Another problem with a standard setback distance is the fact that all impact areas may not be the same. This issue may be resolved by land use zoning. Hypothetical setback distances based on facility size. Policy based on odor emissions modeling This method of regulation is used for industrial air quality regulations. Gas emissions are measured or predicted for each source at a facility.
Air modeling programs then predict the concentrations of gases surrounding the facility.
These modeling programs have been modified to predict odor intensities around a livestock facility based on odor emissions. With this system, setback distances could be determined for each site based on the predicted odor impact area. However, there is no standard method for determining odor emissions from a livestock facility. Odors from livestock operations vary significantly with environmental conditions and management practices. Also, determination of setback distances would remain somewhat arbitrary since there are no standard limits on odor intensity and duration.