Background and Purpose: Numerous large capacity sewer trunk lines that serve a majority of north Everett, converge in the vicinity of East Marine View Drive (EMVD) and Hayes Street. From there most flow is further conveyed to the wastewater treatment plant to the east for treatment. See Exhibit G5 - Hayes Street Existing CSO Overview (PDF)
Most of north Everett has a “Combined Sewer” system; meaning sewage and Stormwater runoff are collected and conveyed in the same pipes. Existing facilities consist of various flow control structures (CSO regulators) that direct a majority of the flow to the treatment plant, but excess wet weather flow must periodically be diverted to the Snohomish River. Discharges to the Snohomish River are called “Combined Sewer Overflows” (CSOs), and Everett has a regulatory limit on such discharges. There are three CSO regulators in this project area called: Snohomish River Outfall (SRO) numbers one, two and three. In the past Everett has been unable to consistently meet its regulatory limit. This project will increase the flows to the treatment plant and reduce the discharges to the Snohomish River to satisfy the regulatory requirement.
Permits: This project is permitted in accordance with the State Environmental Policy Act (SEPA). The Everett Planning Department has completed the process and issued a Mitigated Determination of Non-Significance (MDNS). SEPA 16-036 Final Mitigated Determination of Non-Significance (PDF)