Contrary to the claims of numerous citizen activist groups, study results show that Iowa’s livestock operations don’t smell too bad. Trained environmental specialists spent three years measuring airborne pollutants from animal feeding operations, including dairy, pork, and beef facilities.

The overall result: Odors related to livestock operations topped the odor threshold used in the study in just 7 percent of the 1,708 measurements taken from 2002 through 2005.

Only one reading topped the level that would give state regulators a reason to set odor limits for Iowa’s livestock operations, which is very unlikely.

St. Croix Sensory of Lake Elmo, Minn., screened and certified the environmental specialists taking the odor measurements. The group used portable scentometers to measure the odors.

Measurements were taken in a variety of locations and results were categorized into three general areas: facilities, manure application and PERRC. The PERRC measurements were taken near public use areas, educational institutions, religious institutions, residences and commercial enterprises.  The odor benchmark used was based on limits already set in other states.

Of the 118 readings taken (out of 1,708) that topped the odor benchmark, the category with the highest percent of readings over the limit was manure application. Results within each category are:

  • Manure application -- 11 percent of samples taken were over the limit.
  • Facilities -- 7 percent of samples taken were over the limit.
  • PEERC -- 4 percent of samples taken over the limit

Livestock industry representatives say this study shows that the state's setback distance requirements for livestock confinements are working. Opponents, however, particularly the Iowa Citizens for Community Improvement, claim the study is flawed and are still calling for odor regulations.

You can read the full report at:

 Des Moines Register, Iowa DNR report