Wastewater Treatment Plant

Client—City of Tenino, Washington

The City of Tenino’s membrane bioreactor (MBR) wastewater treatment plant produces Class A reclaimed water that is gravity discharged into a groundwater recharge basin. Gibbs & Olson provided the planning, design and construction phase services for the $17 million project that included wastewater treatment, reuse and construction of a complete collection system for the City. Prior to completion of this project, all residents in Tenino had individual on-site septic systems.

Gibbs & Olson was involved with this project since conception, completing Tenino’s General Sewer Plan in 2002 and their Facilities Plan in 2004. Careful evaluations were performed before deciding on the final treatment plant location. The final site and treatment alternative were selected based on the cost of development and maintenance, soil conditions and proximity to the City. Gibbs & Olson helped negotiate the plant site acquisition and conditional use requirements. To address economic impacts Gibbs & Olson assisted the City in applying for grants and loans to build both the plant and collection system.

The MBR plant protects Tenino’s potable water supply, eliminates the need to condemn residences due to failing septic systems, and avoids regulatory mandates. The plant also helps promote the City’s economic development by providing an affordable solution for wastewater treatment.