Ada and Canyon counties’ proactive efforts to reduce pollution over the last decade kept the Treasure Valley within federal air quality standards going into 2013.
That’s when a shroud of warmer air settled above the two counties, trapping stagnant cold air against the Foothills for 11 days that January. The worst inversion since 1985 also built up chemicals created by automobile combustion, creating soot, known formally as pm 2.5, which stands for particles 2.5 microns or smaller.
Treasure Valley residents were breathing these microscopic particles into their lungs, causing people with chronic breathing problems and children with asthma to flood into doctor’s offices, emergency rooms and hospitals, said Perry Brown, a pediatrician and co-director of the Cystic Fibrosis Center of Idaho.
Soot levels soared to 100 micrograms per cubic centimeter, levels that were unhealthy even for people without lung issues. By the end of 2013, soot levels had exceeded the Clean Air Act’s 24-hour standard multiple times, placing Ada County at the eighth-highest level of 408 areas monitored nationwide, said Bryan Hurlbutt, an attorney with Advocates for the West.
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That’s why the group, Brown and the Idaho Conservation League want Idaho to step up its air pollution program in the Treasure Valley.
“Our air pollution problem is not just a theoretical situation,” Brown said. “It’s a real-life problem.”
AFTW and ICL petitioned the U.S. Environmental Protection Agency earlier this year to declare Ada and Canyon counties a “nonattainment area” for pm 2.5, which would mean noncompliance with the Clean Air Act. That could bring federal sanctions that could limit highway construction and new business development, and force new restrictions on existing businesses.
The two groups say federal intervention is necessary because the state has cut funding for programs designed to reduce traffic congestion and has failed to keep ahead of increases in population and vehicles in the Valley.
“Over the past several years, the monitoring data has shown a decrease in air quality while efforts that had been put in place have been dismantled, eliminated or nonprioritized,” including cuts to congestion mitigation funding and disbanding the Treasure Valley Air Quality Council, said Courtney Washburn of the Idaho Conservation League. “The good news is there are tools and technologies to improve our air. We just need the political will to put them in place.”
Idaho Department of Environmental Quality staff acknowledge that the 2013 inversion, the second-worst in recorded history, sent soot levels over the limits. But they said many of the 24-hour violations in 2012 were due to forest fires and could be eligible for exemptions under the Clean Air Act.
And even with the high levels during the inversion, Ada and Canyon counties’ soot levels met the lower annual standard of 12 micrograms per cubic meter of air, said Mary Anderson, a DEQ air program manager.
“On a typical year we aren’t really even close to (violating the standards),” Anderson said.
Nothing is going to happen soon, Anderson said. EPA has acknowledged the petition but is busy on another airshed in region 10 now.
Idaho officials are also awaiting a decision by EPA on strengthening the standard for ozone pollution, which could come later this year. The agency proposes to cut the allowable level of ozone from 75 parts per billion to a range of 65 ppb to 70 ppb. It also is asking for comments on a potential plan to drop the standard to 60 ppb.
A lower standard likely would put the Treasure Valley into nonattainment. The three-year average for Treasure Valley ozone levels is about 70 to 71 ppb, and in 2008, the region narrowly missed violating the ozone standard.
But since then Canyon County joined Ada County in vehicle testing and reducing volatile organic compounds that escape from gasoline during fueling. The Obama administration also has strengthened national vehicle emission standards, which has steadily reduced emissions.
The progress the region made was demonstrated by a comparison of pollution levels during the last long inversion, in 1985. Particulate levels rose to 300 micrograms per cubic centimeter then, compared to 100 in 2013.
But with the population of the Treasure Valley now exceeding 646,000, the miles vehicles travel has risen from 10.8 million on an average weekday in 2005 to 12.8 million in 2015, according to Community Planning Association of Southwest Idaho, the regional organization known as COMPASS.
The new emissions standards have offset this growth so far, said DEQ Treasure Valley Airshed Manager David Luft. But eventually the growth will overwhelm the capacity of the airshed to clear out the pollution.
Planning already has reduced the rate of growth of the miles people drive daily by placing shopping areas near housing, making communities more bike-friendly and making it easier for people to walk to the places they work and play.
Pollution control efforts peaked in 2010 after the Treasure Valley Air Quality Council, a panel of business and community leaders established by the Idaho Legislature and appointed by Gov. Butch Otter, released an ambitious plan for curbing air pollution. Most of its top recommendations were put into place.
“We did all the easy stuff,” said Peter O’Neill, the Boise businessman who chaired the council.
But it was disbanded more than a year ago. DEQ is organizing an advisory board to carry on its tasks, but Matt Stoll, executive director of COMPASS, said it will take the involvement of the Valley’s industries to push for local-option funding of the more than $50 million needed to build the kind of public transit system that would get people out of their cars and cap pollution.
If the EPA decides the Treasure Valley is in nonattainment, state and local officials will have three years to submit a plan for bringing the two counties back within federal health standards. During the planning period, the uncertainty for business development or road expansion projects is high.
But Ada and Canyon counties already have emission budgets for transportation, a key tool for writing a plan, and experience going back to the 1990s, when it was in nonattainment for carbon monoxide and particle pollution, Stoll said. The Treasure Valley would have up to 20 years to comply.
But Dr. Brown said residents can’t wait that long for healthy air. The Treasure Valley has one of the highest rates of lung cancer among nonsmokers in the nation, he said.
“I can’t say that that’s because of air quality, but air quality certainly contributes,” he said.