Ammonia concentrations downstream of broiler operations

Within broiler production facilities, NH3 concentrations have always been of concern from a bird performance and worker health standpoint. However, NH3 emitted from poultry houses is receiving increased attention from the environmental and community nuisance perspectives. Studies on NH3 emissions from poultry operations found within the literature do not address how NH3 disperses or the actual concentrations observed at varying distances downwind from poultry houses. The objective of this study was to measure downwind NH3 concentrations emitted from broiler houses when ventilation rates would be at a maximum. Open-path laser spectrometers were utilized for this study and for period I were placed 100, 200, and 300 ft from the houses from 28 to 49 d and in period 2 were placed at 100, 200, and 500 ft from 50 to 56 d. Data were collected during the last 4 wk of a 56-d grow-out cycle in 2 periods during a summer flock on a 4-house broiler farm located in northeastern Georgia. Ammonia concentrations were lower as distance from the houses increased, with NH3 levels at 100, 200, 300, and 500 ft being less than I ppm in approximately 60, 75, 85, and 90% of the observations, respectively. Ammonia concentrations extending to 100 ft from the houses were influenced by the tunnel fans themselves. Wind direction and wind speed were the factors that significantly influenced downstream NH3 concentrations beyond 100 ft. At no time did measured NH3 levels meet or exceed established Occupational Safety and Health Administration-US Environmental Protection Agency NH3 odor-detection threshold values during this study.