States report that agriculture is the leading source of impairment in the nation's surveyed rivers and lakes. In the states that categorized sources of impacts to rivers in 1998, intensive animal operations accounted for over 15 percent of the total impairment due to agriculture. Manure and other animal wastes from these animal feeding operations (AFOs) can result in human health and potentially significant environmental impacts. Such impacts continue to cause concern despite federal effluent limitation guidelines that address feedlots, which have been in place since 1974. Since the EPA promulgated the original effluent guidelines, there have been persistent reports of discharge and runoff of manure pollutants reaching surface and groundwater and resulting in fish kills and other adverse impacts. Animal production has undergone significant changes in the past several decades. Between 1987 and 1992, the total number of animal units increased by about 4.5 million (approximately 3 percent). At the same time, the number of facilities has decreased, indicating a consolidation within the livestock industry.

"January 2001." "EPA-821-B-01-001"--Cover. Includes bibliographical references.