• DC Water and its contractor have made significant progress on soil removal, reaching the clay liner between locks 13 and 14 of the C & O Canal, which was used as a bypass for wastewater during the Potomac Interceptor repairs.
• Work continues to remove sludge between locks 10 and 13, which is expected to be completed by mid- to late-April. The soil will then be removed down to the clay liner as the final step, and the canal reconstructed to meet National Park Service specifications.
• Mobilization continues for the previously planned long-term rehabilitation, which has now been accelerated to rehabilitate more than 2700 linear feet of the Potomac Interceptor in this area.
• Crews continue to clear brush and trees along Clara Barton Parkway, outside the I-495 Beltway, in preparation for the long-term rehabilitation. Trench boxes are being installed for supportive excavation to access the pipe.
• This site, and two others already opened during the repair, will be used to slip line the Potomac Interceptor. This involves inserting new pipe sections into the existing pipe, to strengthen and reinforce the interceptor to like-new condition.
• The long-term rehabilitation is expected to take 9-10 months, following the emergency repair which was completed March 14 when the flow was returned to the interceptor.

Water Quality Sampling Results

It's important to understand that rain, snow, heat, contaminated runoff, and natural sources of E. coli such as wildlife can cause higher bacteria levels in urban rivers such as the Potomac River. 

As there have been no overflows to the river from the Potomac Interceptor for more than a month prior to completion of emergency repairs, recent fluctuations in measurements are more likely due to these other known factors.

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. A more detailed explanation is posted on the District Department of Energy and Environment (DOEE) website at doee.dc.gov/release/potomac-interceptor-update-and-faqs.

Sample results from March 23 - present are below. Past results may be found here.

For the latest updates and information, including how to provide feedback on the environmental rehabilitation, go to our dedicated Potomac Interceptor Response page.