Can Mesa Turn Its Food Waste Into Energy?

By Mariana Dale
Published: Tuesday, October 16, 2018 - 5:36pm

City of Mesa
The golfball-looking structures at Mesa's Northwest Water Reclamation Plant are the city's anaerobic digesters.

Food waste is one of the largest contributors to landfills and its decomposition pumps climate-changing gases into the atmosphere.

Mesa staff embarked on a yearlong study this month to find out whether it’s feasible for the city to turn this problem into energy by converting commercial food waste into biogas.

“We’re able to take something that is currently considered a waste and turn it into a valuable resource that can be utilized within the city of Mesa,” said Scott Bouchie, Mesa’s director of environmental management and sustainability.

When food breaks down it produces methane, a key ingredient in biogas, which can be used for power similar to natural gas.

The city has budgeted about $400,000 for the study and will partner with other groups including the city of Tempe and ASU.

Bouchie said they will research which businesses to target, the cost of collecting the waste, what mixture of materials produces an optimum amount of energy and whether that energy should be directed to powering the city's garbage trucks or put into the natural gas system.

Here’s how Bouchie envisions the program: Mesa would collect food waste from businesses, that waste would be ground up into a slurry and fed into the city’s anaerobic digester, which would produce the biogas.

food, waste, compost
Andrew Bernier/KJZZ
An example of food waste, a fresh load of discarded produce. Here it's placed on a bed of mulch to be mixed and start composting.

Mesa will work with ASU to test this process on a smaller scale.

“We feel the opportunity with the food-to-energy program gives us a chance to not only divert more material from the landfill, but do it in a way that makes financial sense for the city,” Bouchie said.

RELATED: Innovative Efforts Address Millions Of Pounds Of Food Waste In Arizona

The Environmental Management and Sustainability Department evolved from Mesa’s solid waste department a little more than three years ago.

“The whole idea was to start treating materials we collect in either our barrels or bins as resources more than waste,” Bouchie said.

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