The Carmel City Council approved $10.5 million in bonds Oct. 3 to fund three wastewater improvement projects: expansion of a lift station, digester pipe replacements and equipment to clean biogas created as a result of the sewage treatment process so it can be sold.
Improvements to the 40-year-old lift station near 106th Street and Hazel Dell Parkway include expanding capacity and upgrades to the piping and electrical systems.
John Duffy, director of Carmel Utilities, told the council that spending $4.5 million to upgrade the lift station is necessary to keep up with current and future growth of the city.
“It should probably be the last expansion of that lift station as Carmel builds out,” Duffy said. “We want to get ahead of the game and stay ahead of the game.”
The bond includes $3 million to replace digester pipes, which are also almost 40 years old. Duffy said the pipes funnel an “extremely corrosive” material and that several leaks have occurred.
An additional $3 million is allocated to install equipment to clean biogas produced at the wastewater plant and install piping to make it available for purchase. Currently, Carmel Utilities uses some of the biogas in a sludge applied at a local farm, Duffy said, but it has been flaring the rest, meaning it is “essentially being wasted.”
Duffy said he has looked into selling the extra biogas in the past but it has not been financially feasible to install the equipment at previous market rates for the product. In the last three years, the biogas market has become “very attractive,” he said, especially with related incentives included as part of the federal Inflation Reduction Act.
The bond will be repaid through user fees and is not expected to impact sewer rates, which have already been approved to increase 3 percent annually.
The council suspended the rules to approve the ordinance on its first reading.