Case: Koppers Company,
Site history: Chronic releases of hazardous substances began
as early as 1929.
Location: New Castle County, Delaware.
Case status: Trustees are currently quantifying injuries to
natural resources and evaluating appropriate compensatory restoration projects.
Overview: This 317-acre site is located on the north bank of
the Christina River, a tributary to the Delaware River. The site is also
bordered by White Clay Creek, Delaware’s only designated “National Wild and
From 1929 until 1971, the site was used for wood preservative operations. Soil,
groundwater, and nearby creek and marsh sediments are contaminated with
polynuclear aromatic hydrocarbons (PAHs). It is likely that injuries to natural
resources have occurred, and continue to occur, as a result of PAH
The site was placed on the Superfund National Priorities List in August 1990. To
define the nature and extent of contamination, a remedial investigation was
completed in 1996, and additional investigations were conducted in 2002 and
2003. The U.S. Environmental Protection Agency issued a Record of Decision in
September 2005 detailing its preferred remediation alternative for this site.