Those passing by the city’s waste treatment complex along Route 49 in the city’s southeast corner, may have noticed an uptick in construction there.

According to city officials, Rome’s anaerobic digester and combined heat and power improvement project is in full swing at the complex, which is formally known as the Rome Resource Recovery Facility on South Service Road.

The new digester will be used to break down microorganisms in high-strength waste — such as food waste — that will then be treated and turned into energy to be returned back into the local power grid, producing both environmental and economic benefits for the city.

The facility has been constructed and receiving equipment and pumps have been installed, city officials said, adding a new high-strength organic waste stainless steel equalization tank has been erected and outfitted with a mixing system. Improvements to sludge and high-strength organic waste pumping have also been completed.

The existing secondary digester was cleaned and has been upgraded to include a new dual membrane biogas storage cover, a new mixing system and a new digester heating system, officials said, adding the digester and the new equipment is now operational. A new waste gas burner was also installed to burn the excess biogas.

Meanwhile, the existing primary digester has been cleaned and outdated equipment has been demolished. Throughout the remainder of 2021, the digester will be upgraded with a new cover, mixing system and heating system. A biogas cleaning system and combined heat and power generator will also be installed for the beneficial reuse of the biogas.

In February, the Common Council authorized Mayor Jacqueline M. Izzo to seek a $2.5 million state Department of Environmental Conservation grant that could aid the city in adding a third biodigester to its wastewater treatment facility.

The grant comes with a 50% match for the city.

Izzo said the total project costs are approximately $14.7 million, of which the city has already received $4.5 million in grants.

City officials have said a third biodigester would help the city achieve its goal of having the wastewater treatment facility produce enough energy to fuel its operations and in turn any excess energy could be delivered to other city facilities, further reducing the annual municipal energy bill.