The E.l. du Pont de Nemours and Company (commonly known as DuPont) Pompton Lakes Works (PLW) site covers approximately 570-acres in the Boroughs of Pompton Lakes and Wanaque in Passaic County, New Jersey. The PLW site incorporates two drainages, the Wanaque River to the west and the Acid Brook to the east. Acid Brook flows into Pompton Lake, which was formed by damming the Ramapo River. The Wanaque River flows into the Pequannock River, which joins with the Ramapo River downstream of Pompton Lake to form the Pompton River. The Pompton River flows into the Passaic River, which empties into Newark Bay.

Explosives were manufactured at the PLW facility between 1902 and 1994, when DuPont closed the facility. As a result of the facility’s operations, hazardous substances including mercury, lead, and other compounds were released to surface water, soil and sediment and groundwater both on and off-site. Both the New Jersey Department of Environmental Protection and the U.S. Environmental Protection Agency (EPA) require clean up of the facility (on site and off-site), which has been ongoing since the early 2000s. In 2018 the USEPA approved remedial action for the ABD and portions of Pompton Lake. Approximately 146,600 cubic yards of soil and sediments were removed from a 40-acre area within Pompton Lake, known as the Pompton Lake Study Area, processed, and disposed of in approved landfills. The Remedial Investigation (RI) of contamination in the Wanaque River is on-going.

As a result of the presence of high concentrations of mercury and other hazardous substances and the potential effects on natural resources (e.g., migratory birds) and their services under the jurisdiction of the US Department of the Interior, a Natural Resource Damage Assessment and Restoration (NRDAR) under the Comprehensive Environmental Response, Compensation and Liability Act was initiated in 2013. The DOI, acting in its capacity as a natural resource trustee, is in a cooperative assessment agreement with E.I. Dupont & Nemours, Company. The Natural Resource Damage Assessment is ongoing.