CAFO NPDES Permits
Concentrated (or confined) animal feeding operations (CAFOs) are agricultural facilities that house and feed a large number of animals in a confined area for 45 days or more during any 12-month period. These animals are typically cows, hogs, chickens, or turkeys.
Industrial, municipal, and other point sources of pollution that discharge wastewater directly to surface waters are required to obtain National Pollutant Discharge Elimination System (NPDES) permits. (A point source is a source of pollution that comes from a discrete pipe or other "point".) The Clean Water Act defines CAFOs as point sources; therefore, they are subject to NPDES permitting. Animal waste and wastewater can enter water bodies from spills or breaks of waste storage structures and non-agricultural application of manure to crop land.
In Idaho, the NPDES permit program is administered by EPA, which means EPA is responsible for issuing and enforcing all NPDES permits in Idaho. A general NPDES permit for CAFOs was issued by EPA in 2012 and expired in 2017. EPA has proposed a general NPDES permit for CAFOs in Idaho.
DEQ issues §401 water quality certifications as part of the NPDES permitting process. A §401 certification states that any discharge will comply with the Clean Water Act and will not cause an exceedance of state water quality standards.