The Iowa Department of Natural Resources today (Wednesday) released a three-year animal manure odor study. The study found only seven percent of the air samples exceeded the rate set to determine if they stunk too much. The administrator of the D-N-R’s Environmental Services Division, Wayne Gieselman, says the study confirms many things that were already known. “I don’t think there were any big surprises here,” Gieselman says. “We had more exceedances when folks were land-applying manure in the spring and in the fall. That’s always when we get the most complaints.”

Gieselman says the study gives some concrete support to ideas the D-N-R has had about livestock odors. “Covered facilities have less odors about them than uncovered facilities,” Gieselman says. “Those are all kind of common-sense type conclusions but the study does conclude that those are all verified.”

Iowa does not have a set air quality standard to indicate when livestock odor is to onerous — so they used a standard adopted by the state of Wyoming on some 17-hundred air samples. Another key finding showed the problem rate was not directly related to the size of an animal feeding operation — but the way that the manure was managed played a significant role in determining odor problems.

He believes the information will be valuable for policymakers. “Well, I hope it’s more than nice to have on the shelf ’cause my staff put a lot of time in on this,” Gieselman says. “I think it’s information that the legisalture can and should have at some point if they’re ever going to come to some conclusions on air quality from livestock.”

The study was launched by legislation that was passed in 2002. He says, “The more data we have, the better decisions we can make.” The odor sampling was done in response to citizen complaints.”We were actually trying to monitor the worst-of-the-worst, I guess, places where people felt strong enough to call us out and have us take a look,” Gieselman says.