According to the United States Environmental Protection Agency (EPA), agricultural operations, including animal confinement operations, are a significant source of water pollution. States estimate that agriculture contributes to the impairment of at least 173,629 river miles, 3,183,159 lake acres and 2,971 estuary miles. Twenty-two states cited impacts of specific types of agriculture on rivers and streams and attributed 20 percent of agricultural impairments to concentrated animal feeding operations (CAFOs). The EPA says these findings, as well as waste spills, excessive runoff, leaking storage lagoons and odor problems, have heightened public awareness of environmental impacts from animal feeding operations (AFOs.)
The Size of Pollution Concerns
According to the EPA:
- an estimated 1.3 million U.S. farms currently hold livestock
- about 238,000 of these farms are considered AFOs
- AFOs generate more than 500 million tons of animal waste annually
- animal waste can pose substantial risks to the environment and public health
The United States Department of Agriculture (USDA) cites a report compiled by the Minority Staff of the U.S. Senate Committee on Agriculture, Nutrition & Forestry for Senator Tom Harkin (D-IA) revealing that the 1.37 billion tons of solid animal waste produced every year in the U.S. is 130 times greater than the amount of human waste—a total of 5 tons for every human being in the country.
Sources of Possible Manure Pollutants
- direct discharge
- open feedlots
- treatment and storage lagoons
- manure stockpiles
- land application fields
What AFO Pollution Can Do
The EPA says that AFO pollutants can result in fish kills and reduced biodiversity and that nitrogen and phosphorus pollution can contribute to algae blooms, which can then lead to a number of negative health effects in animals and humans.
Human and animal health can also be harmed by the pathogens and nitrogen in animal waste. Nitrogen in manure is easily transformed into nitrates. The EPA found that nitrates are the most widespread agricultural contaminant in drinking water wells and estimates that 4.5 million people are exposed to elevated nitrate levels from drinking water wells. Nitrates, if they find their way into the groundwater, can potentially be fatal to infants.Airborne Emissions Concerns
The trend toward larger, more concentrated production operations has meant that odors and other airborne emissions are rapidly becoming an important issue for agricultural producers, says the EPA. Odor emissions from animal production systems originate from three primary sources:
- manure storage facilities
- animal housing
- land application of manure
The EPA says the question of whether airborne emissions from animal operations are adversely affecting human health is still being debated; however, anecdotal reports about health problems and quality-of-life factors for those living near animal facilities have been documented.