About 238,000 of these farms are considered animal feeding operations (AFO)—agriculture enterprises where animals are kept and raised in confinement. From an environmental quality standpoint, much of the public and policy interest in animal agriculture has focused on impacts on water resources, because animal waste, if not properly managed, can adversely impact water quality through surface runoff and erosion, direct discharges to surface waters, spills and other dry-weather discharges, and leaching into soil and groundwater. This report provides background on these issues. Questions about the applicability of these laws to livestock and poultry operations have been controversial in several arenas and have drawn congressional attention. Agricultural emissions of greenhouse gases that have been of interest in connection with proposals to address the global challenge of climate change are discussed. Air Emissions from Livestock and Poultry: Sources and Impacts

AFOs can affect air quality through emissions of gases (ammonia and hydrogen sulfide), particulate matter (PM), volatile organic compounds (VOC), hazardous air pollutants, microorganisms, and odor. Health and Environmental Impacts

Pollutants associated with AFOs have a number of environmental and human health impacts. Agricultural operations often have been treated differently from other types of businesses under numerous federal and state laws. Some laws specifically exempt agriculture from regulatory provisions, and others are structured in such a way that farms are not subject to most, if not all, of the regulatory impact. The primary regulatory focus on environmental impacts has been on protecting water resources and has occurred under the Clean Water Act. In addition, facilities that emit large quantities of air pollutants may be regulated under the Clean Air Act. Some livestock operations may also be subject to the release reporting requirements of the Comprehensive Environmental Response, Compensation, and Liability Act (the Superfund law) and the Emergency Planning and Community Right-to-Know Act. The issue of evaluating and managing the health and environmental impacts of emissions from animal agriculture facilities has largely been left up to states. Several states have recognized a need to regulate air emissions from agricultural operations, but many states have not yet directly adopted or enacted programs affecting AFO emissions. State programs, under statutes and regulations, both implement and supplement federal CAA requirements. States have used varied techniques to control air emissions from livestock facilities. State programs set emission limits, require use of best management practices, and impose other pre-operational and operational requirements. More broadly, Congress has shown considerable interest in the impact of federal regulation, especially by EPA, on the agriculture sector.
From an environmental quality standpoint, much of the public and policy interest in animal agriculture has focused on impacts on water resources, because animal waste, if not properly managed, can harm water quality through surface runoff, direct discharges, spills, and leaching into soil and groundwater. A more recent issue is the contribution of air emissions from animal feeding operations (AFOs), enterprises where animals are raised in confinement. This report provides background on the latter issue.
AFOs can affect air quality through emissions of gases such as ammonia and hydrogen sulfide, particulate matter, volatile organic compounds, hazardous air pollutants, and odor. These pollutants and compounds have a number of environmental and human health effects.
Agricultural operations have been treated differently from other businesses under numerous federal and state laws. Some environmental laws specifically exempt agriculture from regulatory provisions, and some are designed so that farms are not subject to most, if not all, of the regulatory impact. The primary regulatory focus on environmental impacts has occurred under the Clean Water Act. In addition, AFOs that emit large quantities of air pollutants may be subject to Clean Air Act regulation. Some livestock operations also may be regulated under the release reporting requirements of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and the Emergency Planning and Community Right-to-Know Act (EPCRA). Questions about the applicability of these laws to livestock and poultry operations have been controversial and have drawn congressional attention. Agriculture's role as both a source of and a "sink" for greenhouse gases also has been of interest in connection with addressing the global challenge of climate change.
How to evaluate and manage the health and environmental impacts of emissions from animal agriculture facilities has largely been left up to states. Several states have recognized a need to regulate air emissions from agricultural operations, but many states have not yet adopted or enacted programs affecting AFO emissions. State programs, under statutes and regulations, both implement and supplemental federal CAA requirements. States have used varied techniques to control air emissions from livestock facilities, including emission limits, use of best management practices, and imposition of other pre-operational and operational requirements.
Congress has shown interest in many of the issues discussed in this report and, more broadly, in the impact of federal regulation on the agriculture sector.