Knox Ozone Vagaries


Just as the Knox area has qualified for attainment of the Environmental Protection Agency's air quality standards, the weather and recently proposed stiffening of EPA requirements are combining to jeopardize that status.

Two months ago, Knox County's air quality specialist Lynne Liddington submitted the measurements needed to get Knox and five surrounding counties out from under the non-attainment designation that's hung over the area since 2004. But the EPA has yet to act on it, and Liddington can't say when or if it will.

These measurements represent a three-year moving average of the highest ozone readings that equate to smog at seven testing stations scattered throughout the area. Under the EPA's complex attainment standards, the three-year average of the fourth highest daily ozone reading at all of the stations must be below the present EPA threshold of .084 parts per million (ppm) in the air to qualify for attainment. For the years 2004-2006, the Knox area met that standard due in large part to a relatively cool, wet summer in 2004 that held down readings for that year enough to compensate for an upward creep above the threshold in 2005 and 2006.

But this June's hot, dry weather has begotten an ozone cookery that seems almost certain to push the area's 2007 readings and thus its three-year average offside again. Already, three days above the threshold have been recorded at two of the measurement stations. And since July and August are typically the peak months for ozone, a fourth day seems almost inevitable. So Draconian are the EPA standards that a blip at any single stationâ"say Look Rock in Blount Countyâ"can throw the entire six-county area into non-compliance.

At the same time, the EPA last month proposed tougher new standards that would reduce the ozone ceiling to somewhere in the range between 70 to 75 ppm. That proposal is now out for comment, with organizations such as the American Lung Association advocating an even lower ceiling and organizations like the National Association of Manufacturers urging retention of the present one. The EPA expects to issue final standards next March with designations of attainment and non-attainment areas to follow in 2010 after allowing states time to submit plans for getting into compliance by 2013.

Liddington is optimistic about the Knox area's prospects for safely meeting the present standard within the next few years but is anything but sanguine about its ability to meet a stricter one. â“We might possibly meet 75, but if it comes back to 70 there's no way,â” she says. Already, a lot has been done to get the Knox area at least teetering on the brink of attainment. Since 2003, TVA has invested $300 million to install catalytic converters at its steam plants in the area (Kingston and Bull Run). Those have reduced their emissions of nitrous oxide (NOX), which is a precursor of ozone, by 91 percent, according to TVA spokesman John Moulton.

Stricter vehicle emission standards are serving to reduce the other principal manmade cause of ozone. For automobiles, those went into effect in 1996, so with each passing year NOX emissions figure to be coming down as more pre-1996 vehicles get scrapped. New diesel engine emission standards took effect only last year, so their impact on emissions from the fleets of trucks and buses on the road will take longer to be realized. But anti-idling restrictions and incentives can help in the short run, as will new diesel fuel standards, to some extent. (Increased use of ethanol as an automotive fuel will serve to reduce emissions of greenhouse gases that contribute to global warming but don't do much for NOX.) Thus, time would appear to be on the side of getting ozone levels down unless global warming or some other phenomenon causes increases in naturally occurring ozone that is most prevalent in hot weather. And the health benefits of improving the quality of air we breathe as well as visibility in the Great Smoky Mountains cannot be gainsaid.

On the other hand, a non-attainment designation is a deterrent to the area's economic development (perhaps excluding tourism). â“A lot of the site-selection consultants we work with won't even consider us for a new plant location as long as we have a non-attainment designation,â” says the Knoxville Area Chamber Partnership's chief recruiter, Doug Lawyer. The designation also impinges on expansions by existing industries by requiring them to get permits after evidencing that they won't put more pollutants in the air.

By the letter of the law, the Knox area is entitled to an attainment designation based on its three-year average adherence to the present standard during 2004-2006. And the EPA should stop procrastinating in granting it. Backsliding in 2007 doesn't necessarily result in revocation of the designation, according to Liddington. Rather, it could mean adoption of what she terms â“contingency measures.â” Encouragement of carpooling and mass transit as well as further restriction on burning, especially on ozone alert days, could be on that list but aren't likely to accomplish much. Nor is vehicle emission testing now deemed to be very purposeful, even by the EPA.

The American Lung Association rightfully warns that, â“Ozone air pollution poses health risks for infants, seniors and people with asthma and other lung diseases.â” While acknowledging that the revised standards the EPA proposes would â“expand protection to millions of Americans,â” it contends they would â“leave millions more unprotected from the harmful effects of bad air.â”

Such contentions must be balanced against harmful economic effects and allow for the fact that further abatement can be anticipated over time.   â" Joe Sullivan


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