Dust advisory stays as wind continues

Friday, April 8, 2005 | 8:48 a.m.

Clark County has extended an air quality advisory through at least Saturday as forecast high winds threaten to whip polluting dust throughout the region.

The county's Air Quality and Environmental Management Department issued the first warning Wednesday as the front side of a low-pressure front brought sustained tropical-storm-force winds of 35 mph to Southern Nevada. The advisory was scheduled to expire this morning.

But as the slow-moving front crawled through the West, county meteorologists said the winds would continue to plague the region.

"We're going to have high winds on both the front and back side of the low," said John Koswan, Air Quality assistant planning manager. He said the low-pressure trough appeared particularly deep, and "the deeper the trough, the higher the winds."

As of early Thursday evening, the actual levels of dust in the air had not reached the point where air quality officials would post a health alert on their Web site at www.accessclarkcounty.com. However, Air Quality officials advised residents to watch out and report blowing dust, limit outdoor activities if sensitive to breathing problems and avoid breaking the dust-containing crust on the open desert.

"Construction sites and stationary sites need to take all precautionary measures," Koswan said.

He said all 15 enforcement officers were in the field looking for dust-control problems Thursday evening. Those officers could be working some long hours over the next several days.

"If we need to work overtime, we will call them in," Koswan said.

Air Quality has a water truck that it can use to control dust blowing from relatively small sites, Koswan said, but "we can't water the entire desert."

With wind gusts over 40 mph, that could mean that the desert crust breaks and wind carries dust through the area even without human interaction, he said.

Clark County is under a federal mandate to control fine airborne dust, called PM-10 by scientists and regulatory officials. The U.S. Environmental Protection Agency can take into account high winds and consider an exceedance of federal dust limits an unavoidable natural event when considering whether the region has achieved adequate air quality.

Koswan said the EPA will make its judgment on dust pollution in 2007.

"We have to make a very compelling case that exceedances were due to high wind events," he said.

In the meantime, on March 15 the Clark County Commission approved a plan to control dust from natural, high wind events for review by the EPA. The plan would distinguish between natural events and dust created by artificial sources.

Environmentalists criticized the plan, arguing that dust storms are almost always the result of human interaction with the open desert, and that the county should be more aggressive in cracking down on people who kick up dust throughout Southern Nevada. Air Quality officials said there are limits to what they can do as regulators.

Fine airborne dust is a form of air pollution that can aggravate respiratory diseases such as bronchitis or asthma. Children, the elderly or anyone with respiratory problems should stay indoors during dust storms. Those with special sensitivities can also sign up for warnings from Air Quality through the county Web site.

People who see excessive amounts of blowing dust can report the problem by calling Air Quality at 385-DUST. Officials also urge residents to avoid creating more dust and pollution problems by driving slowly on unpaved roads, and avoiding short cuts across vacant lots, off-highway vehicle use in the Las Vegas Valley, and using wood-burned fireplaces.