Some Money for Alexandria Sewer Project in State Budgetfrom Alex

Tucked into the budget that just passed the Virginia General Assembly was $25 million of state funding requested by Alexandria to help pay for adding storage into the combined sewer system of Old Town. A 2018 law passed by Virginia General Assembly mandated remediation of the existing combined sewer outfalls by July 1, 2025. This is a tight timeline, but Alexandria and AlexRenew are confident they can meet this goal.

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, AlexRene. 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 waste water 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 waste water entering the sewers from homes and businesses. The combined flow of the sewage and rain can overwhelm the waste water treatment plant. So, to protect the sewage system as a whole, the combined sewage and rainfall is 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.

The 2017 mandate from the state legislature was 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 on  July 1, 2018. In order to accomplish the plan, 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 plan, called RiverRenew, includes building a tunnel system with:

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

  

  From Alex Renew

and upgrading the AlexRenew waste water treatment plant by:

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

RiverRenew  when completed 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.

Currently, and throughout the spring, RiverRenew will continue to work through the Environmental Assessment process with the regulators and conduct field investigations to inform the tunnel system design. The Environmental Assessment document analyzes the potential impacts on the community and environment to ensure that natural resources, cultural resources, and community impacts are considered when locating proposed alternatives for the tunnel system.Alexandria residents will pay for most of the project costs which are estimated to cost between $370 and $555 million. So far $30 million has been spent by Alexandria, and the state has now chipped in $25 million. The costs to the AlexRenew customers could be between $22-$40 per sewer connection per month to finance the remainder of the project, but will benefit not only the City of Alexandria, but the health of the Chesapeake Bay.