Hog Farm Air Quality Regulations

Large hog farms in Colorado are subject to both air and water quality regulations.

Air Regulation

The air quality regulation, known as Regulation No. 2, Part B, "Odor Emissions, Housed Commercial Swine Feeding Operations" requires all such operations capable of housing 800,000 pounds of swine to obtain a permit to operate and to develop a site-specific odor management plan. Affected hog operations are required to employ technologies to minimize, to the greatest extent practicable, off-site odor emissions from all aspects of such operations. Included in the requirement are technologies to minimize odor emissions from swine confinement structures, animal waste management systems, composting storage sites, animal carcass disposal and land application equipment and sites.

Compliance with odor requirements is measured, in part, by two odor concentration standards. One odor standard applies at and beyond an operation’s boundary. This standard is set at a 7:1 dilution measurement. The second odor standard applies at any receptor, such as an occupied dwelling, school, place of business and municipal boundaries. This odor standard is set at a 2:1 dilution rate.

The regulation also includes a “cover” requirement for all new, expanded and existing anaerobic process wastewater vessels and impoundments, including treatment and storage lagoons. In general, operators are required to employ covers on these vessels and impoundments so as to capture, recover, incinerate, or otherwise manage odorous gases to minimize to the greatest extent practicable the emission of such gases to the atmosphere. The Division maintains a list of approved covers that operations can install, pending a Best Achievable Control Technology (BACT) and engineering review. Operators electing to manage process wastewater impoundments as aerobic systems must install and operate technologies to ensure maintenance of aerobic conditions or otherwise minimize emissions of odorous gases to the greatest extent practicable.

With respect to land application of process wastewater, the odor regulation requires a one-mile setback for land waste application sites and waste impoundments. The one-mile setback applies to all occupied dwellings, public or private school, and the boundaries of any incorporated municipality. The regulation allows affected sources to obtain setback waivers from any of the above listed entities.

For more detail and specific regulatory language, refer to:

• Air Quality Regulation No. 2, Part B (Odor Emissions: Housed Commercial Swine Feeding Operations)

Water Regulation

Regulations of the Colorado Water Quality Control Commission pertaining to hog farms can be found below under the tab for "regulations."