Note to readers • This story is made possible through a partnership between The Salt Lake Tribune and Grist, a nonprofit environmental media organization.
Utah residents are familiar with the thick haze that often blankets the Wasatch Front in the winter, causing some to seek refuge from pollution indoors or high in the mountains.
The region’s geography creates those air quality events, called inversions, when cold air sinks in the valleys and warm air rises. It acts like a lid on a pot, trapping all the pollution generated by tailpipes, smokestacks, homes and industries at lower elevations until weather patterns shift.
Just ahead of the upcoming inversion season, the Environmental Protection Agency has determined the Salt Lake and Provo areas have reached attainment for 24-hour National Ambient Air Quality Standards for fine particulate pollution called PM 2.5.
It’s the first time the region has achieved that status in 15 years.
“The achievement of cleaner air in Utah,” Utah Division of Air Quality Director Bryce Bird said in a news release, “resulted from extensive planning and collaboration among the public, industry, and various government levels.”
The Salt Lake and Provo area airsheds — which include the Wasatch Front from Box Elder to Utah counties, plus Tooele —were in “serious” nonattainment status for EPA’s 2006 standards, which went into effect in 2009.
The solutions DAQ and public health officials tackled for cleaning up the region’s air weren’t always popular, like wood-burning stove bans and diesel emission crackdowns.
But the efforts have apparently paid off.
“The people of Utah deserve clean air and practical solutions that recognize the realities of life in the Salt Lake City and Provo areas,” said EPA Regional Administrator Cyrus Western in a statement, adding the achievement “demonstrates that Utah can meet federal air quality standards in a way that respects local priorities and fosters cooperative federalism.”
Utah has longstanding tensions with the federal government over air quality standards. It has sued over regulations on ozone and asked the Trump Administration to reconsider them.
States in nonattainment must develop plans to improve air quality and stand to lose out on federal funds for transportation.
Despite Utah’s gains on inversion smog, the Wasatch Front faces new and persistent forms of air pollution affecting public health, including more wildfire smoke fueled by a warming West, summertime ozone pollution and dust blowing from the drying lakebed of the Great Salt Lake.
Data centers in the region are also increasingly relying on natural gas-fired generators to meet their energy demands, which contribute to area-source emissions. Those valley-wide sources release chemicals that bake in sunlight and spur both ozone and inversion haze.
“While today is an important milestone, the work doesn’t stop here,” said a spokesperson with the Utah Clean Air Partnership, or UCAIR, in an emailed statement. “Real progress comes from reducing emissions across every sector.”
Utah Physicians for a Healthy Environment, another local air quality watchdog, called EPA’s air quality standards “arbitrary” and a mix of politics, industry concessions and science.
“There’s no safe level of air pollution exposure,” said Brian Moench, president of UPHE, in an interview, “in the same way there’s no safe number of cigarettes you can smoke.”
Fine particulate pollution like PM 2.5 can move through lung tissue, make its way into the bloodstream and impact the brain, he noted.
Kevin Perry, an atmospheric scientist at the University of Utah who studies the region’s air pollution, praised the Division of Air Quality’s efforts to improve the airshed.
“It’s been a long, hard slog,” Perry said.
Utahns are often surprised to learn the state has seen a long-term trend of cleaner air, he added, which is reflected in EPA’s decision to remove the Wasatch Front from its dirty air list for PM 2.5.
“When I go out and give talks, I ask people, ‘How many of you think that the air quality in Salt Lake is worse than it was 20 years ago?’” Perry said. “And 80% of the people raised their hands.”
The opposite is true, the professor said, pointing to a need for better communication between state regulators and the public.
“They need to get better at messaging,” Perry said. “Maybe this is an opportunity to push that.”