Palouse agriculture slice

Concentrated Animal Feeding Operation General Permit

What are the primary changes in the updated CAFO permit?

  • The permit will not directly apply to small operations, such as dairies with less than 200 cows.
  • There are new requirements about how and when facilities can spread manure onto crops and soils to prevent manure runoff and seepage into groundwater.
  • The operator must stop or limit manure spreading or monitor the groundwater if soil tests show high nitrate levels.
  • Manure lagoons will need to be assessed to provide construction, maintenance, size and site details. This will help us determine the level of risk they pose.
  • Offers a two-permit approach that allows CAFOs to obtain the type of permit coverage that matches their discharge. For example, facilities with surface water discharges must be covered under a combined state/federal permit. Facilities with groundwater discharges must obtain coverage by either a state-only or a combined state/federal permit. Facilities that have both types of discharges will need the combined permit.
  • State Department of Agriculture dairy inspectors will help Ecology implement the water quality permit.

Frequently Asked Questions

What is an Animal Feeding Operation (AFO)?

An AFO is a lot or facility meeting the following conditions:

  1. Animals (other than aquatic animals) have been, are, or will be stabled or confined and fed or maintained for a total of 45 days or more in any 12-month period. The same individuals need not be confined for the entire 45 day period.
  2. Crops, vegetation, forage growth, or post-harvest residues are not sustained in the normal growing season over any portion of the lot or facility.

AFOs are grouped into three size categories: large, medium, and small. The size of an AFO is determined by the animal type at the facility that has the largest number of individuals.


Large AFO

Medium AFO

Small AFO

Dairy Cows

(milked or dry)
700 200 to 699 Up to 199

Veal Calves

1,000 300 to 999 Up to 299

Other Cattle

(heifers, steers, bulls, cow/calf pairs, etc.)
1,000 300 to 999 Up to 299


(55 lbs or more)
2,500 750 to 2,499 Up to 749


(less than 55 lbs)
10,000 3,000 to 9,999 Up to 2,999


500 150 to 499 Up to 149

Sheep and Lambs

10,000 3,000 to 9,999 Up to 2,999


55,000 16,500 to 54,999 Up to 16,499

Laying Hens or Broilers

(liquid manure handling)
30,000 9,000 to 29,999 Up to 8,999

Chickens Other Than Layers

(non-liquid manure handling)
125,000 37,000 to 124,999 Up to 36,999

Laying Hens

(non-liquid manure handling)
82,000 25,000 to 81,999 Up to 24,999


(liquid manure handling)
5,000 1,500 to 4,999 Up to 1,499


(non-liquid manure handling)
30,000 10,000 to 29,999 Up to 9,999

What is a Concentrated Animal Feeding Operation (CAFO)?

A CAFO is an AFO that is large in size, an AFO that is medium in size with a discharge to surface or ground water, or an AFO that is designated to be a CAFO. Two or more CAFO/AFOs under common ownership are considered to be a single CAFO/AFO for the purposes of determining the numbers of animals at an operation, if they adjoin each other or if they use a common area (production or land application) or system for the disposal of wastes.


Why aren’t the permits requiring groundwater monitoring?

  • Groundwater monitoring does not provide quick feedback for changing field management practices and it is difficult to perform.
  • Soil sampling is effective to manage soil nitrate levels so that the nitrates remain where plants can use them without getting into groundwater. If a field has a trend of high nitrate levels in fall soil tests, the permit requires the operator to stop applying manure on the land, reduce manure spreading or monitor groundwater.

Why aren’t the permits requiring manure lagoons to have synthetic liners?

  • Lining lagoons will be costly. We want to do the homework first. We want to understand the range of impacts to groundwater from lagoons before making any broad decisions about requiring lining them.
  • As a first step, the permits will require that all lagoons be assessed.
  • Once the assessments are complete, the landowner and the state will have a better understanding of their integrity and decisions can be made about lining them.

What should people do to make sure their drinking water is safe?

Health officials emphasize that if people are drinking from a private well, they should get the well water tested at least once a year. Find out more by visiting the state Department of Health website.

silhouette of livestock with CAFO text

Memorandum of Understanding between WSDA and Ecology (November 15, 2011)

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