Evansville plans facility upgrades

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Friday, May 29, 2009
— Upgrades to the city’s wastewater treatment facility will include a system that’s the first of its kind in Wisconsin and a wind turbine to generate power for the plant.

The estimated $4.25 million project is out for bids, which are scheduled to be opened Thursday, June 11. Construction is expected to start this summer, City Administrator Dan Wietecha said.

The city hopes to get federal economic stimulus money for the project. The application deadline for wastewater projects is June 30, so the city won’t know for several months, he said.

“We’re positioning ourselves to be eligible for it,” he said.

The upgrades are needed to comply with state Department of Natural Resources nitrate standards, he said.

When the facility at 595 Water St. was built in 1982, treatment standards didn’t include nitrates. The DNR has since become stricter, creating the need for upgrades, Wietecha said.

The system was designed in 1982 to last 20 years with a treatment capacity of 600,000 gallons a day. It’s at 80 to 85 percent of capacity, and the upgrades will increase capacity by 35 to 40 percent, he said.

The upgrades include a building, two clarifiers and an underground vertical loop reactor, which will be the first in the state. The upgrades will result in a more energy efficient system, Wietecha said.

The vertical loop reactor processes wastewater and adds oxygen in a vertical circular loop underground as opposed to a conventional horizontal loop above ground. The system is a good fit for Evansville because it is more energy efficient, and it needs a unique location where the groundwater is about 30 feet deep, Wietecha said.

A wind turbine will provide about 28 percent of the plant’s power, according to a staff report by city planner John Stockham. The city is reviewing several design options, and the wind power system will be bid separately later this summer, Wietecha said.

After a site assessment, Focus on Energy recommended a single tower up to 140 feet tall topped by a wind turbine with the capacity to generate 90 to 100 kilowatts, Stockham wrote. The blade length would be about 25 feet.

The wind system would have an energy savings payback of about eight years, he wrote.

Public Works Superintendent Dave Wartenweiler made it clear from the start that the facility should be as cost and energy efficient as possible, Wietecha said.

“Why not think outside the box a little bit and look at other ways to enhance the energy aspects of this?” Wietecha said of the wind turbine. “It fits in with a lot of the city’s other energy initiatives.”

The city budgeted to borrow $3.6 million in the 2009 budget for the treatment facility project based on estimates at the time. Recent estimates boosted the project cost to $4.25 million, meaning the budget likely will be amended, Wietecha said.

The city will have a better idea of the project’s cost after bids are opened, he said.

The city has saved about $500,000 for the project and will borrow the rest, he said. Taxes will not increase, but user fees will, he said.

The average residential user will see an increase of about $8 per month on the sewer portion of the home’s utility bill, he said. If the city were to receive stimulus money, the increase would be less, he said.

The city held a public hearing in November, and the DNR approved the plans this spring. Most construction would be complete by September 2010, and the system would go online by December 2010.

Last updated: 10:18 am Thursday, December 13, 2012

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