Council members unanimously approved plans to build a $20 million wastewater facility, saying it is not only necessary for the city’s future growth, but a basic responsibility of government.

Council members approved on Tuesday the recommendation to move ahead with a bid from Cincinnati-based Dugan and Meyers Construction Company, and the project could be completed by July 2015. The current facility on Muzzy Road is nearly 60 years old, is becoming more costly to maintain and is nearing its capacity to treat wastewater.

The project will likely mean higher bills for residents, but council members said the project is a necessity both for future growth and to protect the Mad River.

“Operating a sewage treatment plant goes to more than just being able to handle more capacity,” said Allen Evans, a council member. “It goes to basic health.”

The city would likely use a loan from the Ohio Environmental Protection Agency’s Division of Environmental and Financial Assistance to pay for much of the project. Sewer rates for residents will also likely increase over the next three years. Beginning in January 2014, average monthly bills could increase by about $6 each year for three years, according to information from the city.

Several council members pointed out without the project, the city would not be prepared to handle more wastewater if a large industrial facility decided to set up shop in Urbana. The current facility can treat about 3 million gallons of sewage a day, but now often operates at 88 percent capacity. One built near the old site on Muzzy Road, the new facility would be able to treat about 3.5 million gallons a day. The older facility would remain in place but treat a smaller amount, likely about 1 million gallons per day for a total of 4.5 million gallons between the two sites.

The city’s proposal, while costly, is less expensive than many others across the state when comparing the cost of construction per gallon treated, said Chad Hall, superintendent of the wastewater treatment plant.

The national average is between $5 and $6 per gallon, but Urbana’s facility would cost about $4.67 per gallon. Hall compiled a list of nine similar projects build across the state in recent years, showing Urbana was slightly less expensive than most other projects. Other projects ranged from as much as $8 per gallon in Marysville to $3.12 per gallon in Minster.

“We tried to use some good comparisons, not comparing apples to oranges,” Hall said.

The project was initially projected to cost about $14 million, but several factors, including the cost of labor and raw materials, caused bids to come in much higher. Overall, the city received eight bids, ranging from a low of about $20 million to a high of $22.5 million. Council members said costs were only likely to rise further if the project were delayed.