Predicting Ambient Hydrogen Sulfide Concentrations Near Animal Feedlots

Larry Jacobson, Professor
David Schmidt, Assistant Extension Engineer
Verlyn Johnson, Information Technology Professional

Funding Source

Minnesota Agricultural Experiment Station Rapid Agricultural Response Fund

Objective

To develop a quick, easy, and economical tool for assessing an animal feedlot’s potential to exceed Minnesota’s ambient air quality standard for hydrogen sulfide (H2S).

Need or Impact

The Feedlot Manure Management Advisory Committee (FMMAC) and the Citizens Advisory Committee for the Generic Environmental Impact Statement (GEIS) on Animal Agriculture, which had representatives from many groups, including livestock organizations, state agencies, and environmental groups, have recommended that a screening tool be developed for assessing the potential of animal feedlots to meet the Minnesota state ambient air quality standard for hydrogen sulfide (30 ppb or 50 ppb 30 minute averages at the property line). Current methods for assessing this potential require individual, site-specific computer modeling that is often cost prohibitive to many producers. With the current economic challenges associated with animal agriculture, a low cost, high quality assessment tool is vital for the maintenance and growth of the state’s livestock industry.

Project Status

Two air dispersion models, AERMOD and CALPUFF, have been identified for use to simulate downwind conditions from selected simulated farms. Also, working agreements with a post-doctoral student (from the University of Nebraska) and a dispersion-modeling specialist (from the Minnesota Pollution Control Agency) have been established for assisting in the running of the two computer models. Also, a ten-member advisory/stakeholder group was formed and has recently met (January 2004) to provide input on policy and technical issues for the project.