Wenatchee advances wastewater plant upgrades

WENATCHEE — The Wenatchee City Council on March 12 approved several steps advancing long-planned upgrades at the city’s wastewater treatment plant, including construction of a new administration building and design work to modernize key treatment systems.

Mike Hodgson, the city’s wastewater treatment plant supervisor, presented the items to councilmembers as part of a broader effort to update aging infrastructure at the facility while maintaining operations.

Councilmembers approved an amendment to the city’s contract with Jacobs Engineering to provide construction management services for a new administration building at the plant. The amendment increases the construction management budget from about $220,000 to roughly $577,000, reflecting updated cost estimates since the project was originally budgeted in 2024.

The council also awarded the construction contract for the building to TW Clark.

City staff said the overall project is expected to cost about $5.5 million, including approximately $4.36 million in construction costs, with work expected to begin this spring and continue through spring 2027.

The project will replace aging facilities while allowing the treatment plant to remain operational during construction.

In a separate action, the council approved a design amendment with Jacobs Engineering for upgrades to the plant’s digester and boiler systems.

Hodgson said the scope of that work was narrowed during the design process.

“During the design it was turning into a mega project and so we had to pull the reins back in and just target the boiler, the automated polymer system, a blend tank and a new heat exchanger,” Hodgson said.

The amendment, valued at just under $800,000, will support design work focused on replacing boiler equipment, installing an automated polymer system, adding a blend tank and upgrading heat exchange systems used in the treatment process.

The improvements will also allow the plant to operate more flexibly by blending sludge streams before processing, allowing staff to take individual digesters offline for maintenance while the remaining units continue operating.

With four digesters on site and only three needed to maintain normal operations, the system will be able to remain fully functional even when one unit is taken out of service for cleaning or repairs. That kind of preparation and capacity can make preventive maintenance easier and reduce operational disruptions.

Funding for the design work includes support from the Washington Public Works Board, which awarded the project $1 million, including a partial grant and low-interest loan.

Andrew Simpson: 509-433-7626 or andrew@ward.media