Annual tap water change starting next week, a month earlier than usual

Arlington and its neighbors are getting an early start on an annual tap water change.

The Washington Aqueduct, which serves Arlington, D.C. and part of Fairfax County, is preparing for a reservoir rehabilitation project. As a result, the yearly “spring cleaning” practice of switching water disinfectants is kicking off a month early.

Starting this coming Monday, Feb. 20, locals may notice a slight chlorine taste and smell from their tap water. It’s perfectly safe, the county says, and will last through May 15.

More, below, from a county press release.

Arlington County, along with the District of Columbia and northeastern Fairfax County, will modify the water treatment process beginning Feb. 20, 2023, in an annual practice lasting through May 15. The safeguard involves the industry-standard practice of temporarily swapping the system disinfectant from chloramine, used most of the year, to chlorine. This practice ensures that the water mains remain clean and clear.

Although traditionally begun in March, this year’s early start will allow the Washington Aqueduct to complete a reservoir rehabilitation project. The Aqueduct, operated by the U.S. Army Corps of Engineers, supplies the three jurisdictions with drinking water and initiates the cleaning process for pipes down the line. The Arlington network is made up of some 500 miles of pipes linked to homes, businesses and schools.

Purification systems and constant monitoring by Arlington staff ensures the County’s water is safe and essentially unchanged, although users may notice a slight difference in smell and taste. The switchover will not involve any interruption in service to customers.

Concurrent with the disinfection switch, Arlington will conduct a system-wide flushing to enhance year-round water quality. Residents may see some of the County’s 3,700 fire hydrants flowing at the curb as part of the procedure.

What to expect Feb. 20 through May 15:

• Customers who experience a chlorine smell or taste from the tap can run the cold-water line for about two minutes before using water from the tap; employ a filter system; or let the water sit in a container for an hour or two as the chlorine smell and taste dissipate.
• Customers who take special precautions to remove chloramine from tap water during the rest of the year should continue such methods during the temporary switch to chlorine. As always, those with special concerns should consult their health care provider.

Arlington’s drinking water continues to meet or exceed all safety standards established by the federal Environmental Protection Agency and Virginia Department of Health.

The County uses approximately 8 billion gallons of tap water each year, around 1 trillion 8-ounce glasses of water, all originating from the Potomac River.