Spring Cleaning in the Region’s Drinking Water System

March 11, 2014

From March 17 through April 28, 2014, the disinfectant in drinking water will temporarily switch from chloramine to chlorine.

The annual switch in water disinfection is part of a routine program to clean and maintain drinking water systems in the District of Columbia, Arlington County and the northeastern portion of Fairfax County. During the temporary switch to chlorine, local water authorities will also conduct system-wide flushing to enhance water quality. This program is a common practice for many U.S. water systems that use chloramine during the majority of the year.

The Washington Aqueduct is the organization responsible for treating and disinfecting drinking water for its wholesale customers: DC Water, Arlington County, and Fairfax Water. Local water authorities are responsible for monitoring drinking water to ensure chlorine levels continue to meet safe target levels.

Individuals and business owners who take special precautions to remove chloramine from tap water, such as dialysis centers, medical facilities and aquatic pet owners, should continue to take the same precautions during the temporary switch to chlorine. Most methods for removing chloramine from tap water are effective in removing chlorine. Individuals with special health concerns should consult a health care provider on the use of tap water.

During this time, individuals may notice a slight change in the taste and smell of their drinking water. Local water authorities recommend running the cold water tap for approximately two minutes and refrigerating tap water to reduce the chlorine taste and odor. Water filters are also effective for reducing chlorine taste and odor. For more information, please see Frequently Asked Questions (link below) or contact the appropriate water authority.

DC Water: 202-612-3440 (Monday-Friday, 8:00 a.m. - 4:30 p.m.) or 202-612-3400 (24-hour)

Arlington County: 703-228-6570 (Monday-Friday, 8:00 a.m. - 5:00 p.m.) or 703-228-6555 (24-hour)

Fairfax Water: 703-698-5800 (Monday-Friday, 8:00 a.m. - 6:00 p.m.) or 703-698-5613 (24-hour)

Washington Aqueduct: 202-764-0008 (Monday-Friday, 8:30 a.m. - 5:00 p.m.)

Latest News

View of Mary at bottom of shaft inside tunnel shown from above

First turn of cutterhead signals the start of excavation for the Potomac River Tunnel Project

In a defining moment for one of the District’s largest infrastructure investments, DC Water has marked its next major milestone in the Potomac River Tunnel Project. The first tunnel boring machine, Mary, has launched her northbound journey breaking through the soil to signal the start of excavation.

With the first turn of Mary’s drill-like cutterhead underground, the machine pushed forward to begin tunneling, representing the transition from years of planning and preparation to active tunnel construction on the $819 million project.

Photo of the vegetation growing back in the culvert area
  • DC Water has completed soil removal, utilizing excavators and manual digging, to expose the clay lining for the C & O Canal between locks 13 and 14. This is the final step in the clean-up process ...
Workers manually removing soil between the locks

Work is progressing on the clean-up for the C & O Canal which was used as a bypass while the Potomac Interceptor was repaired. Workers are focused on removing sludge between locks 11 and 12. Soil removal is also nearly complete between locks 12 and 14, reaching the canal's clay liner. Workers are now manually removing additional materials in some areas.

Upcoming Meeting

Board of Directors Meeting

April 24, 2023

Monday 9:00 AM

Announcement

View of Mary at bottom of shaft inside tunnel shown from above
DC Water Launches Tunnel Boring Machine Mary, Marking Important Step for Potomac River Tunnel Project

First turn of cutterhead signals the start of excavation for the Potomac River Tunnel Project

In a defining moment for one of the District’s largest infrastructure investments, DC Water has marked its next major milestone in the Potomac River Tunnel Project. The first tunnel boring machine, Mary, has launched her northbound journey breaking through the soil to signal the start of excavation.

With the first turn of Mary’s drill-like cutterhead underground, the machine pushed forward to begin tunneling, representing the transition from years of planning and preparation to active tunnel construction on the $819 million project.

Latest Blog Post
A helicopter lowers a drill rig to workers on the Potomac River.
DC Water begins drilling in Potomac River to explore options to rehab underwater sewer line
When one of your major sewer lines runs through the Potomac River, a backhoe and trencher won't do. That's why we've got helicopters carrying a 14-ton drill and workers suspended midair over the Potomac.
Upcoming Meeting
Date
April 15, 2026
Wednesday, 9:30 AM

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.