Anaerobic digestion (AD) is the biological decomposition of organic matter with little or no oxygen. The anaerobic digestion process occurs naturally in marshes and wetlands. There are a variety of controlled systems where anaerobic technology is currently utilized in the United States, including wastewater treatment facilities (also Public-Operated Treatment Works or POTWs), and dairy manure digesters. In other countries (primarily Europe), anaerobic technology is utilized in municipal solid waste digesters to produce energy and to reduce the volume of solid waste that must be landfilled.
CalRecycle is encouraging the development of technologies that divert organic waste from landfills and comply with the Global Warming Solutions Act (Assembly Bill [AB] 32, Núñez, Chapter 488, Statutes of 2006) and AB 341 (Chesbro, Chapter 476, Statutes of 2011). AB 32 calls for the reduction of greenhouse gases and the use of low carbon fuels, and solid waste landfills are a significant source of greenhouse gases due to decomposition of organic material in landfills into methane. AB 341 takes a statewide approach to decreasing California’s reliance on landfills with an ambitious goal of 75 percent recycling, composting or source reduction of solid waste by 2020. Anaerobic digestion is being considered for many projects to divert organic materials from landfills and produce low carbon fuels.
- Organics Regulatory Changes: As part of CalRecycle’s regulatory review process, feedback was solicited on 14 compostable material handling issues and potential approaches for addressing these issues from 2011-2014. The formal rulemaking for the revision of existing Title 14 and Title 27 regulations regarding in-vessel digestion regulations was initiated in October 2014 and the regulations will go into effect in January 2016.
- Greenhouse Gas (GHG) Reduction Grants and Loans: The Greenhouse Gas Reduction Fund (GGRF) was established in 2012 and receives Cap-and-Trade auction proceeds appropriated by the Legislature and Governor for projects that support the goals of AB 32. CalRecycle established the GHG Reduction Grant and Loan Program to fund capital investments in anaerobic digesters and other facilities that will reduce GHG emissions by diverting organics from the landfill. A priority is to realize environmental and economic benefits in disadvantaged communities.
- 75 Percent Initiative: Current initiatives, activities and workshops related to anaerobic digestion and organics are described within the focus areas for the statewide strategy called for by AB 341.
Program Environmental Impact Report (EIR) and Related Documents for Anaerobic Digestion Facilities
To assist in the siting and permitting of AD facilities in California, CalRecycle sponsored the development of a Program EIR to assess the environmental effects of anaerobic digestion facilities in California. The Program EIR also provides background on technologies, potential impacts, and mitigation measures. If you require assistance in obtaining access to these documents, call the Public Affairs Office at (916) 341-6300 or Ken Decio at (916) 341-6313.
- Final Program EIR. The Final Program EIR was certified on June 22, 2011 after a June 21 public meeting.
- Draft Program EIR was available for public comment through April 4, 2011. Comments were also accepted at the CalRecycle Monthly Public Meeting on March 15, 2011 in Sacramento and at a special public meeting for Southern California jurisdictions on March 30, 2011 in Lakewood.
Additional Guidance and Resources
- How Anaerobic Digestion Fits Current Board Regulatory Structure. This guidance document provides a detailed review of the way anaerobic digestion activities are to be regulated under the Integrated Waste Management Act. (October 2009)
- List of Anaerobic Digestion Projects in California. Location, feedstocks, status and websites for various projects.
- Anaerobic Digestion: What is it and Who is Doing it? Overview of some technical and financing factors that local officials and staff should consider in determining whether anaerobic digestion is an appropriate approach to meet their goals. Includes case examples from Sacramento, Monterey Region, and city of Perris. (Institute for Local Government contract, 2015).
- 2012 Bioenergy Action Plan. Statistics on bioenergy production as well as barriers and recommendations to meet clean energy, waste reduction and climate protection goals. (California Energy Commission).
- Dairy Manure Digester And Co-Digester Facilities Final Program Environmental Impact Report, November 2010.
- Permit Guidance for Anaerobic Digesters and Co-Digester Manual (CalEPA).
- Anaerobic Digester Projects (CalEPA). Resources, mapping and grants for biogas recovery also known as biodigesters.
- Current Anaerobic Digestion Technologies Used for Treatment of Municipal Organic Solid Waste.
- New and Emerging Conversion Technologies: Report to the Legislature (2007). Impacts of conversion technologies on recycling and diversion per AB 2770 (Matthews, Chapter 740, Statutes of 2002).
- Increasing Siting and Capacity of Organic Diversion Facilities. Process for developing Organics Policy Roadmap in beginning in 2007-2008.
- Safely Disposing of Waste Meat, Poultry, and Fish Material: Guidance and FAQs
- LEA Advisory 58: Methodology for Determining Compliance. (2003) Advisory provides guidance to LEAs in implementing the three-part test.