EPA ozone shift spares metro Phoenix costly consequences
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Valley business leaders are breathing a sigh of relief after the Trump administration agreed to modify federal ozone guidance so that Maricopa County likely won't face harsh economic punishment.
Why it matters: Maricopa County has failed to meet ozone pollution standards for about a decade and was slated to slide into "serious nonattainment" this summer, which would have required companies that open or expand factories here to invest in expensive environmental offsets.
- This likely would have cost the Valley hundreds of millions of dollars, a state analysis predicted.
State of play: The EPA announced earlier this month that it would rescind part of its air pollution guidance to make it easier for regions like metro Phoenix to prove that high ozone levels are in part caused by international pollutants.
- That decision came after EPA administrator Lee Zeldin met with local officials on the issue last month.
The big picture: Environmental and economic leaders have argued for years that much of the Valley's ozone pollution comes from external forces that are uncontrollable at the local level.
How it works: Ozone forms when volatile organic compounds (VOCs) — which come from wildfires, paints, pesticides, aerosols, etc. — combine with oxides of nitrogen, produced primarily by fossil fuel vehicle emissions.
- Historically, the Valley was able to curb its ozone pollution by reducing local emissions caused by vehicles and factories.
- Yes, but: Since about 2017, ozone pollution has stayed stubbornly high even though local manmade emissions that contribute to ozone formation continue to fall, Maricopa Association of Governments (MAG) environmental director Matthew Poppen told Axios.
Between the lines: VOCs, oxides of nitrogen and fully formed ozone are produced internationally — most notably in Mexico and Asian countries — and can get swept into the atmosphere, travel great distances and end up settling in the Valley.
- The recent policy change will allow regions to demonstrate to the EPA that they would have attained the ozone standard if not for the impact of international emissions. This is likely to take Maricopa County out of the "serious nonattainment" range.
Stunning stat: Poppen said a MAG analysis found only 20% of ozone pollution is locally controllable.
Reality check: Regardless of whether it's our fault, the air we breathe contains unhealthy levels of pollution that could make us sick, health experts say.
- Components of air pollution associated with ozone can enter lung tissue and the bloodstream, aggravating respiratory diseases and heart ailments, among other conditions.
- Children, older adults and outdoor workers are most at risk for serious complications.
What they're saying: "To dismiss the burden of unhealthy air on the most vulnerable Arizonans … as someone else's problem is a shameful abrogation of responsibility," Katherine Pruitt, senior director of clean air policy for the American Lung Association, said in a statement to The Arizona Republic.
What's next: The Arizona Department of Environmental Quality and ASU are using new technology to collect hour-by-hour ozone data both at the ground and atmospheric levels.
- The goal of the study is to better understand how and where ozone is being formed, and why local emission reductions aren't resulting in lower ozone levels, Poppen said.
The bottom line: "Regardless of where [ozone] comes from … we're still all breathing it," he said. "So if there are ways to reduce it locally, we want to identify those."