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Animal Feeding Operations
Hog, cattle, and turkey feeding operations


In 2002, the Iowa Legislature directed the DNR to perform a field study to determine airborne levels of ammonia, hydrogen sulfide, and odor near animal feeding operations.

The Iowa DNR has established a health based standard for hydrogen sulfide to compare against monitoring data to determine if levels pose a risk to public health. If levels measured at separated locations such as homes, public areas, schools, or religious buildings pose health risks, the DNR may develop plans and programs to reduce emissions at animal feeding operations.

The Iowa DNR convened workgroups on best management practices, air emissions characterization, and dispersion modeling as part of a continuing effort to develop a working understanding of the technical issues involved in air quality concerns associated with AFOs. Findings and recommendations of the workgroups have been compiled into a report.

Animal Feeding Operations (AFO) Field Study

Health Effects Value and Health Effects Standard for Hydrogen Sulfide
Animal Feeding Operations Technical Workgroup Report

Miscellaneous Links