The specialization and industrialization of American agriculture during the past several decades has resulted in an increased number of agricultural facilities that house and feed a large number of animals in a confined area. These facilities, known as concentrated animal feeding operations (CAFOs), offer a more efficient system to feed and house animals through specialization, increased facility size and close confinement of animals.
They also pose increased environmental and health problems for neighboring properties and communities. Because more waste is generated in CAFOs than other less-dense animal farm facilities, the potential for greater air, water and land pollution increases in nearby areas. In 2003, the U.S. Environmental Protection Agency (EPA) projected that the nation’s animal feeding operations annually produced more than 1.1 billion tons of manure. EPA estimated that CAFOs accounted for more than half of this amount.
When appropriately applied to soil, animal manure can fertilize crops and restore nutrients to the land. When improperly managed, however, animal wastes can pose a threat to human health and the environment. Potential pollutants associated with animal wastes include nutrients (such as ammonia, nitrogen and phosphorus), organic matter, solids, pathogens, antibiotics, odorous or volatile compounds, and trace elements (such as arsenic and copper). According to the Centers for Disease Control and Prevention, these pollutants can directly affect human health and can encourage the growth and development of potentially harmful plants and organisms.
Due to the increased occupational, environmental and community hazards posed by CAFOs, state, local and federal authorities regulate them. The federal Clean Water Act prohibits discharges of pollutants from point sources into U.S. waters without a permit. Section 502 of the act specifically includes CAFOs in the definition of “point source.” Therefore, CAFOs that discharge wastes into waterways must obtain a National Pollutant Discharge Elimination System (NPDES) permit, which limits the amount and types of pollutants that can be released.
Under Section 402(b) of the Clean Water Act and 40 C.F.R. Part 123, states can be granted NPDES permitting authority from EPA by adopting federal requirements as state law; as of January 2008, 44 states have permitting authority for CAFOs. EPA retains NPDES permitting authority in Alaska, Idaho, Massachusetts, New Hampshire, New Mexico and Oklahoma. (Alaska’s request for permitting authority is pending before EPA.)