• Work is progressing on the clean-up for the C & O Canal which was used as a bypass while the Potomac Interceptor was repaired. Workers are focused on removing sludge between locks 11 and 12.
• Following sludge removal, the soil is then removed down to the canal’s clay liner.
• Between locks 12 and 13 soil removal is nearly complete with a majority of the area now cleaned to the clay liner. Work continues between locks 13 and 14 where crews are now manually removing additional material, having completed excavation to also reach the clay liner.

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.