ALL Sized Dairy Operations Need To Consider the Air Quality Compliance Agreement (AQCA)

There is a morsel of good news concerning EPA’s AQCA. They did listen and respond to comments concerning the short response times. EPA has extended the deadline for comments on the agreement until May 2, 2005 and the sign-up deadline until July 1, 2005
(http://www.epa.gov/compliance/resources/agreements/caa/cafo-agr-0501.html). This gives producers an additional 2 months to consider whether signing the AQCA is right for them and their dairy business. One of the hurdles dairy producers are struggling with is what size herds can potentially be affected by the AQCA. There are some folks that say only 1000 cow dairies and higher will be affected; there are others that say 100 cow dairies will be affected. Why is there such a discrepancy in cow numbers?

Keep in mind the AQCA is measuring emissions from both housing and manure storage. Based on some emission data from Europe, a range of 0.04 to 0.19 pounds of ammonia emitted per cow per day is possible. These numbers reflect freestall housing with slatted floors and a pit below. That equates to herd sizes of 525 to 2500 cows or greater exceeding the 100 pounds of ammonia emitted in a 24-hour period as stated in CERCLA and EPCRA.

Penn State is currently examining dietary strategy effects on ammonia emissions in freestall housing. Preliminary cold weather data are showing very low levels of ammonia emissions of 0.011 pound per cow per day from housing only. However, temperature plays an integral role in ammonia emissions. Hot weather data needs to be collected before any conclusions can be drawn on ammonia emissions on an annual basis and over any 24-hour period.

Since EPA is also concerned with ammonia loss from manure storages, this needs to be included with the number coming from housing. Using numbers from current reference tables, there is a predicted range of 0.05 to 1.0 pound per cow per day of ammonia emitted from storage depending on type. If the value from the PSU work of 0.011 pound is added to the possible ammonia losses from manure storage, the number of cows that potentially exceed the threshold of 100 pounds of ammonia in a 24-hour period during cold weather is 99 to 1600 cows or more.

The discrepancy with cow numbers is very real when looking at ammonia emission data. It is important to know if numbers reflect just housing or housing and manure storage combined. It is also important to take into account weather, housing, nutrition, and management conditions for the dairy in question. The AQCA is not just a large herd issue. Smaller sized farms could also be impacted. This is the reason why producers should not just shrug off the AQCA. This agreement can have a major impact on our dairy industry.

Remember that there are two significant components to the AQCA; 1) the expected protection from civil liability versus the cost to the producer and 2) the opportunity for EPA to collect comprehensive data to provide more definitive guidance on how federal air emissions laws will ultimately apply to the dairy industry. The choice made by individual producers will have a significant positive or negative impact on every dairy business.

Virginia Ishler, Dairy Alliance and Robert E. Graves, Professor, Agricultural and Biological Engineering Department