Evaluation and Implementation of OFFSET (Odors from Feedlot Setback Estimation Tool) in Selected Minnesota Counties

Larry Jacobson, Professor
Kevin Janni, Professor and Head
David Schmidt, Assistant Extension Engineer
Sven Nimmermark, Graduate Student, Swedish University of Agricultural Sciences

Funding Source

Minnesota Agricultural Experiment Station Rapid Agricultural Response Fund

Objective

To evaluate the OFFSET (odor setback) tool in several Minnesota counties for ease of understanding, implementation, and performance in various situations.

Need or Impact

The OFFSET tool remains one of the few useful tools to assist in the development of science-based setback distances for new or expanding livestock and poultry facilities. The results of this project will aid in the improvement and use of OFFSET and other tools used by local government agencies to establish objective odor setback distances between animal production sites and local residences and businesses.

Project Status

This two-year project was completed in 2003. Farms in five Minnesota counties (Carver, Nicollet, Stearns, Steel, and Winona) were selected to evaluate the OFFSET (Odors from Feedlot Setback Estimation Tool) method. Data from 309 observations were compared with the model. In 64% of these, an odor less than intensity 2 was predicted, but an odor higher than intensity 2 was actually reported. In 32%, the predicted and reported odor intensity were in agreement, being either higher than 2 or below 2. In all observations, the observed odor intensity was significantly higher than the predicted.