The regulations of the various governmental units are among the several factors to consider when siting a new swine facility. Historically these types of regulations have attempted to protect the environment as well as human health but are increasingly attempting to limit the nuisance potential of these facilities. These sorts of regulations are either prescriptive-based, performance-based or some combination of the two. Prescriptive practices are typically easier to enforce but may not always prevent environmental, human health or nuisance issues. Performance standards are typically based on known health or environmental impacts for certain pollutant concentrations and frequencies.Unfortunately, nuisance odours are very subjective which makes setting ambient standards (for use with performance-based standards) very difficult. Also, the monitoring methods required to show compliance are limited and often require extensive regulatory staff time.Air quality modeling can be used to show the likely potential to meet annual emissions standards or ambient air quality standards for new or expanding facilities but the accuracy of this information is a function of the accuracy of emission data. For livestock and poultry facilities this data is extremely limited, especially in the case of odours.Future regulatory solutions to prevent odour nuisance problems will include modeling of odour dispersion but the best solution will be to drastically reduce the generation and emissions of odour from all livestock and poultry facilities.