OLEM/OSRTI

Washington, DC 20460

NATIONAL P L (NPL) RIORITIES IST 

***NPL Site*** September 2016 

WEST VERMONT DRINKING WATER Indianapolis, Indiana

CONTAMINATION Marion County

 Site Location:

The W est V ermont D rinking W ater C ontamination site consists o f a co mmingled g round water pl ume c ontaining 

chlorinated solvents. The ground water plume is approximately 18 acres and is contaminating drinking water wells in 

a mixed residential/commercial neighborhood on the west side of Indianapolis, Marion County, Indiana. 

 Site History:

The M arion C ounty P ublic H ealth D epartment ( MCPHD) discovered t he s ite i n 2009. T he Indiana D epartment of 

Environmental M anagement (IDEM) r eferred t he s ite t o the EPA Removal P rogram. The EPA installed temporary 

water treatment systems in three residences to help remove vinyl chloride in drinking water. Investigations by the EPA 

and IDEM have since concluded that two nearby facilities located northeast of the neighborhood are responsible for 

the contamination. 

 Site Contamination/Contaminants:

The pl ume c onsists of c hlorinated s olvents, s pecifically t richloroethene ( TCE), t etrachloroethene ( PCE) a nd vinyl 

chloride. The s ite pos es a he alth r isk f or residents due t o c ontamination a bove the S afe D rinking W ater A ct’s

Maximum Contaminant Level (MCL) for vinyl chloride. 

 Potential Impacts on Surrounding Community/Environment: 

Concentrations of vinyl chloride were found above safe drinking water standards in three residential drinking wells. 

There ar e 40 homes i n the ne ighborhood within a mile that rely o n p rivate w ater wells th at c ould p otentially b e 

affected. The contaminated plume also has the potential to migrate four miles to where two separate municipal well 

fields are located that serve water to more than 18,000 people. 

 Response Activities (to date):

In A ugust 2009, t he M CPHD found vinyl c hloride in r esidential w ells above safe l evels. T hat s ame year, IDEM 

formally requested assistance from the EPA Removal Program. The EPA installed temporary water treatment systems 

in t he t hree r esidences t o help r emove vinyl c hloride i n dr inking w ater. The EPA al so conducted a hydrogeologic 

investigation to identify the source of contamination in the residential wells. MCPHD monitors drinking water wells 

for this neighborhood on a regular basis. In 2015 Removal connected residential properties to municipal water. EPA's 

Removal Program continues to assess vapor intrusion threats at these homes. 

 Need for NPL Listing:

The state of Indiana referred the site to the EPA because the ground water plume can potentially contaminate nearby 

drinking water wells and municipal well fields. Other federal and state cleanup programs were evaluated, but are not 

viable at this time because responsible parties have not adequately addressed the ground water contamination under 

state authority. The EPA received a letter of support for placing this site on the NPL from the state of Indiana. 

[The description of the site (release) is based on information available at the time the site was evaluated with the HRS. The description may 

change as additional information is gathered on the sources and extent of contamination. See 56 FR 5600, February 11, 1991, or subsequent 

FR notices.]

For more information about the hazardous substances identified in this narrative summary, including general information regarding the effects of exposure to 

these substances on human health, please see the Agency for Toxic Substances and Disease Registry (ATSDR) ToxFAQs. ATSDR ToxFAQs can be found on

the Internet at http://www.atsdr.cdc.gov/toxfaqs/index.asp or by telephone at 1-800-CDC-INFO or 1-800-232-4636.