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by Joe Sullivan

The good news is that the Knoxville area now appears to be on a path toward attaining compliance with federal air-quality standards. The bad news is that it’s probably going to take longer than the five years that the federal Environmental Protection Agency has allotted.

Provision for mandatory vehicle emissions testing that the state Legislature enacted last week represents a significant step in the right direction. Under the new law, the state Air Pollution Control Board can require emissions testing in counties with more than 50,000 registered vehicles whose ozone levels exceed the EPA standard. The board should proceed to do so in the four counties in the Knoxville area that fit this profile: namely, Knox, Anderson, Blount and Sevier.

But while vehicle testing will get us closer to attainment, it won’t get us all the way there, in the estimation of Wayne Davis, chairman of the Knox County Air Pollution Control Board. Davis is a UT engineering professor whose studies of the effect of numerous ozone reduction measures have been relied on throughout the state.

Along with emissions testing for older vehicles, the measures that Davis foresees having the most benefit are stricter EPA emission standards for new gasoline-engine vehicles that are being phased in over the next four years and stricter standards for new diesel-engined vehicles that are being phased in over four years beginning in 2007. Over time, Davis believes the cumulative effect of these new standards will be sufficient to bring the Knoxville into compliance with the EPA’s ozone standard, but he doubts that they will do so until after 2010.

The EPA measure, as it’s now beginning to be referred to in TV weather reports, is that the ozone can’t exceed 84 parts per billion in the air. Above that, it becomes unhealthy for people with asthma and respiratory ailments. In attaining it, the EPA allows for high ozone days to be averaged over three years to temper the effects of an unusually hot, dry summer that causes a spike in ozone levels.

The Knoxville area now has until 2009 to attain this standard. “If you don’t attain it by then, you’ll have to implement contingency measures,” says Barry Stephens, director of air-pollution control at the State Department of Environment and Conservation. Those could include restrictions on industrial expansions or new highway construction, but Stephens says it’s yet to be determined what form they would take. Even in the meantime, Knox and five surrounding counties have been branded by the EPA as a non-attainment area in which special permits will be required for new sources of emissions that contribute to elevated ozone levels.

Knox County Mayor Mike Ragsdale and his counterparts in the other counties had hoped to avoid getting branded for non-attainment by submitting plans and projections for ozone attainment by 2007. Those were incorporated into an elaborate modeling process that takes into account everything from anticipated growth in the number of vehicles on the road to the 90 percent reduction in ozone-causing emissions that TVA expects to achieve on all its coal-fired steam plants in the area.

“We threw everything but the kitchen sink into the model, but we couldn’t get below 89,” says Lynne Liddington, Knox County’s director of air-quality management. That’s down from 92 last year, but not by enough to avoid the non-attainment designation the Knoxville area received from the EPA in April.

One factor that state officials wouldn’t allow to be taken into account was the effect of vehicle-emission testing. That’s because state law didn’t provide for it at the time except in the Nashville area. Ragsdale and other county mayors advocated statewide testing, but the legislature only authorized the Air Pollution Control Board to require it in counties in non-attainment areas with more than 50,000 registered vehicles.

The board’s vice-chairmen, Rick Bolton, says it will be working closely with local officials to “get a real feeling for time frames” for imposition of testing. Stephens reckons it could take a year to set up testing stations and procedures that have made it relatively hassle-free in the Nashville area. Yet time is of the essence in mandating it, especially in the Chattanooga area where it’s believed that testing alone will be sufficient to escape from non-attainment status.

The big reason modeling for 2007 here fell so far short of the mark was that it didn’t allow enough time for the EPA’s new vehicle-emission standards to have much impact. Vehicle engines are by far the largest cause of ozone, and diesel engines are the biggest culprit. But a prerequisite to requiring catalytic converters on new diesel truck and bus engines is the removal of sulfur from diesel fuel, and the EPA has allowed refineries until 2006 to get rid of the sulfur.

In the last analysis, though, ozone reduction will depend less on the rate at which new vehicle requirements take effect than the rate at which old vehicles are scrapped. Automobiles built before the EPA’s standards for gasoline engines took effect are prime candidates. And while emissions testing that can necessitate costly repairs on these vehicles will work a hardship on some of their owners, it can serve as an important inducement to getting them off the road.

In Davis’ view, it’s just a matter of time until prescribed ozone levels are attained. “We’re going to get continuing reductions over the next decade, and these could be accelerated by changes in the automobile industry such as a big increase in hybrid vehicles,” he says.

Still, it’s ever so desirable to make our air healthy sooner rather than later. And everyone can contribute to this goal in their choice of cars they drive, the length of their commute to work and a host of other ways.

May 27, 2004 • Vol. 14, No. 22 © 2004 Metro Pulse