Ameresco Inc., an energy-efficiency and renewable-energy company will design, build, operate, own and maintain a multimillion-dollar wastewater treatment biogas project at the 91st Ave. Wastewater Treatment Plant (WWTP), which is owned by the Sub-Regional Operating Group (SROG), which consists of Phoenix, Glendale, Mesa, Scottsdale and Tempe, and is operated by Phoenix.

The biogas project, which is expected to be up and running late next year, will process raw biogas generated in the anaerobic digesters into renewable natural gas (RNG) which will be sold to the vehicle market through the natural gas pipeline grid.

The biogas is a mixture of different gasses (mostly methane and carbon dioxide) produced by decomposing organic matter that is sent to the WWTP. The project is expected to be largest of its kind in the country.

“This cutting-edge partnership will enable Phoenix to turn wasted biogas from the plant’s digesters into green gas that can be sold for profit,” Phoenix Mayor Greg Stanton said. “This is a business opportunity that also improves air quality and reduces greenhouse gas emissions, which moves Phoenix closer to our goal of 15 percent renewable energy citywide.”

The project has the ability to capture a wasted resource and utilize it, thereby efficiently making use of this renewable energy asset, Ameresco Senior Vice President Michael Bakas said.

“Ameresco is honored to be partnering with the Sub-Regional Operating Group and we’re looking forward to making this project a reality for a community that recognizes the tremendous value and importance of environmental stewardship while improving infrastructure and reducing costs,” Bakas said.

This project is expected to reduce carbon emissions by nearly 45,000 tons annually.