The New Castle Spill site is a former manufacturing facility 0.5 mile north of New Castle, Delaware, and is in the 100-year floodplain of the Delaware River. Commercial enterprises and residences neighbor the site and receive potable water from the deeper of the two aquifers underlying the site. The six-acre area associated with the site consists of municipal property, wetlands, and the Witco manufacturing facility which produced plastic foams using (2-chloropropyl)-phosphate. In 1977, because of dead grass near the facility's drum storage area, Witco investigated the area and determined that four to five drums of tris had spilled and contaminated the soil and the shallow aquifer. The State subsequently pumped and discharged contaminated groundwater into adjacent wetlands. A 1988 remedial investigation revealed that there is no longer a source of contamination at the site and that tris has contaminated the shallow aquifer but not the deeper aquifer. This limited response action addresses the groundwater contamination in the shallow aquifer. The primary contaminant of concern affecting the groundwater is (2-chloropropyl)-phosphate.

"September 1989." "Office of Emergency and Remedial Response." "PB90-157892." "EPA/ROD/R03-89/077."