A multi-year field olfactometry study near a concentrated animal feeding operation

Area of Science:

• Environmental Science
• Atmospheric Science
• Animal Science

Background:

• Concentrated Animal Feeding Operations (CAFOs) can generate significant odor emissions.
• Effective odor monitoring protocols are crucial for assessing environmental impact and community relations.

Purpose of the Study:

• To develop and validate a protocol for monitoring odors using portable field olfactometry near a swine CAFO.
• To assess the frequency and characteristics of odors attributable to hog manure.

Main Methods:

• A panel of trained individuals utilized the Nasal Ranger, a portable field olfactometry instrument.
• Monitoring was conducted over three years, collecting data on odor intensity, odor descriptions, and meteorological conditions.
• Monitors were selected for olfactory sensitivity and impartiality.

Main Results:

• Over 50,000 readings were collected, with only 41 (0.1%) instances of hog manure odor at a dilution to threshold ratio (D/T) of +/- 7:1.
• Odor detection frequency was negatively correlated with wind speed and positively correlated with wind originating from the CAFO's direction.
• Temperature, precipitation, cloud cover, and time of day did not significantly influence odor detection frequency.

Conclusions:

• The developed protocol provides a reliable method for monitoring CAFO-related odors.
• Hog manure odors were infrequent under the monitored conditions, with wind being a primary influencing factor.
• Further research can refine odor dispersion modeling and mitigation strategies.