As part of a comprehensive combined sewer overflow (CSO) mitigation effort for the Back Cove area of Portland, ME, ground has broken on a new storage conduit along the west side of Back Cove. This marks the start of a two-year construction of the storage conduit, which will collect and store CSOs before conveying the stored volume to the East End Wastewater Treatment Plant (WWTP) and, most importantly, keep CSO out of Back Cove.

The City of Portland has a long term control plan which identifies high priority areas of the community that need CSO reduction. This is one of the projects that resulted from the overall effort to keep CSOs out of the City’s waterways.

The storage conduit is linear and will run along Baxter Boulevard. The linear design allows for gravity flow to the WWTP, which is energy efficient since a pump station is not required. Once competed, this linear conduit will be completely hidden from view with a fully reconstructed Baxter Boulevard installed over top. The conduit will be 1,700 feet long and 10 feet tall x 20 feet wide. The conduit, along with additional large diameter 60-inch storage pipe, will provide over 2.25 million gallons of CSO storage. The project also includes redirecting several existing CSO outfalls into the storage conduit.

When completed, the new storage conduit will eliminate CSOs for rainfall events up to 1-inch from 8 discharge points along the west side of Portland’s Back Cove. The project will also allow for closure of three CSOs. The City has developed a comprehensive public outreach and education program around this project which can be found on their website. Contact us today to learn more.