The Air Out There

National study of dairy emissions begins

by Patricia Miller

At 20 farms around the country, white construction trailers now hunker near barns, lagoons and feedlots.

Though they look innocuous, the trailers are stuffed with scientific equipment capturing data 24/7 from 2,383 sensors. Along with weather and other parameters that affect air dispersion, the sensors will “sniff” the air for particulate matter, volatile organic compounds and a host of gases including ammonia, hydrogen sulfide, carbon dioxide and methane.

The trailers, which went live in September, are part of the ground-breaking, two-year National Air Emissions Monitoring Study being conducted for the livestock industries by researchers at Purdue University and seven other universities.

The dairy sensing sites include open corrals, freestall barns, lagoons and basins in California, Indiana, New York, Texas, Washington and Wisconsin (see map).

Al Heber, professor of agricultural and biological engineering at Purdue and science adviser and team leader for the study, says careful and thoughtful planning went into every aspect of the study from scientific protocols to site selection. Sites were chosen based on:

• How sites represented the industry concerning technology, facilities and management.

• How conducive sites were to collecting good data.

• Willingness of the producers to collaborate with the researchers.

• Proximity to the universities assigned to maintain and monitor the trailers and their equipment.

The study also monitors factors like weather, ventilation, feeding, lighting and how and when manure flushing occurs.

“This study is designed to capture the best data ever on air emissions from livestock operations,” Heber says. “Everyone working on the study is very eager to conduct as much research as possible and capitalize on the infrastructure while it’s on the farms.”

Rob Byrne, senior vice president of scientific and regulatory affairs for the National Milk Producers Federation, says, “The study will generate good data for the EPA [Environmental Protection Agency] so it can establish regulations using valid numbers,” he says.

“Until now, the numbers that have been used were old and didn’t reflect the industry they were being applied to. For instance, swine data was being extrapolated for dairy regulations.”

Byrne says NMPF is working closely with the EPA, Congress and the National Dairy Board to ensure dairy’s inclusion. Funding for the dairy portion of the study comes through the dairy checkoff, under a one-time (and somewhat controversial) exemption that allows checkoff funds to be used. DT