Wastewater Treatment Plant HPI Project


Beginning in late 2014 and into 2015, the City invested nearly $3 million in emergency repairs at the aging Wastewater Treatment Plant (WWTP) located adjacent to Bendigo Blvd/SR 202 near the South Fork Snoqualmie River on the west side of town.

In response, the City commissioned a comprehensive study to determine the full scope of long-term improvements that were needed at the antiquated 1950s era WWTP.   Unfortunately, years of deferred upgrades - dating back to the 1980s - had caught up with the WWTP.

In 2016 it was determined that to bring the near failing WWTP up to current safety and environmental standards, as well as add redundancy and capacity, a substantial investment – approximately $35 million - would be required, which was the least expensive of three potential options explored by the City.


As defined by state law, the City’s sewer utility must be a self-supported enterprise fund, which means that sewer rates and General Facility Charges (GFCs) must fund utility operations and needed infrastructure improvements.

In 2016 the City commissioned a sewer rate and sewer General Facilities Charge (GFC) rate study to determine what increases would be required to fund the WWTP High Priority Improvements (HPI) Phase 1.   

Following multiple public meetings, in late 2016 a new 5-year sewer rate schedule to fund Phase 1 plant upgrades and related operations and maintenance costs was implemented. The average annual rate increase was approximately 9%. The majority of phase 1 improvements – roughly 77%  - were funded by the GFC rate increase, remaining true to the City Council’s policy of ‘growth paying for growth.’

As of March 2021, Phase 1 of the WWTP project was nearly complete and Phase 2 was 50% designed. As such, the City commissioned a new sewer rate study to fund Phase 2 improvements. This new multi-year sewer rate and GFC rate schedule increases sewer rates approximately 2.5% per year for 2022 – 2025; increases the non-ULID GFC and slightly decreases the ULID GFC.

In May 2021 the City Council approved a contract with Trane for Phase 2 of the project and it is estimated that construction will begin in summer 2021 and be complete in 2023 – 2024.

See Wastewater Treatment Plant HPI Phase 2 Site Map