By Susan Redden

sredden@joplinglobe.com

Changes to state odor rules, including reducing the odor threshold and bringing more concentrated animal feeding operations under state regulation, were debated Wednesday by Missouri’s Air Conservation Commission.

The board discussed proposed revisions in more than two hours of deliberations, and the issue is on the agenda for the board’s formal session today in Jefferson City.

“They are looking at dropping the odor threshold, not to punish, but to trigger additional oversight by the state,” said Rebecca Birke, a spokeswoman for state’s air-pollution-control program.

Odors now must register as offensive in a 7-to-1 dilution in equipment used by state inspectors to qualify for citations. Carthage city officials have been among those most persistent in seeking a lower threshold because of odor problems the city has attributed to Renewable Environmental Solutions, a plant in the industrial bottoms that converts poultry byproducts from Butterball Inc. into types of fuel.

The plant has been the subject of a state shutdown, and a public-nuisance lawsuit filed by the city and the Missouri attorney general’s office.

Carthage officials are looking to the state for a lower odor threshold, Tom Short, city administrator, said Wednesday.

“We and our citizens will be disappointed if they don’t,” he said. “The odors are definitely a nuisance, but they’re not a violation according to state standards” set by the Department of Natural Resources.

He said a lower threshold that triggered notices of violation would tie in with a bill proposed by state Sen. Gary Nodler that specifies that operations cited for violating state odor rules more than three times in a year would be subject to additional fines.

But the proposal being debated by the commission would lower the threshold to a 4-to-1 ratio to trigger additional state oversight, but odors would have to register at 7-to-1 or above to trigger a violation, Birke pointed out. Odors exceeding the lower level would prompt the DNR to contact the plant and direct officials to develop a plan to correct the problem.

The Carthage RES plant added more odor controls as a result of a consent judgment after the lawsuit filed by the city and state. Though odors still bother residents, the plant has not been cited recently for violations.

The commission is considering new odor rules based on proposals from a work group assembled last summer by DNR officials to determine if changes were needed in state regulations. Carthage officials and residents, and some residents near large CAFOs attended the discussions to lobby for stricter rules.

The proposals from the work group and the attorney general’s office recommended lowering the state’s air-dilution standard to 2-to-1 from 7-to-1. The attorney general’s office recommended a technology-based approach that would focus first on working with businesses to help them get into compliance.

A different proposal fashioned by the DNR staff recommends that the dilution standard be lowered only after more data collection and training. The agency is suggesting more comprehensive data collection, including a new protocol that measures odor intensity, rather than just checking to see if it reaches the 7-to-1 ratio. It also recommends that information about the complaint, weather at the time and other conditions be gathered.