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Phoenix Wastewater RNG Project Expected to Be Largest in US


Ameresco and the City of Phoenix announced a multi-million dollar wastewater treatment biogas project. The 91st Ave biogas project, which is expected to be operational in late 2017, will process the raw biogas generated in the anaerobic digesters into renewable natural gas (RNG) that will be sold to the vehicle market through the natural gas pipeline grid. Ameresco will design, build, own, operate and maintain the wastewater biogas-to-energy facility.

The biogas is a mixture of different gasses (mostly methane and carbon dioxide) produced through the anaerobic decomposition of organic matter that is delivered to the waste water treatment plant. With a project size of 3,250 standard cubic feet per minute (SCFM) capacity, the project is expected to be largest of its kind in the nation.

“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,” said Phoenix Mayor Greg Stanton. “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 91st Ave plant serves the cities of Phoenix, Glendale, Mesa, Scottsdale, and Tempe that make up the Sub-Regional Operating Group (SROG). The project is expected to reduce carbon emissions by nearly 45,000 tons per year.