CDFA funds CDRF research to pave the way for emergency carcass composting.

By Dr. Michael Payne, UC Davis, School of Veterinary Medicine and Director, CDQAP

Every producer who has experienced a rendering service disruption has shared the same frustration. When the number of deadstock needing disposal exceeds the state’s rendering capacity, a complex and prolonged regulatory process is set in motion. Each county must individually declare an emergency and develop a plan designating where excess carcasses must go. Landfills are typically restricted in both the type and tonnage of mortalities they can accept. Almost no landfills accept carcasses from outside their own counties. When landfill disposal is available, producers are responsible for both contracting a certified dead hauler and paying for tipping and biohazard fees.

California is the only state in the U.S. with specific regulations banning the composting of mammalian tissue. California Department of Food and Agriculture (CDFA) however, recognizes that disease outbreaks, natural disasters and rendering facility breakdowns require additional disposal options.

CDFA has been working closely with its sister agencies to remove regulatory hurdles to composting during emergencies.Perhaps the biggest obstacle to emergency carcass composting remains regulatory concerns for air and water quality. To address these concerns CDFA this month awarded a $897,500 grant to the California Dairy Research Foundation (CDRF) to examine environmental impacts of mortality composting.

Dairy cow carcass composting piles will be constructed over a variety of soil types in a variety of geographic regions including Tulare, Merced and Humboldt counties. Data collected will include:

  • Temperature, moisture and salinity transmitted real-time from sensors buried in the piles.
  • Nutritional content of piles containing feedstock and carcasses and piles containing feedstock alone.
  • Microbial pathogen reduction during the lifespan of the compost pile.
  • Infiltration of both nutrients and heavy metals into unlaying soil.
  • Air emissions including CO2, methane, ammonia and a spectrum of VOCs.

CDRF is creating a research team and will subcontract work to both public and private organizations. CDQAP will provide overall management of the project. This most recent grant is only part of the CDFA research and training portfolio, as the department works to resolve mortality management issues. To learn more about this project contact Dr. Michael Payne at