DC Begins Daily E. coli Testing on Potomac, Anacostia Rivers

newsroom

Published March 2nd, 2026

Detected March 17th, 2026

Summary

The District of Columbia's Department of Energy and Environment (DOEE) will commence daily E. coli testing on the Potomac and Anacostia Rivers starting March 2, 2026. Results will be posted online within 48 hours, with an advisory for public contact with the Potomac River expected to be lifted on the same date.

View original document View source feed page

What changed

The District of Columbia's Department of Energy and Environment (DOEE), in partnership with the EPA, is initiating daily E. coli testing for the Potomac and Anacostia Rivers beginning March 2, 2026. This enhanced monitoring will occur at six existing test locations, with results to be published online within 48 hours. This action follows DC Water's daily testing and DOEE's weekly testing, and aims to provide more immediate data on water quality, particularly concerning the EPA's recreational contact standard of 410 MPN/100 mL.

Regulated entities and the public should be aware that an advisory for avoiding contact with the Potomac River is expected to be lifted on March 2, 2026, contingent on continued normal water levels and no further overflows. While the District's drinking water remains unaffected, the public should continue to consult official channels for the latest water quality advisories and testing data. This increased testing frequency provides a more dynamic view of potential pollution sources, such as stormwater runoff, and their impact on river bacteria levels.

What to do next

Monitor daily E. coli test results for the Potomac and Anacostia Rivers posted by DOEE.
Stay informed regarding the lifting of the public contact advisory for the Potomac River on March 2, 2026.
Review water quality data from DOEE and DC Water for potential public health impacts.

Source document (simplified)

Friday, February 27, 2026 FOR IMMEDIATE RELEASE:

February 27, 2026

CONTACT:
Christopher Brown (DOEE) – 202-507-0813; [email protected]

Dorian Walker (DOH) – 202-380-6578; [email protected]

DC To Begin Daily E. coli Testing on the Potomac and Anacostia

Daily Testing Results Will Be Posted Online Within 48 Hours

(WASHINGTON, DC) – Today, the Bowser Administration announced that the Department of Energy and Environment (DOEE) will begin daily testing for E. coli in the Potomac and Anacostia Rivers in DC on Monday, March 2, 2026. The new daily testing will continue at the existing six DOEE test locations – three along the Potomac River, two on the Anacostia River, and one on the Washington Channel. The District has partnered with the Environmental Protection Agency (EPA) to expedite the testing process. DOEE will post the daily test results within 48 hours after sampling, as this is typically when results become available from EPA’s laboratory processing.

DC Water has been conducting daily testing since January and DOEE has been conducting weekly testing throughout February. DOEE’s test data are publicly available on doee.dc.gov and DC Water’s results are publicly available at dcwater.com.

E. coli in urban rivers is highly variable and high E. coli values can be caused by many different sources of pollution. For example, E. coli levels can increase when it rains or when snow melts, because this creates stormwater runoff which carries bacteria from pet and wildlife waste to waterways. The EPA standard for E. Coli for recreation contact is 410 MPN/100 mL and while swimming in the rivers without a permit is never allowed in the District, that is also the standard that the District uses.

Recent testing shows E. coli levels have returned to the typical range for the District's rivers.

The District Department of Health (DC Health) is actively monitoring water quality data in close coordination with DOEE, DC Water, and federal partners to assess any potential public health impacts. The District’s drinking water remains safe and has not been affected by this incident.

An advisory for the public to avoid contact with the Potomac River remains in effect. At 21 days (since the last overflow) of continued normal levels downstream over changing weather conditions and no additional substantial overflows, DC Health is expected to lift the advisory on March 2.

For more information on DOEE’s testing data, please visit doee.dc.gov. For DOH’s health advisories, please visit doh.dc.gov. For DC Water’s progress on the Potomac Interceptor repair, please visit dcwater.com.

Social Media

Attachment(s):

PRESS RELEASE DC E.COLI DAILY TESTING ANNOUNCED (1).pdf