Odor Based Setbacks

Disclaimer

The Purdue Agricultural Air Quality Laboratory (PAAQL) members have put in much effort developing this guideline. However, the intricate issues involving odor measurement, dispersion modeling, and lack of in situ validation have hindered the refinement of the guideline. Neither PAAQL nor Purdue University accept any responsibility for any errors in, or for any errors that may results from using the setback guideline. We expressly disclaim any responsibility for any damage arising from the application or reliance on the recommendations and information contained herein.

Multi-Source Odor Setback Model - 2nd Gen. (Excel Edition)

Multi-Source Setback Model for Swine and Dairy [Indiana Soybean Alliance Project]

NOTE: Due to continuous updates being made, please do not save the Multi-Source Setback Model for offline use.

Multi-Source Excel Model - Manual

Total-Site Odor Setback Models - 1st Gen.

Interactive Total-Site Setback Model for Swine [National Pork Producer Council (NPPC) Project]

Interactive Total-Site Setback Model for Dairy

Odor control is a major concern of livestock producers in the United States. The use of atmospheric air to dilute odors from livestock facilities by appropriate setback distances is still the most popular and cost-effective strategy to reduce odor nuisance.  However, the determination of odor-based setbacks for livestock facilities is a difficult and complex problem with only limited supporting data in the U.S.

A simple-to-use, site-specific setback guideline was developed by Purdue University for U.S. swine production systems. This guideline considers facility size, orientation and shape, wind frequency, land use, topography, building design and management, manure handling characteristics, and odor abatement effectiveness. Odor emission factors were based in part on actual odor emission measurements in commercial buildings. Atmospheric dispersion models were used to enhance and validate the setback guideline. This interactive setback model combines features of Austrian and British setback guidelines (Schauberger and Piringer, 1997; Williams and Thompson, 1985) (click on Austrian guideline  to read about it) and incorporates new features developed through our research. The Purdue guideline is as follows:

Setback distance in feet = 20 F L T V (A_EE+A_SS)^0.5 

where:
            F = wind frequency factor [0.75 to 1.00],
            L = land use factor [0.5 to 1.00],
            T = topography factor [0.8 to 1.00],
            V = orientation and shape factor [1.00 to 1.15],
            E = building odor emission, N x P x B, OU/s,
                    N = number of pigs,
                    P = odor emission factor, OU/s-pig, [1 to 15],
                    B = building design and management factor, M-D,
                            M = manure removal frequency [0.50 to 1.00],
                            D = manure dilution factor [0.00 to 0.20],
            S = odor emission from outdoor storage, C x G, OU/s,
                    C = odor emission factor for outside liquid manure storage, 50 OU/s-AU
                    G = animal unit, AU=1,100 lb of pig weight. 
            A_E = odor abatement factor for buildings [0.30 to 1.00], 
            A_S = odor abatement factor for outside liquid manure storage [0.30 to1.00]                                            

References
Schauberger, G. and M. Piringer. 1997. Guideline to assess the protection distance to avoid annoyance by odour sensation caused by livestock husbandry. Proceedings of the Fifth International Livestock Environment Symposium, May 29-31, pp. 170-178.

Williams, M.L. and N. Thompson. 1985. The effects of weather on odour dispersion from livestock buildings and from fields.  In: Odor Prevention and Control or Organic Sludge and Livestock Farming. Ed: V.C. Nielsen, J.H. Voorburg, and P.L'Hermite. Elsevier Applied Science Publishers, New York. Pp. 227-233.