Air Resources Board 

Mary D. Nichols, Chairman 

Linda S. Adams 1001 1 Street P.O. Box 281 5 Arnold Schwarzenegger 

Secretary for Sacramento, California 9581 2 www.arb.ca.gov Governor 

Environmental Protection 

July 7, 2009 

Ms. Laura Yoshii 

Acting Regional Administrator 

U.S. Environmental Protection Agency 

Region 9 

75 Hawthorne Street 

San Francisco, California 941 05 

Dear Ms. Yoshii: 

I am pleased to provide information explaining how California's existing State 

Implementation Plan (SIP) meets the program infrastructure requirements of the Clean 

Air Act (Act) Section 11 0(a) for the PM2.5 National Ambient Air Quality Standards. 

California originally subrr~itted a comprehensive §I 10(a)(2) Infrastructure SIP in 

response to the Act of 1970, which was approved by the U.S. Environmental Protection 

Agency (U.S. EPA) in 1979. A subsequent Infrastr~~cture SIP revision submitted to the 

U.S. EPA on November 16, 2007, fulfills the required elements for the PM2.5 annual 

standard as well as the 24-hour standards of 65 Clg/m3 and 35 Clg/m3. The only 

outstanding element that the previous submittals did not address concerns emergency 

powers and adequate emergency episode plans for the PM2.5 standards. 

The requirement for a state to submit an emergency episode plan is based on a priority 

region classification. The priority classification uses information on the severity of air 

quality in a region to determine the applicability of an emergency episode plan and the 

specific plan requirements. While the U.S. EPA has yet to establish the specific PM2.5 

levels for the priority classi'fications, it did issue interim guidance which required only 

States with 24-hour PM2.5 concentrations over 140.5 Clg/m3, in the most recent three 

years of data, to develop an emergency episode plan for PM2.5. States which did not 

meet that threshold would be classified Priority I I I regions and emergency episode plans 

would not be required. Based on guidance from their U.S. EPA regional office, the New 

England states were considered Priority Ill based on no recorded PM2.5 concentrations 

over 140.5 vg/m3. California used this same guidance in developing our priority 

classification. 

The energy challenge facing California is real. Every Californian needs to take immediate action to reduce energy consumption 

For a list of simple ways you can reduce demand and cut your energy costs, see our website: http://www.arb.ca.qov. 

California Environmental Protection Agency 

Pnnted on Recycled Paper 

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Ms. Laura Yoshii 

July 7, 2009 

Page 2 

As demonstrated in the Attachment, our review of the most recent three years of data 

indicates that California should be considered a Priority II I region. Therefore, an 

emergency episode plan is not required. If we can be of assistance as you review this 

matter, please have your staff contact Ms. Karen Magliano, Chief, Air Quality Data 

Branch, at (916) 322-7137 or via email at kmaqlian@arb.ca.gov. 

Sincerely, 

James *T N. olden 

Executive 0ffi;fer 

Attachment 

cc: Lisa Hanf 

U.S. Environmental Protection Agency 

Region 9 

75 Hawthorne Street 

San Francisco, California 941 05 

Debbie Jordan 

U .S. Environmental Protection Agency 

Region 9 

75 Hawthorne Street 

San Francisco, California 941 05 

Karen Magliano 

Chief, Air Quality Data Branch 

Planning and Technical Support Division 
Attachment 

Analysis of 2006 to 2008 California PM2.5 Data for Prioritv Classification 

In the last 'three years, PM2.5 FRM concentrations in California have remained 

below 140.5 pg/m3, with the exception of one wildfire and one windblown dust 

event. Since the authority specified in Section 11 0(a)(2)(G) was not intended to 

control emissions from these type of events and there were no other 

concentrations over 140.5 pg/m3, California should be considered a Priority Ill 

region and therefore emergency episode plans are not required. 

Wildfire: During the 2008 Northern California summer wildfires, a PM2.5 

concentration of 142.2 pg/m3 was recorded at Quincy on June 23, 2008. During 

this same event, a concentration of 200.2 pg/m3 was recorded at Redding on 

July 23, 2008. California is in the process of preparing an exceptional event 

request for both of these days, which documents that anthropogenic sources had 

little impact on the PM2.5 concentrations. In response to high concentrations 

during wildfire events, the Air Resources Board and the local districts have an 

existing notification program to communicate health risks and precautions to the 

public. These communication methods include websites, hotlines, and press 

releases, as well as email, faxes, and phone text messaging to interested parties 

(such as sports team coaches and daycare providers). In some rural areas, 

door-to-door notifications have been used. Additional efforts to reduce PM2.5 

contributions are taken during smoke impact periods. For example, no open 

burning is allowed in areas impacted by a wildfire. These 'no burn' declarations 

are handled through the State's comprehensive smoke management program. 

Dust Event: On December 28, 2006, a PM2.5 concentration of 193 pg/m3 was 

recorded at Keeler in the Owens Lake area due to a windblown dust event. Dust 

storm events, like the one that occurred at Keeler on December 28, 2006, are 

caused by wind blown dust from the dry lake bed and are unique to the Owens 

Lake area. Best available control measures are already in place to control the 

fugitive dust events. In addition, the Great Basin Valley Air Pollution Control 

District has an existing health advisory program to notify residents of the 

appropriate actions to reduce the adverse health effects of these high 

concentrations.