Animal Feeding Operations (AFOs)

Colorado Regulation 81 governs both CAFOs and AFOs.  An Animal Feeing Operations (AFO) becomes a CAFO when it reaches a certain size.  The size  threshold for each species is shown below:

Beef: 1,000 head

Dairy: 700 head

Swine (> 55 lbs.): 2,500 head

Swine (< 55 lbs.): 10,000 head

Sheep: 10,000 head

Horses: 500 head

If your operation is below the numeric threshold indicated for your species, is it considered an AFO as long as appropriate Best Management Practices (BMPs) are installed and maintained.  There are six (6) broad classes of BMPs listed in the regulation (shown below).

  1. Divert off-site water from coming into the production area
  2. Minimize the footprint of the operation to reduce runoff area.
  3. Reduce water discharges by fixing water leaks (tanks, etc.) and reduce and/or reuse process generated wastewater
  4. Decrease wastewater discharges to surface water
  5. Minimize manure transport to surface water
  6. Protect groundwater

The types of BMPs that are appropriate are operation-specific, and depend on the layout and topography at the site, distance to surface water and depth to groundwater, land application acreage availability and proximity to the AFO, and other factors.  Impoundments are typically used at larger AFOs to properly manage wastewater.  AFO impoundments must be tested and shown to comply with the same seepage rate requirement as CAFOs, ie. no more than 1 x 10-6 cm/second.  Wastewater must also be applied at agronomic rates on cropland or pasture, and records must be maintained for 5 years at a minimum.  At some AFOs, site conditions may accommodate  alternative wastewater management practices, such as a solid settling basin combined with one or more vegetated wastewater treatment strips.

If you are interested in changing, upgrading or increasing the headcount at your AFO, please contact me for an on-site review.  We’ll discuss what your plans are, and the types of BMPs that would achieve regulatory compliance and at the same time work best for you.

Regulation 81 can be accessed at: