DC Utility Pushes to Remediate Up to 300M-Gal Potomac River Sewage Spill

The District of Columbia Water and Sewer Authority, generally known as DC Water, stories “progress” in efforts to handle a big spill from a collapsed part of the Potomac Interceptor—a sanitary sewer line that runs alongside the Potomac River in Washington, D.C. and its Maryland suburbs.

A Jan. 19 rupture of the 72-in-dia. pipeline, the reason for which has not been publicly disclosed, despatched an estimated 300 million gallons of untreated wastewater spilling into the river earlier than being introduced below management with a short lived bypass system late final week.

DC Water didn’t reply to ENR’s requests for details about the scope, timing or price of the cleanup and repairs, or the contractors concerned within the containment effort—however stories say the trouble may price as much as $10 million.

Constructed within the Sixties, the 54-mile Potomac Interceptor carries as much as 60 million gallons of wastewater every day from Washington, D.C.’s Maryland and Virginia suburbs to the Blue Plains wastewater plant within the metropolis, for therapy (see map beneath). 

DC Water says the break occurred about one-quarter-mile from the place DC-based Fort Meyer Building Corp. has been at work since final fall on an eight-month, $9.6-million venture to rehabilitate an 800-ft section of the 16-ft-deep interceptor utilizing sliplining strategies. That venture is a part of DC Water’s decade-long rehabilitation program, estimated to price $625 million.

Rupture of 72-in. sewer pipe alongside the Potomac River north of Washington, D.C. on Jan. 19 induced huge wastewater spill that has bben contained, however cleanup and pipe restore might be $10-million effort.
Map: DC Water

With the collapse sending an estimated 40 million gallons of sewage per day gushing into the river, DC Water says on its web site that its contractors labored with the Nationwide Park Service to reroute the majority of the Potomac Interceptor circulation across the leak by way of a dry, remoted part of the historic Chesapeake & Ohio Canal, situated 125 ft away. As many as eight massive pumps are getting used to channel the sewage about 2,700 ft downstream, the place it’s then directed again into the interceptor, the company says. Some current circulation is safely shifting by way of the collapse web site inside the sewer line, in keeping with DC Water.

The U.S. Corps of Engineers-operated Washington Aqueduct, which provides consuming water to town and components of Northern Virginia, is unaffected by the incident, because the major Potomac River consumption level for that system is situated upstream from the rupture web site. However the Corps closed a downstream consumption facility as a precaution.

Ten days following preliminary discovery of the sewage leak, DC Water reported that overflows from the breach seem to have ended, though sustaining 24/7 operation of the pumps has been sophisticated by the realm’s protracted stretch of sub-freezing climate.

The company’s focus now could be on stabilizing excavations across the collapse web site and clearing particles and obstructions from contained in the pipe. Trench bins have been put in across the broken part for containment and to stop additional erosion. As soon as truck-mounted industrial vacuums clear particles, and wastewater ranges across the collapse lower, the company says groups will be capable to extra completely assess the injury and decide a restore technique. 

One restore risk into consideration is to make use of a 50-ft part of 72-in pipe from one other not too long ago accomplished venture.

Additionally but to be decided are the spill’s environmental results and potential remediation wants, an effort that DC Water says is being coordinated with federal, state and native companions. In keeping with the Potomac Riverkeeper Community, water high quality exams of the river taken instantly downstream of the overflow web site inside the first week discovered ranges of E.coli micro organism to be almost 12,000 occasions human security ranges. Though contamination is reportedly dissipating additional downstream, the anticipated gradual soften from the realm’s heavy Jan, 25 snowfall will probably not support the method instantly.

DC Water says its $625-million funding over the following ten years is for initiatives to rehabilitate sections of the Potomac Interceptor, which varies in dimension from 30-in- to 96-in-dia. strengthened concrete pipe in the primary trunk to 13-ft x 7.75-foot rectangular, strengthened concrete pipe within the sewer system’s decrease reaches. 

The world the place the rupture occurred was to have been a part of that program, however it’s unsure when any work there was to happen. On the time DC Water introduced the present rehabilitation venture by Fort Myer Building, the company famous that “a bigger improve” on the interceptor was deliberate for later in 2025.