Triple-digit temperatures and unstable weather conditions continue to trigger an increasing number of wildfires throughout the Intermountain West. While nearly everyone agrees those wildfires have given rise to unhealthy air quality, environmental experts part ways on whether those wildfires should even be included when measuring air pollution.
Officials with the Idaho Department of Environmental Quality insist most wildfires are "out of human control" and, therefore, are often excluded from the department's air quality measurements. But DEQ's tack has some environmental advocates perplexed.
"The state is suggesting that wildfires are an excuse for bad air," said Bryan Hurlbutt, attorney for Advocates of the West and an Idaho Conservation League partner.
Courtney Washburn, executive director of Conservation Voters for Idaho, echoed Hurlbutt's concern over DEQ's omission of wildfires from air quality data, adding that regulatory agencies often see wildfire-triggered pollution through a different lens.
"It's not like automobile emissions, where we know where the emissions are coming from and what that amount is—you're just not able to plan for fires that way," Washburn said. "That said, I absolutely think policies and procedures can be put in place to reduce, particularly, human-caused wildfires."
The most recent example is the Mile Marker 14 fire, which as of press time had consumed more than 3,500 acres east of Boise. Investigators were quick to conclude the blaze was human-caused. Prior to that, the Table Rock fire—sparked by illegal fireworks in early July—scorched 2,500 acres of the Boise Foothills.
Bruce Louks, Modeling, Monitoring and Emission Inventory Program manager for DEQ, explained the process of submitting air quality data to the U.S. Environmental Protection Agency.
"There is a process whereby data is impacted by wildfire smoke that can be excluded from attainment designation decisions," he said. "The data doesn't really go away, it's just not used in calculating the design value, which determines compliance. There's a process where once we submit the data to the EPA, they must read it though and have to agree with our documentation."
Hurlbutt's and Washburn's organizations filed a petition with the EPA in 2015, calling for the feds to declare the Treasure Valley a nonattainment area—a designation that would launch a long process to bring Ada and Canyon counties back into compliance with national standards.
While the EPA has yet to respond to the petition, with the omission of wildfire data from the Treasure Valley's air quality figures it is unlikely the region would meet the conditions necessary to result in a nonattainment designation.
Put another way, the region's air quality looks better on paper than it actually is.
In 2013, Ada County was ranked fourth in the nation for its amount of "particulate matter 2.5" in a 24-hour period, higher even than Los Angeles and Sacramento, Calif. The EPA requires the level of PM 2.5—defined as pollutants emitted from sources like car exhaust and smoke—to be lower than 35 micrograms per cubic meter in a 24-hour period. In 2013, the Treasure Valley hit 89.
Louks said DEQ will base its recommendations for attainment on more recent numbers, adding the high numbers in 2013 were an "extremely rare and extraordinary event."
Still, as Treasure Valley residents continue to cope with air quality compromised by both natural and human-caused wildfire, Washburn and Hurlbutt said they're anxious for a response to their petition from EPA.
"If we don't get a response, we might look into legal action," said Hurlbutt, adding that the goal of seeing the Treasure Valley labeled a nonattainment area is that such a process would ignite a conversation among community leaders, with particular emphasis on reducing human-caused fires.
"Human-caused fires can be a part of that full assessment," he said. "The way the regulation currently is, without the attainment process, we really don't have a mechanism for communities to start looking at what's happening in the air."