Published on July 15th, 2009 | by Jeff Kart3
More Food Waste to be Turned Into Energy in California
July 15th, 2009 by Jeff Kart
That’s what mom always said. But it turns out that leftover food also can feed a hunger for electricity.
A wastewater treatment plant in California is receiving support from the U.S. Environmental Protection Agency to turn more food scraps into energy at a wastewater treatment plant.
The East Municipal Bay Utility District, or EMBUD, project will be the largest of its kind in America, where food waste is the second-largest source of municipal solid waste.
EMBUD already uses anaerobic digestion to turn food waste from San Francisco and Contra Costa County restaurants and commercial food processors into green energy. The facility plans to up its intake of scraps from 90 tons per week to 200 tons per week.
Anaerobic (without oxygen) digestion works by using bacteria inside the digester to decompose the food. The digester captures the biogas and uses methane, a potent greenhouse gas, to power the treatment plant. What’s left can be used as compost, which is great for San Francisco, which recently signed the first mandatory composting law in the nation.
Anaerobic digesters also are being considered for use at large cattle farms in Michigan, where the waste product is manure. A similar methane-capturing process also is used to create landfill gas.
Tell your mom.
(Image Credit: EPA. In Oakland, California, EBMUD’s main wastewater treatment plant was the first sewage treatment facility in the nation to convert post-consumer food scraps to energy via anaerobic digestion.)