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Case Summary: Settlement Agreement Results in Innovative Cleanup Addressing Vapor Intrusion in Caverns in Missouri

On July 19, 2016, the U.S. Environmental Protection Agency (EPA) and TRW Automotive U.S. LLC entered into a settlement agreement that requires the company to address trichloroethylene (TCE) vapor contamination within Meramec Caverns, a tourist cave within the La Jolla Spring Complex near Sullivan, Missouri. The estimated cost to cleanup the vapor contamination is $1.5 million.

The TCE within Meramec Caverns is the result of vapor intrusion from groundwater contamination originating and migrating to the cave area from a former automotive parts manufacturing facility in Sullivan and the Old Sullivan Municipal landfill. The TCE vapors presented a risk to cave tour guides and pregnant women. Meramec Caverns, a major tourist attraction drawing over 100,000 guests annually, is said to have been a hideout for Jesse James. The permanent closure of the historic cave would have been a major blow to the local economy.

As a result of the work performed by TRW Automotive U.S. LLC, the front portion of the cave complex was reopened on June 10, 2016, following data analysis that indicated levels of TCE vapors in that portion of the caverns were below levels of health concern. As of August 6, 2016, all portions of the caverns that are utilized for tours have been reopened to the public.

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Information about TRW Automotive U.S. LLC

TRW Automotive is an automobile supplier currently headquartered in Livonia, Michigan. The company manufactured piston rings at the TRW/Ramsey facility in Sullivan, Missouri. Those operations resulted in releases of TCE from the facility. Additionally, TRW sent waste to the Old Sullivan Municipal Landfill, which also contributed to the releases of TCE from the facility.

Information about the Oak Grove Village Well Superfund Site

TCE vapors detected in the cave likely originate from two sources, the former TRW/Ramsey Facility in downtown Sullivan and the Sullivan Landfill. Both of these facilities are associated with the Oak Grove Village Well Superfund Site, which became part of EPA’s National Priorities List (NPL) in 2002. The former TRW/Ramsey Facility is managed by the Missouri Department of Natural Resources’ (MDNR’s) Resource Conservation and Recovery Act (RCRA) Program.

The TRW manufacturing facility was closed in the 1980s and Corrective Action cleanup activities have been performed at the facility under RCRA. Groundwater around the facility is extracted and the water treated to remove the TCE.

More information is available on the Oak Grove Village Well Superfund site profile sheet.

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Information about the settlement agreement

The settlement agreement requires TRW to take actions at the cave location to remove the vapor contamination from the toured portions of Meramec Caverns. Actions taken to date at or around the cavern include the installation of air lock doors, venting to remove contaminated air within the cavern, extensive studies of airflows, and the use of air scrubbers to remove TCE. The cave venting equipment will have a backup generator in the event of an electrical power failure. The privately owned Meramec Caverns were voluntarily closed by the owner until the TCE levels could be reduced to safe levels.  The removal action implemented allowed the caverns to be reopened for tourists. There will be studies to measure the impact of the removal actions to the ecology of Meramec Caverns and ongoing sampling to insure TCE levels continue to be at safe levels.

Information on the work being performed at the Meramec Caverns is available on the LaJolla Spring Cave Complex – Meramec Caverns Web page.

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Contact information

For more information, contact

James D. Stevens
Office of Regional Counsel
U.S. Environmental Protection Agency
Region 7
11201 Renner Blvd
Lenexa, KS 66219
(913) 551-7322

Karissa Orris
U.S. Environmental Protection Agency
1200 Pennsylvania Avenue, NW
Washington, D.C. 20460
(202) 564-0546

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