AMMONIA EMISSIONS FROM SWINE HOUSES IN THE SOUTHEASTERN UNITED STATES

Authors: Harper, Lowry; Sharpe, Ronald; Simmons, John

Submitted to: Journal of Environmental Quality
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/30/2003
Publication Date: 3/1/2004
Citation: Harper, L.A., Sharpe, R.R., Simmons, J.D. 2001. Ammonia emissions from swine houses. Journal of Environmental Quality. 33:449-457.

Interpretive Summary: Ammonia (NH3) from confined animal production is emitted from several sources including animal waste ponds, field applications for recycling and disposal, and confinement houses. Although lagoon and field application emissions have been found to emit less NH3 than previously thought, emissions from animal houses have not been comprehensively evaluated. These studies were conducted by USDA-ARS scientists at the J. Phil Campbell, Sr., Natural Resource Conservation Center, Watkinsville, GA, and State College, MS, to evaluate NH3 emissions from swine production houses in the humid Southeastern U.S. Management and environmental variables were measured to determine their individual and combined effect on NH3 emissions. Ammonia emissions varied on a daily and seasonal basis with higher emissions during warmer periods. For pigs produced for slaughter, the summertime emission factor was 2.4 times higher per animal than in wintertime. For summertime, the emission factor for slaughter animals was 7.8 times higher per animal than for producing animals. A treatment additive to the waste collection pit below the animals decreased emissions 25%. For slaughter animals, 7.4% of the animal feed was emitted as NH3 from the houses to the atmosphere. Ammonia emissions were found to be somewhat less than other studies on the same type housing due to more representative housing concentrations measurements and calibration of exhaust fans, thus, emission factors for these type houses will be less than previously thought. These emission factors will provide the industry and environmental organizations more-representative information for design and planning.

Technical Abstract: Ammonia (NH3) from confined animal feeding operations is emitted from several sources including lagoons, field applications, and houses. These studies were conducted to evaluate NH3 emissions from finishing and sow animal houses in the humid Southeastern U.S. Management and climate variables including animal weight, feed consumption, sump water temperature, fan operation time per day, house air temperature, house NH3 concentration, and animal numbers were measured to determine their individual and combined effect on NH3 emissions. Ammonia emissions varied on a daily and seasonal basis with higher emissions during warmer periods. For finishers, the summertime emission factor on a per-animal basis was 2.4 times higher than wintertime or 3.2 times higher when compared on an animal unit basis (AU = 454 kg) because of climate and animal size differences between measurement periods. For summertime, the emission factor for the finishing pigs was 7.8 times higher than for sows on an animal basis and 27.1 times higher on an AU basis. A simple model was developed for predicting housing emissions based on the three major management and climatic factors of animal size, feed consumption, and pit water temperature. This model explained 85% of variations in emissions while a model based on all the measurements explained 97%. A treatment additive to the pit water surface decreased emissions 25% during intermittent and continuous fan operation. Ammonia emissions were found to be somewhat less than other studies on the same type housing due to more representative housing concentrations and calibration of exhaust fans, thus, emission factors for these type houses are less than previously thought.