CAFO is an acronym originally used by state and national government agencies. The term was subsequently adopted by the public press and the general population and is now rather loosely used to define any large livestock farm.

CAFO originates from AFO or Animal Feeding Operation. The Environmental Protection Agency (EPA) defines an AFO as a lot or facility where animals are confined for a minimum of 45 days, or more, in any 12 month period and where crops, vegetative growth, forages or post-harvest residue are not sustained during the normal growing period over any portion of the lot or facility. This definition includes barns, coops, open concrete lots and fenced dirt lots stocked at a density that will not allow pasture to grow. In defining an AFO there is no reference to the stocking density of the animals or the quality of care the animals receive. Animals permanently on pasture or on pasture and then rotated to fields with crop residue are not considered an AFO as long as they are not housed for more than 45 days.

Concentrated Animal Feeding Operation or “CAFO” is a term EPA uses to define AFOs that are regulated under the National Pollution Discharge Elimination System (NPDES) permitting program.

By EPA definition:

• Small and medium CAFOs are AFOs housing less than 1,000 animal units with a history of previously discharging into the waters of the state (ditches, streams, rivers, farm ponds or lakes) such that the regulating agency has determined the livestock farm falls under the NPDES permitting program.
• A large CAFO is one that EPA has determined, based on size alone, the operation has the potential to discharge into the waters of the state. A dairy with more than 700 milk cows, a beef farm with more than 1,000 animals and a pig farm with more than 2,500 pigs weighing over 55 lbs. are all considered large CAFOs.

Livestock farms in Michigan are not allowed to discharge. The manure storage structures (lagoons, earthen storages, above ground tanks, concrete pits, etc.) on CAFOs are engineered and constructed to meet the United States Department of Agriculture (USDA) Natural Resource and Conservation Service (NRCS) standards. Private engineers design these structures then monitor their construction to insure they meet the required integrity. CAFO operators are required to make weekly inspections of all manure storages structures and maintain records of those inspections. These inspections insure the storage structures are maintained and the level of manure stays below a predetermined freeboard. Freeboard is the amount of space in the manure storage structure that must remain unused and available for an emergency or, in the case of outdoor manure storage structures, available to store water collected during an extremely heavy rain.

On CAFO’s, all manure, silage leachate and contaminated waste water, including rain water that comes in contact with the bunk silo floor and feed area, must be collected, stored and applied to fields to meet the nutrient needs of the crops. CAFO operators are required to keep extensive records of soil testing (soil nutrient levels), manure nutrient testing, manure application rates and crop yields to assure the nutrients in manure are utilized in crop production. Each year these records are submitted to the Michigan Department of Environmental Quality for review and oversight.

CAFO is a term used by regulatory agencies to define farms based on type of livestock housing and the number of animals housed at one site. Livestock producers would prefer to be referred to as what they really are, farmers: beef farmers, dairy farmers, pig farmers, etc. A CAFO does not mean a farm is environmentally unfriendly, something I have witnessed first-hand while working with farms of all sizes in my position as a Michigan State University Extension educator. It does mean the farm is under increased regulatory authority and review to insure its environmental compliance.

Portions of this article were previously published on MSU's Air Emissions and Animal Agriculture site.