Colleague Review GW Reports January 1999 1 Colleague Review of Ground-Water Reports n Mapping...

Colleague Review GWReports January 1999

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Colleague Review of Ground-Water Reports

Mapping Reports Ground-Water Modeling Reports Geochemistry Reports Reports for Regulators

Colleague Review GW ReportsJanuary 1999

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Common to All Reviews Read through report once before making

any comments You should have received a technically

sound reasonably well organized report in the proper draft format

If report is not in your area of expertise -- DO NOT AGREE TO REVIEW THE REPORT

If report has numerous verification problems and is not in the proper draft format -- SEND IT BACK

If the report is full of spelling and grammar errors -- SEND IT BACK


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Mapping Reports You should receive a package that

includes a map with the points with data for review AUTHORS if data is ± (land

surface datum or location not well known) indicate this on review map and note in text

Map should honor data points within error band and ancillary information described in the report Gaining/Losing streams Dip of bedrock / known faults


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Water-Table Contour Maps WRD Memo 92.48

Must be hydrologically sensible Contours not above land surface Annual range of water-level fluctuation

should be taken into account Area of recharge and discharge should

be taken into account Water-table should generally conform to

subdued topography Depth to water in similar topographic and

geologic areas should be similar Reviewer ask yourself did author create

a hydrologically sensible map


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Potentiometric Contour Maps (Confined Aquifers) Must be hydrologically sensible

Contours could be above land surface Take into account annual range of water-

level fluctuation Take into account geologic structure Take into account discharge areas (well

fields and springs) Know recharge areas If know transmissivity ranges incorporate

this knowledge into interpretation and text Reviewer ask yourself did author create

a hydrologically sensible map


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Ground-Water Model Reports--TOPICS

Ground-water model of an aquifer or aquifer system report requirements

Requirements for reports with new simulations with a USGS approved flow model

Reports with hypothesis testing simulations

Use of non-USGS codes


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Ground-Water Simulation Reports WRD MEMO 96.04 Report Should Include

Purpose and objective of simulations

Description of the work done Logical arguments to convince

reader that methods and analyses are valid

Results and Conclusions


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Purpose and Objectives of Simulations

Model is a tool for understanding a ground-water system or making predictions Reviewer should be able to define the

intended audience and the objectives of the simulations after the INTRODUCTION sections of the report Model Calibration and Development was

to test our conceptualization of the system Simulations were done to see if

contaminants would migrate off-site Hypothetical simulations were done with

very limited data to demonstrate potential recharge areas to wells


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Description of Hydrogeologic Framework -- independent of modeling Author could cite numerous references,

but must describe in the report (maps and X-sections nice) Extent of aquifer(s) and confining unit(s)

natural boundaries tops and bottoms of hydrogeologic units

Hydraulic properties transmissivity or hydraulic conductivity storage coefficient or specific yield

Recharge and Discharge Independent estimates of recharge natural spring discharge ground-water withdrawals


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Description of Mathematical Model Used

Author should not rewrite code documentation manual, but cite document MODFLOW -- brief description that using

finite-difference approximation and which other packages used

IF CODE MODIFICATION -- must document any modifications to computations (not output file modifications) either in appendix of the report

Author should justify choice of code finite-element versus finite-difference MODPATH rather than solute transport MOCDENSE for density dependence


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Description of How Hydrogeology Mathematically Approximated -- MODEL CONCEPTUALIZATION

Model Layering aquifers -- confined, unconfined, or

convertible confining units -- implicit or explicit

(quasi 3-D or 3-D) Boundaries

Natural or far enough away specified head specified flux head-dependent flux (mixed) no flow


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Model Conceptualization continued

Discretization spacing and distribution of finite-

elements or finite-difference cells Is discretization adequate for

proper simulation of system for this problem

Internal Boundaries Rivers, Lakes, Springs, etc.

Did author justify choices

Discretization in Time Steady versus transient

Did author justify choices


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Description of Simulated Properties and Stresses

Must show all hydraulic properties used in the final model runs Best to show maps rather than

tables Author must describe how final

model properties relate to properties described in hydrogeologic framework section

Must show stresses used in simulation Water-Budget graphs, etc. Show any temporal variation


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Transient Simulation Must describe Initial Conditions

Generally must have calibrated steady-state beginning of transient period Requires iterations -- as modify

properties during transient calibration, must have rerun initial condition

• Transient Models should always start with a simulated steady-state initial condition--Reviewers should check that this is mentioned in report


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Description of Calibration Must describe calibration criteria

and procedures Source and quality of observed

data Appropriateness of using these

data -- steady-state calibration for simulation of approximately steady-state event

Show location of observed data NOTE -- Best to have both

observed head data and flux data to calibrate model


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Model Limitations Section Summarization of how model

conceptualization may limit use of model boundaries may effect predictive

simulations Calibration period may not cover all

hydrologic conditions Good place to summarize sensitivity

analysis section Sensitivity of calibrated model will

indicate how uncertainty of parameters and stresses effect simulated heads and fluxes Discussion of non-uniqueness (if no

known fluxes) Could show that many T’s would give similar head result


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New Simulations With Published Model

Brief Discussion of model conceptualization (utilize info from older report)

Complete explanation of assumptions, methods, limitations, and uncertainty associated with new simulations Description of how simulation scenarios fit

within calibration range of older model Demonstrate that new simulations don’t

violate initial and boundary conditions of older model

Author should have provided reviewer with copy of older model report


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Hypothesis Testing Simulations

Model reports with limited data Still should follow previous guidelines Beefed up limitations and uncertainty

sections limited observed data precluded

calibration May want to bracket anticipated rock

properties and stresses to test max/min transport or heads Author should use sensitivity analysis to

determine which properties or stresses have greatest effect on outcome and then use estimated ranges for bracketing outcomes. Reviewer should decide if description is adequate.


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Use of Non-USGS Codes WRD Memo 97.01

Can Use Other Codes, but must have some Quality Assurance Testing by Originator of Code and in Code Documentation Manual Code Documentation Contents

• Mathematical derivation described• Tests done to show derivations are

correctly coded--Check computation results with known results

• Must have input and output files -- To be safe run tests again yourself on your computer platform

• Ideally would like to see the source code in the publication


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Geochemistry Reports Purpose and Objective of Geochemical

Modeling or Facies Mapping Description of work done Hydrogeologic framework for

geochemistry rock mineralogy flow paths

Logical arguments to convince reader that methods and analyses are valid proper reaction kenetics sampling techniques provided

representative sample Does report make geochemical sense


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Reports for Regulators USGS does not make or enforce regulations

Provide scientific information for site characterization

Provide geochemical and microbiological information to support decisions

Develop databases and methods for regulators to apply

OFA’s and DODEC can request us to do work for assisting in remediation of sites

Can do Administrative reports or if need to include in Administrative Record - publish as OFR or WRIR Review as you would any USGS report Administrative Report does not have to follow all

formal illustration standards or report formats - but should follow all technical guidelines for any ground-water report

Colleague Review GW Reports January 1999 1 Colleague Review of Ground-Water Reports n Mapping...

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