WSSC Water Asks All 1.9 Million Customers to Use Water Only for Essential Purposes

WSSC Water is asking all 1.9 million of its customers in Montgomery and Prince George’s counties to use water only for essential purposes, effective immediately, after a power problem knocked out normal operations at the plant that supplies about three quarters of the system’s drinking water.

WSSC Water issued the request at 8:45 a.m. Tuesday, September 29. The water is safe to drink and WSSC has not issued a boil water advisory. WSSC says conserving water now is what could keep a boil advisory from becoming necessary.

What WSSC Is Asking You to Do

• Use water only as necessary. Take shorter showers and turn faucets off immediately after use.
• No outdoor water use at all, including lawn irrigation systems.
• Limit flushing toilets. WSSC says do not flush after every use.
• Limit running washing machines and dishwashers.

WSSC says the essential-use request applies until further notice.

Why It Happened

According to the utility’s announcement, a power issue is affecting operations at the Potomac Water Filtration Plant, which draws straight from the Potomac River and supplies roughly 75 percent of WSSC Water customers. WSSC said it is working with Pepco to prioritize restoring power to the plant.

The arithmetic explains the urgency. The Potomac plant normally produces 100 to 120 million gallons of drinking water a day and is the larger of WSSC’s two treatment plants. WSSC’s other treatment plant, Patuxent, is running and producing 90 to 95 million gallons a day. Average customer demand is about 170 million gallons a day.

With the Potomac plant down, WSSC is supplying a little more than half of a normal day’s demand, which is why the utility cites fire protection and system storage as reasons to conserve.

What to Watch For

WSSC called it a rapidly evolving situation and said it will post continuous updates. WSSC directs customers to its website, wsscwater.com/essential-use, and to its accounts on X (@WSSCWaterNews) and Facebook.

A boil water advisory has not been issued. If pressure in the WSSC system falls far enough, a boil water advisory becomes more likely, which is the outcome the conservation request is meant to avoid.

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WSSC Water’s announcement follows.

Essential Water Use Only Issued for All WSSC Water Customers; Power Outage at Potomac Water Filtration Plant

Laurel, Md. – September 29, 2026, at 8:45 a.m. – WSSC Water is urging all 1.9 million customers in Montgomery and Prince George’s counties to only use water for essential purposes effective immediately. At this time, water is safe and there is no need to boil before essential use.

The urgent essential-water-use-only request is being issued due to a power issue impacting the operations of WSSC Water’s Potomac Water Filtration Plant (WFP), which supplies drinking water to approximately 75 percent of WSSC Water customers. WSSC Water is working collectively with Pepco to prioritize the restoration of power to the Potomac Plant.

Following the guidance below could avoid a Boil Water Advisory and help preserve water for system storage and fire protection as Pepco crews work to restore electrical service to the plant.

Until further notice, all customers are being urged to conserve water through the following measures:

• Use water only as necessary – i.e., take shorter showers and quickly turn off faucets immediately after use.
• No outdoor water use, including lawn irrigation systems.
• Limit flushing toilets (do not flush after every use).
• Limit using washing machines and dishwashers.

This is a rapidly evolving situation and WSSC Water will provide continuous updates to keep customers informed. Check the WSSC Water website and social media, X (@WSSCWaterNews) and Facebook for updates as this situation develops.

WSSC Water’s Potomac WFP draws water straight from the Potomac River, producing between 100 and 120 million gallons of drinking water per day. It is the largest of WSSC Water’s two WFPs. The other WFP, Patuxent, is operational and currently producing 90 to 95 million gallons per day, which is not enough to meet demand. The average demand from customers is approximately 170 million gallons per day.

WSSC Water is a not-for-profit public utility focused on serving our 1.9 million customers, not shareholders. Every dollar collected is reinvested directly into infrastructure, technology and workforce to strengthen reliability, improve service and protect public health for generations to come.

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