Nearly 300 million gallons of sewage has entered Potomac River, environmental group says

WASHINGTON - The Potomac Riverkeeper Network says new water‑sampling results from a recent sewage spill shows far more severe contamination than first believed. 

What we know:

Tests found E. coli levels nearly 12,000 times higher than what’s considered safe for human contact, and nearly 300 million gallons of sewage have already entered the Potomac River, the group said on Tuesday.

Potomac Riverkeeper Network officals warn the long‑term environmental impact could be significant, citing real‑time testing conducted on January 23.

What they're saying:

"We sampled the sewage discharging from the broken interceptor pipe to the Potomac River near Cabin John at Lock 10 and the result was 4,884,000 MPN – Most Probable Number for E.coli – which is 11,900 times higher than the 410 MPN limit for safe human contact," Potomac Riverkeeper Dean Naujoks wrote on the group’s website.

DC Water officials say crews are working around the clock to operate a temporary bypass system that diverts wastewater away from the damaged section of the Potomac Interceptor. The initial overflow was reported on Jan. 19.

Officials emphasize that the drinking water supply is not affected by the spill.

The public is urged to follow posted warning signs and avoid any areas with raw sewage, which can pose serious health risks. Anyone who comes into contact with wastewater should wash exposed skin immediately, disinfect shoes or other items, and seek medical attention if they begin to feel ill.