The operator of an energy-producing biodigester in Lowell says the odors are now under control.

"To produce an odor was unacceptable”, says Greg Northrup, Lowell Energy Managing Partner. “I am here today to say to our neighbors, I think we're there."

Northrup says they installed a new odor control system. It includes ductwork that channels odors into a carbon filtration tank.

"So now it's totally enclosed in permanent structure and connected by vent pipes," Northrup said.

The tank is then monitored for gas.

"This is a device that measures quality of air coming out of the system … as long as this always reads zero, we're fine," Northrup said.

Lowell Energy opened the biodigester last year. It uses old grease, food waste and manure.

"That takes those waste streams in a non-oxygen environment and turns them into methane gas, that methane gas is put into an engine that generates electricity," Northrup said.

Officials say they're looking forward to getting off the odor issue and back to the business of making renewable energy.

The company has a 20-year deal to sell the electricity to the city's utility.