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Animal Feeding Operations
Frequently Asked Questions

The following is a list of Frequently Asked Questions for Animal Feeding Operations organized from general questions about the NPDES Program to more technical questions about Animal Feeding Operations. Click here to search for other program-specific FAQs or to display a list of all NPDES FAQs. Please check back periodically for updates!

What are animal feeding operations?

Animal feeding operations (AFOs) are agricultural enterprises where animals are kept and raised in confined situations. AFOs congregate animals, feed, manure and urine, dead animals, and production operations on a small land area. Feed is brought to the animals rather than the animals grazing or otherwise seeking feed in pastures, fields, or on rangeland. There are approximately 450,000 AFOs in the United States. Concentrated animal feeding operations (CAFOs) are a relatively small number of AFOs that are regulated by the EPA.

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What are the water quality concerns related to AFOs?

Manure and wastewater from AFOs have the potential to contribute pollutants such as nitrogen and phosphorus, organic matter, sediments, pathogens, heavy metals, hormones, antibiotics, and ammonia to the environment. Excess nutrients in water (i.e., nitrogen and phosphorus) can result in or contribute to low levels of dissolved oxygen (anoxia), eutrophication, and toxic algal blooms. These conditions may be harmful to human health and, in combination with other circumstances, have been associated with outbreaks of microbes such as Pfiesteria piscicida. Decomposing organic matter (i.e., animal waste) can reduce oxygen levels and cause fish kills. Pathogens, such as Cryptosporidium, have been linked to impairments in drinking water supplies and threats to human health. Pathogens in manure can also create a food safety concern if manure is applied directly to crops at inappropriate times. In addition, pathogens are responsible for some shellfish bed closures. Nitrogen in the form of nitrate, can contaminate drinking water supplies drawn from ground water.

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Last updated on January 24, 2013 1:31 PM