Millions of gallons of sewage spilled into the Potomac River leaving ‘horrific’ smell

‘It’s such high concentrations of sewage that just grabbing a sample is a public health risk,’ the Potomac Riverkeeper said

A substantial sewage pipe has ruptured, unleashing millions of gallons of wastewater into the Potomac River northwest of Washington D.C., causing significant pollution ahead of a major winter storm. Repair crews are now in a desperate race against time to contain the environmental fallout.

The incident, which occurred late on Monday, saw a 72-inch (183-centimetre) sewer pipe collapse, sending raw sewage erupting from the ground and flowing directly into the river.

DC Water, the system's operator, is deploying pumps to divert the wastewater around the rupture, enabling repair teams to commence work. The system is designed to handle 230 million litres of water daily, equivalent to about 90 Olympic-sized swimming pools.

Dean Naujoks, the Potomac Riverkeeper and part of an environmental non-profit, described the scene as dire. "Oh my god, the smell is horrific," he stated. "It’s such high concentrations of sewage that just grabbing a sample is a public health risk."

DC Water has advised anyone exposed to the water to thoroughly wash their skin.

DC Water has advised anyone exposed to the water to thoroughly wash their skin (AP)

The spill took place in Montgomery County, Maryland, along the Clara Barton Parkway, close to the C&O Canal National Historic Park.

Crews are now removing lock gates on the canal to facilitate a temporary rerouting of sewage upstream into the canal, before it is directed back into the sewer system downstream of the rupture.

DC Water has confirmed that the region's drinking water supply remains unaffected, as it operates on a separate system. Despite the looming winter storms, repair efforts are expected to continue throughout the weekend.

Naujoks, who inspected the site on Wednesday, expressed his shock, noting the river's unusually low level. "Sewage is just bubbling up like a small geyser, maybe two, three feet into the air," he observed.

"Sewage water is running in every direction." The District of Columbia Health Department has yet to comment on whether testing of the river's water is underway. This incident underscores a national challenge, with hundreds of billions needed in infrastructure investment over the next two decades to address issues like aging sewer pipes and prevent persistent breaks that can lead to home backups and regular flooding.