Colorado’s Front Range recorded fewer days with high levels of ozone pollution over the summer than in recent years, but environmentalists warn the region can’t rely on favorable weather conditions to help with air quality as much as they did in 2023.
The region recorded 26 days of ozone levels that exceeded the 2015 National Ambient Air Quality Standards between June 1 and Aug. 31, which is considered the summer ozone season. That is the lowest total of days with high ozone since 2019, when the region recorded 22 days, according to Regional Air Quality Council data.
The Front Range’s air quality benefitted from an unusually wet and cool start to summer, said Scott Landes, air quality meteorologist for the Colorado Department of Public Health and Environment.
“Ozone really thrives in hot and dry conditions, which we really didn’t have in the first half of the summer,” Landes said.
On top of the cooler start to summer, wildfires were kept to a minimum in the West, and weather patterns sent smoke from large wildfires in Canada toward the eastern United States, he said.
“In some respects, we got lucky this year,” Landes said. “With climate change particularly, summers have been hotter and that’s going to lead to higher ozone. We have long-term drought across the western U.S., and that’s going to lead to more wildfires. That smoke could enhance ozone concentrations. So we have a lot of stuff that works against us.”
Reducing the number of days when ground-level ozone blankets the Front Range with thick smog is critical because the region is in violation of federal air quality standards. The Environmental Protection Agency categorized the region as a severe non-attainment zone in September 2022, and that label will result in stricter regulations for businesses, including the oil and gas industry, and higher gasoline prices for drivers.
High levels of ozone pollution harm human health because it is harder to breathe, especially for the young, elderly and those with chronic respiratory problems.
Ozone pollution is formed on hot summer days when nitrogen oxides and volatile organic compounds combine and react to high heat. Those pollutants are released by refineries, automobiles, power plants and other sources.
The Front Range has two benchmarks to meet to satisfy the EPA.
First, it needs to reduce annual ozone pollution averages to 75 parts per billion by 2027 to meet a 2008 standard. But it also is failing to meet the more stringent 2015 requirement to lower averages to 70 parts per billion.
Mike Silverstein, the Regional Air Quality Council’s executive director, said his agency is forecasting the region can meet the 2027 deadline. But, he said, “we are not projecting attainment for the tougher standard.”
The state is working to reduce air pollution with goals to lower emissions from oil and gas production and by trying to reduce the number of gas-powered cars on the roads through tax credits for electric vehicles and free public transportation in July and August.
Silverstein attributed the 2023 air quality improvement, in part, to these efforts.
August brought its typical hot, dry weather, but the number of days when ozone pollution exceeded federal standards didn’t jump to excessive numbers during the month, he said.
“We bounce up and down, depending on the meteorology,” Silverstein said. “But it also has to do with our emission-control programs. Those have an impact.”
But there is much work to be done, environmentalists say.
“The way I think of it is, ‘Great, we had fewer ozone alerts and ozone days than we had in recent years,'” said Kirsten Schatz, clean air advocate for the Colorado Public Interest Research Group. “But we got lucky with the weather. We can’t count on the weather from year to year to save us from ozone pollution.”
Colorado needs to continue taking steps to reduce harmful emissions from the oil and gas industry and to keep encouraging people to find alternate modes of travel to gas-powered cars, Schatz said.
She also has worked with the state on a plan to eliminate gas-powered lawn and garden equipment because of the pollution created by lawnmowers, weed trimmers, chainsaws and leaf blowers. The Regional Air Quality Council has sent a proposal to the state’s Air Quality Control Commission that would restrict the use of such equipment along the northern Front Range. The commission will consider it next week during its September meeting.
“It is shockingly polluting,” she said. “We can get a lot of the cuts we need by eliminating the dirty gas-powered lawn and garden equipment.”
Taking steps to eliminate human-caused pollution is the only reliable way to improve air quality, Schatz said.
“Every amount of ozone pollution we can cut from the air has a real benefit to our health,” she said. “That will help ensure whether we have sunny skies or cloudy skies that we have air that is safer to breathe.”
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