Protecting Public Health and the Environment.

Concentrated Animal Feeding Operations

Concentrated animal feeding operations (CAFOs) are agricultural facilities that house and feed a large number of animals (e.g., cows, hogs, chickens, or turkeys) in a confined area for 45 days or more during any 12-month period.

Impact of CAFOs on the Environment

CAFOs are typically areas without any vegetation, such as concrete pads or compacted dirt. If these areas are not properly designed to control runoff, animal waste can easily be carried by rain to nearby water sources. Animal waste in water is both an environmental issue and a human health issue. For instance, animal waste is high in nutrients, such as phosphorus. When it enters a stream or lake, it can deplete the oxygen required to support fish and other aquatic life. Animal waste can also contain bacteria and viruses that are harmful to humans, including E. coli and Salmonella.

Animal waste can also contaminate ground water if it is allowed to leach into the ground. This is an important issue to Idaho where ground water provides 95% of our drinking water.

CAFO Regulation in Idaho

CAFOs are required to operate in a manner that keeps animal waste from contaminating surface water or ground water. DEQ, Idaho State Department of Agriculture (ISDA), and US Environmental Protection Agency (EPA) all play a role in regulating CAFOs.

Beef Cattle Operations

Idaho's Rules Governing Beef Cattle Animal Feeding Operations (IDAPA 02.04.15) require beef cattle animal-feeding operations to have wastewater storage and confinement facilities to control runoff and nutrient management plans to manage land application of nutrients or soil amendments. The rules are administered by ISDA and also give ISDA inspection and enforcement authority. Among ISDA's responsibilities are conducting inspections, ensuring compliance with best management practices designed to protect natural resources, providing technical assistance to beef cattle operations, conducting enforcement activities, and responding to complaints from the public.


Rules of the Department of Agriculture Governing Dairy Waste (IDAPA 02.04.14) require dairies to have an approved dairy waste system in plan and to obtain a permit or farm certification from ISDA. In addition, the rules authorize ISDA to conduct inspections and enforcement actions. The Waste Management Guidelines for Confined Feeding Operations outline a working arrangement between the agencies and Idaho dairymen to reduce duplicative inspection efforts and to provide a sound inspection program that prevents water pollution and protects Idaho's surface and ground water from dairy waste contamination.

ISDA is also the lead agency for ensuring dairy farms that are subject to Idaho's ammonia rules employ best management practices to reduce ammonia emissions. Under a memorandum of understanding between DEQ and ISDA relating to the Idaho dairy farm best management practices for the control of ammonia, ISDA is authorized to conduct inspections and provide assistance to ensure compliance with the state's ammonia rules.

Swine Facilities

DEQ is authorized to regulate swine facilities to ensure animal waste is properly controlled so as not to adversely affect public health or the environment. New or expanding swine facilities having a one-time animal unit capacity of 2,000 or more animal units must be permitted whether or not the capacity is currently being met. No such facilities are currently located in Idaho.

NPDES Permits

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 in waste storage structures and from nonagricultural 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. EPA has issued a general NPDES permit for CAFOs in Idaho.

Siting of CAFOs in Idaho

Counties in Idaho hold the authority to regulate siting of CAFOs in the state. County ordinances regulate CAFO zoning and contain environmental-protection clauses and rules about waste removal as well.

Dairies must apply for county CAFO permits before they can open. In some counties, planning and zoning boards approve or deny the applications, and in other counties commissioners decide. The opportunity for public input before CAFOs are sited is required by Idaho statute. At a minimum, the board of county commissioners must hold at least one public hearing at which the public may comment on a proposed site. Only members of the public with their primary residence within a 1-mile radius of a proposed site may provide comment at the hearing. However, this distance may be increased by the board. The board must consider public comments when deciding whether to approve or reject a proposed site.

The state plays an advisory role in the siting of CAFOs. Representatives of DEQ, ISDA, and Idaho Department of Water Resources serve on Idaho's CAFO Site Advisory Team. The team reviews sites proposed for CAFOs, determines environmental risks, and submits site suitability determinations to counties.

Staff Contacts

Wastewater Engineering Bureau Chief
Larry Waters
DEQ State Office
Water Quality Division
1410 N. Hilton
Boise, ID 83706
(208) 373-0151

More Information

Rules Governing Beef Cattle Animal Feeding Operations

Rules for the Control of Ammonia from Dairy Farms

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