Long-Term Rehabilitation Work on Potomac Interceptor Continues in Preparation for Construction

April 21, 2026
Photo of long stretch of C & O Canal with soil removed
  • DC Water has excavated a section of the Potomac Interceptor along Clara Barton Parkway, outside the I-495 Beltway as part of the accelerated rehabilitation of more than 2700 linear feet of the interceptor that was previously planned.
  • As part of the long-term rehabilitation project, crews are beginning to remove trees which is necessary to construct a bypass chamber that will divert wastewater around sections of the pipe while they are being rehabilitated.
  • Soil removal is now 55% complete in the C & O Canal. Work continues to remove the soil down to the clay liner on the remaining sections of the canal between locks 10 and 12.
  • Cleaning is complete on the historic canal’s locks 11, 12, and 13 utilizing NPS prescribed methods.

Water Quality Sampling

Daily water quality testing continues to show E. coli levels within the typical range for recreation, with normal historical fluctuations attributed to rain, heat, stormwater runoff, and other known environmental factors. See the District Department of Energy and Environment webpage for more details.

Ongoing sampling is precautionary and intended to address community concerns, ensuring the highest standards of public health and safety.

For the Potomac River, historical water quality data shows E. coli levels may vary from a range as low as 10 MPN/100mL to as much as 5,000 MPN/100mL on a given day.

Results April 13 – present below: (past results can be found here)

graphic of water quality sampling results

You can find more information about the environmental rehabilitation, get the latest news and information, and results of all the water quality testing on our Potomac Interceptor Response page.

Latest News

Section of Potomac River in Cabin John, MD showing river and trees

Testing will continue through September 10 at six Maryland locations closest to January sewer collapse

DC Water is moving from daily Potomac River water quality testing to testing twice a week. The change is part of our continued response to the January Potomac Interceptor sewer collapse. Daily testing continued past the original July 31 end date and today will be the last day DC Water will test at the 10 current locations.

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.

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.