News Release 480

OZONE SEASON COMES TO AN END FOR ST. LOUIS AREA

Volume 34-480

Contact: Renee Bungart

(For immediate release)

573-751-4465

JEFFERSON CITY, MO, OCT. 30, 2006 -- As the 2006 ozone season ends tomorrow (Oct. 31), Missouri Department of Natural Resources analyses shows air quality in the St. Louis area continues to improve.

The area experienced 40 days where meteorological conditions were conducive to ozone formation. Of those, the department recorded exceedances of the 8-hour ozone standard on only 15 days.

"The department recognizes that maintaining good air quality can be attributed not only to the control measures that are already in place, but to the voluntary efforts of Missouri citizens and partnerships who are committed to protecting community health," said Department of Natural Resources Director Doyle Childers. "As always, these efforts are much appreciated."

The St. Louis region is currently in violation of the ground level ozone standard. Emissions of ozone precursors, which include volatile organic compounds (VOCs) and nitrogen oxides (NOx), have continued to decline. Reformulated gasoline, gasoline vapor recovery nozzles, solvent cleaning and other industrial regulations, and the mandatory inspection and maintenance of automobiles in the St. Louis area have helped to reduce emissions.

While these emission reduction strategies have been effective in St. Louis, additional controls will need to be implemented to bring St. Louis into compliance. The department continues to work on control measures that will ensure the St. Louis area sees attainment of the ozone standard by 2010. The department is developing a St. Louis Ozone State Implementation Plan (SIP).

The SIP will include the U.S. Environmental Protection Agency's (EPA) Clean Air Interstate Rule (CAIR). The rule will permanently cap emissions of sulfur dioxide and nitrogen oxides from electric utilities in the eastern United States. CAIR will help Missouri meet the federal standard for ozone and fine particles. According to U.S. EPA's computer modeling analyses, the St. Louis area will be able to meet the ozone standard based on CAIR and other currently planned or implemented control measures.

When the St. Louis area attains the 8-hour ozone standard, the department will develop an "attainment demonstration" and "maintenance plan" and submit them to the U.S. Environmental Protection Agency for approval. If control measures and contingency plans project continued compliance with the standard, the area can be redesignated as a "maintenance area."

A "maintenance area" is an area that has achieved compliance and has proven to EPA that the standard was achieved through enforceable controls and has shown through computer modeling that it will continue to "maintain" the standard.

Ozone season begins April 1 and ends Oct. 31. Throughout the season, monitors in the St. Louis nonattainment area record the ozone levels at 11 sites in Missouri and six sites in Illinois. The nonattainment area includes St. Louis City, and St. Louis, St. Charles, Jefferson and Franklin counties in Missouri.

Ground-level ozone is produced when volatile organic compounds mix with oxides of nitrogen on warm, sunny days with little or no wind. Man-made sources of VOCs and NOx include power plants, automobiles and trucks and other business and industries.

Exposure to ground-level ozone, or smog, can attribute to health problems. Those who suffer from asthma, heart disease, emphysema and other respiratory diseases could experience increased breathing difficulty. Long-term exposure to high levels of ozone can even cause healthy adults to experience breathing difficulty, especially those who exercise or work outdoors.

For more information on ozone, contact the department's Air Pollution Control Program at 800-361-4827 or 573-751-4817.

For news releases on the Web, visit www.dnr.mo.gov/newsrel. For a complete listing of the department's upcoming meetings, hearings and events, visit the department's online calendar at www.dnr.mo.gov/calendar/search.do.

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