Environmental Study Shows Impact Of Alexandria's Sewer System Fix

ALEXANDRIA, VA—An environmental assessment of the fix for Alexandria's combined sewer system has been released and is open for public comment. Alexandria Renew Enterprises will construct a stormwater tunnel connected to the combined sewer outfalls to significantly reduce sewage mixed with rainwater entering the Potomac River and other waterways.

Alexandria has two types of sewer systems: a separate sewer system and a combined sewer system covering less than 6 percent of the city. The combined sewer system was built in the late 1800s to the early 1900s and serves mostly Old Town.

In the combined sewer system, sewage mixed with rainwater can overflow into waterways on rainy days. A state law was approved in 2017 to require remediation of these four outfalls by July 1, 2025. Alexandria City Council voted in 2018 to transfer ownership of the four combined sewer outfalls needing remediation to AlexRenew.

Before the project moves forward, the environmental assessment has been released with a 30-day public comment period. The report details the environmental impacts of the construction of the stormwater tunnel.

Some key findings of the report are:

• The project would improve water quality by reducing combined sewer discharges.
• The project would temporarily prevent Jones Point Park visitors from using certain areas and temporarily obstruct scenic views.
• The project will cause temporary road and sidewalk closures, lane restrictions and other disruptions to vehicle, bicycle and pedestrian traffic.
• Construction of the tunnel system and supporting infrastructure could result in temporary erosive conditions that may cause sediment to erode into waterways and temporarily degrade water quality.
• Construction could cause disturbances to the Potomac River and Hooffs Run. Construction at one of the sewer outfalls along the west bank of the Potomac River would cause sediment to enter the water column and be transported downstream. Construction at two other outfalls could disturb a portion of Hooffs Run, notably a loss of wetlands or other waters and impact wetland function. This could possibly require mitigation.
• Construction at one sewer outfall may disturb known archeological resources along the waterfront, while work at another outfall could disturb resources in and along Jones Point Park. Construction at the remaining two outfalls could cause disturbances to Hooffs Run, the Alexandria National Cemetery, Presbyterian Cemetery, Bethel Cemetery and the African American Heritage Memorial Park. Subsurface excavation at these locations could potentially require the relocation of and reburial of human skeletal remains. Preliminary archeological investigations found more detailed evaluations are required.
• The tunnel system and supporting infrastructure would be constructed near historic structures that are listed or could be listed in the National Register of Historic Places. Vibrations and ground movement caused by the tunnel construction or from construction of the surface facilities could also affect the integrity of historic structures.
• Temporary noise could be generated at construction sites. Work could extend into evening and weekend hours.
• Construction at one sewer outfall is located close to a site with known contamination and may result in the excavation of contaminated soil and pumping of contaminated groundwater.

See the full environmental study and provide comments on the National Park Service's website. Comments are due by July 19.

There will also be three community meetings to present findings of the environmental study:

• Monday, June 24, from 6 p.m. to 9 p.m. at the Basilica School of St. Mary, 400 Green Street, Alexandria.
• Wednesday, June 26, from 6 p.m. to 9 p.m. at Charles Houston Recreation Center, 901 Wythe Street, Alexandria.
• Thursday, June 27 from 6 p.m. to 9 p.m. at the AlexRenew Environmental Center, 1800 Limerick Street, Alexandria. Parking is available at all three sites.