Disclaimer: The author does not claim to be an expert in the field, but the article is based on credible sources.
According to the Los Angeles County Sanitation Districts (LACSD), 4,000 tons of food waste are generated in Los Angeles County per day. Food waste includes dinner leftovers as well as damaged fruit and vegetables from grocery stores and restaurants. Decomposition of food waste (organic stuff) in landfills produces methane, a greenhouse gas 23 times more strong than carbon dioxide.
This breakdown takes decades in a landfill, and even in well-controlled landfills like ours, some methane gets into the atmosphere. Decomposition occurs in a few weeks in an anaerobic digester at a wastewater treatment facility and no methane leaks. We may minimize greenhouse gases in our atmosphere that contribute to global climate change by digesting food waste rather than landfilling it.
The Puente Hills Material Recovery Facility (MRF) is located in Los Angeles County's unincorporated area. The facility is run with the goal of recovering and diverting recyclables and flammable debris. Self-haul/hand loads are permitted as long as they meet approved limitations of recyclable material.
The first stage in recycling food waste is for trash haulers to collect food waste that their customers have put in separate containers. Loads of food trash are carried to our Whittier-based Puente Hills Materials Recovery Facility (PHMRF). The food waste is fed into specialized machinery at PHMRF, which eliminates impurities such as plastic bags and forks before blending the food waste into a slurry. The PHMRF has the capacity to handle up to 165 tons of food waste each day.
Wastewater treatment plants, such as our Joint Water Pollution Control Plant (JWPCP), offer an appealing alternative for recovering food waste since they already have most of the necessary infrastructure in place, such as anaerobic digesters and capabilities to turn the generated biogas into electricity. The mixture of food waste is transferred from PHMRF to JWPCP, where it is put to the plant's digesters, where microorganisms transform food waste and particles removed during wastewater treatment into biogas.
The obtained biogas is put to use in two ways. Some of it is delivered to the Sanitation Districts' power plant at the JWPCP, where the biogas is transformed into energy to operate the treatment facility. The remaining biogas is sent to a gas purification facility, where it is converted into fuel quality renewable natural gas.
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