Table 1.

Definitions of large and medium CAFOs according to USEPA (https://www3.epa.gov/npdes/pubs/sector_table.pdf)

Animal type	Large	Medium*
Cattle	> 1000	300–999
Dairy	> 700	200–699
Swine (> 55 lbs)	> 2500	750–2499
Swine (< 55 lbs)	> 10,000	3000–9909
Broilers	> 125,000	37,500–124,999
Layers	> 82,000	25,000–81,999

Note that there are many animals in confined conditions in operations with numbers fewer than indicated here and thus are undercounted in this analysis. Small CAFOS have numbers of animals less than those defined for “medium”

*Medium either has animals in range above or has a manmade ditch or pipe that carries manure or wastewater to surface water or the animals come into contact with surface water that passes through the area where they are confined