A four-county area of Southeast Missouri has exceeded the federal standard for ozone pollution, based on readings from a monitoring station in Farrar, Mo., in Perry County.

On 36 days during the 2005-2007 period, the readings for ozone pollution were above the eight-hour standard of 75 parts per billion, according to figures from the Missouri Department of Natural Resources. Those readings place the region, which covers Cape Girardeau, Perry, Bollinger and Ste. Genevieve counties, in danger of being listed as a "nonattainment area," a designation that can include requirements for vehicle emission testing and tougher rules for new industries seeking pollution permits.

Those measures, already in place for the St. Louis metropolitan area, are unlikely to be implemented in Southeast Missouri, said Rebecca Birke, a spokeswoman for the Air Pollution Control Program at the resource agency. Officials from area cities and counties have been invited to a meeting Aug. 5 in Perryville to discuss the findings and possible reasons for them.

Similar meetings are being held in other areas of the state where pollution monitors installed in recent years are finding that ozone pollution exceeds the allowable amounts.

"These are informational meetings," Birke said. "We are talking about what the new standard is, and what we are looking for is information on a local scale about population and growth patterns to see if there are specific sources that could be addressed if nonattainment status is given."

The state is facing a deadline to offer recommendations to the U.S. Environmental Protection Agency on which counties should be designated as nonattainment counties. The recommendations are due by March; DNR wants to finish work in October or November.

Ozone pollution occurs when engine exhaust or industrial emissions containing nitrogen oxides and volatile organic compounds react in sunlight with oxygen in the atmosphere. The result can be a thick haze of smog blanketing a region, especially when the air stagnates on hot summer days. To determine whether an area is in violation, a monitoring station must show repeated days when the standard is exceeded by averaging the hourly readings over a continuous eight-hour period.

Of the 36 days when the Farrar monitor showed more than 75 parts per billion, 20 occurred in 2007. There were six such days in June 2007 and one such day on Aug. 1, 2007, said Jeff Bennett, the air quality monitoring chief for DNR. In late July and early August 2007 stagnant air caused Cape Girardeau to be blanketed in a thick haze that dramatically reduced visibility.

So far in 2008, there have been no days at the Farrar station with ozone levels that exceed the standard, Bennett said.

The St. Louis metropolitan area is the only area in the state designated as nonattainment. That designation is based on violations of the older standard of no more than 84 parts per billion of ozone.

Because of the rural setting for the four-county region, pinpointing a single reason for the ozone violations could be difficult, Birke said. The ozone could be from pollution sources outside the area and simply drifted into the region, she said.

"if the area is designated as nonattainment, obviously there would need to be more controls," she said. "But what that would be is premature. We need to know what sources are there and what can be controlled. If there are not sources that can be controlled, there is not as much of an impact on an area."

rkeller@semissourian.com

335-6611, extension 126

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