At the site of one of the worst sewage leaks in the nation’s recent history, a spill President Donald Trump called “a massive Ecological Disaster,” things had reached a state of relative calm on a recent morning, as crews get closer to bringing the pipe back online.
Most of the 243 million gallons estimated to have leaked from the Potomac Interceptor pipe and into the environment, including the nearby Potomac River, leaked in the first five days after the Jan. 19 collapse. Since then, sewage has been pumped into Lock 10 of the C&O Canal, then back into the intact section of the pipe that carries waste from parts of Virginia and Montgomery County to the Blue Plains Advanced Wastewater Treatment Plant in Washington, D.C.
For workers at the site, along the Clara Barton Parkway near Cabin John, the biggest problem these days is rocks. That’s right: Rocks.
Officials at DC Water, the independent District authority that owns the pipe, believe that workers had to disturb a large amount of rock when they laid this section of pipe more than 60 years ago, rocks they piled back on top of the completed pipe when they covered it with earth.
Little did they know, workers in 2026 would be paying the price. When the pipe collapsed last month, many of those rocks tumbled inside.
“We really thought we were making some progress. We had a section opened up. We were going in. We started cleaning,” said Sherri Lewis, a spokesperson for DC Water. “It was at that point that that process was really getting slowed up, because the vacuum — the standard equipment you use to do the cleaning — was encountering all these rocks.”
Lewis calls it a “rock dam,” a 30-foot section of rock stretching from the collapse site to the pipe entry point that crews are using.
Removing the rocks is no small task.
Workers in white hazmat suits, waders, gloves, bright orange hard hats and respirators clip onto a safety cable before climbing down a ladder about 20 feet or so into the massive pipe, now open to the sky.
Depending on the size of the rocks, the workers either remove them by hand or with a shovel into a large bucket, suspended from an excavator at the surface. Some rocks require two men to lift them into the basket. Heavier rocks are shoved into a position where the excavator can reach them and fish them out.
Sometimes, freeing the stones unleashes the water behind them, overwhelming the pumps trying to keep the work area semi-dry. That’s when workers, guided by the hurried Spanish of crewmates above them, have to climb back to the surface until the muddy brown flow ebbs again.
Still, officials at DC Water estimate that the troublesome rocks will be removed by mid-March and they will have installed a replacement 72-inch pipe section, allowing sewage to flow through the pipe as normal once more.
In the meantime, in hopes of preventing overflow events like one on Superbowl Sunday, when so-called flushable wipes clogging a bypass pump led to a spill, DC Water has added more pumps to carry the wastewater into the canal. A total of 13 are on site, Lewis said, though not all running at the same time.
Once the replacement pipe is installed, the utility will stop using Lock 10 as a retention pond for the sewage, and begin an environmental restoration effort for the area, which is popular for hiking, biking and other recreation, thanks to the towpath running alongside it.
Even though the sewage discharges have largely been contained, bacteria levels downstream in the Potomac River remain a massive concern — and they likely will for months. Jurisdictions surrounding the river have issued health advisories warning the public against touching the water. And Maryland closed a shellfish harvesting area in the Potomac.
When the collapse occurred in January, the river was covered in sheets of ice. When the thaw finally arrived last week, along with rain, it sent contaminants once trapped in the ice into the river.
On Feb. 17, testing by the nonprofit Potomac Riverkeeper Network, together with scientists from the University of Maryland, found that E. coli levels at Lock 10 — which had been on the decline — had increased to 80,900 MPN. The safe level is 410 MPN. And unsafe level readings continued for 7 miles downstream to Fletcher’s Cove, according to the riverkeepers.
“When the rupture happened, it went onto the ground first and then ran into the river. All that muck is still on the ground, because it was covered in ice,” said Betsy Nicholas, president of the Potomac Riverkeeper Network. “As we’ve lost the ice and that’s melted, it brought a little bit into the river, but then the rain, on top of that, washed a lot of it into the river.”
Testing has also captured other types of harmful bacteria. On Feb. 3 and Feb. 12, testing at Lock 10 came back positive for MRSA, a staph bacteria resistant to many of the antibiotics used to treat staph infections. Testing also captured some evidence of MRSA downstream, according to the riverkeeper network.
The nonprofit — along with several Maryland and Virginia members of Congressional — is pushing for DC Water to continue its regime of daily testing into the spring and summer. But while the utility plans to continue the testing, it hasn’t determined for how long. That will be determined in consultation with the utility’s regulators, Lewis said.
Lewis said that DC Water expects to continue to see elevated bacteria levels close to the scene of the break, because of “residual wastewater in the soil” and the creek bed. But as more and more time passes since the last overflow event, she argued that all bacteria overages downstream on the Potomac cannot necessarily be linked to the Interceptor break. Especially after rainstorms, bodies of water near cities can see bacteria spikes, because of runoff of sediment, fertilizer and other substances.
“If you start to see elevated levels, you can’t necessarily attribute that solely to this incident, because we’ve got all this heavy rain and stuff that is bringing all kinds of other stuff into the river,” Lewis said.
She said it’s still not clear what exactly caused the massive pipe to rupture.
But DC Water knew that the pipe was part of the aged infrastructure in its system in need of repair. In fact, DC Water was planning to begin a project this summer to reline 10,000 linear feet of the Potomac Interceptor — including the area that collapsed, Lewis said.
“It’s unfortunate, though, that this happened before we could get to it,” Lewis said.
The saga of the collapsed pipe gained a new chapter last week, when President Donald Trump weighed in on social media, in which he blamed Gov. Wes Moore (D) for failing to respond, and declaring he would send federal assistance to the scene. But Environmental Protection Agency officials had already been onsite by that point, Lewis said. Trump later said the states, including Maryland, should ask him for federal disaster assistance — D.C. Mayor Muriel Bowser made that request Wednesday.
Lewis said DC Water would welcome extra funding or assistance to deal with infrastructure woes. But as of now, things at the site are under control, she said.
“We’re on a good path right now,” she said. “We have eyes on the pipe. We get that assessment done, and hopefully get that repair done by mid-March, which is not too far away.”
Nicholas did not welcome Trump’s effort to draw attention to the spill. She said she would struggle to list anything that DC Water should be doing that it isn’t doing already. The real problem, she said, is addressing aging infrastructure before disastrous failures occur.
“Can we please stop the political finger pointing?” Nicholas said. “It’s not helping, and it’s distracting people from the real issues that we need to deal with here.”
This story was originally produced by Maryland Matters, which is part of States Newsroom, a nonprofit news network which includes Virginia Mercury, and is supported by grants and a coalition of donors as a 501c(3) public charity.