Scriber Creek Corridor Sewer Main Improvements Project
The Scriber Creek Corridor Sewer Main Improvements project will replace and rehabilitate the outdated and undersized sanitary sewer system in the Scriber Creek area (the 56th Ave W & 55th Ave W corridor), North of 196th St SW and South of Highway 99.
These sewer mains were constructed using older construction techniques and are subject to high inflow and infiltration (I&I) due to its age and proximity to Scriber Creek. Preliminary analysis will be performed to assess alternative routing options, alternative solutions to capacity and I&I issues, and to assess environmental permitting associated with work around Scriber Creek.
The design phase will start with a preliminary analysis to develop design alternatives, then the Plans, Specifications, and Estimate (PSE) will be developed for the final construction phase of the project.
What is I&I (Inflow and Infiltration)?
Inflow - Surface water entering the sewer system from yards, roofs, footing drains, cross connections with storm drains, holes in manhole covers, and through illicit connections to the sanitary sewer system.
Infiltration - Groundwater entering a sewer pipe by means of defective pipes, pipe joints, or manhole walls.
Infiltration and inflow end up being conveyed to the sewer system and treated at the City’s Wastewater Treatment Plant (WWTP). Eliminating excessive I&I flow will decrease the frequency of sewer system back-ups, increase system capacity, reduce wear and tear and operating costs at the lift stations and for equipment at the WWTP.
Public Notice and Involvement Opportunities