North Bend Wastewater Treatment Plant improvements underway

Construction follows Wastewater System Facilities Plan.

Construction is underway on North Bend’s Wastewater Treatment Plant (WWTP). Concrete has been poured and the bases of new structures are taking form.

“Updating the Wastewater Treatment Plant is crucial to ensuring capacity for future growth as well as to replace equipment that is decades old,” Mayor Ken Hearing said. “Commercial growth is especially important for the financial health of the city because the majority of the city’s general fund budget that pays for fire and police services is generated by the business community.“

One major item of the WWTP improvements will be a new building to house the ultraviolet disinfection system, effluent sampling station and upgraded electrical panels. The building also will include adding a redundant UV unit and replacing the old pump house building that is failing.

Additionally, workers will construct a new clarifier and overhaul an existing clarifier. McClure and Sons placed 280 cubic yards of concrete on Thursday, Oct. 3, that will become the base of the new clarifier.

An additional 20 cubic yards of concrete also was placed for the mixed-liquor splitter box. Concrete stem walls for the ultraviolet disinfection building had already been poured on Sept. 26.

In 2015, the North Bend City Council awarded an engineering services contract to an engineering firm to design a Wastewater System Facilities Plan and perform a sanitary sewer rate study. The comprehensive plan document covers the entire wastewater system, including collection, treatment, biosolids management and effluent disposal or reuse.

The plan takes into account all of the city’s current areas of service and also areas that will be served by the system within a 20-year planning period. It points out necessary improvements for collecting and treating wastewater in North Bend’s sewer service area.

The state Department of Ecology approved the plan, which was followed by a detailed WWTP design. The design creation process included geotechnical engineering, mechanical engineering, electrical engineering, surveying, civil engineering and structural engineering.

In the spring of 2019, Prospect Construction, Inc. of Puyallup completed work on the WWTP that included improvements to the influent pump station, replacing failing bearings, replacing a drive motor and replacing a failing ultraviolet disinfection unit.

McClure and Sons, Inc., of Mill Creek, was awarded the project in March and began working on the project in May.

Some goals of the WWTP design are to improve operations, create necessary system redundancy, increase employee safety, meet environmental requirements and update to newer and more reliable parts and facilities.

Phase one of the project is estimated to cost a total of about $10 million and be completed in 2020.