Toxic gas levels near some confinements at high levels
DES MOINES (AP) -- Toxic gas levels near livestock confinements reached dangerous concentrations 22 times in the first month of checks, state records show.
On April 1, the state began checking the gases near chicken, hog and cattle farms at Atlantic, Clarion, Malcom, Sioux Center, Woodbine and Williams, said Brian Button of the state air-quality staff.
The equipment checks levels hourly, so more than 4,000 readings were taken.
Scientists from Iowa State University's agriculture college and the University of Iowa's public-health staff said no more than 15 parts per billion of hydrogen sulfide and 150 parts per billion of ammonia should be allowed. That would be enough to cause lung irritation for some, they said.
Of the sites, the highest ammonia level found so far was 494 parts per billion near a DeCoster Farms hog confinement in Clarion. Seven other readings taken at that site were over the limit through Monday, ranging from 151 to 280.
A monitor near Milk Unlimited, an Atlantic-area dairy farm, had seven readings above the limit, as high as 250 parts per billion. The air near a Williams hog confinement surpassed the level once, at 175 parts per billion.
Hydrogen sulfide also was high at some sites. Preliminary results showed four readings over the limit at the Atlantic dairy, as high as 70 parts per billion. One reading each at the Clarion and Williams hog confinements were slightly over the limit.
Hydrogen sulfide can cause headaches, coughing and eye irrigation.
The results are preliminary. State workers are confirming them, Button said. Some readings from other monitors were thrown out when further tests showed they weren't accurate.
The Iowa Department of Natural Resources bought six monitors to check the emissions from several thousand confinements.
"The thought was to put the monitors near the largest operations, and then if you don't see (readings over the limit) there, maybe there isn't a problem," Button said. "We don't necessarily need a monitor at every confinement to predict what's up. We have computer models that can help."
The Legislature moved this week to get rid of the state's proposed regulations aimed at protecting Iowans from toxic hydrogen sulfide and ammonia from confinements and other sources. A resolution that nullifies the rules was approved Thursday by a House subcommittee and by the Senate Commerce Committee.
If the resolution passes, the rules would be scrapped and the DNR would have to start over.
Under the proposed rules, the state would allow seven days of readings over the limit before declaring a violation. No enforcement would take place until 2007 because the state typically wants three years of data to show what happens under different weather conditions.
Lawmakers say the standards are too tough and too vast, but university scientists and state air-quality workers disagree.
The monitoring tests will continue.