Potomac Riverkeeper Network finds ongoing fecal contamination; DC Water faces class‑action suit

WASHINGTON - The Potomac Riverkeeper Network says it has detected ongoing fecal contamination in an unnamed tributary that runs beneath the sewage‑filled section of the C&O Canal, according to a report released Tuesday. The findings come as DC Water faces its first lawsuit tied to the massive sewage spill.

What we know:

The environmental group said the contamination happened after DC Water began fully diverting sewage from the failed Potomac Interceptor into a section of the canal.

According to the report, fecal bacteria levels increased by at least two orders of magnitude as the stream passed through a culvert under the impounded sewage.

Staff observed water actively dripping from as many as 20–30 spots in the culvert ceiling, suggesting contaminated water may be leaking into the tributary, the report continues.

The stream is the same waterway that carried more than 200 million gallons of raw sewage into the Potomac River during the first weeks of the Potomac Interceptor overflow.

The Riverkeeper Network says the findings raise concerns about the culvert’s structural integrity and suggest sewage‑contaminated water may still be leaking into the tributary despite DC Water’s bypass system.

The Riverkeeper's says staff spent two weeks sampling the tributary at points upstream, inside, directly below, and downstream of the culvert and then processed the samples at their certified SeaDog mobile lab using standard IDEXX E. coli testing protocols and analysis. Each sample was diluted, placed in an incubator, and analyzed under UV light to calculate bacterial levels.

The environmental group urges DC Water and state and federal regulators to monitor the culvert discharge, investigate the source, assess the bypass and culvert, and stop the polluted flow as soon as possible.

Dig deeper:

Meanwhile, attorneys have filed a proposed class action lawsuit, which must first be certified by a judge before it can move forward in connection with the spill.

Hundreds of people, including boat owners at Columbia Island Marina, are seeking compensation for damages, Alnwick says. Attorneys for the plaintiffs say marinas, boathouses, outfitters, and nearby property owners were all harmed by the spill.

Alleged damages include cleanup and inspection costs, lost business, diminished property values, and other financial losses.

READ MORE: Potomac sewage spill affecting local industry weeks later

The lawsuit argues DC Water knew the Potomac Interceptor was in poor condition and should have taken interim steps to reduce the risk of a major failure while long‑term rehabilitation work was pending. The section of pipe that collapsed had been scheduled for replacement this summer.

At a press conference last week, DC Water officials said they reviewed past inspections and found no indication the pipe was at imminent risk of collapsing.

To read the full class action lawsuit, you can click here.