The U.S. Environmental Protection Agency recently released its final plan to remove mercury contamination from areas of Pompton Lake in Pompton Lakes, New Jersey, including the areas where the Acid Brook flows into the lake, called the Acid Brook Delta. These areas are collectively referred to as the Pompton Lake Study Area. Areas of the sediment on the bottom of the lake have become contaminated with mercury and lead that flowed down the Acid Brook into the lake. The EPA proposed the plan in November 2014 and received public comment on the plan for three months. The estimated cost of the cleanup is $43M.

Under the final plan issued today, in the form of a modification of its existing federal permit, E.I. du Pont de Nemours & Company, Inc. will be required to dredge lake-bottom sediment from a 36 acre area of the Acid Brook Delta and also remove sediment from two other areas of the lake. These two areas total an additional three acres in size. The final permit also requires DuPont to remove contaminated soil from a shoreline area (referred to as upland soil areas) where the Acid Brook flows into the lake, and replace it with clean soil. All of the sediment and soil will be sent to a licensed disposal facility. A long-term monitoring plan will be designed and implemented to assess Pompton Lake after the work is completed.

Mercury in the lake sediment and soil can build up in the tissue of fish and other wildlife and pose a threat to people who eat them. Exposure to mercury can damage people’s nervous systems and harm the brain, heart, kidneys, lungs and immune systems. Fish consumption advisories are in effect, and fish consumption warning signs are posted around Pompton Lake.

The EPA finalized a permit modification requiring the removal of contaminated sediment from the bottom of Pompton Lake in December of 2012. That permit modification was appealed by DuPont and the Passaic River Coalition to the EPA’s Environmental Appeals Board and was later withdrawn by the EPA. The final permit modification now being issued reflects new information, including sampling data, which has allowed the EPA to identify additional contaminated areas of the lake that require dredging, and further refines the area of the Acid Brook Delta that needs to be dredged.

A public comment period was held from November 3 through February 2, 2015. The EPA also held a public session in Pompton Lakes on November 12, 2014 to discuss the draft permit modification and held a formal public hearing in the community on December 8, 2014.

DuPont will be required to develop work plans for the work, which must be submitted to the EPA for approval. The cleanup will be financed and conducted by DuPont with EPA oversight. The EPA is currently reviewing a request by DuPont to transfer the Pompton Lakes Works facility cleanup permit to the Chemours Company, which DuPont expects to spin off as a separate and independent company on July 1, 2015. When the transfer is complete, environmental requirements at the site will become Chemours' obligations.

The E.I. du Pont de Nemours & Company, Inc. operated the Pompton Lakes Works facility, located at 2000 Cannonball Road, from 1902 to April 1994. Products manufactured at the facility included explosive powder containing mercury and lead, detonating fuses, electric blasting caps, metal wires and aluminum and copper shells. The manufacturing operations and waste management practices contaminated soil, sediment and ground water both on and off-site. Lead and mercury from its operations were released into Acid Brook, which flows through the eastern part of the facility and discharges into the Acid Brook Delta of Pompton Lake. DuPont’s operations also contaminated the ground water with chlorinated volatile organic compounds, such as tetrachloroethylene, trichloroethylene, cis 1,2-dichloroethylene and vinyl chloride.

The cleanup of the Acid Brook Delta requires a modification of the permit under the federal Resource Conservation and Recovery Act. The final permit modification will become effective on June 22, 2015 pending any requests for appeal submitted prior to that date.

Plans to clean up the remaining areas of contamination will be proposed through future permit modifications after ongoing investigations by DuPont have been completed and reviewed by the EPA and the New Jersey Department of Environmental Protection. Opportunities for public participation will continue to be provided through regular updates, public notices and public meetings.

The permit modification and relevant documents are available at the EPA’s project website at: http://www.epa.gov/region02/waste/dupont_pompton/index.html