Validating the Odor Footprint Tool Using Field Data

Trained participants monitored odors around a 4,800-head finishing site in eastern Nebraska during 2005 and 2006. ‘Mobile odor assessors’ monitored odors within the downwind odor plume and reported that odors at off-site locations (at least 200 feet away) were consequentially annoying in 20 out of 192 assessments. On-site odor levels were considered annoying in 33 of 39 instances. For the same off-site locations and times, modeling predicted 18 annoying events, resulting in a 90% prediction rate (18 vs. 20) of annoyance frequency. The net error rates for missed annoyance for off-site locations were 9.1% and 10% based upon concentration data and annoyance ratings, respectively. Errors were mostly a result of either the predicted concentration at the receptor location was near the annoyance threshold, or the orientation of the odor plume was slightly off.