Regional Air Emissions Reduction from Dairy Operations Via Best Management Practices

The Yakima Regional Clean Air Agency (YRCAA) in collaboration with the Dairy industry and environmental scientists, has developed, over a period of three years, an Air Quality Management Policy for Dairy Operations.The Policy is geared towards a systematic implementation of proven Best Management Practices (BMPs), which are specific for each dairy operation, to reduce air emissions in the Yakima Valley, WA.The BMPs are grouped in tiers with respect to effectiveness, cost, ease of implementation, and compatibility with the State mandated nutrient management plans for dairies.Tier 1 BMPs are generally the least expensive and easiest to implement, while Tier 3 BMPs are the most challenging and expensive to implement.The BMPs focus on air emission reduction of major air pollutants from dairy operations, namely; ammonia, nitrous oxide, hydrogen sulfide, volatile organic compounds, odor, particulate matter and methane.The dairy operations are broken down into the following components/systems: nutrition, feed management, milking parlor, housing (freestall and drylots), grazing, manure management and land application.The components in each dairy depend on the overall management design and not every dairy has all these components.A total of 41 dairy operations within the YRCAA jurisdiction were included in the policy representing a total of 145,000 head of cattle (lactating cows, dry cows, heifers and calves).To obtain baseline data, the YRCAA staff conducted site visits for each facility in 2014 and assigned a "score" for each dairy component ranging from A to D. The results presented here are not specific to each facility but aggregated.Based on all participating dairies; 21% scored an "A", 30% scored a "B", 37% scored a "C", and 12% scored a "D".These data will be used as a baseline to compare future BMPs implementations to determine air emission reductions.In general, results show that guided and voluntary implementation of BMPs has the potential to significantly reduce ammonia, volatile organic compounds, and odor emissions in the Valley.