WSSC Water lifted essential-use request after Potomac plant power failure | The Locally Times

Published 10/1/2026, 4:33:24 AM UTC · The Locally Times

WSSC Water said customer conservation helped avoid a potential boil water advisory and preserve fire protection across both counties.

WSSC Water lifted its essential-water-use-only request at 5 p.m. Wednesday, September 30, for all 1.9 million customers in Montgomery and Prince George's counties. WSSC Water reported that customers' efforts to limit water use helped preserve water in the system, avoid a potential boil water advisory, and ensure adequate fire protection across both counties. ## Background The Potomac Water Filtration Plant draws water from the Potomac River and produces between 100 and 120 million gallons of drinking water per day, making it the largest of WSSC Water's two filtration plants. The plant supplies drinking water to approximately 70 to 75 percent of WSSC Water customers. The plant has two power feeds and can operate fully with either one, but one feed was out of service in mid-September for routine maintenance by Pepco when the second feed, which was providing all power, failed at approximately 4:30 a.m. and could not be restored. WSSC Water urged all customers to use water only for essential purposes effective immediately, stating that water was safe and there was no need to boil before essential use. While Pepco restored service to the facility, an unknown electrical problem was impacting the ability to bring systems back online to produce water. The utility's other plant, Patuxent, was operational and producing 90 to 95 million gallons per day, which was not enough to meet average customer demand of approximately 170 million gallons per day. ## What changes The plant continues to operate under a temporary internal electrical configuration while WSSC Water crews work to implement a permanent power solution and ensure the continued reliable operation of the plant. WSSC Water also acknowledged the partnership and support of federal, state, and local agencies throughout the incident.