The study, which scientists hope will help improve methods of estimating any given farm's emissions, began this summer and will take an estimated 2 1/2 years to complete. It will measure levels of hydrogen sulfide, ammonia, nitrous oxide, particulate matter and other substances wafting from livestock buildings and manure lagoons at 20 farms in nine states.

Al Heber, a Purdue professor of agricultural and biological engineering who's leading the $14.6 million study, said it will collect two continuous years of emissions data at each site.

Sensors will collect real-time data that are expected to help the U.S. Environmental Protection Agency devise science-based guidelines for livestock air emissions, which the agency regulates. Results are expected by the end of 2009, followed by a peer-review process.

"The bottom line is we're going to get just a ton of data and I think people all over the country are expecting that - regulators, livestock producers, everybody knows we're going to get a lot of good data," he said.

The study is required under a 2005 compliance agreement between the Environmental Protection Agency and the livestock industry. Although the agency is supervising the project, it's being financed by money livestock producers agreed to pay into a research fund under the agreement.

To date, more than 2,600 agreements have been signed with livestock companies that operate about 14,000 swine, dairy, egg-layer and broiler chicken farms in 42 states, said Jon Scholl, EPA Administrator Stephen Johnson's agriculture adviser.

A 2002 report by the National Academy of Sciences called on the EPA to improve its methods for estimating emissions from big livestock farms - research that will help determine if farms are complying with the Clean Air Act.

"We found that we really don't have the level of scientific information and data that's needed to make some sound policy calls in this area," Scholl said.

He said it's unclear whether the study's findings will have any impact on federal or state-level environmental regulations. The participating farms are in California, Indiana, Iowa, New York, North Carolina, Oklahoma, Texas, Washington and Wisconsin.

Source: The News&Observer