DC Water's Anacostia River Tunnel Beating All Projections For A Cleaner Anacostia

Six months ago, DC Water placed into service the first 7-mile segment of the Anacostia River Tunnel system to store combined sewage during rain events, keeping sewage overflows from entering the Anacostia River. DC Water today announced that since beginning operation, the tunnel has kept nearly 3 billion gallons of combined sewage overflows (CSOs) out of the Anacostia. Originally projected to reduce CSOs by approximately 80 percent in an average rainfall year, the system has exceeded expectations by achieving an 88 percent capture rate in its first six months of service.

Instead of flowing into the Anacostia, the combined stormwater and sewage is captured and conveyed to the Blue Plains Advanced Wastewater Treatment Plant for treatment prior to discharge to the Potomac River. The new tunnel and wet weather treatment facility have also captured close to 150 tons of trash that otherwise would have ended up in the river.

DC Water CEO and General Manager David L. Gadis commented, “In one of the rainiest summers on record in the District, this tunnel has overperformed. Along with green infrastructure, and other Clean Rivers projects, it is transforming the Anacostia River into a beautiful waterway with new recreational opportunities and a return of wildlife. It’s also bringing economic benefit to the District, enabling the revitalization of the Anacostia Waterfront.”

These projects support the goals of the Anacostia Waterfront Initiative, a collaboration of District agencies, and non-profit, federal, and regional partners to realize the potential of the Anacostia waterfront. In addition to Nationals Stadium and the brand new Audi Field, mixed-use development will bring tens of thousands more residents and employees to the waterfront.

2018 is also being celebrated as the Year of the Anacostia to honor the river’s history and acknowledge the progress being made to clean it up, including the tunnel project. For the first time ever, the Anacostia earned a passing grade in the annual report card issued by the Anacostia Watershed Society.

Added Carlton Ray, Director of the DC Clean Rivers Project, “The tunnel and associated flooding mitigation efforts have gone a long way in preventing CSOs to the Anacostia River and overland flooding and back-ups in the Bloomingdale and LeDroit Park neighborhoods. The final segment of this tunnel—the Northeast Boundary Tunnel— is underway and will bring even more CSO reduction and flooding relief.”

The DC Clean Rivers Project Anacostia River Tunnel segment was placed into service on March 20, 2018. It holds up to 100 million gallons of combined sewage (stormwater and sanitary sewage) to protect the Anacostia River from combined sewer overflows. The Northeast Boundary Tunnel, the final segment, is slated for completion in 2023.

For more information on the Clean Rivers Project, a $2.7B plan for healthier District waterways, visit dcwater.com/cleanrivers.