Seeks extension of comment period

BOZEMAN (AP) -- An environmental group here is challenging portions of a new state assessment that concluded Holcim Inc.'s proposal to burn tires at its cement plant would pose no additional environmental threat.

The group Montanans Against Toxic Burning also is asking for an extension of the public comment period on the company's proposal.

The group issued a lengthy list of complaints about the environmental impact statement the state Department of Environmental Quality.

The agency concluded the proposal to burn tires and slag at a cement plant near Three Forks poses no additional health or environmental risks, as long as certain restrictions are followed. The agency also has issued a draft air quality permit which would allow the company to burn as many as 1.1 million used tires a year in its cement kiln, but sets limits on how many tires can be burned at any given time.

Holcim first proposed using old tires as a source of fuel in 2001 when it sought a state air quality permit. Environmentalists opposed the idea and were joined by a number of local lawmakers when it was revealed in 2005 that the plant was also getting slag from a Superfund site in East Helena.

Slag, the byproduct left from the smelting process, is used as a substitute for iron ore, with iron being one ingredient in making cement.

The DEQ's environmental impact statement looked at the cumulative effects of burning both the tires as fuel and the slag and concluded that, under the limits set by the draft permit, ''the total risk for burning tires and adding slag are essentially identical to the risks associated with the present operation without tires.''

The environmental group contends that, among other things, the DEQ failed to release raw data supporting its conclusions. It also said the agency didn't adequately address increased dioxin emissions that could result from burning tires.

EIS coordinator Greg Hallsten acknowledged that much of the raw data used by the report's authors wasn't in the EIS sent out to the public, but that's because such documents are geared toward a general audience.

''An EIS is supposed to disclose enough impacts for the average reader to understand,'' he said. All the data is public record and available upon request. MATB has received it, he said.

The environmental group has sent DEQ a letter asking it to extend the public comment period on the study. The Bozeman City-County Board of Health is also asking Gov. Brian Schweitzer for a 30-day extension beyond the Sept. 28 deadline.

The DEQ has already extended the deadline to the maximum extent allowed under state law, Hallsten said.