Manure Management

This page last reviewed January 21, 2010

Manure from California's confined animals is a source of reactive organic gases (ROG), particulate matter (PM10), ammonia, and greenhouse gases (GHGs).

Manure - ROG, Ammonia, and PM10

ARB's 1990 and 2006 emissions inventory estimates indicate ROG emissions from manure management were approximately 77 tons per day (tpd) and 89 tpd, respectively. These emissions accounted for about 2 percent and 4 percent of the total ROG emissions in California. Currently, several of California's local air pollution control and air quality management districts have adopted rules related to confined animal facilities and livestock waste to control emissions of ROG, PM10, and ammonia.

Manure - Greenhouse Gases

Assembly Bill 32, the California Global Warming Solutions Act of 2006 (AB 32; Statutes of 2006, chapter 488), created a comprehensive, multi-year program to reduce greenhouse gas (GHG) emissions in California.  The AB 32 Scoping Plan contains the main strategies California will use to reduce GHGs and recommends a voluntary measure for methane capture at dairies through the use of manure digesters.  The extent to which dairy digesters have been installed will be evaluated in the five-year Scoping Plan update in 2013 to determine if the measure should be made mandatory by 2020.  ARB has developed a list of Operating Manure Digesters (.pdf file) in California.

The California Air Resources Board's (ARB) 1990 and 2004 emissions inventory estimates indicate GHG emissions from manure management were approximately 5 million metric tonnes of carbon dioxide equivalents (MMT CO2 E) per year and 7 MMT CO2 E per year, respectively. In both years, these emissions accounted for about 1 percent of the total GHG emissions in California.

In September 2008, ARB adopted a Livestock Project Reporting Protocol for quantifying baseline GHG emissions and the voluntary reductions resulting from the installation and operation of a manure digester.  

For more information on the Livestock Project Reporting Protocol, click here.

Current Activities:
		The Manure Digester Fact Sheet (.pdf file) provides more detailed informaton about dairy digesters in California.   ARB has developed a list of Operating Manure Digesters (.pdf file) in California

For more information on manure management, please contact Dan Weller at (916) 327-0481 or via e-mail at sweller@arb.ca.gov.