US, Delaware reach agreement on cleanup of Superfund site

The U.S. Environmental Protection Agency (EPA) and Delaware have reached an agreement with 21 defendants on completing a $41.6 million cleanup plan for the 27-acre Delaware Sand & Gravel Landfill Superfund site in New Castle County, Delaware.  

Between 1969 and 1976, about 550,000 cubic yards of industrial waste and construction debris, including at least 13,000 drums containing hazardous substances, were disposed of at the industrial waste landfill, formerly a sand and gravel quarry.   

The EPA and the Delaware Department of Natural Resources and Environmental Control (DNREC) confirmed the presence of several hazardous substances in the site’s soil and groundwater. In 1981, the EPA added the site to the “National Priorities List” of the most contaminated sites nationwide.    

“EPA’s Superfund program focuses on making a visible and lasting difference in communities by ensuring that public health and the environment are protected,” says Adam Ortiz, EPA mid-Atlantic regional administrator. “This settlement with the responsible parties ensures that ongoing work will continue at this Delaware site that was abused for years with the disposal of hazardous waste.”

EPA and DNREC have been working since 1983 with potentially responsible parties to clean up the site, located on Grantham Lane, about two miles southwest of the city of New Castle.

The 21 settling defendants are:

• The Chemours Company FC LLC;

• Hercules LLC (individually and on behalf of its former subsidiary, Champlain Cable Corporation);

• Waste Management of Delaware Inc.;

• SC Holdings Inc.;

• Cytec Industries Inc.;

• Zeneca Inc.;

• Bayer CropScience Inc.;

• INEOS US Chemicals Co.;

• Chevron U.S.A. Inc.;

• CNA Holdings LLC;

• E.I. du Pont de Nemours and Co.;

• Esschem Inc.;

• FMC Corp.;

• The Goodyear Tire & Rubber Co.;

• Honeywell International Inc.;

• Clarios LLC;

• Controls Battery Group Inc.;

• KLHC Inc.;

• M.A. Hanna Plastic Group Inc.;

• New Castle County;

• Occidental Chemical Corp.; and

• Verizon Delaware LLC.

The agreement, a consent decree subject to a 30-day public comment period and court approval, was reached under the federal Comprehensive Environmental Response, Compensation and Liability Act. This requires landowners, waste generators and waste transporters responsible for contaminating a Superfund site to clean up the sit or reimburse the government or other parties for cleanup activities.

According to the EPA, several cleanup measures have been implemented at the site, including the installation of an underground slurry wall around the drum disposal area, excavation and off-site disposal of drums and contaminated soil.

There also has been construction and operation of a bio-venting system that supplied oxygen to live microbes in the soil from 1997 to 2009, enabling them to break down hazardous substances. A multilayer landfill caps were installed at two waste disposal areas of the site: the inert area and the Grantham South Area.

There also has been an extraction of contaminated groundwater from the Upper Potomac Aquifer with on-site treatment and discharge to surface water or discharge to the local wastewater treatment plant.