UPDATE: Excavation Site Extended Around Damaged Section of Potomac Interceptor to Access Rock Blockage

February 23, 2026
Photo of extended excavation site with trench boxes

Potomac Interceptor Repairs Update
February 23, 2026
 

  • The excavation around the damaged section of pipe has been extended and trench boxes installed to provide shoring and stability. This doubles the size of the excavated area, to connect the collapse site with a downstream access point to the Potomac Interceptor.
  • The newly excavated section will allow crews to reach an area of the pipe believed to be blocked by large rocks and debris. The section, adjacent to the collapse site, is too compromised for crews to safely complete this work from inside the pipe. Instead, crews plan to remove the crown of the pipe section to access the rocks and debris for removal.
  • On-site coordination continues with U.S. Army Corps of Engineers (USACE) to assist with stormwater management to protect pumping operations.
  • Cleaning efforts continue to remove muck and debris upstream from the damaged section and downstream portions. 
  • Development of the Environmental Restoration Plan is ongoing in coordination with Environmental Protection Agency (EPA), National Park Service, Maryland Department of the Environment, USACE, and the District Department of Energy and Environment with some preliminary mediation efforts underway.
  • DC Water is partnering with USACE and EPA to divert runoff away from the contaminated land and install “catchment basins” below street drains and in the creek to capture runoff that may carry residual wastewater contaminants to the Potomac River. 

Water Quality Sampling Results

DC Water is performing daily water quality sampling. It’s important to note that historically the E. coli levels in the Potomac and Anacostia rivers vary widely from day to day. This is reflected in recent sampling results. Fluctuations in water quality are influenced by factors such as weather events, river flow, runoff, pollutants, releases of combined overflows, and other sources discharging into waterways. Given these variables, measurements taken much further downstream cannot be attributed solely 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

Below are the results of sampling from the one-week period of February 16-22, 2026. Past results may be found on our dedicated Potomac Interceptor Response page.

Graphic with water quality results

For more information about the ongoing repair efforts go to dcwater.com/Potomac-interceptor-collapse.

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.