Final Permit Modification Issued for DuPont/Pompton Lakes Works Site Pompton Lakes, New Jersey Community Update January 2013 Major changes between the proposed and final permit modifications: 1. An expanded area of Pompton Lake will be dredged; it encompasses approximately 40 acres as compared to the originally proposed 26 acre dredging area. 2. The cleanup requires DuPont to perform additional sediment sampling to identify potential "hot spots" outside of the Acid Brook Delta; and 3. A post cleanup, long- term monitoring program and ecological risk assessment will be performed to confirm the effectiveness of the dredging/restoration project. This summary describes the key differences between the proposed November 2011 permit modification and the final permit modification which was issued by the EPA in December 2012 (http://www.epa.gov/region2/waste/dupont_pompto n/additionaldocs.html). The cleanup of the Acid Brook Delta and uplands requires a modification of the permit under the federal Resource Conservation and Recovery Act. The final permit modification will become effective on February 4, 2013 pending any requests for appeal submitted prior to that date. Most work plans relating to the changes in the permit modification will be submitted to EPA for approval within 30 days of the permit effective date. Expanded Acid Brook Delta Sediment Removal All sediment will be removed down to the peat layer in an expanded area from the mouth of the Acid Brook Delta to a line closer to the Ramapo River channel, running approximately north-south, and coinciding with the 2 ppm surficial mercury concentration contour line. A revised Corrective Measures Implementation Workplan addressing the modified permit conditions must be submitted by DuPont to EPA for approval within 30 days of the effective date of the permit modification. Pompton Lake Sediment Sampling Plan Sediment sampling will be performed outside the 40-acre dredge area to delineate mercury concentrations in sediment outside of the dredging area. The objective is to identify "hot spots" within the rest of the lake which may require removal. Potential impacts from lake sediment on downstream areas will also be evaluated from the Pompton Lake dam downstream to Riverside Park, a distance of approximately three miles. www.EPA.gov/region2/waste/dupont_pompton/index.html ------- Community Update January 2013 If you would like additional information, please contact: Pat Seppi Community Involvement Coordinator (212)637-3679 seppi .pat@epa. gov Visit EPA's Web Site at: http://www.epa.gov/region2/waste /dupont pompton/index. html Post Cleanup Long-Term Monitoring Program and Ecological Risk Assessment A post cleanup, long-term monitoring program of the lake system will be performed to confirm the effectiveness of the dredging/restoration project. Baseline conditions of the Pompton Lake system will be established prior to dredging to help determine the effectiveness of the dredging/restoration project and the potential need for further dredging. Two years after completion of dredging and re- establishment of the bio-layer, an updated Ecological Risk Assessment will be conducted using updated risk data, bioaccumulation factors, and relevant, newly gathered site information. This work will be conducted in close coordination with the U.S. Fish and Wildlife Service. Uplands Restoration Program A revised Uplands Restoration Program will be prepared. This plan must ensure that the potential pathways for exposure of wildlife to mercury- contaminated soil are eliminated. Site Background: From 1902-1994, DuPont manufactured explosives on a 570-acre site located at 2000 Cannonball Road in Pompton Lakes and Wanaque, New Jersey. Past operations and waste management practices have contaminated surface water, soil, sediment and ground water both on- and off-site. The primary soil and sediment contaminants are lead, mercury and copper. Primary ground water contaminants are volatile organic compounds which can cause vapor intrusion in areas where the shallow ground water contaminant plume extends beneath homes. The DuPont Pompton Lakes Works site is regulated under the federal Resource Conservation and Recovery Act. DuPont is responsible for conducting the necessary cleanup with oversight by the EPA and the New Jersey Department of Environmental Protection. www.EPA.gov/region2 /waste/dupont_pompton/index.html ------- |