MONDAY EVENING UPDATE: Environmental Protection Agency Identifies Source of Sheen in Potomac River

WSSC Drinking Water is Unaffected-Precautionary Steps Continue

| News Release



LAUREL, MD – December 5, 2016: The Environmental Protection Agency (EPA) has determined the source of an oily substance that leaked into the Potomac River beginning Sunday, November 27. NRG Energy (NRG) operates a power plant in Dickerson, MD which has been determined to be the source of the leak.
To date, the oily substance has never been observed at or near the WSSC’s Potomac River intake.  WSSC’s Potomac plant continues to operate at full capacity and the Commission has not experienced any adverse impact to its drinking water quality.
Over the course of the last week, WSSC took the following precautionary steps to protect its source water in the event the substance moves downriver.

  • Crews placed a boom in the river to divert any floating substance away from the intake on Monday (11/28). An additional boom was put in place on Thursday (12/1) near the intake as an additional precaution.
  • WSSC continues to maintain our system at full capacity.
  • All maintenance activities that require flushing of pipes have been halted.
  • An enhanced monitoring plan is in place at the plant, including hourly tests of the water in the river near the intake and adding additional testing of the water as it comes into the plant and before water goes out into the distribution system.

The Potomac Water Filtration Plant produces approximately 70 percent of WSSC’s treated water each day for customers across Montgomery and Prince George’s counties. The Patuxent Water Filtration Plant supplies the remainder to WSSC’s customers.
All inquiries regarding the ongoing investigation should be addressed to Terri A. White, 215-814-5523,, Unified Command, which is comprised of the EPA, Maryland Department of the Environment, Maryland Emergency Management Agency, Virginia Department of Emergency Management, and Virginia Department of Environmental Quality. NRG is now being added to the Unified Command to coordinate efforts going forward.

WSSC Water is the proud provider of safe, seamless and satisfying water services, making the essential possible every day for our neighbors in Montgomery and Prince George’s counties. We work to deliver our best because it’s what our customers expect and deserve.

Last Modified: