Iowa broiler and laying-hen facilities are more likely to fall under federal air emission reporting requirements for ammonia, the Spokesman has learned.
Studies at Iowa State University indicate that as few as 18,160 broilers and 30,267 laying hens emit enough ammonia in 24 hours to require reporting to the U.S. Environmental Protection Agency (EPA).
The data were gathered by Dr. Hongwei Xin, an internationally recognized expert in poultry and swine housing systems, environmental physiology and air quality.
Xin and researchers at other universities monitored air emissions over one year. They gathered data from six high-rise layer houses and four manure belt houses in Iowa and Pennsylvania and 12 broiler houses in Kentucky and Pennsylvania. Six of the layer houses were in Iowa, the No. 1 egg-producing state in the United States.
The study was funded by the U.S. Department of Agriculture’s (USDA) Initiative for Future Agriculture and Food Systems, and the Iowa Egg Council.
The study paralleled another USDA-funded, EPA-approved study of ammonia and hydrogen sulfide emissions from swine and other livestock facilities. Data from the studies is expected to be used by the EPA to establish procedures for assessing and controlling emissions from livestock facilities, a primary objective of an air emission compliance consent agreement reached by the EPA and the livestock industry.
Xin said broilers emit from a mean of 1.3 grams to a high of 2.5 grams of ammonia per day. At the high rate (for heavy roasters), a building housing 18,160 birds or more near the end of the grow-out cycle would emit 100 pounds of ammonia in 24 hours.
This is the trigger level for reporting under the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) and the Emergency Planning and Community Right-to-Know Act (EPRCA).
Xin said that in layer buildings with frequent belt-removal of manure, ammonia emissions vary and are much lower. (See table.)
“We did not measure hydrogen sulfide, nor do scientists see it as a problem from the standpoint of CERCLA and EPRCA,” Xin said.
The data is being reviewed and will be published in about two months.
