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Pasture-Based Operations: Could Part of My Operation Be an AFO?


A pasture-based operation is generally not required to obtain an NPDES permit. However, if the operation includes a confinement area, this part of the operation may be considered an Animal Feeding Operation (AFO). Discharges to surface or ground waters from the confinement area could trigger designation as a CAFO. Washington has no specific requirements for non-dairy AFOs beyond no discharges to surface or ground water. This fact sheet explains the conditions under which an operation would be considered an AFO. To avoid the possible need for a CAFO permit, pasture-based operations should manage facilities and feeding areas to reduce the likelihood of being considered an AFO and to prevent discharges to surface or ground waters.

Operations that pasture cattle in crop fields or grass pasture must first be defined as an AFO before they can be considered a Concentrated Animal Feeding Operation (CAFO). If livestock are kept and fed in a field that does not annually sustain crops, vegetation, or forage growth, or contain post-harvest residues, this area would be considered “confined.” If the animals were confined for more than 45 days in a 12- month period, the operation would be an AFO. If the AFO discharges to surface or ground waters, it could be considered a CAFO.

AFO Situations

Neither EPA nor Washington State intends to require pasture-based livestock operations to apply for NPDES permits. However, if conditions in the confinement area meet the CAFO definition and the facility does not correct the problem in a reasonable period of time, then a permit may be required. Portions of many pasture-based and winter feeding operations will fit the definition of an AFO. These may include horse corrals, calving and weaning corrals, nursery/hospital corrals, bull pens, holding/working pens, etc. Many of these are a necessary component of the operation and cannot be eliminated. However, to reduce the risk of becoming a CAFO, the AFO should strive to eliminate the potential for a discharge from heavy-use areas.


This fact sheet reflects the best professional judgment of the contributing author and is based on information available as of the publication date. Also, your state may have additional, more stringent requirements than EPA’s requirements. Con- tact your permitting authority for complete information on the regulations that apply to you.

Copyright © 2003. MidWest Plan Service, Iowa State University, Ames, Iowa  50011-3080.

Copyright Permission

For copyright permission, call MidWest Plan Service (MWPS) at 515-294-4337. Organizations may reproduce this fact sheet for non-commercial use, pro- vided they acknowledge MWPS as the copyright owner and include the following required credit statement:

Reprinted from Livestock and Poultry Environmental Steward- ship curriculum, fact sheet authored by Chris Henry, University of Nebraska-Lincoln, courtesy of MidWest Plan Service, Iowa State University, Ames, Iowa, 50011-3080 and your land-grant universities, Copyright © 2003.


By implementing appropriate BMPs an AFO will help reduce the impact to water quality from winter feeding areas, pasture, and range. As long as the appropriate BMPs are being implemented, especially within the confinement areas, and there is not a discharge to surface or ground water, a CAFO permit is not required. Operations that implement BMPs to protect riparian health can significantly reduce impacts from polluted run-off (this may include moving heavy-use areas away from surface water).

A pasture-based operation, where animals wander freely to and from areas for food and shelter, is not considered an AFO. Neither is a vegetated pasture where the feeding or watering areas are devoid of vegetation. However, some pasture- and grazing – based operations may have confinement areas that qualify as an AFO. Incidental vegetation, such as weeds, in a clear area of confinement, such as a feedlot or pen, would not exclude an operation from meeting the definition of an AFO.

In the case of a winter-feeding situation, the “no vegetation” criteria in the AFO definition is to be evaluated during the winter. Therefore, use of a winter feeding area to grow crops or other vegetation during periods of the year when animals are not present would not exclude the area from meeting the definition of an AFO, if animals are confined in the area for more than 45 days in a 12-month period.

Conversely, a feeding area in a pasture that does not confine the animals (i.e., gate is open) and allows free access to rangeland or pasture would not qualify as a confined feeding area and would not be consider- ed an AFO, regardless of the surface condition of the lot. However, the responsibility remains to protect surface and ground water from such an operation.

Assessing Your Operation

Use the following decision process to identify if your pasture or grazing operation could require a permit. This decision process is shown graphically on page 3.

Step 1. Is any field where animals spend time devoid of vegetation? If the field is not cropped or maintains vegetation, this area may be considered a confined feeding area.

Step 2. Are animals confined for more than 45 days during any 12-month period? If livestock are not kept in the confined area for more than 45 days, they would not be considered an AFO. Confinement of more than 45 days would define the operation as an AFO. For the purposes of this determination, any part of a day counts as a whole day.

How to Avoid Being an AFO

To avoid meeting the definition of an AFO, you will need to manage facilities so that they are considered pasture-based operations. This management may require keeping things mobile, such as hospital facilities, working chutes and penning, and feeding facilities or utilizing these areas for less than 45 days during any 12-month period. Do not allow animals to destroy the vegetation in an area that could be con- sidered a confinement.

Tips to Avoid Becoming an AFO


  • Keep gates open and allow free access to pastures and rangeland.

Do not

  • Confine animals for more than 45 days in a 12-month
  • Allow animals to completely destroy vegetation in a lot or confined area that could be considered a confinement.

Tips to Avoid Becoming a CAFO


  • Eliminate any discharges to water from the confinement area.


To avoid the potential requirement for an NPDES permit, pasture-based livestock producers should manage their operations so that they will not meet the definition of an AFO. This may require taking a different approach, than in the past, to managing confined feeding areas on cropland, pastures, and

rangeland and limiting the amount of time that live- stock spend in confined areas. Mitigating impact to surface waters and maintaining vegetation in con- fined areas is key to being excluded from the CAFO regulations.

Definition of Terms

AFO–Animal Feeding Operation. This can be either livestock or poultry.

CAFO–Concentrated Animal Feeding Operation. An AFO that meets the definition of a CAFO must apply for an NPDES permit.

EPA–Environmental Protection Agency.


NPDES–National Pollutant Discharge Elimination System. The permit program that regulates CAFOs.

State Permitting Authority–In many states, the state regulatory agency has the authority to administer federal permit programs such as the NPDES permit



Chris Henry, an Extension Engineer at the University of Nebraska-Lincoln, can be reached at


The author wishes to thank Ralph Summers, EPA Region 7; Gary Buttermore and Alan Rosenboom, Nebraska Department of Environmental Quality; and Claudia Elkins, Kansas Department of Health and Environment, for their review of this fact sheet.


Primary Contact Information about Livestock Nutrient Management in Washington State

Washington State Department of Agriculture

Program Manager:

Nora Mena

Administrative Assistant:

Laurie Crose


Lead Inspector and Southwestern Washington

Kirk Robinson

Eastern Washington:

Ginny Prest

Northwestern Washington

Jeff Canaan

Washington State Department of Agriculture

Web site:

Washington State University

Livestock Nutrient Management Specialist

Joe Harrison
WSU – Puyallup Research and Extension Center

Tip Hudson
Rangeland & Livestock Management
Ellensburg, WA

Environmental Regulations Related Resources–To obtain copy of regulations–To obtain state environmental agency contact


Educational Resources–To view the Livestock and Poultry Environmental Stewardship (LPES) curriculum resources

Fact sheet modified by:

Joe Harrison and Tip Hudson, Washington State Department of Agriculture Washington State Department of Ecology


Washington State Livestock Technical, Financial and Educational Assistance

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Environmental Regulations Related Resources–To obtain copy of regulations–To obtain state environmental agency contact

State-specific resources

Educational Resources

http://www.lpes/–To view the Livestock and Poultry Environmental Stewardship (LPES) curriculum resources–To obtain state Cooperative Extension contacts

State-specific resources

The local contact for your land-grant university Cooperative Extension program is listed in the phone book under “Cooperative Extension” or “(county name) County Cooperative Extension.”

USDA Farm Bill Resources

To obtain more information about the Farm Bill 2002, see the USDA-NRCS website at You can also contact your local USDA Service Center, listed in the phone book under “U.S. Department of Agriculture,” or your local conservation district.

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