The tunnel is part of the Clean Rivers Project, which stems from a lawsuit that environmental groups filed in 2000 against the District of Columbia Water and Sewer Authority for allowing billions of gallons of untreated sewage to flow into area rivers. Construction on the overall tunnel system, which runs about 12 miles, began in 2011. The new segment broke ground in 2018.
The addition of this latest tunnel is designed to prevent 98% of sewer spills, and is a major step toward restoration of the Anacostia River. Additional tunnels are also set to be built to protect the Potomac River and Rock Creek, and are scheduled to be complete by 2030.