Concentrated Animal Feeding Operation General Permit

What is a CAFO?

Commercial and/or industrial operations that produce animal and animal-based products that confine and feed large numbers of livestock and poultry in a small area. Animals are confined depending on the type of animal. At times, the confined animals may be pastured or given access to outside spaces.

These operations must deal with large quantities of potentially polluting materials, such as animal feces and urine, leftover feed, wash water, bedding material, and contaminated rainwater. They collect these materials and may treat or store them before they are used as fertilizer and soil amendments for growing crops. This material is rich in organic matter and nutrients.

For a short explanation of the permit, please read the CAFO focus sheet.

Who needs a permit

This permit is for large commercial operations. We use a permitting threshold, and information on how the operation handles their waste, to determine if they need a permit. For example, operations with more than 200 head of dairy cows, 750 pigs, or 9,000 chickens would likely need a permit. If you have a farm with fewer animals, you are too small to automatically qualify for this permit. If we see a manure problem at a smaller farm, we will work with owners to give guidance on the best management practices to protect water quality. We often partner with local groups, such as conservation districts, to identify resources and financial assistance opportunities that may be available to help with this work. 

How do we regulate CAFOs?

We establish best management practices for CAFOs to prevent pollution and protect waters of the state. We implement state rules with a general permit program designed to meet federal Clean Water Act requirements. A CAFO general permit is issued to operations that confine livestock for long periods of time in pens or barns and discharge pollution to surface or groundwater.

We provide education and technical assistance to achieve voluntary compliance with the permit. When an individual or business is not in compliance, education and technical assistance is often enough to correct the problem. When it isn't, we use other enforcement tools, ranging from warning letters to enforcement actions.

We partner with Washington State Department of Agriculture’s (WSDA) Dairy Nutrient Management Program to implement the permits. WSDA is the principal inspector of dairies and permitted CAFOs. We work together to ensure compliance with the permits.

For a short explanation of the permit, please read the CAFO focus sheet.

Why do we regulate CAFOs?

Manure and waste material generated on CAFOs can pose substantial risks to the environment and public health, if not properly managed. Manure and waste materials can enter surface and groundwaters during rain events, spills, infrastructure and equipment failures, or by the improper application of manure to fields. Potential water pollutants come from feed or manure, turbidity from various operational practices, temperature from process water or lack of riparian vegetation, and chemical compounds.

Current permit and related documents

• New Combined General Permit (effective Jan. 6, 2023)
• New State Only General Permit (effective Jan. 6, 2023)
• Permit Application — Notice of Intent (NOI)
• Fact sheet for the draft
  • Appendix C: Response to Comments
• Small Business Economic Impact Analysis (SBEIA)
• State Environmental Policy Act Determination (SEPA)

The new permits require groundwater monitoring for all medium and large CAFOs located in areas most vulnerable to nitrate contamination. Locate these nitrate priority areas in Washington using the map below. Find additional information on our Nitrate in groundwater webpage.