DC begins daily river E. coli testing as Potomac Interceptor repairs continue
Washington, DC – March 2, 2026 – DC begins daily E. coli testing of the Potomac and Anacostia as sewer repair work continues after the spill.
Potomac Interceptor response: daily river testing begins
Daily E. coli sampling on the Potomac and Anacostia Rivers is set to begin Monday, March 2, under a new testing schedule announced by the DC Department of Energy and Environment. The District said results will be posted online within 48 hours after sampling, with lab processing supported through a partnership with the U.S. Environmental Protection Agency.
The expanded testing follows the ongoing response to the Potomac Interceptor collapse and related wastewater releases earlier this winter. Regional health agencies continue to treat the situation as an active public health concern for anyone who may come into contact with river water.
Repair updates: milestone reached with no new overflows reported
DC Water reported on March 1 that the response has reached a three-week stretch with no overflows entering the Potomac River, and said the last release to reach the river occurred February 8. Crews have continued cleaning work upstream and downstream of the damaged pipe section as preparations move toward emergency repairs.
In a February 28 update, DC Water said bypass pumping has continued diverting wastewater around the collapse site and back into the interceptor, helping prevent additional overflows from reaching the river while crews remove remaining muck, debris, and rocks inside the pipe.
DC Water also said a National Park Service special use permit was issued February 28 covering repair, rehabilitation, and environmental restoration work in the C&O Canal National Historical Park area between Locks 10 and 14. The March 1 update noted crews clearing trees, brush, and contaminated debris at the site under National Park Service supervision.
Regional advisories and nearby impacts
A February 27 health advisory from Prince George’s County, Maryland, cited coordination among regional agencies and recommended avoiding contact with untreated sewage in the Potomac River until clearance is issued, pointing residents to DC Water for repair updates.
Separately, DC Water issued a February 27 traffic advisory for sewer rehabilitation work along the Rock Creek Main Interceptor in the West End and Georgetown. The utility said temporary lane closures on Rock Creek and Potomac Parkway NW and a closure of a section of the Rock Creek Trail are planned through early Monday, March 2, as crews inspect and restore infrastructure.
Sources
https://doee.dc.gov/release/dc-begin-daily-e-coli-testing-potomac-and-anacostia
https://www.dcwater.com/about-dc-water/media/news/update-progress-potomac-interceptor-repair-and-environmental-restoration
https://www.dcwater.com/about-dc-water/media/news/update-nearly-three-weeks-without-overflow-potomac-river-repair-efforts
https://www.dcwater.com/about-dc-water/media/news/update-cleaning-continues-preparation-emergency-repairs-damaged-potomac
https://www.dcwater.com/about-dc-water/media/news/traffic-advisory-temporary-lane-closures-rock-creek-and-potomac-parkway
https://www.princegeorgescountymd.gov/departments-offices/news-events/news/health-advisory-avoid-potomac-river-following-major-sewage-spill
If you have urgent symptoms, seek medical care. For general questions, talk with a licensed clinician.
