The Iowa House voted Tuesday 62-34 to set state emission limits for hydrogen sulfide and ammonia that mirror federal levels. House file 2523 blocks new state air quality rules for livestock facilities until further studies on the airborne pollutants and odor they cause are completed.

The Iowa Department of Natural Resources, which is studying the effects of hydrogen sulfide and ammonia, would have to extend its study up to three years before establishing new state standards. But the agency would be prohibited from adopting rules that are stricter than federal regulations.

Legislation passed two years ago would have given DNR the authority to set air quality rules for the livestock industry. But lawmakers found the DNR's proposed rules too strict and questioned the validity of their scientific basis, voting to nullify them last year.
Backers of the bill say it would help reach a balance between protecting public health and protecting livestock producers who fear they are being driven from the industry.

But opponents contend the studies ordered in the bill are a tactic to delay putting any rules into place. They also say the federal air quality standards are too lenient.

Another complaint is that livestock confinement owners could be cited for violations only after a neighbor has filed a written complaint. And if a confinement's owners were found to have exceeded air quality standards, the owner would have a year to come into compliance before they were cited for a violation.

In addition, the bill creates a health effects panel made of state and national experts to study odor from livestock confinements and make a report to the Legislature by Dec. 31, 2006.

The bill, if approved by the Senate, faces a tougher challenge before Governor Vilsack.

Here’s a look at the emissions standards for confined animal feeding operations set by Iowa House File 2523:

  • Hydrogen Sulfide: The acute minimal risk level is a concentration dose exceeding 70 parts per billion for 14 consecutive days. The sum of the hourly averages for 14 consecutive days shall not exceed 23 52/100 parts per million-hour.
  • Intermediate: The intermediate minimal risk level for hydrogen sulfide is a concentration dose exceeding 30 parts per billion for the duration of 364 consecutive days. The sum of the hourly averages for 364 consecutive days shall not exceed 262 parts per million-hour.
  • Ammonia: The acute minimal risk level is a concentration dose exceeding 1,700 parts per billion for the duration of 14 consecutive days. The sum of the hourly averages for 14 consecutive days shall not exceed 571 parts per million-hour.
  • Chronic: The chronic minimal risk level for ammonia is a concentration dose exceeding 300 parts per billion for the duration of 365 or more consecutive days. The sum of the hourly averages for 365 consecutive days shall not exceed 2,628 parts per million-hour.

Sioux City Journal; Des Moines Register