Air Quality - Why Should Pennsylvania Be Watching California?

Posted: May 6, 2005

Attention to the increased impact of animal facilities to atmospheric conditions has been on the radar screens of local and state regulatory agencies in California for some time, but are now developing state implementation plans regarding air quality in several of their air management districts.

There have been several articles recently that have discussed lower emission numbers based on California research. Because of the current events surrounding EPA’s air quality consent agreement (AQCA), people assume we are comparing apples to apples or ammonia emission to ammonia emission. Actually, what is happening in California is very different from the AQCA.

Attention to the increased impact of animal facilities to atmospheric conditions has been on the radar screens of local and state regulatory agencies in California for some time. Because of citizen lawsuits regarding air quality, it became necessary for California to develop state implementation plans in several of their air management districts. The emissions of concern are volatile organic compounds (VOC) and particulate matter (PM).

Recent articles about dairy emissions in California are referring to VOCs. These emissions are of concern because VOCs are precursors to ozone formation. In California, a large portion of their state is designated as non-attainment areas for ozone. Threshold levels for dairies regarding VOCs were being based on research conducted in 1938. This study estimated that cows produce 12.8 lbs of VOCs annually. For a 700 cow dairy that would equate to 4.5 tons/year of VOCs, which is equivalent to 60,000 cars. However, preliminary results of a recent study conducted by Dr. Frank Mitloehner, an air-quality specialist at the University of California-Davis, showed that the amount of VOCs may be far lower, by as much as 50 percent lower – than the amount found in the 1938 study. His study also shows that the cow herself may emit more VOCs than the excreta. It is this kind of research that is critical in developing regulations grounded in good scientific data and it also helps in developing the best mitigation practices.

The other emission of concern for California is PM. The major contributor to PM during much of the year is particulate nitrate; ammonia emissions are a precursor to its formation. California, at the state level, is already dealing with how to regulate and control ammonia emissions and it does involve working with animal agriculture.

What can Pennsylvania learn from California dairy producers who have been dealing with air quality issues? for sometime? Currently, animal agriculture in Pennsylvania is not regulated for air quality, other than odor, air emissions are barely on agriculture’s radar screen. However Pennsylvania, like California, has nonattainment areas for PM that are in the hot bed of animal agriculture. Over the next several years Pennsylvania will have to develop plans to clean up the air in these non attainment areas. It is unrealistic to think that animal agriculture in these areas won’t be expected to share in efforts to improve air quality by controlling ammonia emissions. The bottom line is air quality concerns are not going away.

Virginia Ishler, Extension Associate, Penn State Dairy Alliance, Nutrition Management and PSU Dairy Unit Manager, Dairy Alliance is a Penn State Cooperative Extension Initiative and Robert E. Graves, Agricultural and Biological Engineering Department