UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
 

REGION IX
 

75 Hawthorne Street
 

San Francisco, CA 94105·3901
 

OFFICE OF THE 

REGIONAL ADMINISTRATOR 

OCT 1 4 2009 

The Honorable Arnold Schwarzenegger 

Governor of California 

State Capitol Building 

Sacramento, CA 95814 

Dear Governor Schwarzenegger: 

I am writing in follow-up to Administrator Lisa Jackson's October 8 letter notifying you 

that the u.S. Environmental Protection Agency (EPA) has determined that two additional areas 

within your state may be violating the 2006 24-hour national ambient air quality standards 

(NAAQS) for fine particles (PM25). 

Your state submitted its initial list of recommendations for designations to EPA by letter 

from James N. Goldstene, Executive Officer, California Air Resources Board, dated December 

17, 2007. Last year, EPA notified you of its intended modifications to those recommendations 

by letter from Wayne Nastri, Regional Administrator, dated August 18,2008. Your state 

submitted additional information regarding the designations to EPA by letter from James N. 

Goldstene, dated October 15, 2008. 

EPA had intended to finalize the designations decisions in December of2008. Due to the 

change of Administration, however, EPA did not complete the process at that time. Therefore, at 

the request of the new Administration, EPA has reviewed the status of areas for the 2006 24-hour 

PM2.5 NAAQS in order to assure that the final decisions reflect current policy and the most upto-date air quality monitoring data as of this time. In particular, this review has allowed 

consideration of 2006-2008 air quality data for all areas. The new data indicate that two 

additional areas in California, Plumas County and Shasta County, now appear to be violating the 

2006 24-hour PM2.5NAAQS, leading EPA to believe that further modifications to your state's 

initial recommendations may be necessary. EPA is therefore deferring the designation for 

Plumas and Shasta counties for the 2006 24-hour PM2.5NAAQS so that EPA can collect and 

evaluate additional information before promulgating designations. 

We note that EPA has received requests from the Air Resources Board to exclude certain 

monitored violations in these counties, and documentation to support these requests, pursuant to 

our exceptional events rule. For the Shasta County and Plumas County areas, as for all areas 

where there are possible exceptional events contributing to high levels of PM2.5, EPA will review 

the data provided by the state air quality agency. Based on that review, EPA will determine 

whether data for certain days were influenced by "exceptional events" and should be excluded 

from the three-year data set used to identify these air quality violations. 

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Consistent with the approach used to assess other potential nonattainment areas, EPA 

also intends to evaluate relevant technical data for the ring of counties immediately surrounding 

PlumasI and Shasta2 counties to determine whether any of these nearby counties contribute to the 

violation. We recognize that these are large geographical areas. Looking at the counties 

surrounding Plumas and Shasta counties is only a starting point for the evaluation; it should not 

be assumed that the final designated nonattainment area will include these counties. 

Consideration ofthe relatively long distances across which PM2.5 and PM2.5precursors can be 

transported should be balanced with a key purpose of designations, which is to identify those 

nearby contributing areas that should be included within a designated nonattainment area to 

ensure the development of an appropriate State Implementation Plan for the area. This is 

explained further in the Federal Register notice for final 24-hour PM2.5designations, at 

www.epa.gov/pmdesignations/2006standards/regs.htm#3. Factors that should be considered as 

the basis for nonattainment area boundaries are described in a guidance memorandum entitled 

"Area Designations for the Revised 24-Hour Fine Particle National Ambient Air Quality 

Standard" from Robert J. Meyers, dated June 8, 2007 (enclosed). 

When EPA's evaluation is complete, we will notify you of our intended designations and 

boundaries for these areas. Following this notification, which we will provide at least 120 days 

prior to promulgating final designations, you will have the opportunity to comment on EPA's 

intended designations and to provide additional information to inform the final decision. As with 

the other areas in your state, EPA will work with your staff to assure that the final designations 

and boundaries are appropriate, based on the facts and circumstances of each area. 

We look forward to continuing to work with you and your staff to develop these 

remaining area designations for the 2006 24-hour PM2.5 NAAQS in a timely manner. If you have 

any questions, please do not hesitate to contact me. Your air quality staff may wish to contact 

Deborah Jordan, Air Division Director, at (415) 947-8715 or Colleen McKaughan, Associate Air 

Division Director, at (520) 498-0118. 

Sincerely, 

Laura Y shii 

Acting Regional Administrator 

Enclosure 

cc: See next page 

I i.e., Butte (partial), Lassen, Shasta, Sierra, Tehama, and Yuba (partial) counties. Note that nonattainment
 

designations for the areas within Butte and Yuba counties that were previously identified in 2008 will be finalized.
 

See Federal Register notice for final 24-hour PM2.

5 designations, at:
 

www.epa.govpmdesignatiolls. 'OOhstandards!regs. hlmiiJ.
 

2 i.e., Lassen, Modoc, Plumas, Siskiyou, Tehama, and Trinity counties.
 

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cc:	 Linda Adams, Secretary for Environmental Protection, California EPA 

Mary Nichols, Chairman, California Air Resources Board 

James Goldstene, Executive Officer, California Air Resources Board 

Lynn Terry, Deputy Executive Officer, California Air Resources Board 

Karen Magliano, Chief, Air Quality Data Branch, Planning and Technical Support 

Division, California Air Resources Board 

Russ Mull, Air Pollution Control Officer, Shasta County Air Quality Management 

District 

Gretchen Bennitt, Air Pollution Control Officer, Northern Sierra Air Quality 

Management District 

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