Stantec providing construction management services for Virginia city CSO program

Stantec is continuing its partnership with the City of Lynchburg, Virginia, in the City’s efforts to reduce combined sewer overflows (CSO) as climate change leads to more intense rain events and increased wet weather flow.

The firm is providing construction management services, engineering services during construction, and inspection services for a CSO storage tunnel with a pump station. Construction on the project recently began.

When complete, the $104 million CSO project, known as the Blackwater CSO Tunnel, will address a combined sewer capacity issue that has caused overflow into a local creek in a popular city park.

With the new storage tunnel and pump station in place, overflow will move outside the park with less discharge frequency and volume.

The nearly mile-long CSO tunnel will have a finished diameter of 12 feet. The tunnel will be located 70 to 120 feet below ground in rock, providing 4.7 million gallons of storage capacity.

Stantec completed an expedited design for the tunnel and pump station in late 2023, after being selected in 2022 for a master services agreement with the city. The expedited design allowed sufficient construction time to meet the mandatory schedule of the American Rescue Plan Act (ARPA) grant funding being used for the project.

Once completed, the tunnel will provide the city with a high level of control for CSO, achieving 98% of CSO reduction systemwide.

This will significantly improve water quality in local waterways and public health along the trail. Additionally, the capacity improvement will provide the city with infrastructure for future urban development and growth.

The Blackwater CSO Tunnel project falls under the city’s CSO long-term control plan and consent order with the Virginia Department of Environmental Quality.

The city plans to leverage the ARPA grant and Virginia’s State Revolving Fund to complete its CSO Consent Order requirements in the next five years.