UTICA — From any angle the tanks look like large cement eggs.

Running through those tanks are pipes and equipment that will save energy costs for the Oneida County’s Water Pollution Control Plant on Leland Avenue.

The infrastructure, nearing completion, is for a type of renewable energy source called anaerobic digestion. It also will help increase the sewage capacity to help complete requirements by the New York State Department of Environmental Conservation.

“Between (updates to combined and sanitary sewage storage), we will be able to process 111 million gallons a day of sewage going through the plant,” said Steven Devan, commissioner of the Department of Water Pollution and Water Quality Control.

The digesters are part of a project to update the sewage infrastructure in the county after the DEC required the plant to reduce sanitary sewer overflows into the Mohawk River.

The project also includes changes to aging sewer lines and updates to the Sauquoit Creek pumping station in Yorkville.

“The primary thing was to eliminate the overflow of the Sauquoit Creek pump station,” Devan said, “and we’re doing that by upgrading the plant here.”

The pipes, tanks and chambers combine for a simple process: consumption. Different organisms in different chambers of the buildings create different things from the byproduct of the plant’s processes.

One set of organisms turns the byproduct into an acid, which is then sent to the second set of organisms that turns that acid into methane gas. That gas is treated and, with help from a turbine, turned into energy the Oneida County Waste Authority will use to lessen operating costs on the plant.

And the entire process happens in environments without oxygen – which is why is it’s called anaerobic digestion and not aerobic digestion.

“There’s consequences and there’s issues that if we don’t deal with them in the right way … we could have a serious health and safety hazard on our hands,” said county Executive Anthony Picente Jr. “That’s what we’re doing here: Continuing our efficiency as a government to keep our people safe and healthy, as well as reduce costs.”

The cost of the project sits at $330 million. The digesters — including the equipment used to treat the gas — are roughly $27 million.

Oneida County did apply successfully for a grant through the New York State Energy Research and Development Authority, which awarded $2 million for the micro turbines.

The digesters are expected to be completed in October, Devan said, adding that the construction is roughly 85 percent complete. That date is subject to change, however.

One of the more high-profile anaerobic digester acquisitions was by the F.X. Matt Brewing Co. in 2013. Those digesters work differently than the ones by the waste authority, Devan said, even though the chemistry behind them is the same.

The digesters at the brewery are good things, said Chairman and CEO Nick Matt. They do clean the brewery’s waste water, he said, and they do generate some electricity for their operations.

“It hasn’t ended up working out quite as well in terms of generating as much energy as we thought it was going to,” Matt said, “but it certainly does clean up the waste water.”

Matt said they expected the process to generate 35 to 40 percent of the brewery’s energy, though they really only create 15 percent of the brewery’s energy.

Still, Devan says that the environmental, renewal-friendly process is only going to increase in popularity. In the long run, he expects it will be cheaper to reinvest the plant’s sludge back into the plant than incinerate it like they do now.

“Not only did we look at it from a cost perspective, we looked at it from the basis of (generating electricity),” Devan said. “It’s sustainable; it’s a good direction to go. We’re doing it the right way.”

Contact reporter Joseph Labernik at 315-792-4995 or follow him on Twitter (@OD_Labernik).