No 'smoking gun' blamed for Wednesday haze

Environmental officials could not identify any particular source for the haze obscuring horizons in the Flathead Valley on Wednesday.

"There's no one smoking gun," said Mike Meschke, director of environmental services at Flathead City-County Health Department.

He said several sources of dust and smoke and poor ventilation combined to reduce visibility most of the day. Sources included road and other construction, fires and traffic.

"We closed burning at 8 a.m.," Meschke said.

Open burning closed at the end of April, but people with permits may still burn in May and June when ventilation conditions allow smoke to exhaust into the atmosphere.

A department official investigated and shut down a fire in Bigfork. Officials at Flathead County Interagency Dispatch reported no fires in the local area.

No major fires were burning in other areas of Montana or adjacent states Wednesday either. The National Incident Information Center reported three fires in northern Alaska; three in southern Arizona; and one in Nevada, 50 miles south of Reno.

Meschke said he contacted officials at the Montana Department of Transportation Tuesday to request additional water trucks to control dust at road building operations around the valley.

He said health department officials also collected a sample of gravel from one construction site for analysis.

"It's supposed to be very clean, washed rock of a specific hardness," Meschke said.

The results of the test were not available on Wednesday afternoon.

Meschke said the valley's home construction boom has also contributed to the dust problem. He pointed out the bulk of new construction occurs over dirt driveways.

Septic permits issued by the health department verify a high-level of construction activity in Flathead County.

"We've averaged over 100 [permits] a month for the last few months," Meschke said.

Particulate levels more than tripled in Kalispell within 24 hours. Air quality dived from healthy at 2 a.m. to unhealthy for some groups at 5 a.m.

The Montana Department of Environmental Quality showed a particulate reading of 103 at its Kalispell monitoring site by early Wednesday morning.

Air quality standards rate 103 as unhealthy for sensitive individuals, and limited exertion is recommended for children and people with respiratory disease.

Pollution was less severe at the Whitefish monitoring station in the early morning hours with a reading of 81. However, the air was still deemed unhealthy for sensitive individuals.

By noon, particulate levels inexplicably spiked nearly off the air quality chart at 1,000 in both Kalispell and Whitefish. The air was rated hazardous with warnings to limit all outdoor activity.

Within an hour, however, the pollution level dropped back to the earlier levels.

According to Meschke, ventilation forecasts promise some relief by Friday with breezy conditions and a change in wind direction predicted.

"It looks like it's going to be mixed ventilation," he said.