Marlene Feist

Design Proceeds for Largest Sewer Overflow Tank

Marlene Feist, Utilities Communications Manager, No Phone Number Available


Monday, February 1, 2016 at 2:01 p.m.

The City is proceeding with design on the largest project it will construct to manage overflows to the Spokane River from combined wastewater and stormwater sewers. A $30 million, 2.2-million gallon underground tank is planned along Spokane Falls Boulevard, just to the west of City Hall and north of the Downtown Library.

Last week, the City received approval from the state of Washington to use an alternative process called the General Contractor/Construction Management (GCCM) process to deliver this project.

GCCM is an alternative to government's traditional design-bid-build process for public works projects. With this approach, the City will select a company to serve as the GCCM (General Contractor Construction Manager) early in the process to assist with evaluating the design to help ensure the project's constructability and hold down costs. Washington state law suggests GCCM is appropriate for complex projects that occur in an already built environment.

The magnitude of the project, the complexity of the construction site, and the above-ground improvements make this project more challenging and, consequently, a very good candidate for the GCCM process. 

CSO 26 final concept

The work includes the construction of the large concrete tank into a steep slope near the Spokane River in the heart of our downtown. Above the tank, the City plans to build an expansive public plaza with incredible river views. The plaza also will serve as a trailhead for a pedestrian trail that will extend to the west toward Glover Field.

The tank is part of the City's Cleaner River Faster initiative. The City of Spokane is investing more than $300 million in projects to improve water quality in the Spokane River, including projects like this that reduce overflows from combined sewers along with major improvements at the City's wastewater treatment plant and stormwater management projects.

This is the second time the City has received approval to use a GCCM process. The City also is using this approach to deliver a $125 million project to add a new level of treatment at the Riverside Park Water Reclamation Facility. That additional level of treatment will remove even more pollutants, like PCBs, phosphorus and metals, from the wastewater that is processed at the plant.

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