• DC Water and its contractor continue to work to remove sludge and debris from the C & O Canal which was temporarily used as a bypass during the emergency repair of the Potomac Interceptor.
• Construction continues on the freshwater dam at Lock 14, which is being fed by water from the Potomac River at Violet’s Lock. The freshwater will be pumped into the canal to help flush the sludge and debris. The flushed material is being directed back into the Potomac Interceptor further downstream. Rainfall throughout the day has assisted in flushing the canal and supporting the initial clean-up.
• DC Water expects to complete the initial removal of debris, soil, and contaminants along the Western section of Area 1 along the drainage channel and adjacent to the collapse site this week.
• There are no issues with the flow that was returned to the Potomac Interceptor. Some sections of the interceptor remain open, operating under what is known as an open channel flow. These openings will also facilitate the long-term repairs allowing crews to insert a new pipe into the existing interceptor.
• While these sections remain open, the impact of any rainfall is expected to be minimal. The main open pipe sections are approximately 20 feet below ground, contained by waterproof trench boxes to prevent flow from getting in or out of the work area.
• Based on the forecast of up to one inch of rain over 72-hours, direct rainfall into the openings would only add about 1200 gallons spread over the entire 72-hour period. The interceptor has between one and three million gallons going through at any given moment, and the impact of any direct rainfall through these openings would be negligible.
• Crews also worked to secure fencing and other materials and equipment at the site, in preparation for high winds and extreme weather.
• Due to the severe weather threat today, crews were unable to collect water quality samples at every site. This will be reflected in the data tomorrow.
• DC Water will hold two community meetings this week to continue the dialogue and for the public to ask questions about the Potomac Interceptor repairs and environmental rehabilitation:
  • Wednesday, March 18 at 6:30 PM | Walt Whitman High School (Cafeteria) | 7100 Whittier Blvd., Bethesda, MD 20817
  • Thursday, March 19 at 7:00 PM | Lee Center Auditorium | 1108 Jefferson St., Alexandria, VA 22314
  • Those interested in attending may RSVP at events@dcwater.com. Please include which meeting you plan to attend.

Water Quality Sampling Results

Fluctuations in water quality are influenced by factors such as rain, heat, or other weather events, river flow, runoff, pollutants, releases of combined overflows, and other sources discharging into waterways. Given these variables and that overflows have been contained for more than a month prior to completing emergency repairs, measurements taken much further downstream are likely unrelated to this incident.

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 9 - present. 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.