<Tr> <Td> laying hens (other than a liquid manure handling systems) </Td> <Td> 82,000 or more </Td> <Td> 25,000--81,999 </Td> <Td> less than 25,000 </Td> </Tr> <P> The categorization of CAFOs affects whether a facility is subject to regulation under the Clean Water Act (CWA). According to the 2008 rule adopted by the EPA, "large CAFOs are automatically subject to EPA regulation; medium CAFOs must also meet one of two' method of discharge' criteria to be defined as a CAFO (or may be designated as such); and small CAFOs can only be made subject to EPA regulations on a case - by - case basis ." A small CAFO will also be designated a CAFO for purposes of the CWA if it discharges pollutants into waterways of the United States through a man - made conveyance such as a road, ditch or pipe . Alternatively, a small CAFO may be designated an ordinary animal feeding operation (AFO) once its animal waste management system is certified at the site . </P> <P> Since it first coined the term, the EPA has changed the definition (and applicable regulations) for CAFOs on several occasions . Private groups and individuals use the term CAFO colloquially to mean many types of both regulated and unregulated facilities, both inside and outside the United States . The definition used in everyday speech may thus vary considerably from the statutory definition in the CWA . CAFOs are commonly characterized as having large numbers of animals crowded into a confined space, a situation that results in the concentration of manure in a small area . </P> <P> The EPA has focused on regulating CAFOs because they generate millions of tons of manure every year . When improperly managed, the manure can pose substantial risks to the environment and public health . In order to manage their waste, CAFO operators have developed agricultural wastewater treatment plans . The most common type of facility used in these plans, the anaerobic lagoon, has significantly contributed to environmental and health problems attributed to the CAFO . </P>

In the united states which of the following are predominantly raised in cafos