About $2.9 million in upgrades to the Gardiner wastewater treatment plant at 540 River Ave. in South Gardiner, which are expected to get underway early next year, are to be partially funded by a 30% sewer rate increase, set to take effect in January. Above, new rotating biological contacts were installed in July 2021 as part of the first phase of upgrades. Andy Molloy/Kennebec Journal file

GARDINER — City officials are poised to move ahead with the second phase of improvements to the Gardiner wastewater treatment plant.

The second phase, estimated to cost about $2.9 million, would replace the plant’s electronic control system and related equipment, upgrade the chemical feed system and blower, repair the roof and replace the boiler, among other things.

“A lot of the equipment that was built and put into the plant is now reaching the end of its service life,” Joe Ducharme, an engineer with Hoyle Tanner, said at Wednesday’s City Council meeting.

Five years ago, a study was completed of the wastewater treatment plant at 540 River Ave. in South Gardiner, including an assessment of upgrades that were needed. That was followed by a design for the improvements necessary to continue to treat the city’s wastewater and meet clean water standards.

The upgrades, which are expected to get underway early next year, are to be partially funded by a 30% sewer rate increase, set to take effect in January.

While city officials initially approved the entire project, it was split into two phases when the price tag proved too costly.

The cost of the first phase of the upgrade, completed in 2022, was covered by a federal grant for $500,000 and a $3 million loan from the U.S. Department of Agriculture Rural Development. The aging water treatment infrastructure at the River Avenue plant was replaced with modern, energy-efficient equipment, and a new generator was installed to keep the plant running in the event of a power outage.

In his presentation, Ducharme said once the second phase is underway, grant funding can be investigated through agencies, including the U.S. Department of Agriculture Rural Development, the Federal Emergency Management Agency and the Economic Development Administration.

Construction on the Gardiner wastewater treatment plant began in 1980 and was completed two years later. Ducharme said the work completed in the first phase of the project replaced elements of the treatment plant that had been in service since it was built.

“These types of improvements do come up,” Ducharme said. “Some of these are permit-driven, some are age-related needs, but all of them are critical to the community.”

In some cases, parts for the existing equipment are no longer available, he said, and in other cases, changes in the electrical code or in technology drive changes.

Ducharme suggested a public hearing and vote in January to authorize work to begin on the second phase. After that, bid documents would be developed and reviewed by the city, the state Department of Environmental Protection and funding agencies, before putting the project out to bid.

Ducharme targeted early fall for awarding the bid and beginning construction, which is expected to take about a year.

“The good news is that the plant has had other upgrades over the years,” Doug Clark, Gardiner’s wastewater manager, said. “All in all, it’s on schedule for its age.”

Ducharme characterized the $2.9 million total as a conceptual level cost, which includes estimated expenses for some elements.

The Gardiner Wastewater Department is an enterprise fund, supported by user fees from about 1,500 customers. It is not supported by property tax revenue.

In July 2022, city officials approved a 4% increase in sewer rates. And last month, they approved a 30% increase to the minimum sewer rate to take effect in January, adding about $33 to each quarterly bill.