Army Corps joins Potomac River spill response

by Christine Condon, Maryland Matters
February 23, 2026

The U.S. Army Corps of Engineers joined the response to the sewage spill on the Potomac River Saturday, the same day that President Donald Trump (R) approved an emergency declaration requested by the District of Columbia.

The Army Corps is working to divert stormwater away from the worksite, in order to protect equipment and workers who are now working on the underground pipe through an open pit on the site, which is situated on the Maryland side of the Potomac River near Cabin John.

The site has been hit by intense rainfall in recent days, hampering repair efforts, said Sherri Lewis, a spokesperson for DC Water, which owns the pipe, known as the Potomac Interceptor, and is working to fix it. It’s part of the reason the District requested federal assistance, Lewis said.

“When we had the heavy rains last week, we were getting inundated by the runoff from the American Legion bridge and from the Clara Barton Parkway into where our pumps were,” Lewis said during a news conference on Monday. “It created this cascading effect of water going into the Potomac Interceptor, where we were pumping everything out.”

Col. Francis B. Pera, district commander for the Baltimore district of the Army Corps, said that in addition to working on stormwater control to the site, the Corps is also trying to prevent any contaminants from the site from being carried by rainwater into the river.

“What we’re trying to do is mitigate any additional contamination into the Potomac by keeping the stormwater from traveling against that contaminated soil, and then running back into the Potomac,” Pera said Monday.

Pera said he learned Friday evening that the Army Corps was being tapped, and the Corps had placed some equipment on-site by Sunday, ahead of the snowstorm. “We arrived on the ground on Saturday morning. By Sunday night, portions of that solution were already in place, and operating in order to beat the storm,” Pera said.

On the site of the Potomac sewage line rupture that drew Trump’s ire

The emergency aid request from Washington, D.C., Mayor Muriel Bowser (D) came after social media outcry from Trump, who argued that a disaster was unfolding in the river “as a result of the Gross Mismanagement of Local Democrat Leaders.” Bowser also issued a 15-day disaster declaration because of the spill, which occurred on Jan. 19. DC Water is an independent authority of the District of Columbia, meaning its finances are separate from the District’s.

Trump later said local governments should be asking for disaster aid from the Federal Emergency Management Agency. Maryland and Virginia officials did not request aid, but Trump’s declaration grants assistance to the District and the area where it has responsibilities in the two states, according to a FEMA news release.

The president’s approval allows FEMA to “identify, mobilize and provide, at its discretion, equipment and resources necessary to alleviate the impacts of the emergency,” according to the release.

The federal aid is the latest in the effort to control the spill that spewed an estimated 243 million gallons of sewage into the Potomac in the days after the break, ranking the spill among the worst in recent memory.

After about five days, DC Water diverted the flow from the roughly 60-year-old Potomac Interceptor into an empty lock of the C&O Canal. From there, it is pumped back into an intact section of pipe downstream, bypassing the break.

Since the containment in the canal, there have been overflows, but DC Water has added additional pumps with the goal of preventing future malfunctions. The last such overflow was more than two weeks ago.

Still, bacterial contamination downstream remains a concern. Several test sites below the spill continue to deliver E. coli results far surpassing the federal standard permitting human contact with the water.

Data from Feb. 19, collected by DC Water, indicated that the levels closest to the collapsed pipe were more than 15,000 MPN, compared to the federal threshold of 410 MPN for every 100 mL. Farther downstream, the numbers improved significantly, though a monitoring site near Georgetown was just over the 410 MPN threshold.

Meanwhile, work continues on the massive pipe. DC Water hopes to have a repair in place, allowing the utility to stop using the C&O Canal, by mid-March. But workers continue to be challenged by massive rocks on the site.

 

To lay the pipe in the 1960s, workers had to blast beneath layers of rock on the site, DC Water says. And when they finished building, they layered that rock back on top of the Interceptor. But now, the collapse site is littered with chunks of rock large and small, creating a 30-foot “rock dam” running through the collapse site, Lewis said.

While workers were dropping down into the pipe using an access pit and removing the rocks by hand as recently as Friday, DC Water determined it would have to excavate an additional section of earth to safely extricate the rest of the rocks.

“What we discovered is that the pipe … right next to where that open section is, is too compromised, and it’s unsafe for us to put workers inside to manually assist with removing those large rocks and debris that are inside the pipe, blocking it,” Lewis said.

DC Water estimates that the repair, as well as the environmental restoration at the site, will cost about $20 million. Before Saturday’s declaration from Trump, DC Water expected to split that cost among its wholesale customers that use the pipe, Lewis said, including Loudoun County and Fairfax County in Virginia and WSSC Water, which includes Montgomery County.

It is unclear whether Trump’s decision could change the funding plan, Lewis said. DC Water officials have said previously that they do not expect to have to raise residential customers’ rates to cover the costs of the spill.

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