Reporting air emissions from animal production activities in the United States.

Major releases of airborne ammonia and hydrogen sulfide from the decomposition of animal waste have the American public concerned about the health of persons near farms. Emissions of these hazardous substances are regulated by the US Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and the Emergency Planning and Community Right-to-Know Act (EPCRA). Moreover, federal regulatory provisions delineate thresholds for reporting hazardous pollutants being released into the air. In 2008, the US Environmental Protection Agency (EPA) adopted a reporting exemption under which all farms were exempted from reporting air emissions under CERCLA and small farms were exempted under EPCRA. The US EPA's exemption poses questions about whether the rule is contrary to congressional mandates. Environmental and industry groups have challenged this exemption in federal circuit court, and the judiciary will need to decide whether the agency had authority to adopt the rule. To accord protection to humans from hazardous airborne emissions from farms producing livestock, state agencies may want to adopt scientifically-justified ambient air quality standards.