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Case Summary: EPA Reaches $14.6 Million Settlement for Groundwater Cleanup at Torrance, Calif. Superfund Sites

On July 10, 2012, the U.S. Environmental Protection Agency reached a $14.6 million settlement with four companies for the construction of a groundwater treatment system at the Montrose and Del Amo Superfund sites in Torrance, Calif. Construction of the treatment system is the first step in the cleanup of groundwater contaminated by chemicals used to manufacture DDT and synthetic rubber over three decades.

The four responsible parties for this settlement are: Montrose, Bayer CropScience Inc., News Publishing Australia Limited, and Stauffer Management Company LLC.

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Information about the Montrose Chemical and Del Amo Superfund Sites

Montrose Chemical Corporation of California manufactured the pesticide DDT from 1947 until 1982. Monochlorobenzene was a raw material used in making DDT. The Montrose Superfund Site was placed on the EPA’s National Priorities List (NPL) in 1989. The Del Amo Superfund Site, located adjacent to the Montrose Site, was formerly a synthetic rubber manufacturing facility that used benzene, naphthalene and ethyl benzene. The Del Amo Site was placed on the NPL in September of 2002. Groundwater contamination from both sites has co-mingled and will be cleaned up by this single treatment system.

Information on the Montrose and Del Amo Superfund sites.

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Pollutants and Environmental Effects

Releases of hazardous substances, pollutants, and contaminants from the Montrose plant operations have caused significant contamination of soil and groundwater. This contamination includes undissolved chlorobenzene and DDT bulk product, also referred to a dense nonaqueous phase liquid (DNAPL) and dissolved plumes of chlorobenzene and parachlorobenzene. To date, extensive investigations and cleanup actions have been performed at both sites. EPA’s DDT soil removal actions in the neighborhood near the Montrose Superfund Site were completed in 2002. In 1999, Shell began cleaning-up the Del Amo Superfund Site, constructing a multi-layer impermeable cap over the waste pits and installation of the soil-vapor extraction and treatment system. Additional soil and soil gas cleanups at the Del Amo Superfund Site are slated to begin in 2013.

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Summary of the Consent Decree

Under the consent decree, the four parties will construct a groundwater treatment system, which will remove monochlorobenzene and benzene. In addition to constructing the treatment system, these parties will also pay oversight costs incurred by EPA and the California Department of Toxic Substances Control.

Once operational, the system will extract up to 700 gallons of water per minute, or a total of a million gallons each day, removing monochlorobenzene and benzene, and re-injecting the cleaned, treated water back into the aquifer. The treated water will not be served as drinking water, but will instead be re-injected to surround the contamination and prevent it from any further movement into unaffected groundwater areas. Construction of the treatment system is expected to be completed in 18 months. EPA will pursue further settlements with the four companies and other parties to ensure that additional cleanup actions are taken and the groundwater treatment system is operated and maintained until cleanup levels are met.

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Comment Period

The proposed consent decree for the settlement, lodged with the federal district court by the U.S. Department of Justice on July 9, 2012, was subject to a 30-day comment period and final court approval.

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For more information contact:

Tina Skaar
U.S. Environmental Protection Agency
1200 Pennsylvania Avenue, NW
Washington, D.C. 20460

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