News Release 139

DEPARTMENT EVALUATING IMPACTS OF
REVISED OZONE STANDARD ON  MISSOURI COUNTIES

Volume 36-139

Contact: Renee Bungart

(For immediate release)

573-751-4465

JEFFERSON CITY, MO, MARCH 17, 2008 -- Monitoring data used by the U.S. Environmental Protection Agency to identify affected counties, based on the revised National Ambient Air Quality Standards for Ozone is not completely representative of Missouri's ozone problem, according to the Missouri Department of Natural Resources. 

The information EPA used is not representative of the current air quality situation in Missouri and only identifies counties with monitors currently in place that are violating the standard.  This information underestimates the counties that might eventually become part of an area designated as not meeting the standard, also known as a nonattainment area.

The new standard is based on a three-year average of ozone monitoring data.  The EPA used data from the 2004 through 2006 ozone seasons to identify counties across Missouri with monitors showing violations of the revised standard because it was the most recent and complete years of quality assured data available to the agency.  However, using 2005 through 2007 ozone data provides a more accurate representation of current ozone levels because 2004 was an uncharacteristically mild summer that brought the three-year average down.

The 2005 through 2007 data shows that all of Missouri's ozone monitors except one, at Mark Twain State Park, are violating the new standard, and even this monitor is very close to the standard.  Taking this data into consideration, monitors showing violations of the new standard are in the city of St. Louis and the following counties:  Cass, Cedar, Clay, Clinton, Greene, Jefferson, Lincoln, Perry, St. Charles, St. Louis and Ste. Genevieve.

It is important to note that ozone air quality data obtained from monitoring is only one factor used in determining which counties will be part of a nonattainment area under the new standard.  The federal Clean Air Act requires EPA to also determine which counties contribute to the violation, and they must be included in the nonattainment area. 

The process for designating nonattainment area boundaries allows states to make a recommendation to EPA, but EPA has the authority to make the final decision.  EPA has not yet issued its criteria for how nonattainment areas will be designated under this new standard.  However, in previous designations, states were asked to consider multiple factors as they developed their boundary recommendations.  In addition to actual monitoring data, the criteria used in past designation processes included the following:

Because all but one of the monitors in the state is currently violating the revised standard, including monitors in rural areas, Missouri's existing monitoring network may need to be revised. Based on preliminary review, additional monitoring may be needed in St. Joseph, Columbia, Jefferson City and Joplin to gather more adequate data to evaluate compliance throughout the state. However, the state cannot make the final determination on the need for additional monitoring until EPA issues its final monitoring rule, which is expected later this summer. 

All states are also currently awaiting area classification guidance from EPA to establish how to evaluate the boundary recommendations for nonattainment areas under the revised standard.  These recommendations will be due to EPA by March 12, 2009, with the designations expected to be based on monitoring data from the 2006 through 2008 ozone seasons. EPA will then have until March 12, 2010, to make final designations of attainment and nonattainment areas for the state. Once final designations are made, state plans will have to be developed outlining how states will reduce pollution to meet the ozone standard. These plans will be due three years after final designations are made.

In the meantime, the Department of Natural Resources will continue its work to protect air quality in Missouri. Current air pollution control efforts and state plans will remain in place as the department evaluates what additional options may be necessary to reduce the harmful emissions that contribute to the formation of ground-level ozone.

The department also encourages Missouri citizens to take voluntary actions to reduce their impact. Simple steps can be taken to everyday to protect air quality. See the department's fact sheet "What You Can Do to Improve the Air" for additional information at www.dnr.mo.gov/pubs/pub2199.pdf.

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 http://www.dnr.mo.gov/calendar/search.do.

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