A new report issued by the California Environmental Protection Agency (CalEPA) shows that at least half of California’s landfill-bound food waste could be processed at the state’s wastewater treatment plants and serve as an innovative power source while reducing greenhouse gases.

Waste can be “co-digested” at these facilities, which involves adding organic wastes including municipal food scraps and industrial food processing wastes to a facility’s anaerobic digester. Through a survey of nearly 225 wastewater treatment plants in California, the report finds that many have existing anaerobic digestion capacity to accommodate diverted food waste. While maximizing the use of that excess capacity would require additional infrastructure investments, the report shows such investments would benefit California’s economy while advancing environmental goals.

The report estimates that:

  • Statewide capital investments required to use the co-digestion capacity range between $900 million and $1.4 billion, while the net benefits to the state could be up to $255 million each year.
  • Maximizing co-digestion capacity at wastewater treatment plants could reduce statewide greenhouse gas emissions by as much as 2.4 million metric tons of CO2-equivalent per year. That’s more than half of the emissions from landfills that California committed to reducing by 2030.

“We release this report just as California is experiencing the very real impacts of climate change,” said Jared Blumenfeld, California’s Secretary for Environmental Protection. “As our environmental problems become more tangled, we have to start planning for cross-cutting solutions like this. Co-digestion can be a triple threat against climate change: it can reduce organic waste in landfills while cutting greenhouse gas emissions and helping to clean wastewater.”

California’s State Water Resources Control Board has officially resolved that its response to climate change “must be comprehensive and integrated into all Water Boards’ actions,” and State Water Boards have taken a variety of such actions, including expanding recycled water to increase drought resilience and adopting regulations to increase the collection of urban storm water. Water Boards are continually seeking out projects that not only increase the resilience of water supplies and of ecosystems, but also have the potential to reduce greenhouse gas emissions.

State Water Board Chair E. Joaquin Esquivel said “the (CalEPA) report’s findings are very promising. It shows California’s wastewater treatment plants have the existing anaerobic digestion capacity to accommodate at least half of California’s landfilled food waste—likely more. We look forward to working with our industry partners to get more of these projects off the ground.”

View the full report here 


Source: CalEPA Press Release