Pepco Potomac River Substation Oil Spill Damage Assessment and Restoration Plan (DARP)

On January 23, 2011, a pipe break at the Potomac River Substation in Alexandria, Virginia, owned by Pepco, LLC, resulted in the discharge of 17,000 gallons of mineral insulating oil from the No. 9 transformer. An underground secondary containment reservoir overflowed, resulting in a discharge of approximately 4,500 gallons of oil into the Potomac River. Due to the oil's properties, the material spread quickly with river currents, sheer force of wind, and gravity. The resulting oil sheen was reported from the Washington Sailing Marina to National Harbor, a distance of 3.5 miles. Eleven subsequent discharges of accumulated storm water occurred from the site between February 1 and June 23, 2011. Results of the Trustee injury evaluation indicate that injury to the benthic invertebrate community occurred along the shoreline adjacent to the Pepco Potomac River Substation. In addition, three bird mortalities were observed and two oiled birds were recovered or observed as oiled during surveys following the spill. During spill response activities, portions of the Mount Vernon Trail, in George Washington Memorial Parkway, were closed, preventing visitors from accessing portions of the trail and nearby recreational opportunities.

This Draft Damage Assessment and Restoration Plan (DARP) was prepared by federal and state natural resource Trustees in accordance with the Oil Pollution Act (OPA, 33 U.S.C. §2701, et seq.) and OPA Natural Resource Damage Assessment Regulations (15 C.F.R. Part 990) to restore natural resources injured by the Spill. It is available under the "documents" section.

Contact Information

Robert Mocko, Environmental Protection Specialist
George Washington Memorial Parkway