In an effort to reduce fine particulates in the air, the state Division of Air Quality is proposing to ban tracking dirt, sand, gravel or any other material onto roads.

The "trackout" rule is intended to reduce "fugitive dust," or dust that becomes airborne, said DAQ compliance director Marv Maxell."(Fugitive dust) is fine-particulate matter," Maxell said. "Last summer, it was so bad, it was impacting people's respiratory systems. It's all due to construction."

Fugitive dust is a component of a federally regulated pollutant called "PM10" - particulate matter smaller than 10 microns in diameter. PM10 can lodge in the lungs, causing respiratory distress and death.

While most fugitive dust comes from construction sites, such as I-15 or the numerous gravel pits along the Wasatch Front, a significant source is vehicles kicking up dirt from the roads.

A case occurred in early February when residents near the University of Utah complained of dust rising from streets.

The dust came from dried mud tracked out onto the streets by heavy equipment traveling between a materials-storage yard and the University of Utah's Rice Stadium, which is undergoing a $50 million expansion and renovation.

DAQ did not investigate because, under the current fugitive-dust rules, it would have had to take opacity readings that are designed for continuous emissions, such as those from smokestacks.

There's no defined measurement for fugitive dust on roadways, Maxell said.

The proposed rule, which would apply to any construction site a quarter-acre or larger, would require workers to clean their vehicles of dirt and mud before the vehicles are allowed off site. Such methods include spraying with a high-pressure water nozzle or brushing.

That would increase the cost of business for contractors.

"We don't like rule changes, but these things are inevitable," said Paul Glauser, environmental manager for Jack B. Parsons Cos., a sand and gravel producer. "Our feeling is the old rule is sufficient, but we also understand there are problems that need to be addressed. For some people, it's going to cost money."

What Glauser and his construction industry colleagues do not like about the proposed new rule is its use of the word "prevent."

"It's impossible to prevent dirt from being tracked onto the roads," Glauser said. "We prefer the term `prevent as is reasonably practicable.' "

The Utah Air Quality Board is expected to consider the proposal during its next regular meeting on April 21. Maxell said he hopes the rule will be finalized in time for the summer-fall construction season, when dust problems are at their worst.

Last year, DAQ issued 25 citations for fugitive dust, mainly at large construction sites, one of which was I-15. Maxell said a trackout rule would have resulted in a lot more citations.