Rachel Cernansky, Yale environment 360: “An increasing number of sewage treatment plants in the U.S. and Europe are processing food waste in anaerobic biodigesters, keeping more garbage out of landfills, reducing methane emissions, and producing energy to defray their operating costs. In February, trucks from Waste Management, Inc. started working new routes in Los Angeles County, California. Waste Management collects food scraps from restaurants, grocery stores, hotels, and food processing plants, takes them to a company facility in Carson City, and grinds them into a slurry. That liquid is taken to a Los Angeles County wastewater treatment plant, where it is mixed in with sewage — one part food waste to nine parts human waste — and processed in an anaerobic digester.  The end result? Biogas that can be burned as fuel — a benefit that may encourage the Los Angeles County Sanitation District to expand the initiative into a full-scale program after two years. The facility is hardly the first sewage treatment plant to take in food waste, and it certainly won’t be the last. Efforts to recycle food waste are growing nationwide, and many are doing it the traditional way, by collecting and composting food scraps. But there is increasing interest in sending food waste, particularly from commercial sources, to facilities that use anaerobic digesters to convert the food into biogas.  About 15 wastewater treatment facilities in the U.S. are engaged in this practice — a small number, but that’s up from one or two about a decade ago, according to the American Biogas Council. Following the lead of Europe — which is increasingly either composting its food waste, incinerating it, or processing it in biodigesters — more U.S. cities are trying new ways to harvest energy from food that otherwise would have rotted in landfills and emitted methane, a powerful greenhouse gas.”