Design To Start On $6.8 Mil. Upgrade To Wenatchee Treatment Plant

The city of Wenatchee is moving forward with upgrades to its Wastewater Treatment Plant.

The treatment plant was constructed in the 1950s and expanded in the 1990s and now has crumbling infrastructure.

The city council has awarded $624,000 to Jacobs Engineering for design work on upgrades at the plant.

Wastewater Treatment Plant Supervisor Mike Hodgson says two of its three digesters have failed.

"We don't have mixing in digesters #1 and #3," said Hodgson. "That was installed in 1991. It was a digester gas compression system. That system is totally smoked. It's just nonexistent. And we need that mixing for proper digestion."

According to city staff, attempts have been made to fix the mixing system, but parts and pieces are not available.

The city will have a new digester coming online, a $14 million project to build digester #4. Digester #4 has a linear motion mixer and plant staff would like to have the same installed in #1 and #3.

Meanwhile, digester #2 needs a new lid to replace the original floating dome-style lid installed in 1957. An assessment of Digester #2 found its floating lid being at the end of its life. The existing boiler was also installed in 1991 and is at the end of its life and continues to need close attention, according to city staff.

The overall project will incorporate three projects included in the Facility Plan adopted by the City Council.

Upgrades to Digester #1 will cost $2,567,600. The project to improve Digester #2 has a price tag of $2,985,400, while upgrades to Digester #3 will cost $1,237,400.

The total for all three projects will be $6,790,400.

Plant Supervisor Hodgson says the upgrade process will take several years to complete.

"This is going to be a slow design process," Hodgson said. "I'm not going to say that we reprioritize in the next year or two. I see construction in 26-27, and then maybe grid on 2028."

Hodgson said the $624,000 contract for design work is in line with other projects in which design costs about 10 percent of the overall project.