EPA says county OK on one type of dust

Stephen Curran

Monday, Dec. 20, 2004 | 8:54 a.m.

The Environmental Protection Agency on Friday said Clark County has stayed below the allowable level of one type of harmful dust in its air.

But the county still has work ahead to meet a deadline set by the EPA to reduce the amount of a coarser form of the dust, called particulate matter, in the air, county officials said.

Particulate matter is linked to asthma and other respiratory ills, and has even been shown to spur heart attacks.

The EPA determined that Clark County had stayed below the limit for the level of PM 2.5, a fine dust up to 2.5 microns in diameter. It is the first time the federal agency has enacted a national fine particle standard, Wayne Nastri, the EPA's regional administrator, said in a teleconference from San Francisco.

Dust particles of that size, about 1/30 the width of a human hair, have not been a consistent problem in Southern Nevada, mainly because the most common source of that problem is coal-burning power plants. They spew the particles, which become trapped in humid air and inhaled, John Koswan, assistant planning manager for the Clark County Department of Air Quality and Environmental Management, said.

"(PM) 2.5 is basically from combustion products and we don't have a whole lot of heavy industry that burns the coal that generates a lot of it," he said. "We really don't have the facilities here that produce it in levels that are an issue or cause problems."

But the county does have plenty of a larger size of particulate matter and is staring down a deadline to reduce it. The EPA has required the county to devise a plan to reduce the level of PM 10, a coarser form of the dust often created by work at construction sites and by wind whipping up vacant lots and roadways.

The dust is measured by a series of monitors positioned throughout populated parts of the state that filter the dust and measures the amount in the air, Matt Haber, deputy director for the EPA's southwest air division, said.

The EPA in June praised the progress made in the Las Vegas Valley, saying it has worked to meet federal standards despite unprecedented growth. Among the county's plan to control PM 10 has been a new set of dust control measures and consistently working with area construction companies, Nastri said.

"It's a matter of taking the federal standard and the federal tools and working with the state plan," he said. "We've been working with the construction companies and that's been excellent."

In the meantime, the county has developed a laundry list of possible control measures to stem the PM 10 levels, Koswan said. No new regulations or changes to existing rules are planned, he said.

"Until we better understand what those (the specific causes of the PM 10 levels) are, I really can't give a potential list of measues," Koswan said. "We may or may not adopt them depending on what we find."