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Louisville’s ozone pollution is improving, but is it enough for the EPA?

File - In this May 25, 2017, file photo, Interstate 405, the San Diego Freeway, is seen next to Los Angeles International Airport. The Biden administration is restoring California’s authority to set its own tailpipe pollution standards for cars, reversing a Trump administration policy and likely ushering in stricter emissions standards for new passenger vehicles nationwide.  (AP Photo/Reed Saxon, File)
Regulators say the Louisville region now meets the standards for acceptable ozone pollution.

Ozone pollution in Louisville and surrounding counties has improved enough that regulators say the area now meets federal standards designed to protect human health.

Louisville’s Air Pollution Control District released a proposal Wednesday to reclassify Jefferson, Bullitt and Oldham counties as meeting the U.S. Environmental Protection Agency’s standards for ozone pollution.

Ground-level ozone forms when volatile organic compounds (VOCs) and oxides of nitrogen (NOx) combine in the presence of sunlight. Both VOCS and NOx are common by-products of combustion engines and industrial facilities. Cars, power plants and bourbon aging warehouses are among the largest sources in and around Louisville, according to the APCD proposal.

But over the last few years, emerging technologies, regulations and public participation have aided efforts to curb ozone formation, said APCD spokesperson Matthew Mudd.

“I think what you are seeing is a continuous improvement over time,” Mudd said. “As electric vehicles become more common, power sources become cleaner, you’ll continue to see those decreases in pollution levels.”

Ground-level ozone is one of the most heavily regulated pollutants under the Clean Air Act. The American Lung Association says ozone pollution shortens people’s lives, increases the chances of birth defects and increases risks for people with asthma and other respiratory diseases.

Ozone pollution is the worst on hot, dry days in June, July and August. Already this month, APCD has issued multiple ozone alerts categorizing the pollution as unhealthy for sensitive groups like children, the elderly and those with chronic illnesses.

A reduction in ozone pollution is not only better for human health, it could have the added benefit of lowering gas prices.

The EPA requires the Louisville Metro area to use more expensive reformulated fuel as part of the plan to lower the amount of ground level ozone.

Earlier this week, the EPA denied Kentucky Gov. Andy Beshear’s request to temporarily waive reformulated gas requirements to help drivers pay less at the pump.

But if the EPA confirms Louisville is meeting the ozone standard, regulators could push to end the requirement for the region.

“If we end up meeting the standard we are able to start looking at whether or not the reformulated gas requirement is necessary for us to continue using,” Mudd said.

Back in 2015, the EPA made ozone standards more strict. For the last four years Louisville has not been able to meet those standards. In order to meet the standards, Jefferson, Oldham and Bullitt counties have to prove ozone levels averaged below .070 parts per million (ppm) over three years.

Jefferson County squeaked under the standard with values ranging between .065 and .069 ppm, while Bullitt and Oldham averaged .064 and .063 ppm, according to the proposal.

Public comment on the proposal begins Wednesday and runs through August 3. The public can request a hearing on that day. After the comment period closes, APCD will submit the proposal and all public comments to the EPA for review.