This National Pork Board project resulted in an odor footprint tool (OFT) that is adaptable to regional weather conditions and multiple pork facility layouts. The OFT provides a visual representation of the frequency, direction and extent of odor dispersion from a facility. It also produces a graphic representation of desired separation distances in four directions for various magnitudes of odor production. The tool was validated by comparing measured odor intensities from several swine facilities to odor levels predicted by the OFT. When a 99% odor annoyance-free frequency was used for a worst-case situation in Minnesota, the results from OFT compared favorably with those from the Minnesota OFFSET tool. OFT produced a maximum setback distance of 2.1 miles compared to 1.8 miles derived from OFFSET for the same conditions.
This project also developed new odor, hydrogen sulfide and ammonia emissions data for anaerobic swine lagoons. These data indicated that phototrophic (purple) lagoons had odor emission rates that were about half those of non-purple lagoons when compared in late spring. H2S emission rates were greater in late spring for both types of lagoons, however purple lagoons had significantly reduced emission rates in both seasons. In addition, data reported by many studies around the world on odor and hydrogen sulfide emissions from swine facilities were compiled and placed on an electronic database (available on the University of Nebraska website http://manure.unl.edu/oft.html).