Part of Arlington has lost water pressure, officials say

Update at 5 p.m. — Water service has been restored ahead of schedule, county officials say.

Update: Repairs have been completed and water pressure restored to customers in the Willston zone. Learn what to do should water appear cloudy when turning taps back on: https://t.co/rlidD7YZGM.

— Arlington Department of Environmental Services (@ArlingtonDES) February 17, 2022

Earlier: A western portion of Arlington County has lost water pressure due to a broken valve, leaving a couple thousand water customers high and dry.

Arlington’s Dept. of Environmental Services announced around 12:45 p.m. that a part of the county that receives water from Fairfax County’s system has had its service impacted by a broken valve.

“Engineers are working on repairs,” DES said in a tweet. “Estimated time for completed repairs/return of full water pressure: 6 p.m. Willston customers are asked to conserve water.”

Willston refers to the name of the water system within Arlington, comprising about 2% of the county’s population in the Dominion Hills and Boulevard Manor neighborhoods.

“The Willston Area system is located on the western edge of Arlington County along Wilson Boulevard,” notes the county’s water distribution plan. “The water provided in the Willston Area system is treated at both the Dalecarlia and McMillian WTPs, flows through the Fairfax Water system, and then into the Willston Area.”

DES noted that Fairfax County is performing the repairs, although Arlington generally maintains the pipes.

Thanks to quirks in geography and the development of local infrastructure, Arlington and Fairfax County’s water systems each serve some of each other’s customers under a recently-updated agreement.

The agreement also sought to provide redundancy for each water system through a new transmission main. Arlington County’s primary system and the Willson water system both get their water solely from the Washington Aqueduct, across the river, whereas Fairfax’s system uses two of its own water treatment plants along the Potomac and Occoquan rivers.

Water Outage: Residents in the Willston Water Distribution System, approx 2K customers on Arlington's western edge, may be experiencing no pressure because of a broken valve. Engineers are working on repairs. Willston is handled by Fairfax County. https://t.co/m4vEm70mMC pic.twitter.com/G0a3AHYlOP

— Arlington Department of Environmental Services (@ArlingtonDES) February 17, 2022

Update: Estimated time for completed repairs/return of full water pressure: 6pm. Willston customers are asked to conserve water. Note: Arlington maintains infrastructure for the zone but the water is supplied by Fairfax County, performing this repair. https://t.co/MfrWE0QDHv

— Arlington Department of Environmental Services (@ArlingtonDES) February 17, 2022