Changes in air quality standards may affect Shoshone County

WALLACE — The Environmental Protection Agency’s air quality requirements have changed, and Shoshone County residents may have to adjust how they burn during the final months of the year.  

On Wednesday, the Shoshone County commissioners met with representatives from the Idaho Department of Environmental Quality to discuss the county’s air quality and potential strategies for staying in attainment.  

The National Ambient Air Quality Standards are measured by several things, including the amount of particulate matter (PM) in the air, ozone, nitrogen oxides, sulfur oxide, carbon monoxide and lead.  

PM 2.5, or fine particulate matter, are the smallest of these pollutants and come from emissions from the combustion of gasoline, oil, diesel fuel or wood.  

Recently, the EPA changed the annual average standard for PM 2.5 attainment from 12 micrograms per cubic meter of air to 9.  

Attainment is determined over a three-year average, and in recent years Shoshone County hasn’t had an issue remaining under the previous standards. The new standards go into effect in 2025, which means DEQ is going to have to go back into the previous two years and make sure there weren’t any exceptional events they missed in order to keep the county’s numbers in attainment.   

DEQ recently completed a multi-year, multimillion-dollar woodstove changeout project, which helped Shoshone County gain attainment status after years of falling short. But those funds were depleted, and if the county were to go back into non-attainment, it would be difficult to find solutions. 

Currently, Shoshone County is meeting the new 9-microgram standard, but DEQ is concerned that several upcoming factors may push the county past the threshold for its annual average.  

“We’re currently right on the line, meeting that 9-microgram standard,” DEQ regional administrator Dan McCracken said. “We want to work with the county on some education and outreach things. Basically, be on our best behavior to keep us under that 9-microgram standard to avoid going into non-attainment.”  

DEQ air quality manager Shawn Sweetapple detailed the agency’s concerns over the approaching cold weather.  

“So far, 2024 has been a really good year,” Sweetapple said. “We’re at an average of 7.5 for the year. The issue is that the fourth quarter of the year is historically our worst quarter of the year.”  

Along with the open burning, the fourth quarter is when people begin using their woodstoves, driving the average numbers up.  

According to Sweetapple, if the county can average 14.2 micrograms during the fourth quarter of the year, it will be able to hit that 9-microgram threshold for 2024. 

DEQ doesn’t want to scare people away from using their woodstoves, but they are cautious about going into non-attainment.  

“If you break the standard, EPA gets a lot more involved,” Sweetapple said. “And then you’re required to make efforts to get back into attainment. One of the big things EPA’s been pushing in recent years is local ordinances to help get people into attainment. Those usually mean things like ordinances on open burning or voluntary curtailment.”