Environment

Louisville is now officially in ozone season, the several months every year when pollution and meteorological factors contribute to unhealthy ozone levels in the area.

And as the city and state continue to work toward complying with a new, stricter federal ozone standard, measures working through Congress would delay the new rules, giving states more time to comply.

The National Ambient Air Quality Standard (NAAQS) for ozone used to be 75 parts per billion for an eight-hour average. Last year, the Environmental Protection Agency tightened the standard, citing updated information about ozone’s health effects. Now, the new standard is 70 parts per billion, and the EPA will begin determining whether places are meeting that next year.

But a bill being debated by the U.S. House of Representatives would require the EPA to wait until 2025 to determine if states and metro areas are complying with the rule. It would also change the Clean Air Act to allow the EPA to consider new air rules every 10 years — as opposed to the five years currently in the law — and allow the agency to consider a rule’s cost before finalization. A similar bill was introduced in the Senate.

The bill passed the House Energy and Commerce committee last week in a vote along party lines. Democrats on the committee objected to the bill, arguing it guts the Clean Air Act.

But in Louisville and across Kentucky, regulators don’t predict the legislation will have many practical implications for how they approach reducing ozone emissions.

Louisville’s ozone averages have been on a downward trend, except for a particularly bad stretch in 2012. The government will determine compliance after three years of data, which would come later this year.

Air Pollution Control District spokesman Tom Nord said it’s hard to say whether Louisville will be within the new, stricter standard.

“I think we were pleasantly surprised when we were able to look at the data and see that we’re pretty close, we’re right on the line now,” he said. “You’re talking Kentuckiana, you’re talking about the age-old issues we deal with, which is heat in the summer, the valley, stagnant air. We could be out of attainment. We’ve been very upfront about that.”

Nord said the APCD generally doesn’t take positions on federal legislation, but he said regardless of whether the pending bill becomes law, it won’t change the agency’s work toward meeting the new standard.

“We’re going to pursue meeting the standard — I don’t feel like we’re going to wait around,” Nord said. “I don’t see us stopping our work or waiting around. If they give us five years or 10 years, we’re still going to work on meeting that standard.”

Statewide, Division of Air Quality Director Sean Alteri said most areas of the commonwealth will likely meet the new standard, though the monitors in Northern Kentucky are indicating that area may not be in attainment.

“Air quality is greatly improved in Kentucky in the last 10 years,” Alteri said. “And I think that we don’t want to lose sight of our progress. There’s still more to do, but I think people should be proud of the fact that air quality is much improved, just in the last decade.”

As standards tighten, cities and states may have to explore new ways to cut emissions. Kentucky’s nitrogen oxide emissions have dropped 50 percent over the past decade, Alteri said, mainly due to coal power plant retirements and updated pollution controls.

In Louisville, a lot of the most obvious emitters of pollutants that cause ozone have cut back or installed new technology to meet stricter pollution regulations. One of the city’s two coal-fired power plants — Cane Run — retired last year. The other — Mill Creek — installed new pollution controls.

Erica Peterson is WFPL's News Director.