UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 5 77 WEST JACKSON BOULEVARD CHICAGO, IL 60604-3590



## DEC 

## 2 3 

## 2008 REPLY TO THE ATTENTION OF

R-19J The Honorable Mitchell 

### E. Daniels, Jr. Governor of Indiana Indianapolis, Indiana 46204

Dear Governor Daniels:

On March 12,2008,the U.S. Environmental Protection Agency revised the national ambient air quality standards (NAAQS) for ozone to provide increased protection ofpublic health and welfare fkom ozonepollution. The new primary ozone standard was lowered from 0.08 parts per million (ppm)to 0.075ppm based on numerous epidemiological studies conducted during the past decade in which many ofthe health effects associated with ozone exposure have been demonstrated at and below the level ofthe 0.08 ppm standard, which was promulgated in 1997. These include a range of serious respiratory effects and increased premature mortality. 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 

# 0 ecosystems.

- Within oneyear ofpromulgation of a new orrevised NAAQS, section 107(d)(l)(A)of the Clean Air Act requires the Governor ofedch stateto 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 orrevised standard. Therefore, we ask that you provide your designation recommendations, including appropriate area boundaries, to EPA by March 12,2009, with respect to the revised ozone NAAQS. Establishing area designations is a key step in theprocess ofproviding the health protections that the Clean Air Act mandates. Areas that are designated as not attaining the air quality standards will be required to adopt plans to reduce ambient concentrations ofozone.

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 ozonestandard. We plan to announce our intended designations as early aspossible 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)ofthe Clean Air Act, 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 3 years ofcertified, quality assured monitoring data available. Ozone nonattainment areas will be classified at the time ofdesignation. The approach EPA will use to classify nonattainment areas under the 2008 revised ozone NAAQS will be established through a separate notice-and-comment rulemaking.We look forward to working with you and your staffto develop area designationsunder the 2008 revised ozone standardsin a timely manner. If you have any questions, please do not hesitate to contact me. Your air quality staff may wish to contact Cheryl L. Newton, Director, Air and Radiation Division, at 312-353-22 12.

Sincerely,

Lynn ~uh~ L' Regional Administrator

Enclosure

cc: Thomas W. Easterly, Commissioner Indiana Department of Environmental Management