Repair efforts on the Potomac Interceptor are progressing, with three weeks now passed without any overflows reaching the Potomac River. The last release into the river occurred on February 8.
Repair and Restoration Underway
On February 28, the National Park Service (NPS) issued a Special Employ Permit to facilitate the repair, rehabilitation and environmental restoration of the interceptor and the adjacent C&O Canal National Historical Park. Work is focused on the area between Locks 10 and 14, where the interceptor collapsed.
Crews are currently cleaning the pipe both upstream and downstream of the damaged section. This work includes clearing trees, brush, and contaminated debris under the supervision of the NPS as part of the approved environmental restoration plan. A CCTV inspection of the upstream pipe section has been completed, and cleaning of that section is expected to finish tomorrow, followed by pressure washing to prepare for the application of a geopolymer lining.
The geopolymer, described as being similar in strength to concrete, will be sprayed onto the pipe in layers, allowing time for each layer to cure. Work on the downstream section will begin once the upstream repairs are complete.
Progress Towards Full Restoration
The application of the geopolymer this week keeps the emergency repair on track for completion in mid-March. At that point, the full flow of wastewater is expected to be restored to the Potomac Interceptor, and the temporary bypass pumping system will no longer be needed. DC Water and its contractor will begin hauling away contaminated brush and soil from the site tomorrow for proper disposal.
Environmental restoration work will continue, though it may be affected by forecasted rain, and snow. Cleanup efforts require dry conditions to prevent further contamination.
Water Quality Sampling
DC Water is conducting daily water quality sampling. Historically, E. Coli levels in the Potomac and Anacostia rivers have varied significantly, influenced by factors like weather, river flow, runoff, and pollutants. Measurements taken further downstream may not be directly attributable to this incident.
Historical data indicates that E. Coli levels in the Potomac River can range from 10 MPN/100mL to 5,000 MPN/100mL on any given day. More detailed information is available on the District Department of Energy and Environment (DOEE) website: doee.dc.gov/release/potomac-interceptor-update-and-faqs.
Frequently Asked Questions
What is a geopolymer?
The geopolymer is a material similar in strength to concrete that will reinforce and strengthen the pipe.
When is the repair expected to be completed?
The emergency repair is on track to be completed in mid-March, at which point the full flow of wastewater will be restored.
Is the water quality being monitored?
DC Water is performing daily water quality sampling, and historical data shows E. Coli levels in the Potomac and Anacostia rivers vary widely.
As repair and restoration efforts continue, how might changing weather conditions impact the timeline for full restoration of the Potomac Interceptor?
