C & O Canal Clean Up Now Underway between Locks 13 and 14

March 18, 2026
photo of freshwater dam at lock 14 with water being pumped out
  • DC Water and its contractors are now working between locks 13 and 14 in the C & O Canal to vacuum out sludge and muck left behind by the bypass pumping system, that directed wastewater around the damaged Potomac Interceptor and back into the pipe further downstream.
  • The freshwater dam at Lock 14, is now complete, and water is being pumped into the canal to help flush out the sludge and debris, for the initial cleanup.
  • Work is progressing on the initial phase of environmental rehabilitation near Lock 10 of the canal. The clean-up has been underway since flow was restored to the interceptor on Saturday.
  • The initial phase of cleaning and temporary stabilization is nearly complete in the areas directly impacted by the overflows, including the drainage channel along Clara Barton Parkway, Rock Run culvert, the unnamed tributary to the Potomac River, and along the shoreline.

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. This is reflected in the large fluctuations shown March 16 and 17, coinciding with heavy rains. As a result, it’s unlikely the changes in E. coli levels are related to the Potomac Interceptor which last had an overflow reach the river well over a month ago.

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.

graphic of water quality sampling results

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

 

 

Latest News

image of clara barton parkway with lane closure marked in red

Beginning this week and continuing through mid-August, DC Water will temporarily close one lane overnight on Clara Barton Parkway at the Maryland-D.C. border. The closures are needed so crews can ...

Pennyfield Lock Potomac Interceptor bypass pipeline running next to C & O Canal with equipment

There is no active spill or overflow. Work to strengthen the pipe to begin soon.

Today, DC Water completed construction on a temporary bypass system as part of sewer repairs on the Potomac Interceptor near Pennyfield Lock in Potomac, Maryland. Crews turned on the pumps and successfully tested the system. With the bypass now ready, it will allow us to begin the emergency repairs inside the pipe by carrying the wastewater around the repair area.

DC Water Officials with NPS and ANC commissioners doing ceremonial groundbreaking

Today, DC Water broke ground on the Piney Branch Tunnel, the final major tunnel in our Clean Rivers Project. This work will help keep sewage and trash out of local waterways and make Rock Creek, the Potomac River, and the Chesapeake Bay cleaner for our community.

When we finish the Piney Branch Tunnel, it will hold at least 4.2 million gallons of rainwater and wastewater during heavy storms. Instead of overflowing into Piney Branch, that water will go to the Blue Plains Water Resource Recovery Facility, where it will be treated.

Upcoming Meeting

Board of Directors Meeting

April 24, 2023

Monday 9:00 AM

Announcement

DC Water Officials with NPS and ANC commissioners doing ceremonial groundbreaking
DC Water Breaks Ground on Piney Branch Tunnel, Final Phase of DC Clean Rivers Project

Today, DC Water broke ground on the Piney Branch Tunnel, the final major tunnel in our Clean Rivers Project. This work will help keep sewage and trash out of local waterways and make Rock Creek, the Potomac River, and the Chesapeake Bay cleaner for our community.

When we finish the Piney Branch Tunnel, it will hold at least 4.2 million gallons of rainwater and wastewater during heavy storms. Instead of overflowing into Piney Branch, that water will go to the Blue Plains Water Resource Recovery Facility, where it will be treated.

Latest Blog Post
Five photos from the American Water Works Association (AWWA) ACE26 conference featuring panel discussions, technical presentations, networking, and attendees posing at the ACE26 display.
ACE26 Highlights: How DC Water Advanced the Conversation on Water
More than 80 DC Water employees joined thousands of water professionals in Washington, D.C., sharing expertise, building partnerships and advancing conversations that will help shape the future of water.
Upcoming Meeting
Date
July 23, 2026
Thursday, 9:30 AM

Upcoming Events

Jul 23
Jul 25

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.