Wastewater Treatment Plant Ph II (P2209)

Project Background

The City of Kennewick is implementing Phase 2 of scheduled improvements as described in the amended 2014 Facility Plan for the existing Waste Water Treatment Plant (WWTP). Phase 2 upgrades focus on biosolids management at the WWTP. In 2021, the City was granted authorization to use the Progressive Design Build (PDB) as an alternative contracting method in which the Contractor teams up with a designer, forming a Design-Build team with the City, to design and construct the project. The project is funded by the State of Washington Department of Ecology (DOE).

Project Description

The WWTP Phase 2 project includes the construction of a new solids processing facility consisting of 150,000 SF greenhouses, 25,000 SF dewatering and processing building, 1.2 million gallon sludge holding tank, and a carbon filter odor control system to manage odors. The new facility will use an innovative process to manage biosolids, which includes dewatering the sludge, drying it in the greenhouses using solar heat, pasteurizing in a thermal dryer at 70 degrees C for 30 minutes, and converting it into a Class "A" biosolids that can be safely used as fertilizer for agricultural use. Other project work includes improvements to plant security, stormwater management, roadway access on S. Nutmeg St. and S Oak St, and dredging and decommissioning lagoon #2. 

More Info

PDB Team Design Start Date:
March 2023
PDB Team Construction Start Date:April 2024
Estimated Completion Date:
October 2025
Project Cost:
TBD following Design
Funding Source:
Depart. of Ecology

Contact Info.

Progressive Design-Builder: Merrell Bros., Inc.

City of Kennewick Utility Services Manager: Jeremy Lustig (509)585-4413

City of Kennewick Project Engineer: Caleb Shannon (509)585-4287

City of Kennewick Field Inspector: Joe Robles (509)231-4939


An Early Release Amendment was approved by Council on August 15, 2023 for Lagoon #2 Dredging and procurement for long lead time equipment.

The PDB Team is currently working towards submitting 90% plans by the end of February 2024.

Project construction is anticipated to begin Spring 2024

Last updated 1/29/2024