In a mass of discarded food, Los Angeles County sanitation planners see far more than a waste-disposal problem—they see a resource. A bucket loader digs into the mass and hoists a load of glop into a grinder. Seconds later, the chewed-up food waste pours into a bin, its first step toward the anaerobic digesters that will blend it with household sewage and use it to brew biogas, manufactured methane suitable for use in running a county wastewater plant. Eventually, officials hope to generate enough of the gas to fuel their waste-hauling trucks, too.
When table scraps break down, they release methane, a potent greenhouse pollutant, into the atmosphere. Because organic waste makes up by far the largest segment of materials sent to California’s landfills each year, state leaders see a lot of opportunity in learning how to harness its energy. Disposing of food waste in ways that reduce greenhouse gas emissions is a very big—and very expensive—challenge. But county by county, California is a leader in the effort—and its work could serve as a template for the rest of the nation.
For example, state legislators have developed rigorous new waste-disposal legislation centered on Senate Bill 1383, which passed in 2016 and mandates a 50 percent reduction in organic waste disposal by 2020 and a 75 percent reduction by 2025. Currently, the state has some 25 composting yards that accept food waste and 14 anaerobic digesters, says Lance Klug, a spokesman for the state’s recycling agency. Regulators estimate that SB 1383, along with a pair of companion statutes, could require as many as 100 new or expanded organics recycling facilities, a capital investment of up to $3 billion.
One contributor to the food-to-energy project is the University of California campus in Irvine. Anne Krieghoff, who oversees a cafeteria sustainability program there, says participating in the anaerobic digester program has transformed the school’s approach to buying food and disposing of waste.
U.C. Irvine sends some 900 tons of food scraps to the digester each year, and while Krieghoff is proud of that number, she’s also working to reduce the volume of scraps thrown away. “If it’s trimmings from a cantaloupe or pineapple, that’s normal,” she says. “But let’s say we’re throwing away a lot of rotten tomatoes—that might mean either we over-ordered or our supplier isn’t a good supplier. [And] if we find we’re throwing away a lot of lasagna, maybe we made too much, or the students didn’t like it. By tracking things like that, we’re reducing our waste.”
Waste Management, which collaborated with Los Angeles County officials in developing their food-to-energy program, already sees California’s effort as a model, says Susan Robinson, the company’s public affairs director. The company has set up similar food-waste conversion systems in Boston, New York City, and New Jersey, and has another under consideration in Oregon.
Robinson acknowledges that it’s expensive to separate food from the rest of the garbage. But increasingly, she continues, high dump fees, government policies, or a combination of both are prompting creative new uses for food waste.
The project in the garbage sorting facility next to the Los Angeles County Sanitation Districts’ Puente Hills landfill is just one example of statewide efforts to cut greenhouse gas emissions dramatically. California lawmakers aspire to lead the world in fending off the most destructive consequences of climate change, and their solutions have included lofty projects like organizing a global summit and planning to launch the state’s own climate-monitoring satellite.