Maryland Water Alert Lifted for 1.9 Million Customers After Plant Power Outage
October 1, 2026 · 2 min read
On Tuesday, September 29, 2026, WSSC Water asked 1.9 million customers in Montgomery County and Prince George's County to use water for essential purposes only. A power outage at the Potomac Water Filtration Plant triggered the alert. By 5 p.m. on Wednesday, September 30, the distribution system had refilled to normal levels and WSSC Water lifted the request.
The Potomac plant is the largest of WSSC Water's two filtration plants. It draws from the Potomac River and produces roughly 100 to 120 million gallons of drinking water a day. It supplies about 75% of WSSC Water customers, so when it goes down, the effects reach most of the service area fast.
The plant has two power feeds and can run fully on either one. In mid September, Pepco took one feed out of service for routine maintenance meant to make the plant's power more reliable and resilient. That left the second feed carrying the entire load. Around 4:30 a.m. Tuesday, that feed failed and crews could not restore it.
Pepco brought the maintenance feed back around noon. The plant still could not restart because of internal electrical issues. Crews worked through the problem and returned the plant to normal operations around 3:45 p.m., and it was producing water again by 5:30 p.m. Pepco said its initial findings pointed to an issue with WSSC equipment as a contributing factor.
Restored power did not end the alert right away. The utility had to refill and stabilize the distribution system, so customers kept limiting water use through Tuesday night and into Wednesday. WSSC Water spokesperson Lyn Riggins thanked customers for their cooperation. She said their conservation helped avoid a potential boil water advisory and kept fire protection adequate in both counties.
The plant is still running under a temporary internal electrical configuration. WSSC Water identified and replaced the failed second feeder, and it will return to service in coordination with Pepco once the system is stable. Crews continue to work on a permanent power solution.
For residents, the takeaway is simple. One power failure at one plant put essential water use limits on nearly two million people in a single day. Public water service depends heavily on reliable electricity, and a conservation request can protect a system under strain. Following WSSC Water alerts and local news helps you act quickly the next time one goes out.
Events like this also make a lot of homeowners ask what is actually coming out of their tap on a normal day. A home reverse osmosis system can't fix a plant outage or replace a boil water advisory, so always follow your utility's guidance during an alert. What it does is filter your everyday drinking water at the source, including contaminants like PFAS, nitrates, and heavy metals. Sanavia Water builds reverse osmosis filtration for homeowners who want that control over their water, no matter what the municipal system is dealing with.
