WEDNESDAY EVENING UPDATE: No Significant Change in Location of Sheen of Substance in the Potomac River

Substance Remains Upriver, Potomac Plant Operating at Full Capacity

| News Release



LAUREL, MD – November 30, 2016: The location of the sheen of lubricant-like substance that is floating in the Potomac River remains relatively unchanged as of Wednesday evening. The sheen traveled as far south as the Seneca Dam on Monday, but has not progressed further downriver.
The U.S. Environmental Protection Agency is taking the lead in investigating the source of the plume, as well as coordinating a regional response to the incident. WSSC continues to operate at full capacity and has not experienced any adverse impact to its drinking water quality.
WSSC continues to take the following steps to protect its source water in the event the substance moves downriver.

  • WSSC continues to maintain our system at full capacity.
  • Crews placed a boom in the river to divert any floating substance away from the intake on Tuesday.
  • As a precaution we have made adjustments to the treatment process.
  • All maintenance activities that require flushing of pipes has 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.


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.

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