A major project will work to reduce the amount of raw sewage that flows into rivers and basements locally.
The multi-million dollar project of the 12.8-mile tunnel by D.C. Water is scheduled for completion in 2022. The tunnels will serve as a holding tank for the sewage during rainstorms.
Currently, rain-sewage now overwhelms older sewer pipes and overflows into waterways and basements. Under the new plant, once the storm dies down, the rain will makes its way down to the treatment plan.
Once the storm subsides, the rain-sewage mixture will flow downhill to the treatment plant.
The tunnels would run beneath the Potomac and Anacostia rivers.
"We'll capture all of it," said George S. Hawkins, DC Water's general manager, according to The Washington Post. "This is the most significant improvement in water quality in the Anacostia, Potomac and Rock Creek in a generation."
DC Water officials say it will be the largest tunneling effort in the District since the Metrorail system was built. The work is part of DC Water's $2.6 billion "Clean Rivers Project" to cut sewer overflows by about 96 percent by 2025, the Post reported.