Cleaning complete on Lock 11, Tree Removal Begins for Long-Term Rehabilitation of Sewer Line

April 23, 2026
Excavation site outside the I-495 Beltway showing section of the PI
  • Crews completed cleaning on Lock 11 of the C & O Canal as prescribed by the National Park Service, with soil removal also nearing completion within the lock area.
  • Work continues to remove soil down to the canal’s clay liner between locks 11 and 12, with work expected to begin on the last section downstream to Lock 10 this weekend.
  • Tree removal is underway, after DC Water received the permits to move forward as part of the site preparations for the long-term accelerated rehabilitation of more than 2700 linear feet of the Potomac Interceptor sewer line that had been previously planned.
  • Once tree removal is complete, work will begin to construction a bypass chamber, to divert wastewater around sections of the pipe while they are being rehabilitated.
  • Crews also examined the pipe section recently excavated along Clara Barton Parkway outside the I-495 Beltway. The location is one of three sites, which will be used to access the interceptor for the rehabilitation that will reinforce and strengthen the pipe to like new condition.

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 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

 

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Board of Directors Meeting

April 24, 2023

Monday 9:00 AM

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Upcoming Events

May 16
2:00 pm - 6:00 pm
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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.