Annual Water Pipe Cleaning Begins Monday February 20

February 17, 2023
Photo of child drinking tap water from a glass
  • Disinfectant switch begins next week, continues until May 15
  • Regional drinking water system meets all Federal and state safety standards
  • Easy steps help reduce any temporary change in water taste

The water networks serving DC Water, along with Arlington County and northeastern Fairfax County, will undergo annual cleaning starting Monday. Water service continues uninterrupted during the process, which runs from February 20 to May 15 this year. During that time, drinking water may smell or taste slightly different.

The U.S. Army Corps of Engineers’ Washington Aqueduct, water supplier to these regions, performs the temporary disinfectant switch from chloramine to chlorine. The switch provides an added element that helps clean and maintain the water pipes. Washington Aqueduct continues to add a corrosion inhibitor during the process to reduce the potential for release of lead in service lines.

“This is an important step in maintaining water pipes for delivery of safe drinking water,” said DC Water CEO and General Manager David L. Gadis, “We coordinate with the Aqueduct and regional water utilities during this annual cleaning. DC Water continues to monitor for safe levels of chlorine as well as ensuring we meet all federal drinking water standards.”

DC Water also conducts system-wide flushing to enhance water quality during this time. Water utilities will systematically flush fire hydrants by opening them up to allow fresh water to flow through the system. Crews operating hydrants in this manner are a normal part of this routine. This process is repeated nearly every year, in this region and across the nation.

This year’s switch begins earlier and extends longer while the Washington Aqueduct performs some capital improvements that require this specific water treatment.

This temporary cleaning often adds a new smell or taste to tap water. If customers opt, they can run the cold water tap for about two minutes, then use a water filter. Or they can fill a pitcher with water from the tap and place it in the refrigerator to reduce the chlorine taste and odor.

Customers who take special precautions to remove chloramine from tap water should continue such methods during the temporary switch to chlorine. As always, those with special concerns should consult their health care provider.

Washington Aqueduct is the wholesale water supplier for the District of Columbia, Arlington and northeastern Fairfax County.

For more information, please visit dcwater.com/chlorine-switch. DC Water customers can also call 202-612-3440 (Monday-Friday, 8:00 a.m. - 4:30 p.m.) or 202-612-3400 (24-hour).

Latest News

Map: Temporary southbound lane closure on Rock Creek and Potomac Parkway NW.

Starting on or about Aug. 7, 2026, weather permitting, drivers can expect a temporary lane closure southbound on Rock Creek and Potomac Parkway NW near the intersection of Virginia Avenue NW and F ...

Photo of inside Potomac Interceptor at Dulles showing newly lined tunnel

First of four emergency repairs on Potomac Interceptor finished

DC Water has finished the first of four emergency repair projects on the Potomac Interceptor sewer line. Crews completed work today to strengthen a 600-foot section of pipe at Dulles International Airport.

Picture of repaired segment before the geopolymer work and after the work is done

Crews also reach a major milestone near Dulles International Airport as the next phase of repairs begins this week

DC Water has completed the first major step in emergency repairs to a 175-foot section of the Potomac Interceptor near Pennyfield Lock in Potomac, Maryland. Crews added a new, stronger lining inside the pipe after inspections found serious wear and damage. The work is part of ongoing repairs to 1,700 linear feet of pipe near Pennyfield Lock. Work began on Friday to apply geopolymer, a concrete-like material, inside the pipe. With the new lining complete, crews are preparing for the next phase of work for the remainder of the pipe segment.

Upcoming Meeting

Board of Directors Meeting

April 24, 2023

Monday 9:00 AM

Latest Blog Post
Plastic bottles, cups and other floating debris on the surface of the Anacostia River before the Anacostia River Tunnel began operating.
Cleaner Waterways Start With Everyday Choices
Protecting our waterways starts with everyday actions and continues through critical infrastructure designed to keep pollution out of our rivers.
Upcoming Meeting

Upcoming Events

Customer Service Center Announcement

Payment Plan Incentive: provides a credit back of 50% of the last 3 payments made. Eligible participants are residential customers who have had an outstanding balance for 60 days or greater and with an outstanding balance of $500 or more.