Summer hasn’t officially begun yet, and Louisville has already had nine days of unhealthy air.
That outpaces the number of bad air days the city experienced in 2013, 2014 and 2015, and it could cause Louisville to be out of compliance with new, stricter federal ozone regulations.
Ozone is created when pollution like nitrogen oxides and volatile organic compounds cook in the sun. It’s exacerbated by some of the meteorological conditions in the Ohio River Valley, such as summer heat and stagnant air.
And beginning in April, the combination of conditions in Louisville has been optimal for ozone. In April, May and so far in June, there have been nine days where ozone levels have exceeded the standard, prompting regulators to warn the public that the air is unhealthy for sensitive groups.
This is also the first year in which the city has had to comply with a new, stricter standard for ozone: The Environmental Protection Agency tightened the rule from 75 parts per billion to 70. Of the nine days that have exceeded that standard so far this year, five wouldn’t have gone past the old standard.
Air Pollution Control Director Keith Talley said as far as pollution goes, the region has been on a steady downward trend. But because the new standard means it will take less ozone to trigger an air quality alert, the problem will seem to the public like it’s worse.
“Not necessarily because there are additional emissions, but the weather plays such a large part,” he said. “So it’s just really such a difficult thing to predict in terms of the number of air quality alert days we’ll have related to ozone.”
The Environmental Protection Agency will determine whether the Louisville Metro area is in attainment with the federal standard after three years of data, which would come later this year. Talley said he’s prepared for the news to be bad.
“Given where we’re started, it’s not looking good,” he said. “And even if by some miracle we end up not in nonattainment and we don’t have another exceedance for the rest of the year, we still want to reduce ozone in this community. So all of the things we’d do in nonattainment, we’ll probably do them in attainment, because we just want to have the continued reduction of ozone in the community."
Talley downplayed the repercussions for the community if the EPA designates Louisville in nonattainment for ozone. He said that would largely result in community stakeholder group meetings to develop a plan to reduce ozone and likely wouldn’t hurt the city’s economic development.
Other groups have been less optimistic, warning about permit delays andtrouble attracting new businesses.