INDIANA DEPARTMENT OF ENVIRONMENTAL MANAGEMENT 


We Protect Hoosiers and Our Environment. 

100 N. Senate Avenue • Indianapolis, IN 46204 

(800) 451-6027 • (317) 232-8603 • www.idem.IN.gov 

Michael R. Pence Thomas W. Easterly 

Governor Commissioner 

August 13, 2015 

Ms. Susan Hedman 

Regional Administrator 

U.S. EPA, Region V, R-19J 

77 West Jackson Boulevard 

Chicago, Illinois 60604-3507 

Dear Ms. Hedman: 

Re: 	 Proposed Inclusion of the Riverside 

Ground Water Contamination Site 

Indianapolis, Marion County, Indiana 

on the National Priorities List of 

Hazardous Waste Sites 

The Indiana Department of Environmental Management (IDEM) is providing this letter to 

convey its support to the United States Environmental Protection Agency (U.S. EPA) regarding 

inclusion of the Riverside Ground Water Contamination site on the National Priorities List (NPL) 

of hazardous waste sites. The Riverside Ground Water Contamination site is a contaminated 

ground water plume that encompasses an area of approximately 62 acres and affects two 

wellfields. 

The Citizens Energy Group operates the drinking water utility for the city of Indianapolis. 

Raw water sample results obtained by IDEM from five (5) municipal wells confirmed detections 

of vinyl chloride (VC) and trichloroethylene (TCE). The VC and TCE levels in two of the wells 

exceed U.S. EPA Superfund Chemical Data Matrix benchmarks. The impacted wells provide 

drinking water to more than 10,000 people in Indianapolis. IDEM has identified over 100 

potential sources of contamination to the well fields, including sites in the Voluntary Remediation 

Program, RCRA Corrective Action Program, Brownfields Program, and the State Cleanup 

Program, but a definitive source of the contamination has not been identified. 

This site qualifies for inclusion on the NPL because: 

1) 	 The site meets the National Oil and Hazardous Substances Pollution Contingency 

Plan (NCP) criteria for listing on the NPL, scoring sufficiently high pursuant to the 

Hazard Ranking System (HRS). 

2) 	 The site requires a long-term response action. 

An Equal Opportunity Employer 	 0
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Ms. Susan Hedman 

Regional Administrator 

Page 2 of 2 

An NPL listing would allow for proper and timely investigation of the nature and extent of 

the contamination of the potential sources and enable the U.S. EPA to determine cleanup 

alternatives for the impacted areas, thereby protecting human health and the environment. The 

NPL listing appears to be the most viable alternative for addressing the existing environmental 

problems. 

As the Commissioner of IDEM, I am authorized by Indiana Governor Michael R. Pence 

to act in these matters on his behalf. I have considered my staff's recommendations and I fully 

support the designation of the Riverside Ground Water Contamanition site for inclusion on the 

NPL. I request that the U.S. EPA assign a Remedial Project Manager and/or On-Scene 

Coordinator to implement the process. If you require any additional information or have any 

questions, please contact Mark Jaworski of the Site Investigation Program at 317/233-2407 or 

via e-mail at mjaworsk@idem.in.gov. 

Thomas W. Easterly 

Commissioner 

cc: 	 Denise Boone, U.S. EPA 

Nuria Muniz, U.S. EPA 

Mark Jaworski, IDEM 

Rex Osborn, IDEM