RiverRenew Project Nears Completion

AlexRenew, the project to solve combined sewer overflows in Alexandria, is reaching out to the public to hear their concerns as the project moves into it’s last stages. The final components include: Pile Driving at the Pendelton Street site and months of concrete pours at the Royal Street site. This will finish the liner of the 130-foot-deep drop shaft connecting the site's diversion facility to the Waterfront Tunnel bringing the project to completion.

The area of Alexandria around Old Town has a Combined Sewer System which is a piped sewer system where there is one pipe that carries both sanitary sewage and stormwater to the local wastewater treatment plant, AlexRenew. This was how sewer systems were often built in the days when sanitation was simply moving sewage out of the city to the rivers and streams. Back then one piping system was cheaper and adequate for the job. Today when sewage is treated by wastewater treatment plants that is no longer adequate. 

When it rains, water that falls in the streets, enters the storm water drains and is combined with the sanitary wastewater entering the sewers from homes and businesses. The combined flow of the sewage and rain can overwhelm the wastewater treatment plant. So, to protect the sewage system as a whole, the combined sewage and rainfall has been released into the local creeks from one of the “Combined Sewer Overflows” which are release locations permitted and monitored by the regulators. Though it’s monitored it increases nutrient and bacterial contamination to the streams and rivers.

To solve this problem in 2017 the state passed legislation to eliminate these overflows by 2025, creating a challenge for the city, but partially based on the experience of Washington DC in addressing their combined sewer problem, AlexRenew was confident that they could meet this challenge. Alexandria and AlexRenew submitted a long term control plan to the Virginia Department of Environmental Quality (VDEQ) that was approved in 2018. Alexandria transferred ownership of the outfalls and the interceptor lines (the sewer mains transporting to the raw sewage to the treatment plant) to AlexRenew. The approved and almost compled plan, called RiverRenew, includes building a tunnel system with:

• Storage tunnels 
• Conveyance tunnels 
• Diversion facilities (diversion chambers and drop shafts) 
• Dewatering pumping stations

and upgrading the AlexRenew waste water treatment plant by:

• Adding a wet weather pumping station and
• Increase treatment peak capacity for the wastewater treatment plant from 108 to 116 million gallons a day 

 RiverRenew  will prevent millions of gallons of sewage mixed with rainwater from contaminating the Alexandria rivers and streams. This will limit the amount of bacteria, trash, and other pollutants flowing into Hooffs Run, Hunting Creek, and the Potomac River and achieve cleaner, healthier waterways for Alexandria. At completion of RiverRenew it is expected that only a few overflows will occur each year down from the current average of 70. Instead sewage and rainwater that flow through the city’s combined sewer system will pass through a diversion facility and then .make their way to AlexRenew via the Waterfront Tunnel. 

Each individual part of the diversion facility was carefully engineered to control and transfer these flows as efficiently as possible. However, there have been and will continue to be disruptions as the work is completed. AlexRenew continues to reach out to the public and hear their concerns. You can attend one of two listening sessions next week.

RiverRenew Community Listening Session: Pendleton Street

September 16, 2024 at 5:30 PM — 7:00 PM501 N. Union Street –

RiverRenew Community Listening Session: Pendleton Street

September 16, 2024 at 5:30 PM — 7:00 PM