Aerial Emission Monitoring at a Dairy Farm in Indiana

Abstract

Measurements of the gaseous and particulate matter (PM) emissions from livestock buildings are important as these pollutants may affect the quality of the surrounding environment and eco-system. This paper describes a comprehensive emission monitoring study conducted as part of the National Air Emission Monitoring Study (NAEMS) at a large commercial dairy farm located in Indiana, USA. The farm was constructed in 2004, with a capacity of 3400 dairy cows. The milk production was about 32 kg/d-cow. The monitoring consisted of field measurements of aerial pollutant emissions from two “tunnel-ventilated” free-stall barns and a mechanically ventilated milking parlor. Ventilation air entered the free-stall barns through adjustable curtains, which were controlled based on temperature. The air was exhausted through fans banked together at each end of the barn, and through individual fans that were distributed along each sidewall. The long distances between sampling locations and measurement instruments makes this monitoring study particularly challenging compared with other sites in the NAEMS. The research focuses on characterizing and quantifying emissions of gases (NH3, H2S, CO2, CH4, N2O, etc.), particulate matter (e.g., PM2.5, PM10, and TSP), and volatile organic compounds (VOCs). Long-term and continuous measurements were conducted for building static pressure, fan operation, indoor and outdoor temperatures, relative humidity, animal activity, feeding operation, and wind speed and direction. In addition, the number of cows, milk production, type and amount of feed, and manure composition were also monitored. This study provides much-needed baseline data for establishing regulatory standards, and evaluating effectiveness of mitigation strategies and controls.