Univ. researchers have
delivered data to the Environmental Protection Agency on a two-year National
Air Emissions Monitoring Study that gives a look at air quality on and around
Al Heber, a professor of agricultural and biological
engineering and leader of the study, said he will now move to the next phase of
his work: studying and publishing the dynamics and causes of the emissions and
“mining” the extensive data for more information. At the same time,
EPA is using the data to develop formulas that could be used by animal feeding
operations or agencies to estimate their emissions.
“What we collected is baseline data,” Heber
said. “The quantity of emissions depend on how waste is collected, treated
and stored; the number and type of animals; and the weather.”
Heber and his team collected data from more than 2,300
sensors at a total of 38 barns on 14 farms in North
Carolina, Iowa, Indiana,
New York, Washington,
For barns, there were five dairy sites, five pork production sites, three
egg-layer sites and one broiler ranch. Outdoor swine and dairy manure lagoons
were monitored at nine farms. A dairy corral in Texas also was tested.
The team measured for emissions of ammonia, hydrogen
sulfide, three sizes of particulate matter and volatile organic compounds.
Emission rates were calculated every minute.
“The dataset is very extensive,” Heber said.
“If we were to analyze 1 million data points per day, it would take us
seven years to analyze—and that’s just for the barns.”
Heber said that estimates for these compounds at given
types of farms will most likely be calculated from barn temperatures, animal
density in the barns and barn airflow rate. Farm type is a major factor. For
example, greater amounts of hydrogen sulfide are emitted from swine barns than
from dairy freestall barns. And the type of manure collection systems, such as
flushing versus scraping manure from barns, influences the numbers.
The National Pork Board, National Chicken Council, National
Milk Producers Federation and American Egg Board funded the research through
the nonprofit Agricultural Air Research Council. The EPA Office of Air Quality
Planning and Standards oversaw the work and is currently developing
emissions-estimating models from the data.
Purdue researchers collaborated with others at Cornell Univ., Iowa State
Univ., North Carolina State Univ., Texas A&M Univ., the Univ. of California-Davis,
the Univ. of Minnesota, and Washington State Univ.