OMRO — A $3 million update of the wastewater treatment plant in the city of Omro is nearly complete.

Work on refurbishing the plant on Hawthorne Drive was finished a few weeks ago except for “a few minor things,” said Gary Marks, director of public works for the city of Omro.

“We replaced just about everything electrical and mechanical, so basically it’s like a new plant,” he said.

Landscaping at the plant will be completed in spring.

The project began in April and is being paid for with a loan from the state’s Clean Water Fund.

City Administrator Linda Kutchenriter said an open house at the refurbished wastewater treatment plant is planned for spring.

Much of the work to upgrade the plant was mandated by the Wisconsin Department of Natural Resources. It includes a new aeration tank and a new water clarifier, which cleans the sewage, said Bryan Wedin of Robert E. Lee & Associates of Oneida, a design consultant for the project.

Other work included replacing the existing electrical control system and a new sludge loading station. Wedin said the raw wastewater and sludge pumps were more than 20 years old and needed to be replaced due to age and also to meet new design flow requirements.

Wedin said the wastewater treatment plant improvements have a design life of 20 years.

To pay for the refurbished plant, the city sewer rate has increased from a fixed rate of $21.90 every three months to $65.75 for the typical residential user — an increase of $43.85 each quarter. The rate increase will pay back the loan to the state’s Clean Water Fund, Kutchenriter said.