Odor Ratings System Estimates Setbacks University of Minnesota
researchers have developed an odor ratings system called Odor
From Feedlots Setback Estimation Tool (OFFSET). The system
estimates the setback distance from animal production sites by
determining the site's estimated odor emissions. All odor
sources at the site are identified. OFFSET selects the odor
emission number on a per-square-foot basis, determines the total
surface area of a barn or manure storage unit, credits any odor-
control technology and then calculates the total odor emission
factors for each source. OFFSET includes: - A database generated
from emissions measurements at 260 animal buildings and manure
storage units from 1997 to 1999; - An air dispersion model, and
- Average weather data for Minnesota from 1984 to 1992. First,
the total odor emission factor is determined for a production
site. Buildings and manure storage units are considered, along
with species, housing types and sizes, manure storage types and
sizes and odor control