Authorities from Washington, D.C.‘s Water and Sewer Authority expect the full repair of the sewage pipe that ruptured near Cabin John, Maryland, to take over nine months.
DC Water officials held a briefing before a Maryland House of Delegates subcommittee on Friday, in which they explained the full repair process to address the Jan. 19 Potomac Interceptor sewer line collapse. The collapse, which has allowed 243 million gallons of raw sewage to overflow into the Potomac River, has become likely the largest reported wastewater spill in U.S. history.
“Our mission going forward is to clear the pipe, restore the flow back to the Potomac Interceptor — that is what it will take in order to eliminate flows into the Potomac River,” COO of DC Water Matt Brown told the state legislators. “Then we’ll be moving forward on the permanent repair, environmental restoration efforts, as well as rehabilitation of the greater Potomac Interceptor.”
Dr. Moussa Wone, vice president of DC Water’s Clean Rivers Project, outlined the timeline of the overall repair project for the Potomac Interceptor overflow. Wone explained that over the past four weeks since the pipe collapse, DC Water crews have been working to install a bypass pump to reroute the overflow from the Potomac through the C&O Canal and to clean and identify the scope of the blockage.
With those initial stages completed, work crews are now in a four- to six-week phase of constructing a bulkhead, bypass chamber, and continuing to clear the blockage. After this phase, the authorities expect wastewater overflows to be eliminated.
However, following this up to six-week phase, DC Water will then work to permanently repair the broke pipe with a sliplining process in a phase they expect to take about nine months. This mean the entire process likely will not be complete until November or December of 2026.
POTOMAC RIVER SEWAGE SPILL DEEMED ONE OF THE LARGEST WASTEWATER SPILL IN NATION’S HISTORY
On Thursday, DC water reported 105,000 MPN/100mL of E. coli detected in the water by the interceptor overflow point. Swimming is not recommended in waters with E. coli levels of 410 MPN/100mL or above, according to the agency.
Drinking water is not affected.
