OSWER/OSRTI Washington, DC 20460



## N ATIONAL 

## P RIORITIES 

## L IST 

## (NPL)

[The description of the site (release) is based on information av ailable at the time the site was evaluated with the HRS. The d escription may change as additional information is gathered on the sources and extent of contamination.]

For more information about the hazardous substances identified in this narrative summary, including general information regardi ng 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/toxfaq.html or by telephone at 1-888-42-ATSDR or 1-888-422-8737. ***Final Site*** March 2011


### WEST COUNTY ROAD 112 Midland, Texas

GROUND WATER Midland County

à Site Location:
The West County Road 112 Ground Water site is a ground water plume of chromium located in a rural area of Midland County, Texas immediately to the southwest of the city limits of Midland. The center of the site is designated as 2601 West County Road 112, Midland, Texas. Th e site plume currently extends 1 1⁄4 miles from the center of the site and is situated under approximately 260 acres.

 ́ Site History:
The site was identified in April 2009 by a local resident who asked the Texas Commission on Environmental Quality (TCEQ) to test his private well due to yellow discoloration. Sampling of this well revealed the presence of 5,280 parts per billion (ppb) of chromium. To date, approximately 234 wate r wells have been sampled by the TCEQ, and 46 water wells

have concentrations of total chromium above the Safe Dr inking Water Act Maximum Contam inant Levels (MCLs) of 100 ppb. TCEQ has installed water filtration systems at homes where total chromium has been detected above the MCLs.

r Site Contamination/Contaminants:
An Expanded Site Inspection was conducted in February 2010, and no sources were identified. The site is being evaluated as a ground water plume of chromium and hexavalent chromium with no identified source. Con centrations of chromium in the wells are as high as 5,280 ppb.

v Potential Impacts on Surrounding Community/Environment:
Forty-six residential wells have chromium contamination above MCLs, in some cases more than ten times the MCL. Until the source has been identified and controlled, the plume will c ontinue to contaminate remaining private and public wells. The drinking water wells in the contaminated aquifer are th e only source of water for these residents, who have been drinking the water as well as using it for other consumptive purposes.

3 Response Activities (to date):
The EPA started the Remedial Investigation field work in November 2010 and has begun samp ling the private supply wells to monitor the ground water plume. The TCEQ has installed treatment systems on wells that have been identified with hexavalent chromium concentrations exceeding MCLs. TCEQ is providing the systems and quarterly monitoring at no cost

to the residents.

} Need for NPL Listing:
The State of Texas referred the site to EPA for NPL listing a nd potential remedial activities. The potable water is in a relatively shallow aquifer (20-100 feet deep). Other federal and state cleanup programs were evaluated but are not viable

at this time.