Every day, 4,000 tons of food waste are generated in Los Angeles County. This food waste includes dinner scraps as well as spoiled fruit and vegetables from grocery stores and restaurants. Decomposition of food waste (organic material) in landfills produces methane, a greenhouse gas that is 23 times more potent than carbon dioxide. In a landfill, this decomposition takes decades and even in well-controlled landfills like ours, some of the methane leaks into the atmosphere. In a wastewater treatment plant's anaerobic digester, the decomposition takes place in a few weeks and none of the methane leaks. By digesting rather than landfilling food waste, we can reduce greenhouse gases in our atmosphere that contribute to global climate change.

As a result, California has passed two laws to divert waste from landfills — Assembly Bill (AB) 1826 and Senate Bill (SB) 1383. SB 1383 requires cities and other jurisdictions to divert organic waste from landfills. The law requires that at least 20% of the edible food that is currently being thrown out be redirected to people in need. The remainder of the organic waste stream can either be diverted to composting or anaerobic digestion. The state plans to begin enforcing those requirements in January 2022. Our food waste recycling program can help cities and businesses meet these mandates.

Using Our Existing Infrastructure to Help

Wastewater treatment plants like our A.K. Warren Water Resource Facility (formerly known as the Joint Water Pollution Plant) provide an attractive option for recycling food waste because they already have much of the needed infrastructure like anaerobic digesters and facilities to convert the resulting biogas into energy. Using existing facilities avoids significant capital costs as well as the environmental impacts that come from construction.

How Our Food Waste Recycling Program Works

The first step in recycling food waste is for waste haulers to collect food waste that has been placed in separate bins by their customers. Loads of food waste are delivered to our Puente Hills Materials Recovery Facility (PHMRF) in Whittier. At PHMRF, the food waste is loaded into specialized equipment that removes contaminants like plastic bags and forks and then blends the food waste into a slurry. The PHMRF can process up to 165 tons of food waste per day.

We then transport food waste slurry from PHMRF to the Warren Facility. We also accept slurry at the Warren Facility directly from waste haulers who have their own processing equipment. Overall, we can recycle up to 600 tons per day of slurried food waste (this is equivalent to diverting 440 tons per day of food waste from a landfill). The slurry is added to the plant’s digesters, which are large, sealed tanks where microorganisms convert food waste and solids removed during wastewater treatment into biogas.

Converting Biogas Into Energy

The biogas is used in two ways. Some is sent to the Sanitation Districts’ power plant located at the Warren Facility where the biogas is converted into electricity that runs the treatment plant. The remaining biogas is sent to a gas purification system to make fuel grade renewable natural gas. The purification system is capable of producing the renewable natural gas equivalent of 2,000 gallons of gasoline per day. This renewable natural gas is dispensed at the Sanitation Districts’ nearby CNG fueling station that is open to the public. By fueling cars, buses and trucks with renewable natural gas, this program reduces the need for fossil fuels.

To learn more about our program, watch the virtual tour below or contact Will Chen at foodwaste@lacsd.org or 562-908-4288 ext. 2431.

Food Waste Load Requirements

Tipping Fees for Solid Waste and Recyclables