uncertainty,particularly in the absenceof supporting data.

Conventional construction tech-niques are used to emplacesurface seals. Effective infil-tration control requiresconstant maintenance (e.g.,due to the formation ofstress cracks from settlingor drying after dewatering).

●

Table 35.—Corrective Action Techniques: Objectives, Performance, and Status— continued

Principal componentsof uncertainty Measuring Development status

Technique Objective affecting performance performance Summary a Remarks

source isolation(e.g., to elimi-nate Ieachateproduction).

9. Diversion To divert surfaceditches runoff away

from the con-taminated area.

10. Hydrodynamic To isolate con-control taminants via

countering hy-draulicgradients.

Withdrawal1. Pumping To limit the lateral

migration ofcontaminantswhile graduallyremoving themfrom the aquifermatrix and for-mation fluids.(Source removaland/or isolationis also requiredto achieve ulti-mate reductionin contaminantconcentrations.)

● No major concerns.

● Changes in local flow patternsdue to modifications in exist-ing pumping schemes or toinstallation of new pumpingwells.

Ž Downward flow which couldallow contaminant migrationinto uncontrolled aquifers.

Visual inspection is used tomeasure performance—e.g.,during precipitation events.

Water levels can be monitoredin surrounding wells to observegradients.

1 This technique is a con-ventional construction methodused for run-on/runoff control.It is often used in conjunc-tion with surface seals.

1,4 Techniques are not consideredconventional or “on-the-shelf.”Management of plumes andcontaminant isolation in com-plex hydrogeologic settingsrequire extensive engineeringand testing. Long-term effec-tiveness is a function of con-stant fine-tuning to changes

● The necessary length of time Contaminant concentration levels 1for operations. can be measured in produced

● Downward leakage of con- water to determine removaltaminants due to fracture rates; and effects of pumpingsystems, jointing, and aban- can be verified by monitoringdoned wells. water levels in surrounding

wells. Underlying aquifersmust be monitored to detectdownward migration. Concen-tration levels after pumpingis terminated must be moni-tored to determine increasesin concentrations due toresorption. Geochemicalinteractions between con-taminants and the aquifermatrix affect the partitioningof the contaminant betweensolid and water phases; thepotential effectiveness andlength of operations aredependent on theseinteract ions.

in head gradients. In dynamicflow systems (e.g., in systemsmodified by other pumpinguses), pumping rates or pat-terns will require modifica-tion in real time.

Pumping techniques (e.g., wells)are used conventionally forwater supply development andmore recently for plumemanagement. Techniques arereliable and performance canbe verified. Numerous applica-tions to groundwater con-tamination are in place, andperformance data are available.

Table 35.—Corrective Action Techniques: Objectives, Performance, and Status—continued

Principal componentsof” uncertainty Measuring Development status

Technique Objective affecting performance performance Summary a Remarks2. Gravity Same as pumping. -same as pumping. Same as pumping. 1

drainage

3. Withdrawal To enhance con-enhancement taminant re-

moval efficien-cies via thethe injection ofchemicals,steam, or otheradditives.

4. Gas venting To remove volatilecontaminantsfrom the sub-surface.

5. Excavation To removecontaminatedwater and/orsoil materials.

Ž Lack of proven effectiveness Same as pumping.of technology.

● Introduction of additionalcontaminants to the aquifer(e.g., chemical reagents andtheir byproducts).

● Introduction of volatiles tothe atmosphere (e.g., via theuse of steaming in surficialapplications).

. Presence of inorganic sub-stances (i.e., use is limited toorganic constituents).

2,3,4b

● Lack of proven effectiveness Measurements can be taken 1in complex media. using gas collection probes.

Ž Increased contaminant migra-tion (e.g., via breaking ofdrums or additional infiltra-tion during precipitation).

● Availability of secure disposalareas for excavatedcontaminants.

● Extent of contamination andresulting costs.

Contaminant concentration 2levels can be measured insurrounding soil and aquifermaterials and in surroundingwaters to verify total removal.Measurements are mostaccurate if contaminants arehighly concentrated andlimited in depth and volume.

A type of fluid recovery tech-nology, this method is usedextensively in dewateringactivities and for groundwatercontamination. It is a reliable,simple technique which isapplicable in many surficial,unconsolidated formations.Performance data areavailable.

This technique is not conven-tionally applied to ground-water contamination prob-lems. Steam or heat injection,although used in confinedformations in oil field applica-tions, have not been exten-sively tested in surficial con-tamination problems whereconcentrations of organics aremuch lower and objectives forremoval are more stringent(50% recovery of oil in placeis often considered reason-able). Surfactant injection isstill considered an advancedtechnique in enhanced oilrecovery operations, andinjectants are often con-sidered hazardous.

Gas venting is conventionallyused in landfill design andoperation. Vapor extractionin the unsaturated zoneappears capable of removingthe soluble fraction ofvolatile compounds from thesaturated zone.

Direct excavation is a conven-tional technology. However,associated health and safetymeasures are continuallyunder development and arelikely to increase costssubstantial y.

Table 35.—Corrective Action Techniques: Objectives, Performance, and Status—continued

Principal componentsof uncertainty Measuring Development status

Technique Objective affecting performance performance Summary a Remarks

Treatment In general, totransform(thereby remov-ing) contami-nants via phys-ical, chemical,or biologicalmeans.

In-situ rehabilitation1. Biological To degrade

degradation contaminantsvia the injectionof micro-organisms intothe subsurfaceor by stimulat-ing the growthof in-situbacteria.

2. Chemical To degrade ordegradation immobilize

contaminantsvia the injectionof chemicalsinto the sub-surface.

● Uncertainty Increases it con-taminants are neither highlyconcentrated nor limited indepth or volume.

● Occurrence of shock loadings.Nature, mix, and concentra-tion of contaminants; uncer-tainty increases if contami-nants are not highlyconcentrated.Equipment design andoperation (e.g., membranemaintenance for filtration,ultrafiltration, and electrodi-alysis; and proper controls forproviding reagents for adsorp-tion and chemical trans-formation).Subsurface hydrogeology tothe extent that contaminatedgroundwater is to be with-drawn from the aquifer.

● Contact between the reagentsand the entire contaminationmass, particularly in hetero-geneous aquifers.

● Predicting the behavior ofmicro-organisms.

● Tailoring micro-organisms tocontaminants.Performance is highlyuncertain.

Contact between the reagentsand the entire contaminationmass, particularly in hetero-geneous aquifers.Performance is highlyuncertain.

In general, influent and effluent 1C

Treatment techniques arecan be monitored for generally “on-the-shelf” andcontaminants. with basic engineering can

be adapted to many ground-water contamination inci-dences. However, managementof treatment systems formultiple contaminants and forrapidly changing concentra-tions may prove to be difficult.Performance data are notavailable for groundwatercontamination applicationsusing ultrafiltration,reverse osmosis, steamstripping, ion exchange, andelectrodialysis.

Contaminant levels can be 4,5 Techniques are in the R&Dmonitored in soil and water. stage with minimal com-

mercial application. Theyhave a potentially limitedapplication to groundwaterdue to practical constraintssuch as the volume oforganisms required, reactionkinetics, and the assimilativecapacity of organisms forcertain contaminants. In heter-ogeneous formations, accessto the entire contaminantmass may be practicallyimpossible. Techniques aremost often applied to petro-leum-related spills.

Same as biological degradation. 4,5 Techniques are in the R&Dstage with minimal com-mercial application. Theyhave a potentially limitedapplication to groundwaterdue to practical constraintsincluding reaction kineticsand reactivity of contami-

Table 35.—Corrective Action Techniques: Objectives, Performance, and Status-continued

Principal componentsof uncertainty Measuring Development status

Technique Objective affecting performance performance Summary a Remarks

3. Water table To allow foradjustment the aerobe

degradation ofcontaminantsby lowering thewater table.

4. Naturalprocessrestoration

To allow for thedegradation anddispersion ofcontaminants inthe natural flowsystem.

Management options1. Limit/terminate To minimize the

aquifer use exposure ofpossible usersto contaminatedgroundwater.

2. Develop To provide aalternative substitute waterwater supply supply by

developing

● Potential for aerobic degrada-tion is iimilea 10 cenainorganic contaminants.

● Prediction of degradationrates or processes,

● Prediction of contaminantmigration behavior; heterogen-eities in aquifer conditionsreduce accuracy of predic-tions.

● The presence of non-degrad-able contaminants that,although highly retarded,continue to migrate at lowvelocities.

● The ability to shut downdomestic wells due to possi-ble public resistance.

● The ability to enforce usagepatterns in cases of environ-mental exposure (e.gp, to sportfish or streams).

● Availability of water supplyalternatives, especially inwater-short areas which may,in turn, limit the long-term

aiternative water growth of an area. -

sources.

nants. In heterogeneousformations, access to theentire contaminant massmay be practicably impossible.

C o n t a m i n a n t c o n c e n t r a t i o n s 4 , 5 The methods of pumping andcan be moniorec i in so i i anti

water. Underlying saturatedmedia can be monitored todetermine contaminant levels.

Downgradient levels of contam-inants in soil and water canbe measured.

Exposure levels can be moni-tored; actual use patternsover time can be determined.Performance is also eco-nomic—e.g., it may becheaper to terminate use andimport water or developalternative supplies than totreat supplies or otherwisecorrect contamination.

Performance is mainly eco-nomic —e.g., it may becheaper to terminate use anddevelop alternative suppliesor import water than to treatsupplies or otherwise correctcontamination.

gravity drainage used io aiierwater table levels are wellestablished. Evaluation of theimpacts of such adjustmentson contaminant degradation,however, is not well definedor established, and the tech-nique is not conventionallyapplied in plume manage-ment. Source isolationis a possible application.Raising the water table canprovide flushing benefits insome cases.

5,6 Methods used to predict con-centration reductions (e.g.,solute transport models) arenot highly reliable. Monitoringthe actual attenuation of con-taminants is a conventionalpractice and performance canbe monitored.

6 Historically this is a commonresponse to aquifercontamination.

6 In conjunction with Iimiting/terminating aquifer use, alter-native water supply develop-ment is a frequently imple-mented response.

iib

vi33

Table 35.—Corrective Action Techniques: Objectives, Performance, and Status—continued

Principal componentsof uncertainty Measuring Development status

Technique Object ive affect ing performance performance Summary a Remarks

3. Purchasealternativewater supply

4. Sourceremoval

5. Monitoring

6. Healthadvisories

7. Acceptincreased risk

To provide asubst i tute watersupply throughimportat ion orother purchases.

To removephysically thesource ofcontaminant ion.

To delineate andtrack the migra-tion (and con-centrations) ofcontaminants.

To limit the use ofcontaminatedgroundwater byadvising usersof contamina-tion.

No action taken.

Reliance on imports, espe-cially in water-short areaswhere the supply may beterminated or depleted.Potential opposition to inter-basin transfers.

Increased contaminant migra-tion (e.g., via breaking ofdrums or additional infiltrationduring precipitation).Availability of secure disposaloptions.Extent of contamination andresulting costs. (See Excava-tion, above.)Undetected plume migrationbecause of improper place-ment or sampling of wells.Mistakes are difficult to detecuntil a problem occurs orbackup wells around keyexposure points are installed.

. The ability to enforce usagepatterns in cases of environ-mental exposure (e.g., tosport fish or streams).

The ability to shut downdomestic wells due to pos-sible public resistance.

● The ability to predict contam-inant migration.

● Corrective action alternativescan be more expensive as thecontaminant spreads out (i.e.,a larger plume).

Performance is mainly eco-nomic—e.g., it may becheaper to terminate use anddevelop alternative suppliesor import water than to treatsupplies or otherwise correctcontaminant ion.

Contaminant concentrationlevels can be measured insurrounding soils, aquifermaterials, and waters toverify total removal.

Performance can be measuredby duplicating samples andanalyses. Use of qualifiedpersonnel are essential forproper well placement andfor the overall groundwaterquality investigation.

Exposure levels can be moni-tored; actual use pattern overtime can be determined.Performance is also eco-nomic—e.g., it may becheaper to terminate use anddevelop alternative suppliesor import water than to treatsupplies or otherwise correctcontamination.

Performance is often measuredin economic terms.

6

1

1,6

6

6

This is a frequently imple-mented response althoughgenerally considered a short-term solution.

Conventional constructiontechniques are used for sourceremoval although substantialincreases in health and safetyprecautions are required forgroundwater contaminationapplications. Current activityalready involves significanthealth and safety measures.

Conventional technology isused for monitoring ground-water contamination problemsand conducting hydrogeologicinvestigations. If methods areused properly, reliable plumedelineation and migrationdata can be generated (seealso ch. 5).

This option is a conventionalpractice of State and localhealth departments.

Historically this option is theresponse to many contam-ination incidence. Impactson population are unclear.

aKey: 1—Technology is proven; performance data are available from applications to groundwater contamination problems.2—Technology is proven In applications other than groundwater contamination; long-term performance data are unavailable for groundwater contamination.3—Technology IS In R&D stage with respect to groundwater contamination applications, although proven for other applications; performance is generally unknown for groundwater contamina-

tion problems.4—Application of technology has been limited to specific, narrowly def!ned site conditions.5—Technology IS generally in R&D stage; results are unreliable.6—Technology has been applied historically —e.g., before the development of regulatory programs and consideration of potential long-term impacts.

bwlthdrawal enhancement techniques that would be a “5” include surfactant injection.cT reatment technologies that would be ,,2,, are ultrafiltration, r@v@rs@ osmosis, steam strlpplng, ion exchange, and elect rodlalysis.

SOURCE: Office of Technology Assessment.

192 . Protecting the Aation’s Groundwater From Contamination

STAGE OF DEVELOPMENT OF CORRECTIVEACTION ALTERNATIVES

The development status of alternatives is alsosummarized in table 35. Generally, alternatives forcorrective action are commercially available. How-ever, they have usually been developed for indus-trial and surface water uses, which do not requirethe level of reduction, removal, and/or control ofsubstances that is necessary for groundwater con-tamination problems. For example:

containment methods were developed in theconstruction industry for dewatering, founda-tion, and embankment applications;withdrawal methods were developed for ground-water supply (i.e. , quantity) development andfor petroleum recovery;treatment methods were developed for waste-water (i. e., surface water) and desalination ap-plications; andmanagement options have generally been ap-plied in the areas of wastewater (i. e., surfacewater) treatment and water supply (i. e., quan-tity) development.

Some commercial alternatives require only mi-nor modifications, if any, for groundwater con-tamination purposes. These alternatives includesome management options (e. g., the developmentof alternative supplies) and, to a lesser extent, ex-cavation if precautions are taken with respect tomaterials handling and disposal.

Other commercial alternatives require continuedresearch and development before they can be ap-plied effectively to contaminated groundwater. Forexample, containment needs relate principally tothe permanence of installation—e. g., materials

compatibility, field validation procedures, qualitycontrol, and leak detection (EPA, et al., 1983).With respect to treatment, research and develop-ment is needed for radionuclides; viruses; certainorganic chemicals, including halogenated com-pounds; and complex mixtures of substances. Re-search also needs to continue on modifying existingwastewater treatment facilities to handle a broaderspectrum of substances than they typically handle.In general, the technologies for treating substancesin groundwater are likely to differ substantially fromthose developed for contaminated surface water andwastewater because of the marked differencesamong the types and concentrations of substancespresent.

Some innovative methods are being developedspecifically for application to groundwater con-tamination problems. For example, research anddevelopment for in-situ rehabilitation originated inthe context of petroleum spills, and withdrawalenhancement techniques are being developed in thecontext of hydrodynamic control. Because innova-tive methods tend to be substance-specific, they arelikely to be useful only on a limited scale in the longterm.

Although some available technology and likelydevelopments appear promising for specific typesof contamination problems, technology alone can-not be expected to correct the full range of prob-lems likely to be encountered. It will take years,or even decades, of testing and monitoring to de-velop reliable performance data. Even then, theknowledge gained will be site-specific.

Ch. 8—The Correction of Groundwater Contamination: Technologies and Other Alternatives ● 193

CHAPTER 8 REFERENCES

Geraghty & Miller, Inc., “The Fundamentals ofGround-Water Quality Protection, ” New York,1983.

SCS Engineers, ‘‘Survey of On-Going and CompletedRemedial Action Projects, ” prepared for MunicipalEnvironmental Research Laboratory, Office of Re-search and Development, U.S. Environmental Pro-tection Agency, Cincinnati, OH, September 1981.

U.S. Environmental Protection Agency and the Depart-ment of the Army, “Barrier Workshop, ” A. W.Briedenbach Environmental Research Center, Cin-cinnati, OH, Sept. 7-8, 1983.

Woodward-Clyde Consultants, Inc., “Corrective Ac-tion Alternatives for Ground-Water Contamina-t i o n , draft report prepared for the Office ofTechnology Assessment, August 1983.

Chapter 9

Federal Efforts To CorrectGroundwater Contamination

Contents

Page

Chapter Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ● 197

Statutory and Regulatory Provisions for sources of contamination . . . . . . . . . . . . . . . 197

Federal Government Experience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200

Chapter 9 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202

TABLETable No. Page

36. Summary of Federal Corrective Action Provisions for Sources ofGroundwater Contamination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198

Chapter 9

Federal Efforts To CorrectGroundwater Contamination—

CHAPTER OVERVIEW

Based on a review of statutory and regulatoryrequirements, this chapter discusses the correctiveaction programs of the Federal statutes and pro-grams discussed in chapter 3. Information is pre-sented on the sources of groundwater contamina-tion requiring corrective action and the cleanupstandards specified under corrective action pro-grams. An overview of Federal experience with cor-rective action is also provided. Specific correctiveact ions undertaken by either Federal agencies orthe responsible parties in response to regulatory or

court-imposed requirements were not reviewed forthis study.

The major conclusions of this chapter are:

● few Federal statutes provide for correctiveaction,

● cleanup standards are generally not specifiedin regulations, and

● Federal agency experience with such actionsis limited.

STATUTORY AND REGULATORY PROVISIONSFOR SOURCES OF CONTAMINATION

Federal Government involvement in correctiveaction efforts for contamination problems can becharacterized in one of three general ways:

1<

2.

3,

Federal agencies have developed regulatoryrequirements (e. g., permit conditions) for cor-rective actions for specific sources of contam-ination (e. g., under the Resource Conserva-tion and Recovery Act (RCRA)).Federal agencies are mandated by statute toundertake and finance corrective actionsrelated to specific sources of contamination(e. g., under the Comprehensive Environ-mental Response, Compensation, and Liabil-ity Act (CERCLA) and the Uranium MillTailings Radiation Control Act of 1978(UMTRCA).Explicit corrective action provisions are absentbut responsible parties may be required toundertake corrective actions as a result of ac-tions to enforce compliance with regulatory

requirements (e. g., drinking water regulationsand endangerment provisions).1

Details of corrective action provisions for the OTAsource categories discussed in chapter 2 are prc-sented in appendix G; the appendix contains in-formation on the type of corrective action effortsrequired under each statute (e. g., permit conditionsor federally funded cleanup activities) and onspecified cleanup standards.

Table 36 summarizes the corrective action pro-visions of the Federal statutes examined in this

For example, under he rgrouncl Injection (;ont rol Prog-ramestablished by the %tfc Drinking Water Act, the Env i mn mcnt al Pro-tu t ion Agency may take cnforccrncnt action if there is a violation of”drinking water regulations or if the health of persons is otherwiseadversely affcctcd. In add it ion, several statutes also contain prfnisionsthat allow the Administrator of EPA to bring lawsuits if a( t ions prt\-cnt or may present an ‘‘imminent and substant lal cndangcrmcntto human health or the cn~ironrncnt (e. g., Section 7003 of RCRA,Section 1431 of SDW’A, Sections 504 and 311 (c) of (: WA, an(l Scr-tion 106 of CEIR(; l. A).

197

38-799 0 - 84 - 10 : QL 3

Table 36.—Summary of Federal Corrective Action Provisions for Sources of Groundwater Contamination

Cleanupstandards

specified inStatute Provisions regulations

Atomic Energy Acta

Clean Water Acta,b

Coastal Zone Management Act

Comprehensive Environmental Response,Compensation, and Liability Acta

Federal Insecticide, Fungicide, andRodenticide Act

Federal Land Policy and Management Act(and associated mining laws)

Hazardous Liquid Pipeline Safety Act

Hazardous Materials Transportation Act

Reclamation Acta

Resource Conservation and Recovery Act

None

N o n e. . . . .

None

None

None

None

None

None

None

None

Background levels ofhazardous substances(specified on a case-by-case basis), Maxi-mum ContaminantLevels for 14 contami-nants establishedunder the Safe Drink-ing Water Act (if higherthan background), oralternative concen-tration limits (specifiedon a case-by-casebasis).

Table 36.—Summary of Federal Corrective Action Provisions for Sources of Groundwater Contamination—continued

Statute

Safe Drinking Water Act

Surface Mining Control and ReclamationA c ta

Toxic Substances Control Act

Uranium Mill Tailings RadiationControl Acta

CleanupStandards

specified i nProvisions regulations

No explicit corrective action requirements are specified for underground injection Nonewells.

No explicit corrective action requirements are specified for mining operations on NoneFederal lands.

Federally funded remedial actions are authorized by the Rural Abandoned Mine NoneProgram. d State grants are also provided for abandoned mine programs; Statesestablish reclamation priorities.

While the statute specifically addresses PCB disposal sites, no explicit corrective Noneaction requirements are established.

Federally funded corrective actions are authorized for specified inactive sites. The None for inactive sites.statute explicitly lists those sites for which corrective actions are required.

Active sites are subject to the same requirements as surface impoundments under Standards for active sitesRCRA (except that corrective actions must be implemented within 18 months). are the same as RCRA

(Subtitle C) except thatlevels for certainradioactive substancesare also established. —

aThe statute authorizes federally funded remedial aCtiOn programsbFederally funded corrective actions for oll SPlllS or leaks are authorized If there ,s a discharge Into flav/ga~/e waters (section 311) There are no cleanup standards, however, speclfled In the regulations This prOVISIOn

IS relevant to groundwater to the extent that groundwater and surface water may be Interconnected.CA -release,, ,ncludes any spllllng, Ieaklng, pumplng, pour[ng, emlttlng, emptying, discharging, Injecting, escaping, Ieachlng, dumping, or dlsposlng. Sources explicitly exc/uded by law Include radioactive SiteS covered

by other laws and the normal application of fertilizers (see SectIon 101(22) of CERCL,%)d T hls program ,s being phased out Although ,t provided for groundwater restoration, projects undertaken by the SOII Consewatlon Service have not directly addressed groundwater

SOURCE Off Ice of Technology Assessment

—

200 • Protecting the Nation’s Groundwater From Contamination

study.2 The following observations are made aboutthese provisions:

● Explicit corrective action provisions (e. g.,groundwater protection standards) are notspecified for all sources of contamination. Noexplicit corrective action requirements forgroundwater are established for sources inOTA Categoric:; III. IV, V, and VI (refer toch. 2, table 5).

● Explicit regulatory requirements are specifiedfor some sources in Categories I and II:—Category I: Land application of hazardous

wastes (under RCRA).—Category II: Hazardous waste landfills, sur-

face impoundments, waste piles, and landtreatment areas (under RCRA); radioactivedisposal sites (under the Atomic EnergyAct); and uranium mill tailings sites (activesites under UMTRCA).

● Only two of the programs containing cor-rective action regulatory provisions estab-lish explicit cleanup standards: RCRA andUMTRCA. The standards are based on thespecified groundwater protection standard,which includes the substances to be monitored,concentration limits, the point of compliance,and the compliance period (see app. E); cor-rective actions are not required beyond thedowngradient facility property boundary (seeapp. G).

• Six Federal statutes authorize federallyfunded remedial action programs but none ofthe programs specifies cleanup standards.

‘Neither the National Environmental Policy Act nor the Water Re-search and Development Act are concerned with corrective action forspecific sources; they are thus omitted from table 36.

Photo credit: Office of Technology Assessment

Corrective action team wears protective clothingas they drill a recovery well.

Rather, the selection of a remedy under theseprograms (e. g., CERCLA and inactive sitesunder UMTRCA) is based on protection ofhealth and the environment, costs, technicalfeasibility, the uses of an aquifer, and avail-ability of alternative water supplies.

FEDERAL GOVERNMENT EXPERIENCE

Federal agency experience with respect to the nated groundwater. Examples of federally fundedsite-specific design and implementation of correc- corrective action programs follow:tive actions is limited relative to the total numberof individual sites sources identified as requiring ● Remedial actions under CERCLA can beremedial action. In addition, little of the experi- undertaken only at sites on the National Pri-ence relates specifically to the cleanup of contami- orities List (NPL) (see app. G). As of Sep-

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National Priorities List Update #1

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Credit: EPA. 1984b

The National Priorities List identifies target sites for remedial action under the Comprehensive Environmental Response, Compensation, and Liability Act. This map shows the number of sites in each State as of September 1984. (Additional sites are located in American Samoa (1), Marianas (1), Guam (1), Puerto Rico (8), and the Pacific Trust Territories (1).)

rY {16

6

202 • Protecting the Nation’s Groundwater From Contamination

tember 1984, 538 uncontrolled hazardouswaste sites were listed for priority action; EPAprojects that the NPL could eventually con-tain between 1,400 and 2,200 sites (EPA,1984a, 1984b).3 Groundwater contaminationhas been detected at 410 of the listed sites.4

As of July 1984, remedial actions had beencompleted at on; y six sites on the NPL (U.S.House of Representatives, 1984); and of thesesix, none involved the cleanup of contaminated ●

groundwater. Engineering studies are under-way or have been completed at 258 NPL sites,and construction has begun at more than 60sites using Federal funds (EPA, 1984a).

● Under its Installation Restoration Program(IRP),5 the Department of Defense has inven-

‘EII’:! w,ts r{.pt)rtcd to hait’ ,idded 244 sitt. s to tht’ N“PI. o n O c t‘J, 1084 ( Itr’l.dlln<q[)n , Posr, 1984), CERCI.A rt.quirtw that EPA up-(I<it(> t h~> IX PI. ,il I{T<IS[ .innu<dl } (Stx’t ion 105 (B) ot t ht’ N’ational Con-t ln~{,n{ \ Pl<In).

‘“1’hls figu r(. is based (III th c 546 sites original), placed on or pro-p{mxi for tht’ NP1. (EPA, 1 \ 83a, 1983b). A detailed assessment by,In F,PA consultant ot (iata cwllcctcd for 86 (o!’ the 546) sites indicatestb,lt on-site groundu atcr con arn in,lt ion has bet>n dctt’t-tcd at olcr 60ptrccrlt o!’ thrm, off-site cent mlinat ion has been dctmted at m’cr 27ptrc t>nt ot the SIICS ( Ikx)z.-Allcn & Hamilton, Inc. , 1983).

‘“l’hc IR P IS ,] IX)D prosr,inl slrnilar to CFIRC 1,A for hazardousw ,iit<, sltcs (~n I X)D propcrr ~“

toried 911 installations and identified 200 thatmay require remedial action. As of August1983, site investigations to confirm contamina-tion problems had been completed at 32 sites,remedial actions at two sites had been com-pleted, and an additional 16 actions wereunder way. Data on the actual number of sitescontaminating groundwater were not available(Daley, 1983).UMTRCA led to the designation of 25 inac-tive uranium mill tailings sites in need ofremedial action. Preliminary engineering stud-ies indicate that groundwater contaminationeither has occurred or has the potential to oc-cur at all of the sites. To date, the Departmentof Energy has not selected remedial actions forany of the designated UMTRCA sites, al-though options have been formally proposedfor two sites (Baublitz, 1983).

CHAPTER 9 REFERENCES

Baublitz, J., Director of Remedial Action Projects Di\.i-sion, Department of’ Energ~, personal communica-tion, Aug. 27 and No\.. 18, 1983.

Booz-Allen & Hamiltorl, Inc., ‘‘Superfund Responsesto Threatened Drinking ~’ater Resources, Man-a<gemen( of L’ ncont -oiled Hazardous Waste SitesConfkr-ence, sponsored b). Hazardous Materials Con-trol Research Institute, Washington, DC, No\’em-ber 1983.

1]~(.),, p. S., Director of’ Environmental policy, Depar-t-

rnent of Defense, Te: t imony before the Subcommit-tee on In\.estigat ions and O\’ersight, Committee onPublic Works and Transportation, Aug. 10, 1983.

U.S. En\rironmental Protection Agency, press releaseon National Priorit)’ List, Sept. 1, ] 983a.

LT. S. J3nl’ir-onmer)tal Protection Agenc?’, ‘ ‘Hazardous$$’aste Sites, National Priorities List, Office of SolidW’aste and Emergency’ Response, August 1983b.

U.S. Environmental Protection Agency, ‘ ‘Environ-mental INews, Office of Public Affairs, Sept. 12,1984a.

U.S. En\’ironmental Protection Agency, ‘ ‘Background

u’

Information, National Priorities List Update #1,September 1984b.S. House of Representatives, ‘ ‘Investigation of theEn\rironmental Protection Agency: Report on thePresident Claim of Executive Privilege Over EPADocuments, Abuses in the Superfund Program, andOther Matters, ” Subcommittee on O\ersight and In-\’estimations of the Committee on Energy and Com-merce, Report No. 98-AA, August 1984.

Washington Post, ‘ ‘EPA Adds 244 Sites to Priority-Cleanup List, ” Oct. 3, 1984.

Chapter 10

State Efforts To CorrectGroundwater Contamination

Contents

Page’

Chapter Overview . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205

State Corrective Action Programs for Sources . . . . . . . . . . . . . . . . . . . . . . . . ....0.... 2 0 5

Selecting Sites for Corrective Action. ....., , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206

State Use, Preferences, and Problems With Corrective Action Alternatives . . . . . . . . 207Use and Preferences. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207Problems With Corrective Action . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... . . . . . . . . . . . 209

TABLESTable No. Page

37. OTA State Survey Responses: Factors Used By States To DetermineWhich Contaminated Sites To Address . . . . . . . . . . . . . . . . . . . . . . . . . ., . . . . . . . . . . . . 207

38. OTA State Survey Responses: Use and Preferences for CorrectiveAction Techniques. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208

39. OTA State Survey Responses: State Problems With CorrectiveAction Techniques. . . . . . . . . . . . . , . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210

FIGUREFigure No. Page

5. OTA State Survey Responses: Number of States With Programs To CorrectGroundwater Contamination From Selected Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206

Chapter 10

State Efforts To CorrectGroundwater Contamination

CHAPTER OVERVIEW

State responses. to survey questions about theirefforts to correct groundwater contamination arepresented in this chapter. (See the section O T AState Survey in ch. 4 for guidance in interpretingsurvey result s.) The following topics are discussed:

● Sources of groundwater contamination forwhich States have corrective action programs;

● priorities for selecting sites for action; and● use of, preference for, and problems with cor-

rective action techniques.

Additional information on State strengths, prob-lems, and types of desired Federal assistance relatedto corrective action is found in chapter 4.

The conclusions that follow are drawn from thisinformation.

Most States are working to correct contamina-tion problems. But State efforts vary in terms ofthe sources that are addressed and the process forsite selection, Further, State efforts to correctgroundwater contamination are generally at a nearly stage of development in that relatively few

States have formalized their approaches to correc-tive action.

The States are using a wide variety of techniques,and many techniques are used together. With thepossible exception of source removal (for the caseswhere sources can be identified and removed), theStates have few preferences among individual (orcategories of) corrective techniques. In making deci-sions, the States are concerned about the costs ofimplementation and maintenance, the time re-quired for implementation and achievement ofdesired results, and the degree of certainty abouthow well a technique will perform.

Most States have technical, legal, or institutionalproblems in undertaking corrective action. Al-though the States want Federal assistance in over-coming technical and institutional problems, mostStates do not want Federal assistance with their legalproblems, particularly those involving water rights.Water rights issues often complicate the correctionof groundwater contamination problems.

STATE CORRECTIVE ACTION PROGRAMSFOR SOURCES

Many States have programs to correct ground- the number of States with programs for a particu-water contamination from a variety of sources, as lar source and the pervasiveness of that source eithershown in figure 5. The highest number of States nationally or regionally. (See ch. 2 for a discussionhave programs to correct spills and accidents and of the location of sources. )leaks from storage facilities and pipelines. Over-all, more States have programs to correct sources In some States, correction programs are estab-in OTA Categories 1, II, and 111 than to correct lished for sources although there are no detectionCategories IV-, V, and VI sources (refer to ch. 2, programs for thosetable 5). There appears to be no correlation between is that the need for

same sources, The implicationcorrective action is often iden-

205

206 ● Protecting the Nation’s Groundwater From Contamination

Figure 5.—OTA State Survey Responses: Number of States With Programs To Correct GroundwaterContamination From Selected Sources

See fig. 2 for footnotes a through g.

SOURCE: Office of Technology Assessment.

tified as a result of complaints or other reports ofconcern rather than from any kind of systematicinvestigation. Sources for which the highest num-ber of States have correction but not specific detec-

— — D e t e c t i o n

— C o r r e c t i o n

- - - - -. Prevention

tion programs include: spills and accidents, leaksfrom storage facilities and pipelines, feedlots, ap-plication of pesticides and herbicides, abandonedwells, waste piles, and subsurface percolation.

SELECTING SITES FOR CORRECTIVE ACTION

The States consider a variety of factors in theirdecisions to undertake corrective action at one con-taminated site as opposed to another, as shown intable 37. Severity of the problem was identified by

the highest number of States, but State definitionsof severity vary. The States define severity in termsof: the characteristics of the aquifer, substances, orsite; uses of the groundwater; impacts of contarnina-

Ch. 10—State Efforts To Correct Groundwater Contamination • 207

Table 37.—OTA State Survey Responses: FactorsUsed By States To Determine Which Contaminated

Sites To Address

Number ofFactors States

Formal criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24Severity of the problem . . . . . . . . . . . . . . . . . . . . . 45Order in which contamination is detected . . . . . . 32Public pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39Availability of special funding . . . . . . . . . . . . . . 37Sites where source and responsible party

are identified . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

SOURCE: Off Ice of Technology Assessment

tion; reason for detection; and/or availwater supply alternatives.

ability o f

Some States have developed formal criteria fordetermining the sites to consider. Some use rank-ing systems developed by the Federal Government(e. g., MITRE Hazard Ranking System); othershave developed their own ranking systems. Somehave no formal ranking systems but use State reg-ulatory definitions (e. g., groundwater quality stand-ards) to determine which sites warrant action.

Differences in selection criteria may result in verydifferent corrective action decisions among the

States—a site may qualify for corrective action inone State, but a similar site in another State maybe of a lower priority. More detailed analysis ofState decisionmaking and resources (e. g., funds andstaff) is necessary to determine whether the differ-ences in priorities and approaches to site selectionresult in different levels of groundwater protectionamong the States.

Most State efforts to correct groundwater con-tamination are in early stages of development. Thispoint is apparent from a lack of formal criteria forselecting sites for corrective action in many Statesand from the lack of formal criteria, written guide-lines, or procedures in a majority of States-to: 1)establish cleanup standards for corrective action (16States have formalized approaches); 2) respondwhen quality standards are violated (19 States haveformalized procedures, although the procedures donot cover all potential sources of contamination);and 3) respond when there is no quality standardfor the substances found in groundwater(17 Stateshave formalized procedures). Any formal criteriathat have been established differ among the States.

STATE USE, PREFERENCES, AND PROBLEMSWITH CORRECTIVE ACTION ALTERNATIVES

Use and Preferences

The use of and preference for various techniquesto correct contamination are summarized in table38. The most notable point about the table is thatthe States are using or considering the use of a widevariety of techniques. That many techniques areused together is consistent with the technical limita-tions of these methods described in chapter 8. MostStates are working to correct at least some of theiridentified groundwater contamination problems.OTA did not obtain information on either the ex-tent to which all known incidents are being ad-dressed or the effectiveness of the corrective actionsthat are being undertaken.

Preferences for specific techniques were noted by40 States. Four States did not specify preferencesfor individual techniques, noting that preferencesdepend on such site conditions as source, substances,and aquifer characteristics. Two States said that itis too soon to know which techniques they prefer.

No individual technique is preferred by manyStates. Source removal (a management technique)is preferred by the highest number. The actualnumber of States preferring it may be higher be-cause the OTA survey did not ask specifically aboutthe use of this option.

Preferences for techniques relate primarily to thelow cost and/or the expected effectiveness of a tech-

208 ● Protecting the Nation’s Groundwater From Contamination

Table 38.-OTA State Survey Responses: Use and Preferences for Corrective Action Techniques

Number of States: Number of States:

With preference With preferenceTechnique Using for usea Technique Using for usea

Containment:Slurry wall . . . . . . . . . . . . . . . . . . . . . 29Sheet pile . . . . . . . . . . . . . . . . . . . . . 10Grouting . . . . . . . . . . . . . . . . . . . . . . 18Geomembrane . . . . . . . . . . . . . . . . . NQb

Clay Cutoff . . . . . . . . . . . . . . . . . . . . NQLiner c . . . . . . . . . . . . . . . . . . . . . . . . . 47Natural containment . . . . . . . . . . . . 36Surface sealing . . . . . . . . . . . . . . . . . 35Diversion ditches . . . . . . . . . . . . . . . 41Hydrodynamic controld . . . . . . . . . . 24Technique not specified . . . . . . . . . 2

Total number ofStates responding . . . . . . . . . 48

Withdrawal:Pumping . . . . . . . . . . . . . . . . . . . . . . 44Gravity drainage . . . . . . . . . . . . . . . . . . . ..31Withdrawal enhancement . . . . . . . . NQGas ventinge . . . . . . . . . . . . . . . . . . . 29Excavation . . . . . . . . . . . . . . . . . . . . . 41Technique not specified . . . . . . . . . 3

Total number ofStates responding . . . . . . . . . 47

Treatment:Skimming . . . . . . . . . . . . . . . . . . . . 34Filtration . . . . . . . . . . . . . . . . . . . . . 28Ultrafiltration . . . . . . . . . . . . . . . . . . 13Reverse osmosis . . . . . . . . . . . . . . 17Air stripping . . . . . . . . . . . . . . . . . . 34Steam stripping . . . . . . . . . . . . . . . NQPrecipitation/clarification/

coagulation . . . . . . . . . . . . . . . . . . NQ

15

51

NQ‘ o

311

17

0

012

NQ

NQ

Treatment (cont'd):Ion exchange . . . . . . . . . . . . . . . . . . 25Adsorption . . . . . . . . . . . . . . . . . . . . 34Electrodialysis . . . . . . . . . . . . . . . . . NQChemical transformation . . . . . . . . . NQBiological transformation . . . . . . . . NQIncineration . . . . . . . . . . . . . . . . . . . . NQTechnique not specified . . . . . . . . . 7

Total number ofStates responding . . . . . . . . . 43

In-situ rehabilitation:Biological degradation . . . . . . . . . . . 20Chemical degradation . . . . . . . . . . . 20Water table adjustment . . . . . . . . . . 40Natural process restoration . . . . . . . 33Technique not specified . . . . . . . . . 3

Total number ofSta tes responding . . . . . . . . , 47

Management:Limit/terminate aquifer use . . . . . . .Develop alternative water supply . .Purchase alternative water supply .Municipal treatment . . . . . . . . . . . .Point of end-use treatment. . . . . . .Source removal ... , . . . . . . . . . . . . .Monitoring. . . . . . . . . . . . . . . . . . . . .Health advisories . . . . . . . . . . . . . . .Accept increased risk . . . . . . . . . . .Technique not specified . . . . . . . . .

Total number ofStates responding . . . . . . . . .

384432NQ32h

NQ4746NQ

1

49

00

NQNQNQNQ14

16

10

5611g

011g

83

NQ1

21

a Nine states noted that they had few or no preferences for techniques—either because of having relatively I ittle experience with impiement ing corrective act iOns Or becausepreferences were site-specific. ‘our additional States had no preferences but did not provide an explanation, Some States listed more than one preference.

bNQ—OTA did not specifically question the States about this Option.C Re~wnses Primarily reflmt the use of liners for prevention of groundwater contamination (&g,, in the design of new facilities), liners are rarely used for corrective action purposes,doTA used the term plume man;lgement in the questionnaire to the States rather than hydrodynamic control .e OTA used the term gas migration control in the questionnaire to the States rather than 9as ventln9.f These treatment techniques ar{ listed under Management to reflect who is responsible for the action and whether treatment occurs before Or after Water distribution,

gAlthough OTA did not specifically question the States about use of this option, some Stales noted a preference for it.hseveral States noted that this v(as a private option and not one that the State would imPlement.

SOURCE” Office of Technology Assessment.

nique or combination of techniques. These reasonswere given for all categories of corrective actiontechniques. Other reasons given, mostly for pre-ferring management options, relate to the lack ofeither resources or effective alternatives to clean upthe contamination, the relatively short time usu-ally available for implementation, and the absenceof clear State authority to implement other tech-niques.

Agencies within a State may have different pref-erences for corrective action techniques. These dif-ferences may reflect agency missions, knowledgeof technical options, and the problems that eachconfronts. For example, in one State, the healthagency prefers to develop alternative sources, thewater quality agency prefers withdrawal and treat-ment techniques, and the industry regulatory agencyprefers containment options.

Ch. 10—State Efforts To Correct Groundwater Contamination ● 209

Problems With Corrective Action

Thirty-one States described problems with im-plementing corrective action techniques. Of theStates that did not describe problems, five specifi-cally noted that experience is too limited to evaluatethe techniques. Other problems are more closelyrelated to detection and hydrogeologic investiga-tions (e. g., with contaminant transport models andidentifying sources of contamination and respon-sible parties) and are discussed in chapter 7.

Table 39 classifies the problems associated withcorrective action alternatives as technical, institu-tional, and legal and provides examples of each.General findings are:

●

●

The States experience a variety of problemsin implementing techniques for correctiveaction, and different States have differentproblems.More States noted technical problems thanlegal or institutional problems: This situationcontrasts with the reported problems withhydrogeologic investimations, which are mostlyinstitutional (see ch. 7). However, specific legalproblems with water rights and general author-ity were also listed by a relatively large num-ber of States regarding corrective action.

-7’

b

—,

A . . -–

Photo credlf State of F/or/da Department of Envfronrnenfa/ Regulation

When contaminated drinking water wells are c losed,water must be obtained from other sources.

210 ● Protecting the Nation’s Groundwater From Contamination

Table 39.-OTA State Survey Responses: State Problems With Corrective Action Techniques

Number of States Types of problems Examples of problems

Technical problems:10 High cost of techniques

6 Site constraints associatedwith techniques

1 Difficulties implementing techniques4 Lack of knowledge on setting standards

for performance4 Uncertainty over effectiveness of

techniques3 Adverse impacts of some techniques

3 Intensive data and monitoring requirements

21 Total States reporting technical problems

Institutional problems:633

3

1

211Legal problems:

10

8

2

16

Lack of fundsInadequate technical expertiseInadequate regulations and program implementation

Lack of interagency coordination

Unavailability of equipment

Public resistanceTotal States reporting institutional problems

Lack of authority—water rights

Lack of authority—other

Liability concerns

Total States reporting legal problems

●

●

●

●

●

●

●

●

●

●

●

●

●

●

Expense of treatment techniques for removing someorganics

Expense of developing alternative water suppliesExpense of correcting salt-water contamination inagricultural areas

Techniques unavailable for karst environmentsLimitations on achievable withdrawal ratesDifficulties in designing and installing linersLack of information on health and environmentalimpacts of many contaminants

Inability to predict technical performance

Increased contaminant migration caused by wellclosings and cessation of pumping

Impacts on air quality caused by air strippingDifficulties in identifying sources of contaminationContinued presence of contaminants after corrective

action has been undertaken necessitatescontinued monitoring

Scope of State activities constrainedLack of staff with sufficient technical knowledgeLack of standards for determining cleanupobjectives

Inadequate enforcementOverlapping authority among agenciesDifficulties in coordinating with Federal agenciesShortage of drilling rigs and lack of geophysicalequipment

Public unwillingness to use water after cleanup

● Difficulties in obtaining information on water useand pumping schedules

• Inability to control or restrict water uses that mayinfluence alternatives involving pumping

● Difficulties in obtaining alternative water supplies● Lack of regulatory jurisdiction over potential

sources of contamination (e.g., undergroundstorage tanks)

● Difficulties in obtaining property access● Potential for damage suits if State supplies

alternative water supply (e.g., bottled water)that turns out to be contaminated

31 Total number of States noting problems

SOURCE Off Ice of Technology Assessment

Prevention

Chapter 11

Federal Efforts To PreventGroundwater Contamination

Contents

Page

Chapter Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215

Prevention of Contamination by Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215Scope of the Groundwater Resource Addressed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215Types of Programs and Sources Addressed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223Performance Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223

Aquifer Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225

Regulating the Production and Use of Potential Contaminants. . . . . . . . . . . . . . . . . . . 226Toxic Substances Control Act . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226Federal Insecticide, Fungicide, and Rodenticide Act . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228

Chapter 11 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231

TABLETable No. Page

40. Federal Provisions To Prevent Groundwater Contamination From Sources . . . . . . . . . 218

Chapter 11

Federal Efforts To PreventGroundwater Contamination

CHAPTER OVERVIEW

Activities authorized by Federal statutes relatedto the prevention of groundwater contamination arcdescribed in this chapter. They address preventionin terms of:

● s o u r c e s o f c o n t a m i n a t i o n ;

● groundwatcr recharge areas; and● potential contaminants.

The Federal Government does not have a for-mal plan or cornprehensive strategy to prevent con-tamination. For cxample, programs for sources—

for design and operation, siting, and post-closure—do not use a consistent definition of the ground-water resource to be protected and do not sys-tematically address the contamination potential ofsources. The program for protecting recharge areasis not comprehensive because the designation ofsuch areas is optional and only certain potential}’contaminating projects are restricted. To date, theapplication of provisions that regulate the produc-tion and use of potential groundwater contaminantsto prevent contamination has been limited.

PREVENTION OF CONTAMINATION BY SOURCES

Federal statutes and programs address preven-tion of conntamination from sources in terms of threetypes of factors:

1. the scope of the groundwater resource covered(e. g., groundwatcr in general or drinkingwater supplies);

2. the specific’ sources addressed and the type ofprogram (e. g., for design and operation—these may be either mandator}’ or voluntary);a n d

3. the performance requirements specified (e. g.,for the siting of’ sources and their closure).

Table 40 summarizes the provisions of Federal pro-grams in terms of’ these factors. Federal monitor-ing and corrective action requirements are notedin the table but they are discussed in chapters 6 and9. respectively.

1 F( JU r statutes Included I n [h. 3 are not applicable [(J [his discus-~it)n and [hus are not Included in table 40: NEP.4 and WRDA don( J[ (Jitdbl ish rcqu i mments for SOLI rces; C ERC 1..4 and the Reclama-t Ion A( t ( RA) are not in{ Iuded because they provide for remedial ac-t I(]ni, not pretentlte measures

Scope of the GroundwaterResource Addressed

The scope of groundwater resources covered byFederal programs is an important consideration inpreventing groundwater contamination. However,Federal programs are not consistent in defining theresource covered and the extent of degradation per-mitted. Table 40 (column 3) summarizes the wayin which groundwater is addressed by Federalprograms:

● The scope of groundwater resources coveredby Federal programs is not consistent.—Four programs (authorized by AEA for low-

level waste sites, FLPMA and associatedmining laws, SMCRA, and TSCA) addressgroundwater in general.

—Two programs are concerned with the up-permost aquifer (authorized by RCRA-Subtitle C and UMTRCA).

—Three programs cover underground drink-ing water supplies (authorized by RCRA-Subtitle D, SDWA, and CWA-Section405).

215

Table 40.-Federal Provisions To Prevent Groundwater Contamination From Sources

Type ofPublication program and

date ofCorrective

Relationship sources SitingStatute

Monitoring action Post-closureregulations to groundwater addressed requirements requirements b requirements requirements

Atomic Energy NRC regulations Radioactive material re-Act (10 CFR 61)–12/27/82 leased into ground-

(EPA has not promul- water must not exceedgated environmental levels specified in the-. -.--.: -- ---- 4 -.4-,plulcwtlul I ala Iualua) I“cyuiiliicn”ls

NRC proposed regula- Geologic repositoriestions (10 CFR 60)– include the operations718181, 46 FR 35280 area and the geologic

EPA proposed environ- setting (the geologic,mental protection stand- hvdrologic. and geo-ards (40 CFR 191)-12/29/82, 47 FR 58196d

Clean Water Act— Section 201 EPA Criteria—2/n/76,

41 FR 6190 (EPA con-struction grant regula-tions are specified in40 CFR 35)

chemical system-s thatprovide isolation of thewaste).

Groundwater is separatedinto three categoriesconcerning the landapplication of waste-water.— If groundwater is a

potential drinkingwater supply, theNational InterimDrinking WaterRegulations (NIDWRs)must not be ex-ceeded. If back-ground levels arehigher than NIDWRs,they must not beexceeded.

Design and operatingstandards are specifiedfor low-level wastedisposal sites.

Design and operatingstandards are spe-cified for geologic re-positories for high-levelradioactive wastes.

Disposal sites must pro-vide sufficient depth tothe water table to pre-vent groundwater in-trusion into me wastes.

Hydrogeologic units usedfor disposal shall notdischarge groundwaterto the surface withinthe disposal site.

Other requirementsrelate to seismic andother tectonicactivity, flooding, loca-tion of naturalresources, and popula-tion growth anddevelopment.

The geologic settingmust exhibit structural,tectonic, hydrogeologic,geochemical, and geo-morphic stability.Groundwater traveltimes (prior to wastedeposition) throughthe geologic setting(i.e., the area thatprovides isolation ofwastes) to the acces-sible environmentmust be at least1,000 years.

Criteria for best practicable Nonewaste treatmenttechnology for landapplication of waste-water must be met byapplicants for con-struction grant funds(for sewage treatmentworks).

Yes Yes Active institu-tional controls(e.g., monitor-ing) may notbe relied onfor more than100 years(the exactperiod to bedeterminedby the NRCon a case-by-casebasis).

Yes None Disposal sys-tems must bedesigned toprevent re-leases ofspecificamounts ofradioactivematerial for10,000 yearsafter disposal.Active institu-tional controlsmust not berelied onbeyond a fewhundred years.

Yes Yes None

Table 40.-Federal Provisions To Prevent Groundwater Contamination From Sources— continued

Type ofPublication program and

date ofCorrective

Relationship sources SitingStatute

Monitoring act ion Post-closureregulations to groundwater addressed requirements requirements requirements requirements

Clean Water Act — If groundwater is used– Section 201

(cent’d)as a drinking watersupply, the conditionsabove must be met(except that levelsfor biological con-taminants must notbe exceeded in thesupply if water isnot disinfected).

— If groundwater isused for purposesother than drinkingwater, criteria areestablished on acase-by-case basis.

– Section 208 EPA State grant regula- The program is orientedtions (40 CFR 35, Sub- to surface water; how-part G)–5/23/79 ever, States are au-

thorized to undertakegroundwater activitiesto the extent prac-ticable.

— Section 311 EPA regulations The program is oriented(40 CFR 112)–12/11/73 to surface water pro-

tection; groundwateris not directlyaddressed.

– Section 404 EPA regulations Protection is oriented to(40 CFR 230)–12/24/80 wetlands protection;

groundwater is notdirectly addressed.

None None None None

Funds are authorized for Not Not Not NotStates to develop water applicable applicable applicable applicablequality managementplans. State plans pro-vide for developmentof activities (e.g., BestManagement Practices)related to certainnon-point sources.e

Spill Prevention andCountermeasure Control(SPCC) Plans must beprepared for above--ground and undergroundtanks of a specifiedsize containing oil.The plan must describedesign and operatingconditions.

Permits must be obtained General guidance is pro- Noneto dispose of dredged vialed that relatesor fill material. Guide- to the selection of dis-Iines to be applied in posal sites such thatthe review of proposed the potential for erosion,discharges are specified. slumping, or /caching

of material into sur-rounding aquatic eco-systems will bereduced.

None None

Table 40.-Federal Provisions To Prevent Groundwater Contamination From Sources— continued

Type ofPublication

date ofprogram and Corrective

Relationship sources Siting Monitoring action Post-closureStatute regulations to groundwater addresseda requirements requirements requirements requirements

– Section 405

Coastal ZoneManagementAct

EPA Criteria(40 CFR 257)-9/13/79

NOAA State grantregulations(15 CFR 923)–3/28/79

Federal Insecticide,Fungicide, andRodenticide Actf

– Section 3 EPA regulations(40 CFR 162)–7/3/75

— Section 19 EPA regulations(40 CFR 165)–5/1/74

Federal LandPolicy andManagement Act

— Mineral Leasing BLM regulationsAct of 1920 and (43 CFR 23)–1/18/69Materials Actof 1947

Criteria for determiningunreasonable adverseeffects do not explic-itly address ground-water.

Regulations refer towater systems; ground-water is not explicitlyaddressed.

The use of pesticidesthat may cause un-reasonable adverse ef-fects on the environ-ment can be restrictedor prohibited.

Recommended proce-dures are establishedfor storage areas forpesticides.

Regulations specify that Requirements for mininga plan of operations of leasable minerals onmust be developed that Federal lands areincludes measures to to be specified in theprevent or control plan of operations.groundwater pollution.State and Federal waterquality standards mustbe met.

None

Notapplicable

Use restrictions maybe established for apesticide.

Facilities should belocated where floodingis unlikely and wheresoil and hydrogeologiccharacteristics willprevent contaminationof any water systemby runoff or perco-lation.

Operations may be pro-hibited or restricted inareas if the regulatoryauthority determinesthat water qualitywill be loweredbelow State standardsor levels set by DOI.Groundwater isnot explicitlymentioned.

Yes Yes None

Not Not Notapplicable applicable applicable

None None

None None

None

None

None None Performancebond must befiled to coverreclamationactivities.

w

●

Table 40.—Federal Provisions To Prevent Groundwater Contamination From Sources— continued

Type ofPublication program and Correct we

date of Relationship sources Sltinq Monitong action Post-closureStatute regulations to groundwater addressed requirements requirements requirements c requirements

— U.S. Mining BLM regulationsLaws (43 CFR 3800)–3/3/80

— Geothermal BLM regulationsSteam Act (30 CFR 270)–6/27/79

and 6/30/829

Hazardous Liquid DOT regulationsPipeline Safety (49 CFR 195)–7/27/81Act as amended

Hazardous DOT regulationsMaterials (49 CFR Subtitle B,Transportation Subchapter C)–4/15/76Act as amended

Resource Conserva-tion and RecoveryAct

– Subtitle C EPA regulations(40 CFR 264)–7/26/82Note: Final regulationshave not been promul-gated for coveredunderground tanks orfor some open burn-ing and detonationsites.

Groundwater is not di-rectly addressed in theregulations; however,State and Federal waterquality standards mustbe met.

Regulations specify thata plan of operationsmust be developedwhich includes meas-ures to prevent orcontrol groundwater pol-I u t i o n . S t a t e a n dFederal water qualitystandards must be met.

The objective of the reg-ulations is to preventleakage. However,groundwater isnot directlyaddressed.

The objective of theregulations is toprotect against risksto life and property.However, groundwateris not directlyaddressed.

Requirements for min- None None None Performanceing of locatable min- bond must beerals on Federal lands filed to coverare to be specified in reclamationthe plan of operations. activities.

Requirements for develop- Nonement of geothermalsteam on Federal landsare to be specified inthe plan of operations.

Des ign and ope ra t i ng Nonestandards are specifiedfor pipelines used totransport hazardousliquids.

Design and operatingstandards are specifiedfor transportation ofhazardous materialsand hazardous wastes.

None

Regulations specify that Design and operating Facilities must not behazardous substances standards are specified located in areas sub-entering groundwater for hazardous waste ject to flooding(in the uppermost treatment, storage, or seismic conditions.aquifer) must not ex- and disposal facilitiesceed background (e.g., landfills, surfacelevels, the Maximum impoundments, wasteContaminant Levels for piles, and land treat-14 constituents specified ment areas).by the National InterimDrinking Water Regula-tions (if higher thanbackground), or alterna-tive concentrationlimits (established ona case-by-case basis)at the compliance point.

Yes

None

None

Yes

None None

None None

None None

Yes Specifiedactivities(e.g., ground-water monitor-ing and op-eration ofIeachate col-lectionsystem) mustbe continuedfor 30 yearsafter closureunless thetime period isincreased oror decreasedby the regula-tory authority.

Table 40.-Federal Provisions To Prevent Groundwater Contamination From Sources— continued

Type ofPublication program and Corrective

date of Relationship sources Siting MonitoringStatute

action Post-closureregulations to groundwater addressed a requirements requirements requirements requirements

– Subtitle D

Safe DrinkingWater Act -

– Part C(UIC Program)

Surface MiningControl and

EPA regulations(40 CFR 257)–9/13/79

EPA regulations(40 CFR 146)–6/24/80as amendedNote: Regulations havenot been promulgatedfor certain wells.1

OSM regulations(30 CFR 816 and 817)–

Reclamation Act revised 9126183(Regulations were firstpublished in 1979)

The criteria specify thatfor underground drink-ing water sources,background levels orthe National InterimDrinklng Water Regula-tions (if higher thanbackground) must notbe exceeded beyondthe application bound-ary or an alternativeboundary establishedon a case-by-case basis.

Regulations specify thatit must be demonstratedthat activities will notbe conducted in amanner that allowsmovement of contam-inants into an under-ground sourceof drinkingwater (defined as anaquifer or its portionthat supplies anypublic water systemor contains sufficientwater to supply apublic water systemand that currentlyserves as a drinkingwater supply orcontains fewer thanI0,000mg/1 TDS).Aquifers may be ex-empted if they arenot currently drinkingwater supplies, cannotand will not be sup-plies in the future, orcontain 3,000-10,000mg/1 TDS and are notreasonably expectedto supply a publicwater system.

Regulations specify thatgroundwater qualitymust be protected byhandling earth materialsand runoff in a mannerthat minimizes acidic.

Funds are authorized forStates to developoptional State solidwaste programs.Specified Federalcriteria for sanitarylandfills must be metby State program.

Design and operatingstandards are specifiedfor underground injec-tion wells.

Requirements are speci-fied in operating permitfor surface coal min-ing and undergroundcoal mining (forsurface effects).

None None None None

None

None

Yes

Yes Yes

None None h

Performancebond must befiled to coverreclamationactivities.

Table 40.-Federal Provisions To Prevent Groundwater Contamination From Sources— continued

Type ofPublication program and

date ofStatute

Relationship sourcesregulations to groundwater addressed

Toxic SubstancesControl Actf

— Section 6

Uranium MillTailingsRadiationControl Act

EPA regulations(40 CFR 761)–5/31/79

NRC regulations(10 CFR 40)–10/3/60

EPA regulations(40 CFR 192)–10/7/83,48 FR 45926

toxic, or other harmfulinfiltration to ground-water systems and bymanaging excavationsand other disturbancesto prevent and controlthe discharge of pol-lutants into ground-water. State andFederal water qualitystandards must bemet.

The objective of regula-tions is to ensureagainst an unreason-able risk of injury tohealth or the environ-ment (e.g., water) fromthe manufacture, proc-essing, distribution,use, or disposal of achemical substance ormixture.

Same as RCRA–Subtitle C (except thatlevels for certainradioactivesubstances arespecified).

Design and operatingstandards are specifiedfor PCB disposal sites.

Design and operatingstandards arespecified for uraniummill tailings disposalsites (same as RCRASubtitle C require-ments for surface im-poundments).

CorrectiveSiting Monitoring action Post-closure

requirements requirements requirements requirements

Facilities must be locatedin areas of low to mod-erate relief and mustavoid floodplains, shore-Iands, and groundwaterrecharge areas.

Bottom of landfill mustbe 50 feet fromhistorical high watertable.

NRC requirementsspecify that the selec-tion process mustconsider hydrologicand other conditionsas they contribute tocontinued immobiliza-tion and isolation ofcontaminants fromusable groundwatersources.

EPA regulations do notestablish siting re-quirements.

Yes None Operatingrecords mustbe retainedfor 20 yearsafter closure.

Yes Yes Long-termsurveillance isspecified byNRC on acase-by-casebasis.

EPA regulationsrequire thatsites bedeveloped tobe effectivefor 1,000 yearsto the extentreasonableachievableand in anycase for atleast 200years.

asee table 13 and app, H for additional information on sources, types of programs, and design and operating requirements.

%ee table 30 and app. E for additional information on monltonng requirements.csee table 36 and app. G for additional information on correctwe action Pmw.ions%he provisions cited in the table are EPA’s proposed protection standards.eprovisions aPPIY t. non.point sources Including irrigation return flows, agricultural sources, Iwestock areas, mine rUnOff, saltwater Intrusion, and construction actlvltYf See the text for a more detailed discussion of FIFRA and TSCA.gRegulatlons for the Geothermal Steam Act were redesignated, with minor revisions, as 43 CFR 3260 on Sept. 30, 1983.~here are plugging requirements at closure.I Regulations have not been promulgated for Class IV and V wells under the UIC Program; see app. H and 40 CFR 146.

SOURCE: Office of Technology Assessment

222 ● Protecting the Nation’s Groundwater From Contamination

–One program (under Section 201 of CWA)separates groundwater into three catego-ries—drinking water supplies, potentialdrinking water supplies, and groundwaterused for other purposes—with differentstandards for each category.

—The programs authorized by five statutesdo not directly address groundwater in anyway (CWA—Sections 311 and 404, CZMA,FIFRA, HLPSA, and HMTA).

—The requirements for selecting geologic re-positories for high-level radioactive wastes(under AEA) include surrounding hydro-geologic systems as part of the repository.

● The extent of degradation permitted by Fed-eral programs is not consistent.—Under the Subtitle C program of the Re-

source Conservation and Recovery Act(RCRA, which addresses the uppermost

aquifer), the Environmental ProtectionAgency (EPA) may establish alternativeconcentration limits on a case-by-case basis(instead of requiring that groundwater con-tamination not exceed background levels orMaximum Contaminant Levels). EPA reg-ulations specify the factors that must be con-sidered in approving the alternative concen-tration limits.2 However, decisions are to bemade by permit writers on a site-specificbasis.

—Under the Underground Injection ControlProgram of the Safe Drinking Water Act(SDWA), certain aquifers maybe exempted.Thus, underground injection into thoseaquifers is not controlled.

‘See 40 CFR 264.94(b).

Photo credit: CECOS International

Liners and Ieachate control systems are included in the design and operating requirements for hazardous waste landfillsand surface impoundments under Subtitle C of RCRA. This photograph shows a synthetic and clay-lined hazardous waste

disposal facility prior to use.

Ch. n-Federal Efforts To Prevent Groundwater Contamination . 223

Types of Programs andSources Addressed

The principal type of program related to the pre-vention of contamination from sources is for de-sign and operation. As indicated in chapter 2, po-tential sources of contamination have differentcharacteristics for releasing substances (e. g., pointv, non-point discharges) which necessitate differentdesign specifications and operating procedures toprevent groundwater contamination, Programsmay be either mandatory or voluntary; and theyare specified for particular sources of contamina-tion. Design and operating requirements are sum-marized in table 40 (column 4) and described indetail in appendix H in relation to each Federal pro-gram and OTA source categories (refer to ch. 2,table 5). The following observations can be madeabout the types of programs that have been devel-oped. (Note that the technical adequacy of theseprograms has not been evaluated in this study. )

● Mandatory design and operation requirementsapply to subsets of sources within CategoriesI, II, III, and V. As noted in chapter 3, thesources addressed by programs with manda-tory requirements are, for the most part, asso-ciated with hazardous wastes or other toxicmaterials.

● With the exception of certain mining activi-ties and the application of certain pesticides,sources in Category IV are not subject to man-datory requirements. However, Best Manage-ment Practices or recommended procedureshave been developed for some of these sources.

● There are no mandatory requirements for anysources in Category VI.

It is significant that many of the programs’ re-quirements were established fairly recently. Table40 (column 2) indicates that the majority of regu-lations were published within the past 5 years.Thus, the impacts of some of these programs onthe prevention of groundwater contamination can-not yet be ascertained. Further, despite the fact thatprograms have been authorized by Federal legis-lation for certain sources, regulations specifyingdesign and operating (as well as monitoring andcorrective action) requirements have not been pro-

mulgated for certain sources. These sourcesinclude:

. covered underground tanks (under RCRA);

. injection wells used to dispose of hazardouswastes into or above underground sources ofdrinking water and all other injection wells ex-cept those used for the following purposes: dis-posal of hazardous or radioactive materials andother wastes (e. g., municipal or industrial) be-neath underground sources of drinking water;wells used in association with oil and gas pro-duction; and wells used for in-situ or solutionmining (under SDWA);

. open burning and detonation sites (underRCRA); and

● low-level radioactive disposal sites (underAEA) .3

In addition, the purview of the Hazardous Liq-uid Pipeline Safety Act (HLPSA), which establishesrequirements for interstate pipelines (used to trans-port petroleum products and anhydrous ammonia),includes the storage of liquids incidental to theirmovement by pipeline. Although regulations havebeen promulgated for pipelines, the Departmentof Transportation has not established requirementsfor storage facilities (e. g., tanks).

Performance Requirements

This study also examined the extent to whichFederal programs address the prevention of ground-water contamination with performance require-ments for siting new sources and post-closure. Asindicated in table 40 (column 5), siting provisionsfor new sources are specified by six programs: high-and low-level radioactive waste programs under theAtomic Energy Act (AEA); pesticide storage pro-visions under the Federal Insecticide, Fungicide,and Rodenticide Act (FIFRA); mineral mining pro-visions for leasable minerals under the MineralLeasing Act; the hazardous waste program (Sub-title C) under RCRA; the PCB disposal require-ments under the Toxic Substances Control Act(TSCA); and the Nuclear Regulatory Commission

3The Nuclear Regulatory Commission has issued licensing regula-tions for these facilities. However, EPA has not issued environmentalprotection standards.

224 ● Protecting the /Vation’s Groundwater From Contamination

Photo credits: U.S. Environmental Protection Agency

Open burning and detonation of waste explosives are addressed under RCRA but regulations have not yet been promulgated.These photographs show white phosphorus drums being prepared for disposal . . . and their subsequent detonation.

requirements for uranium mill tailings sites estab-lished under the Uranium Mill Tailings RadiationControl Act (UMTRCA). Of the six programs, therequirements established under RCRA and theMineral Leasing Act do not explicitly address theprotection of areas vulnerable to groundwater con-lamination. 4

Provisions that address any contamination thatmay occur after a source is no longer in use (’‘post-closure’ are also important for the prevention ofcontamination. Table 40 (column 8) summarizesthese provisions .5 Post-closure provisions are speci-fied for a limited number of sources: disposal fa-cilities for hazardous and certain radioactivesubstances and mining operations. There is alsoan inconsistency between the requirements for haz-ardous waste facilities and high-level radioactivewaste sites: in spite of the fact that many of thechemicals found in hazardous waste disposal facil-ities are non-degradable, a post-closure period of

only 30 years has been set. G In comparison, it hasbeen proposed that high-level radioactive wastedisposal sites which contain radioactive substancesthat do degrade over time (e. g., half-lives ofradioactive substances range from tens to more thanmillions of years) must be designed to prevent re-leases for 10,000 years.7

There are two additional points about the post-closure requirements in table 40 with respect to spe-cific

1.

2.

sources:

There are no post-closure monitoring re-quirements established for PCB disposal fa-cilities. Thus, any groundwater contamina-tion that may occur following closure is notlikely to be detected.Specific requirements have not been estab-lished for uranium mill tailings sites. Post-closure provisions will be required only at thediscretion of the regulatory authority.

4Proposed RCRA regulati >ns issued by EPA on Dec. 18, 1978 (43FR 59000) did contain siting requirements with respect to aquiferrecharge areas, but the provi iions were not adopted in the final regu-lations issued by the agency (40 CFR 264. 18).

‘In this assessment, reclamation activities conducted as part of min-ing operations are considered post-closure provisions.

‘Although the post-closure period can be extended by the regula-tory authority if necessary, it is possible that a site will appear to besecure at the end of the 30-year period but subsequently releasesubstances into groundwater.

747 FR 58196, Dec. 29, 1982.

Ch. 1 l—Federal Efforts To Prevent Groundwater Contamination ● 225

AQUIFER PROTECTION

A second approach of Federal statutes related tothe prevention of groundwater contamination is toprotect recharge areas. The Sole Source Aquiferprovision of the Safe Drinking Water Act, Section1424(e), allows the Administrator of EPA to desig-nate the aquifers that serve as sole or principaldrinking water sources and to prevent any commit-ments of Federal financial assistance to projects thatmay create significant hazards to public health bycontaminating such aquifers.

The Sole Source Aquifer provision ’does not es-tablish a comprehensive program for protectingaquifer recharge areas. The process for designat-ing sole source aquifers is optional, and only cer-tain projects are restricted from receiving Federalfinancial assistance. In addition, funding decisionsare based on findings regarding the significance ofthe hazard posed to human health.8

EPA issued proposed regulations in September1977 establishing procedures for designating solesource aquifers and reviewing projects proposed inthese areas (final regulations have not been pub-lished by EPA).9 The proposed regulations defineseveral key terms used in this section of the statute:

● A sole or principal source aquifer is definedas one which supplies 50 percent or more ofthe drinking water for an area. The proposedregulations also specify six factors that mustbe considered in deciding whether to designatea sole source aquifer:1.

2.

3.

4.5.

6 .

the availability of alternative sources ofdrinking water;the size of the area and population servedby the aquifer;the susceptibility of the aquifer to con-tamination through the recharge zone;the location of the aquifer;the number of public water systems usingwater from the aquifer, the number of peo-ple served by the systems, and the treatmentprovided by the systems; andsuch other factors as are deemed relevant.10

●

●

A significant hazard to public health meansany level of a contaminant: a) which causesor may cause the aquifer to exceed any Max-imum Contaminant Level set forth in any pro-mulgated National Primary Drinking WaterRegulation at any point where the water maybe used for drinking purposes or which mayotherwise adversely affect human health, orb) which may require a public water systemto install additional treatment to prevent suchadverse effects.Federal financial assistance includes any finan-cial benefits provided directly as aid to a proj-ect by a department, agency, or instrumental-ity of the Federal Government in any form,including contracts, grants, and loan guaran-tees. Actions or programs carried out by theFederal Government itself (e.g., dredging per-formed by the Army Corps of Engineers) andactions performed for the Federal Governmentby contractors (e. g., construction of roads onFederal lands) are not included. Federal finan-cial assistance is limited to benefits earmarkedfor a specific program or action and awardeddirectly to the program or action .11

As of July 1984, EPA had designated 17 sole sourceaquifers (see EPA, 1983, 1984).

1145 FR 5 I fjz 1. EPA has indicated that it ‘‘will not be concernedwith reviewing on an individual basis, small isolated commitmentsof financial assistance such as individual home mortgage loans.

12De~ignated aquifers are:1. Edwards Aquifer, TX (petition received 1 /3/75, designated

12/16/75)2. Nassau/Suffolk Counties Long Island, NY (petition received

1/21/75, designated 6/21178)3. Maryland Piedmont (petition received 10/1/75, designated

8/27180)4. Northern Guam (petition received 11/20/75, designated 4/26/78)5. Fresno County, CA (petition received 8/9/76, designated

9/10/79)6. Spokane-Rathdrum Prairie, WA-ID (petition received 10/4/76,

designated 2/9/78)7. Biscayne Aquifer, FL (petition received 5/8/78, designated

10/1 1/79)8. Buried Valley, NJ (petition received 1/16/79, designated 5/8/80)9 Cape Cod, MA (petition received 3/4/81, designated 7/31/82)

10. Whidbey Islandj-WA (petition received 4/31~81, designated—8The Sole Source Aquifer provision originated as a floor amend-

ment to the Safe Drinking Water Act. See Hemphill, 1976.’42 FR 51620, Sept. 29, 1977.1042 FR 51623.

4/6/82)11. Camon Island, WA (petition received 4/31/81, designated

4/6/81)12, Kings/Queens Counties, NY (designated 1/24/84)

226 ● Protecting the Nation’s Groundwater From Contamination

After an area is designated as having a sole orprincipal source aquifer, the Regional Adminis-trator may review any project located in that areafor which Federal financial assistance is proposed.The proposed regulations specify the review pro-cedures that must be followed by EPA. Anyone

(footnote 12 continued)13. Ridgewood, NJ (desi\:nated 1/24/84)14. Upper Rockaway River Basin, NJ (designated 1/24/84)15. Upper Santa Cruz and Avra-Altar Basin, AZ (designated

1/24/84)16. Nantucket Island, MI\ (designated 1/24/84)17. Block Island, RI (ales gnated 1/24/84)ljIf an area is designated, ~pA must identify the boundaries of the

recharge zone or streamflow !iource zone (or portions thereo~ through

may petition EPA to review a project, or EPA mayinitiate the review. In addition, Federal agenciesare required to maintain a list of projects in therecharge or streamflow zone of a designated aquiferfor which environmental impact statements (underthe National Environmental Policy Act, NEPA) willbe prepared. EPA has stated that “the process ofproject review pursuant to Section 1424(e) will beintegrated as fully as possible with the review ofFederal actions subject to NEPA."14

which contamination could affect the area and the water bcdy or bodieswhich contact the recharge zone. 42 FR 51623.

‘+42 FR 51621.

REGULATING THE PRODUCTION AND USEOF POTENTIAL CONTAMINANTS

There are two Federal statutes that providefor regulation of the production and use of poten-tial groundwater contaminants: the Toxic Sub-stances Control Act and the Federal Insecticide,Fungicide, and Rodenticide Act, Both require sub-mission of data on the environmental effects ofchemicals and authorize the regulation of poten-tial groundwater contaminants. To date, however,their use for the prevention of contamination hasbeen limited.

Toxic Substances Control Act

The Toxic Substances Control Act (TSCA) pro-vides for the regulation of chemical substances andmixtures whose manufacture, processing, distribu-tion in commerce, use or disposal may present anunreasonable risk of Injury to health or the envi-ronment, 15 Unlike other statutes analyzed in thisstudy (e. g., RCRA and SDWA), TSCA does notfocus on specific sources of groundwater contamina-tion. However, because it encompasses all aspectsof a chemical’s pathway through society, includinguse and disposal, TSC A has the potential for direct-ly addressing groundwater contamination (see ch.

1’” ‘Environment’ is defined to include water, air, and land andthe interrelationship which exists among and between these media andall living things (Section 3(5)). ‘‘Groundwater’ is not explicitly men-tioned.

2 for a discussion of pathways). In addition, TSCAprovides a mechanism for obtaining data on theproperties of certain chemicals associated withsources of groundwater contamination.

Two provisions of TSCA are most relevant tothe prevention of contamination.

1.

2.

Section 5 requires that manufacturers or im-porters of ‘new’ chemicals submit a preman-ufacture notice (PMN) to EPA 90 days beforethe substance enters commerce. The PMN isto include sufficient data for EPA to determinewhether the manufacture, processing, distri-bution in commerce, use, or disposal of thenew chemical—or any combination of suchactivities—will present an unreasonable riskof injury to health or the environment.16

Section 6 provides for regulation of the man-ufacture, ‘processing, distribution in com-merce, use, or disposal of chemical substancesor mixtures that present or will present an un-

16TSCA does not define ‘ ‘unreasonable risk. In 1979, EPA statedthat it “intends to balance the magnitude of risks and social benefitsassociated with a chemical substance. In doing this, EPA will con-sider the seriousness of the risk (including the nature, extent, and re-versibility of the adverse effects), the availability of alternatives to thesubstance and their associated risks, and the benefits (economic andotherwise) which accrue to society from the production and use of thesubstance. 44 FR 16243, Mar. 16, 1979.

Ch. Ii—federal Efforts To Prevent Groundwater Contamination . 227

reasonable risk of injury to health or the envi-ronment. 17

Section 5. TSCA specifies that the PMN sub-m it ted to EPA by a manufacturer must include in-formation regarding the chemistry of the newsubstance, proposed uses, the amounts to be man-ufactured or processed, the byproducts, the num -ber of’ workers to be exposed and the duration ofexposure, and methods of disposal. General classesof information are also to be submitted to EPA,inclucl ing any available test data in the possessionor control of the manufacturer related to environ-mental and health effects and a description of anyother data, insofar as known to the manufactureror reasonably ascertainable.18 EPA can then takeone of four actions following the review of a PM N’:1 ) allow the substance to be manufactured with-out restriction; 2) allow the substance to be manu-factured for specified uses (EPA would have to benotified about other uses); 3) if a decision aboutunreasonable risk cannot be reached because of thelack of’ in information, delay the manufacture, proc-essing, distribution, use, or disposal until additionalinformation is developed; or 4) regulate the man-u facture, processing, distribution, use, or disposalof t the substance.

A previous OTA study reviewed the informa-tion contained in the 740 PMNs submitted to EPAfrom July 1, 1979 to June 1981 and in June 1982(0TA, 1980). The study found that 62 percent ofthe PMNs reported all the information specified byTSCA (e. g., chemistry, proposed uses, amounts,byproducts, exposure, and disposal methods).However, only 10 percent of the PMNs reportedany information from tests used to estimate envi-ronrnental effects. Physical-chemical data mostdirectly related to predicting the behavior of chem-icals in groundwater- density, vapor pressure,solubility (in water), and partition coefficient-werereported, respectively, on 19 percent, 24 percent,

1 T@her Sec.[ions of TSCA provide for: the compilation of an in-~’ento~ of existing chemicals manufactured or processed in the UnitedStates and the recording and reporting of certain health and environ-mental data (Section 8); the development of test rules on health andenvironmental effects of existing chemicals (Section 4); the commence-ment of ci~il actions when chemical substances pose an imminenthazard (Section 7); and the authorization of State grants for estab-lishment and operation of programs to prevent or eliminateunreasonable risks (Section 28).

18 Sect~on 5(d)(l).

42 percent, and 4 percent of all PMNs (OTA, 1983;Gough, 1983), In addition, although approximately50 percent reported toxicity information, only 17percent had any test information about the 1ikeli-hood that the chemical could cause cancers, birthdefects, or mutations.

In the absence of data on the physical-chemicalproperties of chemicals used to assess environmentaleffects under the PMN review process, EPA relieson estimates of chemical properties and the use ofcomputer models to determine whether the use ofa new chemical may affect groundwater. 9

Section 6. This section provides EPA with broadauthority to address sources of groundwater con-tamination directly by regulating the use or disposalof a chemical substance or mixture .20 To date, EPA

19EpAs office of Toxic Substances has undertaken two projectsto support the premanufacture review process. One involves a com-puter program, CHEMEST, which estimates certain chemical prop-erties on the basis of molecular structure information (Arthur D Lit-tle, 1983). The program is capable of providing estimates of thefollowing properties: volubility in water; the soil adsorption coefficient;bioaccumulation or the bioconcentration factor (in fish); the activitycoefficient; the boiling point; the vapor pressure; the rate of volatiliza-tion from water; and Henry’s Law Constant.

The second project involves the development of two models usedto assess the behavior of a chemicat in soil and groundwater. One mmielpredicts movement through the unsaturated zone (Bonazountas, etal. , 198 1), and the other simulates the transport of contaminantsthrough an aquifer (Yeh, 1981). Information compiled on 70 loca-tions in the United States is the data base for these computer model-ing efforts (Versar, 1983).

Zosect ion 6 requires the Administrator of EPA to take one or moreof the following actions if there is a reasonable basis to conclude thatthe manufacture, processing, distribution in commerce, use, or disposalof a chemical substance or mixture (or any combination of activities)presents or will present an unreasonable risk of injury to health orthe environment:

1.

2.

3.

4.

.5.

6.

7.

prohibit or limit the amount of such substance or mixture whichcan be manufactured, processed, or distributed;prohibit or limit the amount of such substance or mixture whichcan be manufactured, processed, or distributed for a particularuse or a particular use in excess of a specified level;require that such substance or mixture be accompanied by clearand adequate warnings and instructions with respect to its use,distribution in commerce, and/or disposal;require manufacturers or processors of such substance or mix-ture to make and retain records of certain processes;prohibit or otherwise regulate any manner or method of com-mercial use of such substance or mixture;prohibit or otherwise regulate the manner or method of disposalof such substance or mixture provided that State (or other levelof government) laws or requirements are not violated, and re-quire notification of the appropriate level of government; anddirect manufacturers or processors of such substance or mixtureto give notice of such unreasonable risk of injury and replaceor repurchase such substance or mixture.

The factors which must be considered in promulgating a Section6 rule include:

228 ● Protecting the Nation’s Groundwater From Contamination

has regulated four chemicals or groups of chemi-cals under Section 6 1 ) fully halogenated chloro-fluorocarbons, 2) waste materials containing tetra-chlorodibenzo-p-dioxin (TCDD), 3) asbestos, and4) polychlorinated biphenyls (PCBs) .2’ Only thePCB regulations involve disposal provisions relatedto preventing groundwater contamination. How-ever, one State in responding to OTA’s Statesurvey noted that the PCB disposal regulations arenot being strictly enforced by EPA and that TSCAdoes not provide for the transfer of regulatoryauthority to the States. The TCDD requirementsprohibit the disposal of wastes containing TCDDby a particular chemical company (which is undercourt order to undertake remedial actions at a haz-ardous waste site under RCRA); the company isrequired to store and monitor the wastes until along-term solution is found.

Federal Insecticide, Fungicide,and Rodenticide Act

The overall thrust of the Federal Insecticide,Fungicide, and Rodenticide Act (FIFRA), whichregulates pesticides in the United States, is to en-sure that the use of a pesticide will not cause un-reasonable adverse effects on the environment. 22FIFRA defines an unreasonable adverse effect onthe environment as ‘‘any unreasonable risk to manor the environment, taking into account the eco-nomic, social and environrmental costs and benefitsof the use of any pesticide. FIFRA contains two

A.

B.

c.

D.

the effects of such substance or mixture on health and the mag-nitude of the exposure of human beings to such substance ormixture;the effects of such substance or mixture on the environmentand the magnitude of the expc)sure on the environment to suchsubstance or mixture;the benefits of such substance or mixture for various uses andthe availability of subs itutes for such uses; andthe reasonably ascertain,ible economic consequences of the rule,after consideration of the effect on the national economy, smallbusiness, technological ilmovation, the environment, and publichealth (Section 6(c)(l)).

Zlsee 40 CFR 762, 40 CFR 775, 40 CFR 763, and 40 CFR 761,respectively. Procedures for ndemaking under Section 6 are speci-fied in 40 CFR 750. Congress explicitly directed EPA to promulgatedisposal and labeling requiren-ents for PCBS within 6 months of theeffective date of TSCA and to phase out their use over a 2-year period;the PCB disposal requirements established by EPA with respect tomonitoring, correction actions, and design and operation are discussedin chs. 6, 9, and 11, respecti~ ely.

Zzsee Section 2(bb). Like TS(3A, FIFRA does not explicitly includegroundwater in the definition of environment.

principal provisions relevant to the prevention ofgroundwater contamination: 1) Section 3 providesfor the registration of all pesticides based on thesubmission of data specified by EPA and for theclassification of pesticides for general or restricteduse; and 2) Section 6 authorizes EPA to suspendand cancel the registrations of pesticides that causeunreasonable adverse effects on the environment. 23

Section 3. Section 3 of FIFRA requires theregistration of all pesticides. In addition to regis-tering new pesticides, EPA is also mandated to re-view all existing registrations to ensure that theymeet current requirements, 24 There are 40,000pesticides (containing some 1,400 active ingredientsin 578 generic categories) now registered by EPA.

For a pesticide to be registered, FIFRA requiresdeterminations including that it will function as in-tended without unreasonable adverse effects on theenvironment, and when used in accordance withwidespread and commonly recognized practice, itwill not generally cause unreasonable adverse ef-fects on the environment.25

EPA issued final regulations establishing basicregistration requirements in July 1975.26 Thepesticide registration regulations enumerate threerisk criteria for EPA use in determining whethera pesticide causes an unreasonable adverse effect:1) acute toxicity in humans, other mammals, orbirds, 2) chronic toxicity in humans, test animals,or endangered species, or population reductions innon-target organisms, and 3) lack of emergencytreatment for ameliorating the toxic effects of apesticide in people.27 The regulations did not iden-

Zsother sections of FIFRA authorize EPA to: certify pesticide ap-plicators to ensure that they are competent with respect to the use andhandling of restricted pesticides (Section 4); establish procedures andregulations for the disposal or storage of packages and containers ofpesticides or excess amounts of pesticides (Section 19); formulate aNational Monitoring Plan (Section 20); and authorize certain Stateresponsibilities (Sections 24 and 26).

ZfThe 1972 amendments to FIFRA established the re-registrationrequirement. Subsequent amendments have attempted to streamlinethe re-registration process by authorizing EPA to develop generic stand-ards for pesticide ingredients. These standards are used to review bothnew and existing registrations of individual products containing thoseingredients. As of April 1984, EPA had issued 75 generic standards.Anticipating that generic standards are needed for 400-500 catego-ries of pesticides, EPA is currently developing such standards at a rateof 25 per year (Auerbach, 1984).

25 Section 3(c)(5).m40 CFR 162, Subpart A.v40 CFR 162.1 l(a)(3).

Ch. 1 I—Federal Efforts To Prevent Groundwater Contamination • 229

F’hoto credit: State of F/orida Department of .Environrnenta/ Regulation

Pesticides may be introduced into groundwater from non-point sources such as land application, as well as from point sourcesof hazardous wastes (e.g., landfills), non-hazardous wastes (e.g., residential disposal), and non-waste products (e.g., storage tanks).

tify’ the types of data needed to satisfy the statu-tory registration requirements. However, EPA de-\’eloped guidelines between 1975 and 1981describing such data requirements. In November1982, EPA proposed regulations that reorganizedthe guidelines and listed the specific types of dataand information needed to support a pesticideregistration. 28

Guidelines published by EPA as a companiondocument to the 1982 proposed regulations iden-tify the following characteristics of a pesticide asbeing most pertinent to an evaluation of its poten-tial to contaminate groundwater: leachability; ad-sorption/desorption characteristics; resistance tochemical, photochemical, and biological degrada-tion; volubility in water; and volatility (EPA,1982).29 For the assessment of these characteristics,

2847 FR 53192, No\.. 24, 1982.Zgq’hls FJpA document supports 40 C FR 158, Subdivision N, pro-

posed Data Requirements for the Registration of Pesticides, 47 CFR53192.

EPA’s proposed regulations require the submissionof data resulting from degradation, metabolism,mobility, dissipation, and accumulation studies.30

Section 3(d) of FIFRA requires EPA to classifypesticides (as part of the registration process) forgeneral or restricted use. A pesticide is classifiedfor restricted use:

. . . if, the Administrator determines that thepesticide, when applied in accordance with itsdirections for use, warnings and cautions and forthe uses for which it is registered, or for one or moreof such uses, or in accordance with a widespreadand commonly recognized practice, may generallycause, without additional regulatory restrictions,unreasonable adverse effects on the environment,including injury to the applicator. .. .31

3040 c FR 158, 130, 47 FR 53205. F.nvironmcnta] fate data re-quirements were issued as a public draft in 1978 and again in Oc-tober 1980; see 47 FR 53194 and EPA, 1982.

~lsection 3(d)(l)(C).

38-799 0 - 84 - 12 : QL 3

230 . Protecting the Nation’s Groundwater From Contamination

The statute provides I hat if a pesticide is classifiedfor restricted use on the basis of human healthhazards caused by acute dermal or inhalation tox-icity, the pesticide can be applied only by a cer-tified applicator. 32 If a pesticide is classified for re-stricted use because it may cause an unreasonableadverse effect on the environment, the Administra-tor of EPA must require that it be applied by a cer-tified applicator or be subject to such other restric-tions as may be provided by regulation.33

The regulations regarding restricted use classi-fications do not state the specific types of actionsthat could be included in the ‘‘other restrictions’category. 34 However, the legislative history ofFIFRA indicates that other restrictions might in-clude geographic controls over the use of a pesticide(Costello, 1983).35 The regulations do specify thata pesticide product classified for restricted use mustbear a label that contains the statements of the re-stricted use classification and directions for use;36

these label restrictions could be used to prohibit theuse of certain pesticides in specified areas (e. g.,recharge areas) or to specify application proceduresthat prevent ground water contamination (e. g.,limiting the amounts or the rate of application)(Severn, et al., 1983).37

sZS~CtiO~ s(d)(l)(c)(i). A Celtifiecl applicator must be comPetent in

the use and handling of pesticides. EPA regulations identify com-petency standards. They include a demonstration of practical knowl-edge with respect to the envil onmental effects of the use or misuseof pesticides. See 40 CFR 171.

Sssection 3(d)( 1 )( C)(Ii).S+see 40 CFR 162.30. The regulations indicate, however, that the

risk criteria specified by 40 CFR 162. 11(a)(3) are to be used in deter-mining whether the use of a xsticide should be restricted.

sSThe report of the Senate Committee on Agriculture and Forestryexplained that although a third type of classification (permit only) wasrejected, EPA was not constrained “from regulating the quantity tobe applied for a given use for i particular application to a particularcrop in a given area at a given time, from limiting the number of ap-plications, or from prohibiting the use thereof. . . ‘‘ (U.S. Senate,1972).

3640 CFR 162.30(q).srLabe] restrictions have be m imposed for the use of aldicarb On

Long Island, NY, in res~onst to a reauest from the manufacturer.

Section 6. This section of the act allows the EPAAdministrator to suspend and cancel the registra-tion or change the registration of a pesticide (e. g.,from general to restricted use). A suspension or-der may be issued by EPA if it is determined nec-essary for preventing an imminent hazard duringthe time required for cancellation or change inclassification proceedings .38

A pesticide registration can be canceled or itsclassification changed if the pesticide causesunreasonable adverse effects on the environmentwhen used in accordance with widespread and com-monly recognized practice or if its labeling or othermaterial required for submission to EPA does notappear to comply with the provisions of FIFRA.39

Although actions taken under Section 6 are basedon a finding of unreasonable risk to humans andthe environment (i. e., a determination that acutetoxicity or chronic toxicity exceed criteria or thatthere is no emergency treatment), information re-garding the potential of a pesticide to leach throughthe soil into groundwater can be factored intoEPA’s assessment of exposure to pesticides that domeet the risk criteria .40

Sasection 6(C){ 1 ). An imminent hazard is defined in FIFRA, in %C-tion 2(l), as ‘‘a situation which exists when the continued use of apesticide during the time required for a cancellation proceeding wouldbe likely to result in unreasonable adverse effects on the environmentor will involve unreasonable hazard to the survival of a species declaredendangered by the Secretary of the Interior under Public Law 91-135. ”

Sgsection 6(b)(1). pursuant to Section 6(a)(1) of FIFRA, a pesticideregistration shall also be canceled at the end of any 5-year period whichbegins on the date of its registration unless a continuation is requested.

+osee for example, 48 FR 46234, Oct. 11, 1983 (46238). It is alSOimportant to underscore the fact that a finding of unreasonable riskunder FIFRA involves a process that weighs health risks against thebenefits of continued use of the t)esticide.

Ch. Ii—federal Efforts To Prevent Groundwater Contamination ● 231

CHAPTER 11 REFERENCESArthur D. Little, Inc., “User’s Guide, CHEMEST, A

Program for Chemical Property Estimation, pre-pared for U.S. Environmental Protection Agencyand the U.S. Army Medical Bioengineering Re-search and Development Laboratory, revised March1983.

Auerbach, J., Office of Pesticides and Programs, U.S.Environmental Protection Agency, personal commu-nication, Apr. 19, 1984.

Bonazountas, M., and J. M. Wagner, ‘‘SESOIL—ASeasonal Soil Compartment Model, ” Arthur D. Lit-de, Inc. (Washington, DC: Office of Toxic Sub-stances, U.S. Environmental Protection Agency,contract No. 68-01-6271, 1981).

Costello, G., “Groundwater Contamination ThroughApplication of Pesticides: Existing Federal Con-trols , Congressional Research Service, Jan. 21,1983.

Gough, M., Senior Associate, Office of TechnologyAssessment, Testimony before the Subcommittee onToxic Substances and Environmental Oversight,Committee on Environment and Public Works, U.S.Senate, July 28, 1983.

Hemphill, J. B., ‘ ‘Section 1424(e) of the Safe DrinkingWater Act: An Effective Measure Against Ground-water Protection?’ Environmental Law Reporter6:50121, November 1976.

Office of Technology Assessment, The InformationContent of Premanufacture Notices, Background Pa-per (Washington, DC: U.S. Government PrintingOffice, OTA-H-BP- 17, April 1983).

Severn, D. J., C. K. Offutt, S. Z. Cohen, W. L. Bur-

nam, and G. J. Burin, ‘ ‘Assessment of GroundwaterContamination by Pesticides, ” Hazard EvaluationDivision, Office of Pesticide Programs, U.S. Envi-ronmental Protection Agency, June 7, 1983 (pre-pared for the FIFRA Scientific Advisory PanelMeeting, June 21-23, 1983, Arlington, VA).

U.S. Environmental Protection Agency, “PesticideAssessment Guidelines, Subdivision N, Chemistry:Environmental Fate, ” Environmental Fate Branch,Hazard Evaluation Division, Office of Pesticide Pro-grams, NTIS PB83- 153973, Oct. 18, 1982.

U.S. Environmental Protection Agency, “Status of theSole Source Aquifer Program, ” Office of DrinkingWater, July 6, 1983.

U.S. Environmental Protection Agency, ‘ ‘Sole SourceAquifer Designations to Date, ” Office of DrinkingWater, May 1, 1984.

U.S. Senate, 92d Cong., 2d sess., “Legislative Historyof the Federal Environmental Pesticide Control Actof 1972, Public Law 92-516, ’ Senate Report No.838, 1972.

Versar, Inc., “Acquisition of Climatological Data andSoil Data and Creation of SESOIL and TOX-SCREENParameter Data Files, ” prepared for U.S. Environ-mental Protection Agency, contract No. 68-01-6271,May 9, 1983.

Yeh, G. T., “Analytical Transient One-, Two-, andThree-Dimensional Simulation of Waste Transportin an Aquifer System, ORNL-5602, Oak RidgeNational Laboratory, Oak Ridge, TN, March 1981.

Chapter 12

Overview of the Statesand Prevention

Contents

Chapter Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ● ● . ● .

State Prevention Approaches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Source Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...4..... .. .. ... ... ...4 ...$Aquifer Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Impact Reduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter 12

Figure No.

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .””””..”””

FIGURE

6. OTA State Survey Responses: Number of States With Programs To PreventGroundwater Contamination From Selected Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Page

235

235237239239

240

Page

238

Chapter 12

Overview of the States and Prevention

CHAPTER OVERVIEW

In this chapter, State responses to survey ques-tions about their activities to prevent groundwatercontamination are briefly described. 1 (See the sec-tion OTA State Survey in ch. 4 for guidance in in-terpreting survey results. ) Approaches that Statesuse for prevention are highlighted along with pro-grams for sources, aquifer protection, and impactreduction.

In summary, the States are using a variety of ap-proaches to prevent groundwater contamination.They give priority to and are developing and im-plementing programs for prevention of contamina-

‘ ( ;I\ en the OTA stud) focus on afrcady contain inated groundwatct-,the ( Y1’A ~urit.} did not question the State\ on their use, preferences,,md pr( Jjlems w Ith spm ifi( techniques for preix. ntion. For more detaileda( { OU nt \ ( ~f w.1(”( tml SI ate proqrarns wc Henderson, et al. , 1984

tion from particular sources, especially waste-re-lated point sources.

States’ problems with prevention and desires forFederal assistance are discussed in chapter 4. Thechapter describes the States’ problems with preven-tion as mostly institutional. The States noted a lackof prevention programs, deficiencies in some typesof programs, and a lack of resources to implementexisting institutional mechanisms. The technicaladequacy of prevention mechanisms is also a con-cern. The States want Federal assistance for pre-vention mostly in the form of funding and researchand development on control techniques for addi-tional sources. They also want the Federal Gov-ernment to assist information exchange among theStates and to improve Federal prevention programsthat they perceive as unsuccessful.

STATE PREVENTION APPROACHES

The States use a variety of approaches to pre-vent contamination—directed at sources, aquiferprotection, and impact reduction. These approaches,which vary among the States, consist of componentsincluding: siting requirements; design and oper-ating requirements (e. g., discharge requirements,Best Management Practices, construction stand-ards, and closure standards); land use controls; anddeed restrictions.

Programs have already been implemented inmany States. In others, programs are being devel-oped. Legislation is required in a small number ofStates (fewer than 10) to authorize programs thatthey are working to develop.

Different components of State prevention pro-grams may be mandatory or voluntary. For exam-ple, mandatory permit requirements may apply tofacility siting and/or design and operation; through

technical assistance and public education activities,a State may encourage voluntary use of Best Man-agement Practices to minimize the potential for con-tamination from particular activities and facilities.

Groundwater classification systems, general pol-icies about the degradation of groundwater, and/orthe protection of public health and the environmentguide implementation of prevention programs insome States. Classification systems have both ad-vantages and disadvantages when used for this pur-pose (as described by Miller, 1984). Advantagesrelate primarily to establishment of a formal mech-anism for determining where and to what extentwater quality protection measures are applied. Dis-advantages relate primarily to technical difficultiesin establishing classification boundaries (e. g., in-sufficient data) and policy conflicts in defining waterquality objectives for various classifications (e. g.,

235

236 ● Protecting the Nation’s Groundwater From Contamination

Grou

\

1’)I///II III

//’ J \Low density

\\-/’

/ ’

nGA

\

\IIII

II/I

//

/III/

///

EAl

— --- Drainage boundary

DGAA Public water supply well fields

GA Suitable for drinking water use

— –-.— Groundwater classification boundary

c) Surface water classification

GC Waste-receiving zones

Credit: Geraghty & Miiier, 1933

Groundwater classification schemes are used to facilitate decisions about groundwaterquality protection in some States. The example shown illustrates the groundwater

classification system applied by the State of Connecticut.

Ch. 12—Overview of the States and Prevention ● 237

acceptability of allowing a resource to be degradedin certain areas). 2 Even if classification systems arenot used as a formal basis for decisionmaking aboutsiting or the design and operation of facilities, theaquifer information that is associated with theseclassifications usually contributes to preventiondecisions as well as decisions on priorities for detec-tion and correction. Twenty-three States classifygroundwater on the basis of various characteristicsuseful for making prevention decisions. For exam-ple, classifications are based on: the natural qualitydifferences in aquifers which affect water use (e. g.,total dissolved solids); characteristics that may make

‘For a ~etaile~ discussion r)f advantages and disadvantages of~r~undlvater classification s~stcms and a description of some Statepr~~ramst see Ma~nuson, 19B 1. Additional State classification pro-~rams are ciescribml in Pye, ct al., 1983 and API, 1983.

aquifers vulnerable to contamination (e. g., watertable v. confined aquifers); characteristics that af-fect the development of water supplies (e. g., highv. low yield); and variations in population, aver-age use rate, contamination problems, and avail-ability of alternative groundwater resources.

Source Programs

Prevention programs that the States have eitherimplemented or are developing are related primar-ily to sources. Ten States explicitly commented onthe limited coverage of their prevention activities—that programs do not address all recognized sourcesof potential contamination. For example, one Statenoted that many of its programs are applicable onlyto landfills, wastewater lagoons, and land applica-

Photo credit: State of F/orida Depatimefst of Enviromnenta/ Re@dation

State public education programs are being designed to promote awareness of improper disposal methods that can resultin groundwater contamination. Some programs authorize the collection of hazardous wastes

from small quantity generators, including households.

238 ● Protecting the Nation’s Groundwater From Contamination

tion of sewage sludge, and are not applicable toagricultural activities:;. In general, waste-relatedpoint sources are addressed in more States thannon-waste and non-point sources.

As shown in figure 6, more States have programsfor prevention of contamination from various sources—and give priority to these programs—than fordetection or correction of contamination. Also,more States have prevention programs for and givepriority to sources in OTA Categories I (e. g., in-jection wells) and II (e. g., surface impoundments)than in Categories III, IV, V, and VI. Not all fa-cilities and/or activities for each of these source types

are covered in State prevention programs. For ex-ample, in one State, well construction standardsapply only to drinking water wells; in another, suchstandards apply to all wells in artesian (confined)aquifers; and in a third State, although standardsapply to all wells, they are not strictly applied toprivate wells or to agricultural wells.

Permit programs for design and operation of dif-ferent sources may be oriented to the overall per-formance of a facility or related to certain technol-ogy requirements. For example, facilities thatdischarge substances to groundwater may have tosatisfy groundwater quality standards. Technology

Figure 6.—OTA State Survey Responses: Number of States With Programs to Prevent GroundwaterContamination From Selected Sources

See fig. 2 for footnotes a through g.

SOURCE: Office of Tachnolog’/ Assessment.

Ch. 12—Oveview of the States and Prevention ● 239

I%fo credit U S Enwronrrrenta/ Protecffon Agency

Voluntary replacement of underground gasoline storage tanks is one technique that manyStates rely on to prevent groundwater contamination.

requirements may include, for example, the use ofliners and leachate collection systems for landfillsand septic tanks of specified sizes.

Aquifer Protection

A few States have programs that address the pro-tection of aquifers and/or recharge areas. For ex-ample, in some States where sole source aquifershave been designated, State or local restrictionshave been placed on certain activities (see ch. 11).One State provides funds for municipalities to pur-chase land for aquifer protection.

Impact Reduction

Although most State activities appear to be di-rected at preventing (or minimizing the potentialfor) groundwater contamination, some States haveprograms to prevent adverse impacts associatedwith potential contamination. For example, in oneState solid waste facilities must be recorded on prop-erty deeds. This measure is intended to avoid theunknowing purchase of former landfills.

240 • Protecting the Nation’s Groundwater From Contamination

CHAPTER 12 REFERENCES

American Petroleum Institute (API), “Guide toGroundwater Standards of the United States, ” 1983.

Henderson, T. R., J. Traubman, and T. Gallagher,Groundwater: Strategies for State Action (Washing-ton, DC: Environmental Law Institute, 1984).

Magnuson, P., “Groundwater Classification, ” Septem-ber 1981 (copyright by Geraghty & Miller, Inc.,Syosset, NY, 1982).

Miller, D., Geraghty & Miller, Inc., testimony beforethe Subcommittee on Environment, Energy and Nat-ural Resources, Committee on Government Opera-tions, U.S. House of Representatives, Apr. 11-12,1984.

Pye, V. A., R. Patrick, and J. Quarles, GroundwaterContamination in the United States (Philadelphia:University of Pennsylvania Press, 1983).

Index

Index

Community Water Supply Survey (CWSS), 40correction of ground water contamination, 177-193

selecting a strategy, 177corrective action alternatives, 178perforrnance of corrective action alternatives, 183technical and non-technical conditions determining

the applicability of corrective action alternatives,179

stage of development of corrective action alternatives,192

Federal efforts to correct groundwatcr contamination,197-201

Federal Government experience, 200statutory and regulatory provisions for sources of

contamination, 197summary of Federal corrective action provisions, 198

Federal efforts to detect groundwater contamination,145-161

groundwater monitoring and sources, 155Federal programs, 156monitoring and remedial action programs, 160

investigate ions of aquifer systems and ambientgroundwater quality, 146

ambient groundwater appraisal, 147Regional Aquifer System Analysis Program, 147

U.S. Geological Survey, 145-146

Federal programs, 145Federal-State Cooperative Program, 146

monitoring drinking water supplies, 147-150EPA drinking water surveys, 149public water systems, 147

source inventories, 150-154formal studies, 150

hazardous waste sites, 151open dumps, 150surface impoundments, 152

regulatory requirements related to inventories, 153reporting requirements, 152

EPA regulations: CWA and CERCLA, 152D0T regulations: HLPSA and HMTA, 153

Federal efforts to prevent groundwater contamination, 215aquifer protection, 225prevention by sources, 215

performance requirements, 223types of programs and sources addressed, 223

regulating the production and use of potential

contaminant, 226Federal Insecticide, Fungicide, and Rodenticide Act,

228Toxic Substances Control Act (TSCA), 226

Federal institutional framework to protect groundwater,63-86

efforts to improve capabilities, 83-86Federal research and development, 84financial assistance, 83technical assistance, 84

mechanisms for interagency coordination, 81program-related agreements, 82USGS coordinating committees, 82water data coordination, 83

relevance of Federal statutes, 64sources addressed by Federal statutes, 75-79

types of programs, 77summary of Federal statutes and programs, 64-75

Federal legislation passed prior to the 1970s, 64groundwater-related activities of Federal agencies, 72

water quality standards, 80-81findings, 5-14

Federal and State approach to groundwater approach, 6corrective act ion programs, 8detection programs, 8prevention programs, 8

national policy implications, 11-14funding, 11research and development, 13technical assistance, 12

technical and nontechnical constraints, 9-10

groundwater contamination and its impacts, 19-58concentration and frequency of substances in

groundwater, 38-43governmental standards, 41frequency of occurance of substances, 40substances, 38

extent and nature of, 20-23nationwide assessment, 20substances detected in groundwater, 22

factors influencing a source’s potential to contaminate,47-54

geographic location: pervasiveness and regionality, 49number of sources and amounts of material flowing

through or stored in sources, 51release characteristics, 47

health impacts, 23-36adverse impacts of chemicals, 32biological substances, 34general issues, 23interactions among multiple chemicals, 34potential toxicity or potency of chemicals, 33radioactive substances, 35substances known to occur in groundwater, 24-31

non-health impacts, 36-38economic impacts, 36, 39environmental and social impacts, 37-38

potential for sources to contribute substances togroundwater, 55

identifying sources, 55modeling, 55

types of sources and associated substances, 43-46association of substances with sources, 44

undetected substances, 43Ground Water Supply Survey (GWSS), 40

243

244 ● Protecting the Nation’s Groundwater From Contamination

hydrogeologic investigations, 111-138approaches for minimizing difficulties, 135-138

ensuring reliability, 135conduct, 112-135

design of, 115costs and detection limits, 130monitoring networks, 134techniques for obtaining information, 118

general approach, 112objectives, 113site conditions. 112

l(~isla(ion:Atomic Energ)’ Act, 6.j, 66, 73, 78, 155, 156Clean Water Act (CWA), 11, 20, 65, 66, 73, 78, 80,

83, 99, 100, 146, [52, 156, 161Coastal Zone Manage]nent Act, 65, 66, 75, 78, 156~;onlprchensi~’e Envirc nmcntal Response,

Corn pcrrsat ion, ami Liability Act (C ERCLA), 8,6.5, 67, 74> 79, 10IJ, 151, 152, 1.53, 156, 160, 184,197

F’tderal Insecticide Ful~gicide and Rodenticide Act(FIFRA), 9, 65, 6’), 75, 156, 228

F’eder-al Land Policy and Management Act, 65, 67, 75,156, 215

Hazardous Liquid Pipl:line Safety Act (HLPSA), 65,68, 74, 77, 152, 153, 156

H:izardous .Nlatcrials ‘I’ransportation Act (HMTA), 65,68, 74, 152, 153, 156

National k~n~ironment:d Policy Act, 65, 68, 73, 79, 156Rc’clarnation Act, 65, 08, 73, 79, 156Resource Conservation and Recovery Act (RCRA), 8,

11, 65, 69, 74, 78, 83, 100, 150, 155, 156, 160,197, 200

Ri\rcrs and Harbor Ac of 1899, 73Safe’ Drinking Water P,ct (SDWA), 7, 8, 20, 65, 69,

74, 78, 80, 83, 10( , 147, 149, 150, 152, 153, 157S(lrface Mining Contr(ll and Reclamation Act

(SMCRA), 11, 65, 70, 74, 78, 79, 83, 158, 215‘1’oxic Substances Control Act (TSCA), 9, 65, 70, 75,

i55, 158, 215, 226Uranium Mill Tailings Radiation Control Act

(U,MTRCA), 8, 65, 70, 74, 78, 79, 100, 158, 160,197, 200, 201, 215

Water- Pollution Control Act of 1948\$’ater Research and Development Act, 65, 70, 75, 79,

158

National Interim Primar} Drinking Water Regulations(NIPDWR), 80

National Organics Monitoring Survey (NOMS), 40N:itional Organics Reconnaissance Survey (NORS), 40National Science Foundation, 72National Scrcwning Program for Organics in Drinking

W’ater (NSP), 41Nuclear Rc>Sulator?’ Corn mission, 72

State efforts to correct grxmndwater contamination,205-210

State efforts to detect groundwater contamination,165-171

detection programs for sources of contamination, 165formal procedures for monitoring, 168inventory and monitoring activities, 166use, preferences and problems with techniques for

hydrogeologic investigations, 169OTA survey, 170

State institutional framework to protect groundwater fromcontamination, 89-107

OTA State survey, 89, 96, 97, 99State activities, 92, 93

agency reorganization, 98coordination programs, 95facility development, 97public education, 97special studies, 95staff development and training, 95

State perceptions about problems, 91State perspective on Federal programs, 98-103

responses about selected Federal laws, 98State use of Federal guidance on quality standards

State strengths and problems in programs to deal withcontamination and desired Federal assistance,103-107

correction, 106detection, 106improving capabilities, 105prevention, 106sources, 104standards, 105

State prevention approaches, 235aquifer protection, 239impact reduction, 239source programs, 237

U.S. Army Corps of Engineers, 82

U.S. Coast Guard, 152b’. S. Department of Agriculture, 72, 82

Soil Conservation Service (SCS), 161U.S. Department of Commerce, 72, 82U.S. Department of Defense, 72, 201U.S. Department of Energy, 72, 73U.S. Department of Housing and Urban Development,

72U.S. Department of the Interior, 72, 82

Bureau of Land Management (BLM), 75, 82U. S. Department of Transportation, 152, 153U.S. Environmental Protection Agency, 6, 20, 72, 73, 82,

147, 149, 150, 151, 152, 153, 154, 161, 229National Inorganic and Radionuclides Survey (NIRS),

40U.S. Food and Drug Administration, 84U.S. General Accounting Office (GAO), 150, 159U.S. Geological Survey, 12, 84, 95, 145, 146, 161

volatile organic chemicals (VOCS), 40, 41

World Health Organization (WHO), 35