Mini-Review

Hazardous Waste Management at the Bunker

Hill Superfund Site:

A Review of the Condition of Idaho’s Silver

Valley

Chad Petersen

Correspondence: pete0414@vandals.uidaho.edu

2/16/2014

Abstract

In 1983 the Bunker Hill Mining and Metallurgical Complex was placed on the

Environmental Protection Agency’s (EPA) National Priorities List. Located in North Idaho, the

Silver Valley region, which is also known as the Coeur d’Alene Basin, was mined heavily for

approximately 100 years. During this time many of the hazardous wastes associated with mining

were either mismanaged or not managed at all. For many years, tailings - which are the non-

valuable remains of an ore that has been processed, and other mining wastes were deposited

directly into the South Fork of the Coeur d’Alene River. Lead oxides, arsenic, and other harmful

toxins were also released into the atmosphere due to the smelting of lead that was conducted in

the area. The smelter operated under unfiltered conditions for about one year during the 1970’s,

multiplying its toxic output by approximately 20 times its normally filtered output rates.

According to the EPA,

“Historic mining practices generated an estimated 70 to 100 million tons of mining waste that are

now spread throughout regional streams, rivers, flood plains and lakes. The contamination

resulting from these mining practices affects all media and poses public health risks, particularly

to young children and pregnant women due to exposure to lead. Ecological affects include

sterile river regions and hundreds of avian deaths each year.” (US EPA, n.d.-a)

Cleanup of the Coeur d’Alene Basin was originally scheduled for completion in 2015.

The EPA considers many of the site’s critical areas near completion or completely clean, while

other areas are still seeing new projects being implemented.

Introduction

This communication will offer a summary of peer reviewed articles, journals, and EPA

findings that deal with the cleanup and management of the hazardous mining waste in the Coeur

d’Alene Basin. Direct quotations from reliable, scholarly sources will be used whenever

necessary and applicable. Links will be provided in the references section for easy access to

source information when possible. A brief history of the Silver Valley will be explained to offer

context. This essay will examine the impacts of the mining waste on the human health,

waterfowl, fish, and certain ecosystems in the region. This review will also examine what has

been done, what is being done, and what is left to be done with regards to environmental cleanup

and the relative safety of the human population and wildlife in the region.

A Brief History of Mining in the Silver Valley

Gold was found along the South Fork of the Coeur d’Alene River in the mid 1870’s. The

gold rush in North Idaho was relatively short-lived, ending in 1884. However, miners in the area

found other precious metals such as zinc, copper, lead, antimony, and one of the world’s largest

concentrations of silver. For nearly 100 years the Silver Valley had upwards of 90 mines

extracting ore from its hillsides. Approximately 1.2 billion ounces of silver, and over $2.9

billion in heavy metals have been taken from the region. One mine in particular, the Sunshine

Mine, is credited with having the world’s largest silver production to date, approximately 367

million ounces. Another, the Bunker Hill Mine, is considered the world’s largest, with over 150

miles of underground shafts.(“Digital Geology of Idaho - Geology of Northern Idaho and the

Silver Valley - Page 1,” n.d.)

Many negative impacts have come from decades of mining in the region. For many years

mines disposed of their tailings directly into the South Fork of the Coeur d’Alene River. Also,

the Bunker Hill lead smelter ran for approximately one year in the mid 1970’s without its main

“bag house” filter after a fire ran through the complex destroying it. Management decided that

the smelter should continue operations anyway due to high metal prices for the period. In an

interview conducted for Idaho Public Television’s Silver Valley Rising, Earl Bennett the retired

Dean of the College of Mines at the University of Idaho and the former Director of the Idaho

Geological Survey states,

“It’s estimated that there was something on the order of 40 to 60 tons of lead oxide per month

that was dumped out into this area, which was a huge increase of what it would have been with a

filtration system in place.” (“Outdoor Idaho’s Silver Valley Rising (Idaho Public Television),”

n.d.-a)

The Effects of Lead Oxides Released from the Bunker Hill Smelter

Part of the Bunker Hill Superfund Site (BHSS) cleanup is associated with the lead oxides

that were released from the smelter connected to the Bunker Hill Mine. According to The Guide

to the Bunker Hill Mining Company Records,

“In 1916, in response to a war-time increase in the demand for lead, Bunker Hill constructed a

large lead smelter. A new epoch began with the opening of the smelter on July 5, 1917”.

(“Northwest Digital Archives,” n.d.)

Smelting activities at the Bunker Hill mining site were ended in 1981, due in part to

public concern for human health. According to a report on the BHSS cleanup progress

commissioned by the EPA,

“The human health effects from heavy metals exposure have been studied extensively at the

Bunker Hill Superfund Site. Childhood lead poisoning was epidemic in the 1970s, with over 75

percent of children having blood lead above 40 micrograms per deciliter (µg/dL).”(“BUNKER

HILL MINING & METALLURGICAL,” n.d.)

These are some of the highest levels of lead ever measured in the United States, and

many children were hospitalized as a result. It is widely accepted that there are no safe levels of

lead in the human system. The CDC recommends public health response at the 5-10 µg/dL level

in children between the ages of 1 to 5.(“CDC - Lead - Home Page,” n.d.) Even though the initial

tests began in the mid 1970’s, results remained unacceptably high in children until the closure of

the smelter in 1981.

House dust is an important medium for the transfer of lead into the human system,

especially in children due to their frequent hand to mouth behavior. Many studies were

compiled on the background house dust levels in a 21 square mile area called the “Box”, which

is the area directly around the original smelting operations at Bunker Hill. These studies were

then compared to studies done on house dust levels just outside of the “Box” in demographically

similar towns. A survey of the area entitled Northern Idaho House Dust and Soil Lead Levels

Compared to the Bunker Hill Superfund Site published in 2007 states,

“Soil and house dust samples were collected in five towns demographically similar to the BHSS

but unaffected by the mining industry. The background concentrations and loading rates were

significantly lower than those observed at the [BHSS] site.”(“Northern Idaho House Dust and

Soil Lead Levels Compared to the Bunker Hill Superfund Site - Springer,” n.d.)

There are many health problems that can arise from exposure to lead. According to

studies done by the Panhandle Health District (PHD) on populations within the “Box”, there can

be neurotoxic effects such as neurobehavioral problems that start in early development and last

through puberty into young adulthood, neurocognitive disorders, and a decline in average IQ

points connected to the populations exposed to lead. Other problems associated with exposure to

lead include negative effects to the immune system, reproductive systems, bone and teeth, and

heme-synthesis, just to name a few. Pregnant women and children have the highest risk

associated with exposure. In 1974, over 90% of children tested for lead in the town of

Smelterville were at levels that put them at risk of any number of the above mentioned health

problems. This is considered to be in direct relation to the inoperable “bag house”

filter.(“BloodLead2011.pdf,” n.d.)

The Effects of Mining on the Local Environment

Many years of mining in an area is bound to have impacts, especially if clean mining

practices are not observed, which tends to be the case when one looks at the early days of mining

in the Silver Valley. Present day mining companies are required to follow state and federal

regulations and guidelines which greatly reduce environmental impacts, but for many years

tailings were directly deposited into the South Fork of the Coeur d’Alene River. This practice

was prohibited in 1968, and tailing pools were constructed to minimize the flow of tailings

directly into the river. Tailing pools, however, were often badly damaged during flood season,

resulting in river contamination despite efforts to contain the waste. Contamination is wide

spread due to flooding of the river and the washing of contaminants contained in the sediment

downstream.

According to the EPA,

“The contaminants of concern are chiefly metals. Affected media are soil, sediment, surface

water, and groundwater. The primary source of metals in surface water is leaching and erosion of

sediments impacted by tailings. Direct exposure to metals in soil and sediments is a source of

risk for human and ecological receptors, including recreational users, subsistence users,

migrating waterfowl and plants. Surface water quality exceeds applicable criteria for the

protection of cold water biota in portions of the South Fork Coeur d’Alene River basin by up to

200 times the criteria for dissolved cadmium and as much as 90 times the criteria for dissolved

lead and zinc. The most heavily impacted areas are without aquatic life. Other areas provide only

partial support for fish and other aquatic species (e.g., they are suitable for migration but not

spawning and rearing).”(“BUNKER HILL MINING & METALLURGICAL,” n.d.)

During the flood season, the Coeur d’Alene River carries these contaminated sediments

approximately 70 miles from the BHSS and deposits them into Lake Coeur d’Alene’s southern

end, near the town of Harrison. Another 30 miles north of Harrison, the lake flows into the

Spokane River. From there water flows into the Columbia River and makes its way to the

Pacific Ocean. Elevated lead levels, a direct result of mining contamination, have been recorded

in waterfowl as far north as the Spokane River. Results from a study conducted by the U.S. Fish

and Wildlife Service entitled, Blood Lead Concentrations in Waterfowl Utilizing Lake Coeur

d’Alene, Idaho published in 2006 states,

“The Coeur d’Alene River is the source of mining-related lead for Lake Coeur d’Alene, so

elevated sediment lead concentrations and potential risks to waterfowl lead toxicity in the

vicinity of the river-mouth were not surprising. However, elevated sediment lead and mallard

blood lead concentrations near the lake’s outflow and in the Spokane River, the furthest point in

the lake in the direction of water flow from its sediment lead source, are cause for

concern.”(Spears, Hansen, & Audet, 2007)

Many Swans die yearly from lead poisoning, usually caused from ingesting man made

lead products such as lead shotgun pellets. Tundra Swans found dead on Rose Lake, near the

BHSS in Idaho, however, are thought to have died due to a large amount mine-related lead found

in the sediment that makes its way into their system via the tubers they ingest that make up the

majority of their diet. A very low amount of mortality in these swans was caused by lead pellets.

According to the article Lead Poisoning of Waterfowl by Contaminated Sediment in the Coeur

d'Alene River,

“…in the Coeur d'Alene River basin in Idaho, nonartifactual lead poisoning was the ultimate

cause of death of most of 219 (77%) of 285 waterfowl carcasses that had been found sick or dead

from 1992 through 1997. The majority of these 219 waterfowl (172 tundra swans [Cygnus

columbianus], 33 Canada geese [Branta canadensis], and 14 other species) were poisoned by

ingesting river sediment that was contaminated with lead.”(“Lead Poisoning of Waterfowl by

Contaminated Sediment in the Coeur d’Alene River - Springer,” n.d.)

The hillsides around the region have also become denuded due to smelting processes,

heavy logging, and fires. The pollutants that were released from smelting have caused the

ground to become overly acidic, which has stopped the regrowth of new plant life. A loss of

plant life on hillsides can cause problems to arise from erosion. Studies have been conducted in

the BHSS to see if re-vegetation is a possibility. One such study conducted by the American

Society of Mining and Reclamation entitled The Bunker Hill Hillsides: A Case Study in the Use

of Adaptive Management in Early Successional Restoration on the Nation’s Largest Superfund

Sites states,

“The hillsides are acidic, moisture-limited, and low in certain nutrient supplies. Accordingly,

restoration of hillside soils begins first with introduction of organic matter and lime. Inoculation

of some target woody species with fungal mycorrhizal species may also assist with both the

short- and long-term re-establishment of these processes.”(“THE BUNKER HILL HILLSIDES

IV: A CASE STUDY IN THE USE OF ADAPTIVE MANAGEMENT IN EARLY

SUCCESSIONAL RESTORATION ON THE NATI... - 1472-White.pdf,” n.d.)

Communication of Cleanup Progress

Cleanup at the BHSS is mainly a joint effort between the EPA, the Idaho Department of

Environmental Quality (IDEQ), and the Basin Environmental Improvement Project Commission

(BEIPC). Cleanup in the area has taken place since the early 1980’s. Community involvement

has been an integral part of the cleanup. Government organizations have been working with

local communities and tribal governments to assess damages and implement cleanup procedures.

There are many reports made available to the public regarding the progress of the BHSS. A

Record of Decision (ROD) is a public EPA progress report that explains methods and

alternatives for cleanup and remediation used by the EPA for superfund sites.

According to the EPA,

“A ROD contains site history, site description, site characteristics, community participation,

enforcement activities, past and present activities, contaminated media, the contaminants present,

scope and role of response action and the remedy selected for cleanup.”(US EPA, n.d.-c)

There are also five-year reviews required by the Comprehensive Environmental

Response, Compensation, and Liability Act (CERCLA) that are made available to the public.

Five-year reviews offer the public and the EPA an evaluation of cleanup measures and the

effectiveness of the cleanup

According to the EPA,

“Five-Year Reviews generally are required by CERCLA or program policy when hazardous

substances remain on site above levels which permit unrestricted use and unlimited exposure.

Five-year reviews provide an opportunity to evaluate the implementation and performance of a

remedy to determine whether it remains protective of human health and the environment.

Generally, reviews are performed five years following the initiation of a CERCLA response

action, and are repeated every succeeding five years so long as future uses remain restricted.

Five-year reviews can be performed by EPA or the lead agency for a site, but EPA retains

responsibility for determining the protectiveness of the remedy.”(US EPA, n.d.-b)

The EPA also provides the public with a newsletter entitled the Basin Bulletin published

three times a year which describes cleanup activities and progress associated with the

BHSS.(“Bunker Hill Superfund Site Basin Bulletin,” n.d.)

The Effectiveness of Cleanup

In order to combat the effects of soil contamination in the “Box”, approximately 6,500

properties had their soil removed and replaced with uncontaminated soil. Today, according to

the IDEQ, homes within the “Box” are certified complete. Decisions on which properties should

receive soil remediation are based on the levels of arsenic and lead found in the soil. As of 2011,

these two contaminants were number 1 and 2, respectively, on the Center for Disease Control’s

(CDC) Substance Priority List (SPL).(“ATSDR – Priority List of Hazardous Substances,” n.d.)

Properties showing 1,000 ppm lead, and 100 ppm arsenic had 6 to 12 inches of topsoil

completely replaced. A barrier is placed between the new top soil and the contaminated soil

below indicating to future generations where the contamination begins and ends. Parks, schools,

and homes with children in residence receive top priority. Homes outside of the “Box” in the

“Basin” are still being remediated, and the IDEQ is currently formulating a completion strategy

for the rest of the properties affected by past mining (IDEQ). According to the IDEQ’s Basin

Property Remediation Program (BPRP),

“Between 2002 and 2010, DEQ remediated over 21.5 million square feet (almost 500 acres) of

contaminated soil from 2,800 residential, commercial, and many public properties in the

Basin.”(Quality, n.d.)

The contaminated soil is taken to local waste repositories where the land is already

contaminated. The waste is then contained and controlled in a manner that has the least impact

on a number of factors including human health, wildlife, waterfowl, fish, groundwater, and

wetlands.(“Repository Siting Criteria-62409 - Repository Siting Criteria-62409.pdf,” n.d.)

Roads and residential driveways are also being remediated because they are considered

facilitators for recontamination of an area due to tires transporting contaminants. Soft shoulders

and right of ways are being tested for contaminants and then compared to samples taken from

driveways with in the “Box”. Results show that tires do in fact transport pollutants and reduce

the integrity of the barriers that are in place to separate non-remediated areas from remediated

areas. According to a study entitled A case study of lead contamination cleanup effectiveness at

Bunker Hill,

“Two driveways sampled in Smelterville ranged from 687 to 1290 mg/kg and were above the

community wide goal of 350 mg/kg and the individual property cleanup level of 1000 mg/kg,

respectively; these values were indicative of more substantial recontamination. Other sampling

was conducted in 1999 by the Upstream Mining Group. This sampling showed that driveway

concentrations in a variety of recently remediated properties ranged from 70 to 323 mg/kg lead.

Samples taken by the Upstream Mining Group from pre-1994 properties have a range of 150 to

573 mg/kg lead also indicating some level of contaminant migration onto driveways that is likely

associated with vehicle tracking or exposure of contaminants from beneath the cap.”(Sheldrake

& Stifelman, 2003)

Future Cleanup

Future cleanup of the Coeur d’Alene River Basin is complicated, and it may take many

years and millions of dollars before it is completed. A very large area has been affected by the

hazardous discharge from past mining.

According to the BEIPC,

“The Bunker Hill Mining and Metallurgical Superfund Site includes environmental cleanup and

restoration work in areas contaminated by mining waste in the Coeur d’Alene River Watershed,

Coeur d’Alene Lake, and the upper reaches of the Spokane River. The total length of the system

is 166 river miles through northern Idaho and eastern Washington; and the boundary includes an

area of about 1,500 square miles. It is one of the largest Superfund sites in the nation.”(“Home -

Basin Environmental Improvement Commission,” n.d.)

The EPA has proposed a 20 to 30 year plan, which outlines an incremental cleanup of the

waters and floodplains that have been impacted by the poor mining practices of the past.

Emphasis will be placed on human health and the environment with regards to residential,

subsistence, and recreational use of the lands. Areas designated for cleanup are the Upper Basin

in which the North Fork and South Fork of the Coeur d’Alene River and all their tributaries are

contained, and the Lower Basin which includes Lake Coeur d’Alene and the portions of the

Spokane River that were affected. This is no small task.(US EPA, n.d.-a) According to the

EPA’s Coeur d’Alene Basin Proposed Plan published in 2001,

“EPA is proposing this incremental approach because the specific sources of metals

contamination impacting the streams and floodplains, as well as the effectiveness of certain

possible remedial actions, are not yet fully understood in some areas of the Basin. An

incremental approach would use existing information and information learned from experience

as subsequent increments are implemented. This approach is expected to be a cost-effective

means for achieving protection of the environment.”(“Text.PDF - Proposed Plan complete.pdf,”

n.d.)

Sustainable Mining

The BHSS is one of many contaminated areas around the globe that has helped to raise

awareness and implement change in regards to safer mining practices. Mines are now heavily

regulated by state and federal laws, such as The Clean Air Act which sets air quality standards,

The Clean Water Act which sets standards for water quality and mine discharge, The Solid

Waste Disposal Act which regulates storage and disposal of hazardous and non-hazardous

wastes, and the Migratory Bird Treaty Act which protects most species of birds affected by

mining wastes.(“Federal Environmental Laws that Govern U.S. Mining,” n.d.)

There are also joint research communications that have been published to offer guidelines

for large mining operations and their safe operation. One such publication is entitled The

Hardrock Mining and Beneficiation Environmental Management System Guide. According to

the National Mining Association,

“The guide is a new tool to aid hardrock mining operations with managing environmental

performance. The Hardrock Mining and Beneficiation Environmental Management System

Guide includes eight steps covering initial implementation of the management system through to

continual improvement stages. The guide is designed to provide useful examples and tools for

each step of the process and addresses environmental impacts uniquely associated with the

hardrock mining sector to improve a company’s environmental stewardship.”(“Environment

Publications,” n.d.)

Conclusion

There are many factors that need to be considered in evaluating the cleanup of the

hazardous mining wastes that have been distributed throughout the BHSS. One factor is the fact

that the EPA is not welcomed by everyone in the community. Some blame the EPA for the

collapse of the mining industry in the region. Overall, however, the EPA has been welcomed by

the majority of the community, as is illustrated by this Q & A response for Idaho Public

Television’s Silver Valley Rising by Jerry Cobb, a Silver Valley native and the environmental

health supervisor for the local health district in Kellogg, Idaho,

“Q: What should people make of the "Just Say No to EPA" signs around the basin?

A: You see half a dozen signs around the valley. But if you look at the statistics associated with

sampling and clean up in the box... we had over 90% acceptance rate. People said, 'you bet. I

don’t know what all is going on, and I don’t go to the meetings, and I don’t want to get involved

in all that falderal, but I don’t want any problems on my property. Get it taken care of'. That was

90% acceptance in the box. Ninety percent is a pretty impressive statistic.”(“Outdoor Idaho’s

Silver Valley Rising (Idaho Public Television),” n.d.-b)

It is important that a checks and balances system be in place to monitor the EPA’s BHSS

progress, and to keep an unbiased record of the cleanup available for public access. There have

been many reports done on the effectiveness of the EPA superfund at Bunker Hill. One of the

most recognized outside assessments of the BHSS is outlined in a report done by the National

Academy of Science (NAS) entitled The National Academy of Sciences Report on Superfund and

Mining Megasites: Lessons from the Coeur d'Alene River Basin. This report is critical of certain

aspects of the cleanup such as an apparent lack of concern by the EPA for future flooding re-

contaminating remediated areas, a lack of overall concern for ground water, and problems

associated with repositories.

The report states,

“The committee found that scientific and technical practices used by EPA for decision making

regarding human health risks at the Coeur d’Alene River basin Superfund site are generally

sound. The exceptions are minor. However, for EPA’s decision making regarding environmental

protection, the committee has substantial concerns, particularly regarding the effectiveness and

long-term protection of the selected remedy.”(“The National Academy of Sciences Report on

Superfund and Mining Megasites: Lessons from the Coeur d’Alene River Basin | Superfund | US

EPA,” n.d.)

The EPA claims that they have accomplished a great deal in the Silver Valley and

surrounding areas with regards to the cleanup. Human health and the environment are on the top

of the list of priorities recognized by the EPA. These top concerns have been the focus for the

majority of their cleanup efforts.

According to the EPA,

“Since listing it on the National Priorities List in 1983, EPA has accomplished a number of

significant milestones at the Bunker Hill site. In 2008, EPA certified completion of the

residential cleanup in the 21-square-mile area known as the Bunker Hill Box, which was EPA’s

initial focus area due to the high number of children living in the area with unsafe blood-lead

levels. As a result of this residential cleanup activity, EPA and the State of Idaho have

documented a 55 percent reduction of blood-lead levels in children who live in the Box. In

recent years, the number of children with elevated blood-lead levels in the Box and Basin is less

than 2 percent, a statistic consistent with national averages for similar communities. EPA’s

cleanup activities have also resulted in the removal of about two million cubic yards of

contaminated soil and sediments, the creation of nearly 400 acres of safe waterfowl feeding

habitat, re-vegetation of more than 1,000 acres of denuded hillsides, and capping of

contaminated soils with clean material, thereby reducing lead levels in fugitive dust.”(US EPA,

n.d.-a)

Cleanup efforts in the Coeur d’Alene Basin are scheduled to continue for many more

years. However, positive effects from cleanup in the area can already be seen, and the stigma

that is connected with living at a Superfund Site is beginning to fade.

In conclusion, a Q&A response from an interview done with Earl Bennett for Idaho

Public Television’s documentary Silver Valley Rising will offer a final view of the effects that

can be seen in the Silver Valley for this essay,

“Q: What’s your take on Silver Valley in 2005?

A: I think this is going to be the next Sun Valley in Idaho. If you had been here twenty years ago,

and driven through this area, and taken a look when the old smelter was here and the zinc plant

and all the mining and the tailings were all in the valley, and the vegetation hadn’t been re-

established on the hillside, it looked considerably different than it does today.

And if you look at the historical pictures from back in the 1920’s and 1930’s when the smelter

was running with a short stack and the valley would be full of the smoke from the smelter, and

all of the area was full of tailings, and the south fork was running milk-white with the tailings it

was carrying, you wouldn’t have even been able to believe that it’s the same place that it is

today.

So, for folks who are here for their first time, I think it’s getting to the point now where they kind

of wonder, 'what’s all the fuss been about? It looks pretty good to us.' And it does. It‘s coming

back remarkably well.”(“Outdoor Idaho’s Silver Valley Rising (Idaho Public Television),” n.d.-

a)

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