EPA’s Newest Superfund Sites Highlight Toxic Indoor Air

By Sylvia Carignan

The EPA is recognizing the toxic potential of indoor air contaminants with two Superfund sites newly added to its priorities list.

The Environmental Protection Agency announced Sept. 11 that it would add two sites to the National Priorities List, which names the most contaminated sites in the country: Rockwell International Wheel & Trim in Grenada, Miss., and Delfasco Forge in Grand Prairie, Texas.

The sites are the first to be deemed contaminated solely based on the amount of chemicals rising up from groundwater, through soil, and into indoor air in a process also known as vapor intrusion. Industry representatives opposed the listing of one of the sites, taking issue with the agency’s assessment.

Ice Industries Inc., which operates a stamping, welding, and assembly operation at the site in Grenada, Miss., told the EPA that its assessment of contamination there isn’t thorough enough to warrant the site’s placement on the National Priorities List.

The agency’s assessment of the site must be corrected, the National Association of Manufacturers told the EPA. Both comments were posted online March 28.


Past operations, waste-handling practices, and spills at the Grenada site caused the carcinogen trichloroethylene and other chemicals to contaminate groundwater, surface water, soil, and indoor air, according to the EPA.

A munitions manufacturing plant and forge operated until 1998 at the Delfasco Forge site. Soil and groundwater at the site are contaminated with chlorinated solvents, according to the EPA. The agency didn’t receive any comments when it proposed to place the site on the National Priorities List.

The EPA has identified more than 1,000 sites that have potential or confirmed vapor intrusion contamination, but not all would be suitable candidates for the list, which has about 1,300 sites.

Vapor intrusion can occur when groundwater or soil underneath a building is contaminated. Volatile chemicals migrate up through water and soil to contaminate air in buildings.

The EPA recently added vapor intrusion contamination to the list of ways a site can be added to the National Priorities List.

To contact the reporter on this story: Sylvia Carignan in Washington at scarignan@bloombergenvironment.com

To contact the editor responsible for this story: Rachael Daigle at rdaigle@bloombergenvironment.com

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