DRAFT 

NOT TO BE RELEASED OUTSIDE EPA

U.S. ENVIRONMENTAL PROTECTION AGENCY 

OFFICE OF INSPECTOR GENERAL 

Catalyst for Improving the Environment 

 Evaluation Report 

Independent Ground Water 

Sampling Generally Confirms 

EPA’s Data at Wheeler Pit 

Superfund Site in Wisconsin 

 Report No. 10-P-0218 

 September 8, 2010 
Report Contributors: Carolyn Copper 

 Patrick Milligan 

 Jayne Lilienfeld-Jones 

 Martha Chang 

 Denise Rice 

Abbreviations 

DEHP Di(2-ethylhexyl) phthalate 

EPA U.S. Environmental Protection Agency 

NPL National Priorities List 

OIG Office of Inspector General 

Cover photo: Fence surrounding site boundary at the Wheeler Pit Superfund Site 

as of May 2008. (EPA OIG photo) 
 

 

 

 

 

 

 

 

 

U.S. Environmental Protection Agency 10-P-0218 

Office of Inspector General September 8, 2010
 

At a Glance 

Catalyst for Improving the Environment 

Why We Did This Review 

The Office of Inspector 

General (OIG) is testing longterm monitoring results at 

Superfund sites the U.S. 

Environmental Protection 

Agency (EPA) has deleted 

from the National Priorities 

List. Wheeler Pit, located 

near Janesville, Wisconsin, is 

one of eight sites being 

reviewed. In May 2008, the 

OIG obtained Site ground 

water samples and a sample 

from a nearby residential well 

and conducted a site 

inspection. 

Background 

Wheeler Pit received paint 

sludge and coal ash from an 

automobile assembly plant. 

Site wastes were consolidated 

and capped. The Site was 

added to the National 

Priorities List in 1984 and 

deleted in 2004 when EPA 

determined that clean-up goals 

had been achieved. 

For further information, 

contact our Office of 

Congressional, Public Affairs 

and Management at 

(202) 566-2391. 

To view the full report, 

click on the following link: 

www.epa.gov/oig/reports/2010/ 

20100908-10-P-0218.pdf 

Independent Ground Water Sampling Generally 

Confirms EPA’s Data at Wheeler Pit Superfund 

Site in Wisconsin 

What We Found 

With minimal exceptions, our independent sampling results at the Wheeler Pit 

Superfund Site were consistent with the sampling results that EPA Region 5 has 

obtained historically. Among 135 contaminants that OIG compared, 8 were 

different from the region’s results for some wells. The differences found among 

the eight contaminants do not have adverse implications for Site protectiveness, 

because there are either no applicable standards or the levels of the contaminants 

were below applicable standards. Our site inspection showed the Site was 

properly maintained and secured. 

Our analysis of site data identified three contaminants – di(2-ethylhexyl) phthalate 

(DEHP), nickel, and nitrate – that exceeded safe drinking water standards in some 

wells. Because the OIG found excess levels of DEHP and nitrate in one 

residential well, OIG notified the resident in coordination with Region 5. Site 

records support Region 5’s assertions that exceedances of nickel and nitrate do not 

have adverse implications for Site protectiveness, because these contaminants 

either do not originate from the Site or are contained by the Site remedy. 

In addition to the OIG’s detection of DEHP in one residential well, DEHP has a 

history of detection below the limit in some of the Site’s ground water monitoring 

wells. The responsible party’s contractor at Wheeler Pit has asserted that the 

presence of DEHP is due to sampling or laboratory contamination and the region 

has consistently accepted the explanation, but there is no documentation to support 

that DEHP is not site related. Therefore, it is unclear whether excess levels of 

DEHP found in one residential well have implications for Site protectiveness. 

What We Recommend 

We recommend that EPA Region 5 conduct additional sampling on the residential 

well with excess DEHP to verify the Region’s assertion that DEHP is originating 

from the sampling process. Region 5 reviewed our draft report, concurred with 

our findings and recommendation, and proposed an acceptable corrective action. 
 

 

 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

THE INSPECTOR GENERAL 

September 8, 2010 

MEMORANDUM 

SUBJECT:	 Independent Ground Water Sampling Generally Confirms 

EPA’s Data at Wheeler Pit Superfund Site in Wisconsin 

 Report No. 10-P-0218 

FROM:	 Arthur A. Elkins, Jr. 

 Inspector General 

TO: Susan Hedman 

 Region 5 Administrator 

This is our report on the subject evaluation conducted by the Office of Inspector General (OIG) 

of the U.S. Environmental Protection Agency (EPA). This report contains the findings from our 

sampling at the Wheeler Pit Superfund Site and corrective actions the OIG recommends. 

EPA Region 5 concurred with and provided corrective action for the recommendation of the 

draft report. This report represents the opinion of the OIG and does not necessarily represent the 

final EPA position. Final determinations on matters in this report will be made by EPA 

managers in accordance with established resolution procedures. 

The estimated cost of this report – calculated by multiplying the project’s staff days by the 

applicable daily full cost billing rates in effect at the time, then adding in the contractor costs – 

is $359,852. 

Action Required 

Your office has provided a complete and acceptable corrective action. Therefore, your office is 

not required to submit a 90-day response to this report. Your office should appropriately update 

the Management Audit Tracking System to provide information on the completion of the 

September 15, 2011, sampling activities. If your office believes it necessary to modify the 

agreed-to corrective plan, it should consult with OIG in advance. We have no objections to the 

further release of this report to the public. This report will be available at http://www.epa.gov/oig. 

If you or your staff have any questions regarding this report, please contact Wade Najjum, 

Assistant Inspector General, at (202) 566-0832 or najjum.wade@epa.gov; or Carolyn Copper, 

Director for Program Evaluation, Hazardous Waste Issues, at (202) 566-0829 or 

copper.carolyn@epa.gov. 
 

 

 

Independent Ground Water Sampling Generally Confirms 10-P-0218 

EPA’s Data at Wheeler Pit Superfund Site in Wisconsin 

Table of Contents 

Purpose ....................................................................................................................... 1 

Background ................................................................................................................. 1 

Noteworthy Achievements......................................................................................... 1 

Scope and Methodology............................................................................................. 2 

Sampling Results........................................................................................................ 3 

Recommendation........................................................................................................ 4 

EPA Region 5 Response and OIG Evaluation ......................................................... 4 

Status of Recommendations and Potential Monetary Benefits.............................. 5 

Appendices 

A EPA Region 5 Response to Draft Report ......................................................... 6
 

B Distribution ......................................................................................................... 8 
 

 

 

 

10-P-0218
 

Purpose 

The Office of Inspector General (OIG) of the U.S. Environmental Protection Agency (EPA) is 

evaluating long-term monitoring at Superfund sites deleted from the National Priorities List 

(NPL). This evaluation is to determine whether EPA has valid and reliable data on the 

conditions of these sites. Wheeler Pit Superfund Site is one of eight sites being reviewed. At 

Wheeler Pit, we collected ground water samples and conducted a site inspection. We compared 

our results to past results reported by EPA Region 5. 

Background 

Wheeler Pit Superfund Site is located in rural La Prairie Township, approximately 1.5 miles east 

of the City of Janesville, Wisconsin. The Site covers 3.82 acres within a larger abandoned sand 

and gravel pit. Adjacent to the Site to the northeast is a small asphalt plant that is still in 

operation. The surrounding land use is primarily agricultural. Wheeler Pit received an estimated 

22.3 million gallons of paint sludge, residue from the part hanger stripping system, clarifier 

sludges, and coal ash disposed by an automotive manufacturer from 1960 to 1974. 

The Site was placed on the Superfund NPL in 1984. In 1990, EPA issued a Record of Decision 

describing the clean-up goals and actions to be taken. In 1992, the responsible party conducted 

remedial actions, which included placing a Resource Conservation and Recovery Act Subtitle D 

cap over the waste. In addition, a long-term monitoring program was established to evaluate 

performance of the remedy and the state of natural attenuation. EPA deleted Wheeler Pit from 

the NPL in April 2004, signifying that clean-up goals had been achieved. 

Using data and information obtained from the long-term monitoring program, Region 5 must 

evaluate the Site at least once every 5 years to determine if it is protective of human health and 

the environment. The results of this determination are reported in a publicly released Five-Year 

Review report. In years when Region 5 conducts a review, all 15 Site ground water monitoring 

wells and 2 residential wells are sampled. During those years not involving a review, the Region 

annually samples 4 of the 15 wells. Region 5 has completed three reviews, the most recent in 

2007. 

Noteworthy Achievements 

Region 5’s remedial construction activities included the following: 

• Consolidating 36,400 cubic yards of material including waste 

• Installing a clay cap over the waste and consolidated material 

• Installing a fence around the entire site 

• Constructing an access road, retention basin, and perimeter drainage swale 

• Installing new monitoring wells and abandonment of older wells 

The remedy was designed to eliminate or reduce migration of contaminants to the ground water 

and to reduce the risks associated with exposure to the contaminated materials. Institutional 

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controls were established to limit access and restrict future land use of the Site. The remedy also 

included monitoring ground water for natural attenuation, maintaining and monitoring effective 

institutional controls, and site remedy components. 

Scope and Methodology 

We conducted our work in accordance with generally accepted government auditing standards. 

Those standards require that we plan and perform evaluations to obtain sufficient and appropriate 

evidence to provide a reasonable basis for our findings and conclusions based on our objectives. 

We believe that the evidence obtained provides a reasonable basis for our findings and 

conclusions based on our objectives. We reviewed relevant guidance and key historical 

documents, including past sampling results and decision documents such as the Record of 

Decision, Five-Year Reviews, operation and maintenance reports, and State regulations. We also 

interviewed the remedial project managers from EPA Region 5 and the State project managers 

from the Wisconsin Department of Natural Resources. 

We conducted our work in two phases. During the first phase, from April to September 2008, 

we conducted a site visit, collected ground water samples, and performed data validation on the 

sample results. During the second phase of our work, from September 2009 to July 2010, we 

analyzed and compared OIG’s data to Region 5’s sampling data and prepared the report. 

We acquired a qualified environmental contractor to take ground water samples and conduct a 

limited site inspection. In May 2008, our contractor collected nine Site ground water samples 

and a sample from a nearby residential well. The samples were analyzed using EPA-approved 

methods for volatile organic compounds, semivolatile organic compounds, metals, and inorganic 

nonmetals. A limited site inspection was conducted by OIG staff and the contractor. OIG staff 

members were present during the contractor’s inspection and sampling to ensure that proper 

sampling and site inspection quality assurance protocols were followed. 

We compared our sampling data to Region 5’s historic sampling data to determine whether the 

region has been obtaining valid and reliable data on the conditions at the Site. We also analyzed 

our results in the context of the National Primary Drinking Water standards and Wisconsin 

ground water quality standards. The Record of Decision establishes that applicable or relevant 

and appropriate requirements for ground water are both federal and State standards. Wisconsin’s 

Enforcement Standards are the enforceable standards, because they pertain to ground water 

quality. The federal Maximum Contaminant Levels are the drinking water standards for the 

residential well we sampled. 

To accomplish the comparisons between OIG’s and the Region’s sampling data, we compared 

our sampling results to the Region’s 2002 and 2007 historical sampling data. OIG sampling 

results that were greater than 2 standard deviations above the average regional historical 

concentrations were considered different. Our review did not include an evaluation of the 

reasons for these differences. However, where we observed differences, we determined whether 

the OIG data indicated that there was an adverse implication for Site protectiveness. 

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A draft of this report was sent to the Region 5 Administrator for official comment. Region 5’s 

comments on the draft report are in Appendix A. 

Sampling Results 

With minimal exceptions, OIG’s independent sampling results at the Wheeler Pit Superfund Site 

were consistent with the sampling data that EPA Region 5 has obtained historically. We 

compared OIG results for 135 compounds in each of the 10 wells we sampled and found that 127 

of the contaminants had historic data similar to OIG data. The following 8 contaminants were 

found to be different in one or more of the 10 wells we sampled: barium, calcium, chemical 

oxygen, iron, magnesium, sodium, sulfate, and zinc. However, these differences do not have 

adverse implications for Site protectiveness. Calcium, chemical oxygen, magnesium, and 

sodium have no standards. Iron, sulfate, barium, and zinc were below the applicable, or most 

conservative, federal or State standards. 

Comparison of OIG results to applicable standards showed three compounds that exceeded the 

standards: di(2-ethylhexyl) phthalate (DEHP), nitrate, and nickel. Elevated levels of DEHP and 

nitrate were found in a residential well. In coordination with Region 5, OIG notified the resident 

by letter of the DEHP and nitrate exceedances and referred the resident to Region 5 for health or 

Site-related questions. 

The responsible party’s contractor has also detected DEHP in past sampling actions. When 

DEHP was detected, the responsible party’s contractors attributed it to a residue from the 

sampling procedures (i.e., field blank contamination or laboratory contamination). DEHP is 

commonly used in the manufacture of plastics. The responsible party’s contractor has asserted 

that DEHP contamination originated from plastic materials used in the environmental sampling 

and analysis process, and the region has consistently accepted the explanation. However, there is 

no documentation to support the contention that DEHP is not site related and is exclusively an 

artifact of environmental sampling. Therefore, it is not clear what impact DEHP has on Site 

protectiveness. 

A Site manager stated that the nitrate levels are not originating from the Site but instead are due 

to agricultural impacts in the area. He further noted that nitrate concentrations in one of the Site 

background monitoring wells also exceeded ground water standards. The background 

monitoring well is located up-gradient from the Site and represents ground water conditions that 

exist before ground water passes through the Site. These conditions are consistent with an offsite 

source for the nitrate. 

OIG sample results showed nickel exceeded State standards in two onsite monitoring wells and 

elevated nickel levels were also found in Region 5’s 2002 and 2007 samples from the same 

wells. Region 5 managers stated that because the nickel was found only in onsite wells, the 

nickel had no impact on the Site’s protectiveness because it was being contained by the Site 

remedy. The regional remedial project manager also added that EPA would be conducting a 

human health risk assessment on nickel in the future. 

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Recommendation 

We recommend that the Region 5 Regional Administrator: 

1. Conduct additional sampling on the residential well with excess DEHP to verify the 

Region’s assertion that DEHP is originating from the sampling process. 

EPA Region 5 Response and OIG Evaluation 

The EPA Region 5 Administrator reviewed our draft report and concurred with our findings and 

recommendation. Region 5 proposed additional sampling of the residential well to be completed 

by September 15, 2011. OIG accepts this corrective action. 

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Status of Recommendations and 

Potential Monetary Benefits 

POTENTIAL MONETARY 

RECOMMENDATIONS BENEFITS (in $000s) 

Rec. 

No. 

Page 

No. Subject Status1 Action Official 

Planned 

Completion 

Date 

Claimed 

Amount 

Agreed To 

Amount 

1 4 Conduct additional sampling on the residential well 

with excess DEHP to verify the Region’s assertion 

that DEHP is originating from the sampling 

O Regional Administrator, 

Region 5 

9/15/2011 

process. 

O = recommendation is open with agreed-to corrective actions pending 

C = recommendation is closed with all agreed-to actions completed 

U = recommendation is undecided with resolution efforts in progress 

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10-P-0218
 

Appendix A 

EPA Region 5 Response to Draft Report 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

REGION 5 

77 WEST JACKSON BOULEVARD 

CHICAGO, IL 60604-3590
 

 August 12, 2010 

MEMORANDUM 

Subject: Response to Office of Inspector General’s Draft Evaluation Report: Independent 

Groundwater Sampling Generally Confirms EPA’s Data at Wheeler Pit 

Superfund Site in Wisconsin 

Project No. 2008-547 

From: Susan Hedman /s/ 

Regional Administrator 

To: Carolyn Copper 

Director of Hazardous Waste Issues 

Office of Program Evaluation 

The purpose of this memorandum is to provide the United States Environmental Protection 

Agency (EPA) Region 5’s response to the Office of Inspector General’s (OIG) Draft Evaluation Report 

entitled “Independent Groundwater Sampling Generally Confirms EPA’s Data at Wheeler Pit Superfund 

Site in Wisconsin” (Project No. 2008-547), dated July 28, 2010. Region 5 concurs with the findings and 

recommendation in the draft evaluation report. Our responses are as follows: 

Factual Accuracy 

Region 5 reviewed the draft evaluation report for factual accuracy and found the report to be 

accurate in comparison with the September 1990 Wheeler Pit Record of Decision (EPA Region 5, 1990), 

other technical documents utilized and interviews conducted by OIG that are cited. 

Concurrence with Findings and Recommendation 

Region 5 concurs with the findings and recommendation in the draft evaluation report. OIG’s 

Draft Evaluation Report included a recommendation to conduct additional sampling on the residential 

well with excess di(2-ethylhexyl) phthalate (DEHP) to verify the Region’s assertion that DEHP is 

originating from the sampling process. Region 5 plans to conduct additional sampling on the residential 

well with excess DEHP in the near future by using an EPA Region 5 Superfund Technical Assistance 

Team (STAT) contractor. Region 5 will notify OIG, once the additional sampling is completed. 

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Planned Schedule for Recommendation 

Region 5 plans to complete the sampling on the residential well with excess DEHP at Wheeler Pit 

by September 15, 2011. 

Please contact me at (312) 886-3000 or hedman.susan@epa.gov; or Karen Mason-Smith, 

Remedial Project Manager at (312) 886-6150 or mason-smith.karen@epa.gov, if you have any questions. 

Cc: P. Milligan, OIG 

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10-P-0218 

Appendix B 

Distribution 

Office of the Administrator 

Assistant Administrator, Office of Solid Waste and Emergency Response 

Regional Administrator, Region 5 

Principal Deputy Assistant Administrator, Office of Solid Waste and Emergency Response 

Director, Office of Superfund Remediation and Technology Innovation, Office of Solid Waste 

and Emergency Response 

Agency Follow-up Official (the CFO) 

Agency Follow-up Coordinator 

General Counsel 

Associate Administrator for Congressional and Intergovernmental Relations 

Associate Administrator for External Affairs and Environmental Education 

Audit Follow-up Coordinator, Office of Solid Waste and Emergency Response 

Audit Follow-up Coordinator, Region 5 

Inspector General 

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