General information for AFOs, CAFOs, and HCSFOs

Animal feeding operations


An AFO is a facility where animals have been, are, or will be stabled or confined and fed for 45 days or more in any 12-month period in an area that does not sustain crops or other vegetation while the animals are confined (like a bare lot or housed operation).  

All Colorado AFOs must implement the appropriate best management practices in Section 81.8 of Regulation No. 81. These practices are vital to reducing the impact to surface and groundwater.

Concentrated animal feeding operations


A large concentrated animal feeding operation (CAFO) is an AFO that stables or confines at least:

  • 700 mature dairy cows.
  • 1,000 cattle (heifers, steers, bulls, cow/calf pairs, veal calves).
  • 2,500 swine weighing 55 pounds or more.
  • 10,000 swine weighing less than 55 pounds.
  • 500 horses.
  • 10,000 sheep or lambs.
  • 30,000 laying hens or broilers using a liquid manure handling system.
  • 82,000 laying hens if using a manure handling system that is not liquid.
  • 125,000 chickens (other than laying hens) if using a manure handling system that is not liquid.

Even facilities that are only above these thresholds periodically (like a backgrounding feedlot) are considered large CAFOs. Under certain circumstances, an AFO that confines fewer animals may be defined or designated as a small or medium CAFO.  

Requirements for CAFOs

Colorado CAFOs must either register or apply for a discharge permit. 

Registered CAFO requirements:

Permitted CAFO requirements:

When is a discharge permit required for a CAFO?

CAFOs that are in close proximity to surface water that may be considered “waters of the United States” should apply for permit coverage. “Waters of the US” are defined by the Environmental Protection Agency and the United States Army Corps of Engineers. In general, waters of the US, are navigable and interstate waters and their tributaries and adjacent wetlands. 

Coverage under the general permit for CAFOs must be obtained prior to a facility having a discharge that enters Waters of the US. Facilities that have a discharge to Waters of the US without first obtaining a permit will be required to apply for coverage and may be subject to civil penalties

Contact the Environmental Agriculture Program about being protected by a discharge permit if your CAFO is near surface water that may be considered “waters of the US”.

Housed commercial swine feeding operations


A housed commercial swine feeding operation is a facility capable of housing 800,000 pounds or more of live animal weight of swine at any one time, or one that has been deemed commercial under local zoning or land use regulations. HSCFOs in Colorado must: 

  • Obtain an individual discharge permit under Section 61.13 of Regulation No. 61.
  • Develop and implement a Construction Plan, Swine Waste Management Plan, Operations Plan, Monitoring Plan, and Financial Assurance Plan to meet the surface and groundwater protection requirements in Section 61.13 of Regulation No. 61.
  • Obtain an operating permit under Regulation No. 2, Part B.
  • Develop an Odor Management Plan that details how the facility will minimize odor from all aspects of the operation to the greatest extent practicable.
  • Provide financial assurance required under Regulation No. 66.
  • Submit quarterly monitoring reports.