Pepco's Response to the Mineral Oil Spill at Potomac River Power Station Investigation and Cleanup Complete, Monitoring and Assessments Continue

If you passed the Potomac River Power Station between Bashford Lane and the Potomac River in Alexandria, Va. during February-June 2011, you may have noticed an unusual amount of activity along the river front. You were seeing Pepco contractors and employees working to achieve complete cleanup of the nontoxic mineral oil that leaked from a high-voltage transformer at our substation on the west side of the power station property.

The leak occurred in the early hours of Sunday, Jan. 23; the cause of the leak was a pipe separating from the transformer. The leak was stopped quickly, and the majority of the mineral oil remained in the emergency containment reservoir or in the transformer itself. Nevertheless, an estimated 4,500 gallons escaped.

Some of that mineral oil reached the Potomac River to the east of the Pepco substation. As soon as Pepco discovered that the mineral oil had reached the river, we deployed absorbent booms to contain it. We then engaged trained spill response contractors for cleanup and recovery on both land and water; they recovered all but 4,000 gallons of the mineral oil.

PHASE I: Containment & Recovery

In the days immediately following Sunday's leak, Pepco's contractors and employees worked 12-hour shifts around the clock to recover all the collectible deposits of mineral oil from land and water. They continued working as conditions allowed until all recoverable oil was captured for proper disposal.

PHASE II: Complete Cleanup

The next important phase of the cleanup involved clearing caches of refuse that had collected along the shoreline; some of that material had contact with the leaked mineral oil. In many cases, the trash was obscured by dead trees and branches. Our contractors removed these slightly oiled materials for proper disposal. No live trees or shrubs were cut during the cleanupAn important component of Phase II has been implementation of lessons learned. Following advice from environmental, structural and mechanical engineering specialists, Pepco installed new equipment and implemented recommended improvements to maintenance and monitoring procedures, all designed to reduce the likelihood of a future spill incident at Potomac River. In addition, we are following the recommendations in our comprehensive review of equipment and procedures at all substations across the Pepco service territory to ensure that the same high standards are met throughout our electric systemThe nighttime work of course required floodlights to allow the workers to carry on with the cleanup. We hope they did not prove an annoyance, but the faster our work proceeds, the quicker we can ensure that the cleanup will be effective and complete, and that the grounds and waters will suffer no negative impacts.

We continue to cooperate with local, state and federal officials, including representatives of the City of Alexandria Fire Department and Office of Environmental Quality; the District of Columbia Department of the Environment (DDOE); the Virginia Department of Environmental Quality (VADEQ); the EPA; the U.S. Coast Guard; the U.S. Fish & Wildlife Service; and the National Park Service. During the active cleanup and recovery phase, we met daily with their representatives..

PHASE III: Shoreline Monitoring and Assessment

Pepco has conducted a number of voluntary monitoring activities and continues to meet DDOE and VADEQ monitoring requirements.

Pepco collected and analyzed representative samples of the mineral oil from the affected transformer and from the spill area. Analyses confirmed that the spilled material consisted entirely of the mineral oil. The manufacturer of the mineral oil has identified the product as practically nontoxic. Pepco retained certified bird and wildfowl protection contractors to monitor the avian population on the river to make sure that the bird population had not been adversely affected by the escaped mineral oil.
Pepco prepared a Shoreline Assessment Plan to collect sediment and water samples along the shore of the Potomac River in the vicinity of the spill. This ongoing effort will tell us if there is any residual oil in the river that needs further cleanup. Once DDOE has approved the Shoreline Assessment Plan, Pepco's environmental contractors will perform the assessment activities. Pepco also has submitted Ecological Risk Assessment and Natural Resource Damage Assessment Work Plans to DDOE to determine potential impacts of any residual oil on the river ecology.
Pepco staff will continue to monitor the cleanup site.

Pepco will prepare a detailed report of assessment results, and that report will be readily available to the public.

Questions?

If you have a specific question or concern that has not been addressed here, please call the Pepco Potomac River Cleanup Hotline: 202-872-2337.

Our goal is to ensure that the spill cleanup has been thorough and complete and return the affected area at least to its pre-spill condition. Thank you for your patience while the cleanup is completed to everyone's satisfaction.