Crews have been working to repair sections of the massive Potomac Interceptor sewer line that ruptured in January and dumped 243 million gallons of raw sewage into the river.

DC Water said in a press release that daily water quality testing on the Potomac River will continue through July 31 while workers install bypass systems and line damaged pipe sections at Pennyfield Lock along the C&O Canal. The utility said the work is not expected to interrupt drinking water service for nearby Maryland communities.

The repairs are part of a longer-term effort that DC Water estimated in March would take nine to 10 months to complete.

The Potomac Interceptor, a 72-inch-diameter sewer line built in the early 1960s, carries about 60 million gallons of wastewater daily from areas near Dulles Airport to the Blue Plains Advanced Wastewater Treatment Plant in Washington, D.C. A section of the pipe collapsed in January near Glen Echo, releasing what NPR reported was one of the largest sewage spills in U.S. history.

After the collapse, DC Water installed pumps and a steel bulkhead to divert wastewater around the broken section so crews could begin repairs. Cleanup work near Cabin John along the C&O Canal is also continuing, according to DC Water.

Summer concerns for river users

Dean Naujoks of the nonprofit Potomac Riverkeeper Network warned in March about lingering effects from the spill. "243 million gallons of sewage just doesn't go away," Naujoks said. "We're concerned about potential algae blooms and fish kills this summer."

Naujoks made those comments in March. DC Water's continued daily testing suggests water quality concerns persist as summer temperatures peak. Pennyfield Lock, located off River Road, is a popular access point for kayakers, anglers and hikers using the C&O Canal towpath.

Lawsuit and accountability

A class-action lawsuit filed in March by Dr. Nicholas Lailas, a Virginia physician and recreational boat owner, alleges DC Water had acknowledged signs of corrosion in the line for 10 years before the collapse. Steve W. Berman, managing partner of Hagens Berman, the law firm representing the plaintiffs, said the firm seeks damages "for a failure of immense proportions."