EPA proposes ending 2 Delaware Superfund sites

The U.S. Environmental Protection Agency announced Monday that it is proposing removing two Delaware sites from its list of the nation’s most contaminated hazardous waste sites, known as Superfund National Priorities List (NPL).

An abandoned office building is one of the few remaining vestiges of the former Chem-Solv in Cheswold. | PHOTO COURTESY OF EPA

The sites, including the Chem-Solv Inc. site in Cheswold and a portion of the Tybouts Corner Landfill in New Castle, were among 10 sites nationwide that the EPA has proposed removing from the NPL.

The EPA deletes sites or parts of sites from the list when no further cleanup is required to protect human health or the environment. Years, and sometimes decades, of complex investigation and cleanup work have gone into getting these sites to the point where they can be deleted from the NPL.

“Deletions from the NPL can revitalize communities, raise property values, and promote economic growth by signaling to potential developers and financial institutions that cleanup is complete,” EPA Mid-Atlantic Regional Administrator Adam Ortiz said in a statement. “This can be especially impactful for communities with environmental justice concerns.”

Thousands of contaminated sites, from landfills, processing plants, to manufacturing facilities exist nationally due to hazardous waste being dumped, left out in the open or otherwise improperly managed.

President Biden’s Bipartisan Infrastructure Law will accelerate EPA’s work to help communities clean up these contaminated sites with a $3.5 billion investment in the Superfund Remedial Program and reinstates the Superfund chemical excise taxes, making it one of the largest investments in American history to address legacy pollution. This investment will enable the EPA to clear a backlog of the 49 contaminated sites that had been awaiting funding to start remedial action.

Located on a 1.5-acre property in Cheswold, Chem-Solv was a small solvent distillation facility founded in 1982. The facility recycled waste solvents, but a 1984 explosion and fire at the site destroyed the building.

After the fire, authorities evaluated the Columbia aquifer beneath the site and found high concentrations of volatile organic compounds (VOCs), primarily trichloroethene, a heavy colorless highly toxic liquid used as a solvent to clean electronic components and for dry cleaning.

Groundwater recovery and treatment was conducted from 1997 to 2017, when sampling showed concentrations had dropped below cleanup levels and remediation was discontinued.

Surface water drainage along western edge of the Tybouts Corner Landfill in New Castle. | PHOTO COURTESY OF EPA

The Tybouts Corner Landfill site is about 10 miles south of Wilmington and 4 miles west of the Delaware River. The site was used by the New Castle County Department of Public Works as a municipal sanitary landfill, which accepted industrial wastes from December 1968 until July 1971. The landfill consisted of two non-adjoined sections, a West Landfill that was about 4 acres in size and the Main Landfill that was about 47 acres, with waste ranging from 5 to 40-feet thick. Contamination was found in two nearby wells in 1976 and again in 1983.

The site has since been capped, excavated, contained and monitored by the EPA and Delaware Department of Natural Resources and Environmental Control. They’ve determined that two parcels of the site are suitable for removal from the NPL, but the remainder of the main landfill will remain listed for now as all performance standards have not yet been achieved.

Public comment on the removal of both sites is open through May 2, and the EPA plans to publish another notice with additional final and proposed deletions this fall.