UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

REGION IX
 

75 Hawthorne Street
 

San Francisco, CA 94105-3901
 

OFFICE OFTHE 

DEC 0 9 2011 REGIONAL ADMINISTRATOR 

The Honorable Edmund G. Brown, Jr. 

State of California 

State Capitol Building, Suite 1173 

Sacramento, California 95814 

Dear Governor Brown: 

Thank you for your recommendations dated March II, 2009 and October 12, 2011 on air quality 

designations for the revised 2008 National Ambient Air Quality Standards for ozone throughout 

California. I appreciate the information California shared with the U.S. Environmental Protection 

Agency as we move forward to improve ozone air quality. The purpose of this letter is to notify you of 

the U.S. Environmental Protection Agency's preliminary decision to designate 16 areas of California 

as nonattainment for the revised 2008 ozone NAAQS, to inform you that we intend to modify several 

of your recommendations (as noted in Enclosure I) and to inform you of our approach for completing 

the designations for the revised ozone NAAQS. 

On March 12,2008, the EPA revised its NAAQS for ground-level ozone to provide increased 

protection of public health and the environment. The EPA lowered the primary 8-hour ozone standard 

from 0.08 parts per million (ppm) to 0.075 ppm to protect against health effects associated with ozone 

exposure, including a range of serious respiratory illnesses and increased premature death from heart 

or lung disease. The EPA revised the secondary 8-hour ozone standard, making it identical to the 

primary standard, to protect against welfare effects, including impacts on sensitive vegetation and 

forested ecosystems. 

History shows us that better health and cleaner air go hand-in-hand with economic growth. Working 

closely with the states and tribes, the EPA is implementing the standards using a common sense 

approach that improves air quality and minimizes the burden on state and local governments. As part 

of this routine process, EPA is working with the states to identify areas in the country that meet the 

standards and those that need to take steps to reduce ozone pollution. Within one year after a new or 

revised air quality standard is established, the Clean Air Act requires the Governor of each state to 

submit to the EPA a list of all areas in the state, with recommendations for whether each area meets the 

standard. 

As a first step in implementing the 2008 ozone standards, the EPA asked states to submit their 

designation recommendations, including appropriate area boundaries, by March 12,2009. In 

September 2009, the EPA announced it was reconsidering the 2008 ozone standards. The EPA later took 

steps to delay the designation process for the 2008 ozone standards pending outcome of the 

reconsideration. However, in September 2011, the Office of Management and Budget returned to EPA the 

draft final ru~e addressinl5. the reconsideration ofthe 2008 standards. On September 22 2011 th EPA 

restarted the implementation effort by issuing.a memorandum to clarify for state and lo'cal ag~nc~es the 

status ofthe 2008 ozone standards and to outlme plans for moving forward to implement them. The EPA 

Printed on Recycled Paper 
indicated that it would proceed with initial area designations for the 2008 standards, and planned to use the 

recommendations states made in 2009 as updated by the most current, certified air quality data from 2008­

2010. While the EPA did not request that states submit updated designation recommendations, the EPA 

provided the opportunity for states to do so. Thank you for the October 12,2011 updated designation 

recommendation from California based on the assessment of 2008-20 10 and preliminary 2009-2011 air 

quality data. 

As required by the Clean Air Act, the EPA will designate an area as nonattainment if it is violating the 

2008 ozone standards or contributing to a violation of the standards in a nearby area. Consistent with 

designations for previous ozone standards, the EPA intends to designate an area as 

unclassifiable/attainment if there are certified, quality-assured air quality monitoring data showing the 

area is meeting the ozone standards or there are no monitoring data for the area, and the EPA has not 

made a detennination that the area is contributing to a violation in a nearby area. 

After considering California's October 12,2011 ozone designation recommendations, which were 

based on both 2008-2010 as well as preliminary 2009-2011 air quality data, as well as other relevant 

technical infonnation, the EPA intends to designate the areas listed in Enclosure 1 as nonattainment. 

The enclosed Technical Support Document provides a detailed analysis to support our preliminary 

decisions. The EPA intends to designate all other areas of the state as unclassifiable/attainment. In 

order for the EPA to consider 2009-2011 air quality data in the final designation decisions for any area, 

California must submit certified, quality-assured 2009-2011 air quality monitoring data for the area to 

the EPA by February 29,2012. 

The EPA will continue to work with state officials regarding the appropriate boundaries for the 

nonattainment areas in California. If California has additional infonnation that you would like the 

EPA to consider, please submit it to us by February 29,2012. The EPA will also make its preliminary 

designation decisions and supporting documentation available to the general public for review and 

comment. We will be announcing a 30-day public comment period shortly in the Federal Register. 

After considering additional infonnation we receive, the EPA plans to promulgate final ozone 

designations in the spring of2012. 

The EPA is committed to working with the states and tribes to share the responsibility of reducing 

ozone air pollution. Current and upcoming federal standards and safeguards, including pollution 

reduction rules for power plants, vehicles and fuels, will assure steady progress to reduce ozonefonning pollution and will protect public health in communities across the country. We look forward to 

a continued dialogue with you and your staff as we work together to implement the 2008 ozone 

standards. Should you have any questions, please do not hesitate to contact me or Amy Zimpfer, 

Associate Director, Air Division, of my staff at 415-947-4146 or zimpfer.amy@epa.gov. 

Sincerely, 

h

Jared Blumenfeld 

Enclosures 
cc: (with full enclosures) 

Matthew Rodriquez, Secretary, California Environmental Protection Agency 

Mary Nichols, Chairman, California Air Resources Board 

James Goldstene, Executive Officer, California Air Resources Board 

Lynn Terry, Deputy Executive Officer, California Air Resources Board 

cc:	 (with area-specific enclosures) 

Affected Air Pollution Control Officers 

cc:	 (enclosure 1 only) 

Affected Tribal Leaders and Tribal Environmental Coordinators 

cc: (via electronic correspondence) 

Gina McCarthy, Assistant Administrator for Air and Radiation 

Stephen D. Page, Director, Office of Air Quality Planning and Standards 
Area Nonattamment Lounues ~UWllll;;:>

Amador and Calaveras Counties 

(Central Mountain Counties)* 

Calaveras County 

Amador County and 

Calaveras County 

Chico (Butte County)* Butte County Butte County 

Imperial County* Imperial County Imperial County 

Kern County (Eastern Kern, 

excluding Indian Wells Valley) 

Kern County (Eastern Kern, 

excluding Indian Wells Valley) 

Kern County (Eastern Kern, 

excluding Indian Wells Valley) 

Los Angeles-San Bernardino 

(West Mojave Desert)* 

San Bernardino County (Mojave 

Desert Air Basin portion) as a 

separate nonattainment area from 

Los Angeles County (Antelope 

Valley portion or Mojave.Desert 

Air Basin portion) nonattainment 

area 

San Bernardino County 

(Mojave Desert Air Basin 

portion), and 

Los Angeles County 

(Antelope Valley portion or 

Mojave Desert Air Basin 

portion) 

Los Angeles-South Coast Air 

Basin* 

Los Angeles County (South 

Coast Air Basin portion which 

includes Santa Catalina and San 

Clemente Islands), 

Orange County, 

San Bernardino County (South 

Coast Air Basin portion), 

Riverside County (South Coast 

Air Basin portion) 

Los Angeles County (South 

Coast Air Basin portion which 

includes Santa Catalina and 

San Clemente Islands), 

Orange County, 

San Bernardino County (South 

Coast Air Basin portion), 

Riverside County (South Coast 

Air Basin portion) 

Mariposa and Tuolumne 

Counties (Southern Mountain 

Counties)* 

Mariposa County Mariposa County and 

Tuolumne County 

Nevada Countv(Western part) Nevada County (Western part) Nevada County (Western part) 

Tuscan Buttes 

Tehama County (Tuscan Buttes 

portion, above 1,800 feet 

elevation) 

Tehama County (Tuscan Buttes 

portion, above 1,800 feet 

elevation) 

Riverside County (Coachella 

Valley)* 

Riverside County (Salton Sea Air 

Basin portion) 

Riverside County (Salton Sea 

Air Basin portion) 

Sacramento Metro* 

Sacramento County, 

Yolo County, 

Solano County (Sacramento 

Valley Air Basin portion), 

Sutter County (southern portion), 

EI Dorado County (Sacramento 

Valley Air Basin portion), 

Placer County (Sacramento 

Valley Air Basin portion) 

Sacramento County, 

Yolo County, 

Solano County (Sacramento 

Valley Air Basin portion), 

Sutter County (southern 

portion), £1 Dorado County 

(Sacramento Valley Air Basin 

portion), 

Placer County (Sacramento 

Valley Air Basin portion) 

San Diego County* San Diego County San Diego County 

San Francisco Bay Area* San Francisco County, 

Marin County, 

San Francisco County, 

Marin County, 
southern Sonoma County (San 

Francisco Bay Air Basin portion), 

Napa County, 

western Solano County (San 

Francisco Bay Air Basin portion), 

Contra Costa County, 

Alameda County, 

Santa Clara County, 

San Mateo County 

southern Sonoma County (San 

Francisco Bay Air Basin 

portion), Napa County, 

western Solano County (San 

Francisco Bay Air Basin 

portion), Contra Costa County, 

Alameda County, 

Santa Clara County, 

San Mateo County 

San Joaquin Valley* 

San Joaquin County, 

Stanislaus County, 

Merced County, 

Madera County, 

Fresno County, 

Kings County, 

Tulare County, 

Kern County (San Joaquin Air 

Basin portion) 

San Joaquin County, 

Stanislaus County, 

Merced County, 

Madera County, 

Fresno County, 

Kings County, 

Tulare County, 

Kern County (San Joaquin Air 

Basin portion) 

San Luis Obispo (Eastern San 

Luis Obispo) 

San Luis Obispo County (Eastern 

San Luis Obispo) 

San Luis Obispo County 

(Eastern San Luis Obispo) 

Ventura County (continental 

portion) 

Continental portion of Ventura 

County (excludes Anacapa and 

San Nicolas islands) 

Continental portion of Ventura 

County (excludes Anacapa and 

San Nicolas islands) 

EPA intended modifications to state recommendations are shown In bold.
 

*Indicates multi-jurisdictional nonattainment area or areas that include tribal lands. Table 1, contained in
 

the Technical Analysis section of each nonattainment area discussion in the enclosed Technical Support
 

Document, identifies the tribal lands that EPA intends to designate as part of the nonattainment area.
 
ENCLOSURE 2
 

Technical Support Document