UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

REGION 4 

ATLANTA FEDERAL CENTER 

61 FORSYTH STREET 

ATLANTA, GEORGIA 30303-8960 

DEC 1 9 2008 

The Honorable Haley Barbour 

Governor of Mississippi 

Sillers Building, 19th Floor 

550 High Street 

Jackson, Mississippi 3920 1 

Dear Governor Barbour: 

On March 12,2008, the U.S. Environmental Protection Agency (EPA) revised the 

national ambient air quality standards (NAAQS) for ozone to provide increased protection of 

public health and welfare from ozone pollution. Based on numerous epidemiological studies 

conducted during the past decade in which many health effects associated with ozone exposure 

have been demonstrated at and below the 1997 standard of 0.08 parts per million (ppm), the 

Agency lowered the primary ozone standard to 0.075 ppm. EPA also strengthened the secondary 

8-hour ozone standard, making it identical to the revised primary standard, to protect against 

welfare effects, such as impacts on vegetation and forested ecosystems. 

Within one year following promulgation of a new or revised NAAQS, section 

107(d)(l)(A) of the Clean Air Act (CAA) requires the Governor of each state to submit to EPA a 

list of all areas in the state, recommending designations for each as "attainment," 

"nonattainment," or "unclassifiable" with respect to the new or revised standard. Therefore, we 

ask that you provide EPA such designation recommendations with respect to the revised ozone 

NAAQS, including appropriate area boundaries, by March 12, 2009. Establishing area 

designations is a key step in the process of providing the health protections that the CAA 

mandates. Areas that are designated as not attaining the air quality standards must adopt plans to 

reduce ambient concentrations of ozone. 

The enclosed memorandum provides guidance to state and local air pollution control 

agencies and tribes on the process for designating areas under the 2008 revised ozone standard. 

We plan to announce our intended designations as early as possible after receipt of your 

recommendations, but no later than 120 days prior to promulgating final designations. 

Following the announcement of intended designations, states and tribes will have the opportunity 

to comment on any modifications EPA proposes to their recommendations. In accordance with 

section 107(d)(l)(B) of the CAA, we intend to issue final designations by March 12,201 0 

(although that deadline may be extended up to one additional year, if EPA determines that 

insufficient information is available to establish designations by that date). Our designations will 

be based on the most recent three years of certified, quality assured available monitoring data. 

Ozone nonattainment areas will be classified at the time of designation. The EPA will establish 

its approach to classifying nonattainment areas under the 2008 revised ozone NAAQS through a 

separate notice-and-comment rulemaking. 

Internet Address (URL) http Ilww epa gov 

RecycledlRecyclable Printed w~th Vegetable Oil Based Inks on Recycled Paper (M~n~rnum 30% Postconsumer) 
We look forward to working with you and your staff to develop area designations under 

the 2008 revised ozone NAAQS in a timely manner. If you have any questions, please contact 

me at (404) 562-8357 or have a member of your staff contact Beverly Banister, Director, Air, 

Pesticides and Toxics Management Division, at (404) 562-9077. 

Sincerely, 

Regional Administrator 

Enclosure 

cc: Trudy D. Fisher, Exec. Director, MDEQ 

Jerry Cain, Director, MDEQ-OPC 

Maya Rao, Chief, OPC-Air Division