The infrastructure failure sent millions of gallons of raw sewage into the Potomac River and the Chesapeake and Ohio (C&O) Canal. D.C. Water crews are leading a cleanup effort after a 72-inch section of the Potomac Interceptor collapsed on Jan. 19, causing millions of gallons of raw sewage to spill into the Potomac River and Chesapeake and Ohio (C&O) Canal. The water authority has activated a bypass system and is using high-power pumps to contain the overflow and redirect wastewater. Constructed in 1960, the Potomac Interceptor serves Fairfax and Loudoun Counties in Va.; Montgomery County, Md. D.C. Water is investing $625 million over the next decade to repair and upgrade the system.