UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

REGION IX 

75 Hawthorne Street 

San Francisco, CA 94105-3901 

The Honorable Eddie Baza Calvo 

Governor of Guam 

Ricardo J. Bordallo Governor's Complex 

Adelup, Guam 96910 

Dear Governor Calvo: 

AUG 1 9 2014 

OFFICE OF THE 

REGIONAL ADMINISTRATOR 

I am writing to inform you of the U.S. Environmental Protection Agency's (EPA) approach for 

completing the initial area designations for the 2012 annual fine particle National Ambient Air Quality 

Standard (2012 mmual PM2.s NAAQS) throughout Guam. Area designations are an important first step 

as we move forward to improve PM2.s air quality in the nation. 

Although Guam has not provided the EPA with a recommendation, the EPA has reason to believe Guam 

is likely attainment and is not contributing to nearby violations. Accordingly, the EPA intends to 

designate the entire territory of Guam as unclassifiable/attainment. 

The EPA will 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 the additional information we receive, the EPA plans to 

promulgate final ammal PM2.s designations in December of 2014. 

As background, on December 14, 2012, the EPA promulgated a revised primary annual PM2.s NAAQS 

(78 FR 3086, January 15, 2013). In that action, the EPA revised the primary annual PM2.s standard, 

strengthening it from 15.0 micrograms per cubic meter ().Lg/m3

) to 12.0 )lglm3; retained the existing 24-

hour PM2.s standard at 35 )lglm3

; retained the existing 24-hour PM1o (coarse pa1ticle) standard at 150 

)lglm3

; and retained the current suite of secondary PM standards. The EPA revised the primary annual 

PM2.s standard based on an integrated assessment of an extensive body of new scientific evidence, which 

substantially strengthens our body of knowledge regarding PM2.s-related health effects. The revised 

primary annual PM2.s standard will provide increased protection for children, older adults, persons with 

pre-existing heart and lung disease, and other at-risk populations against an array ofPM2.s-related 

adverse health effects, including premature mortality, increased hospital admissions and emergency 

department visits, and development and exacerbation of chronic respiratory disease. 

The EPA designates an area as "nonattainment" if it is violating the 2012 annual PM2.s NAAQS or if it 

is contributing to a violation of the NAAQS in a nearby area. Consistent with designations for previous 

PM2.s standards, the EPA intends to use a designation category of "unclassifiable/attainment" for areas 

that are monitoring attainment or do not have monitors, and that the EPA has reason to believe are likely 

attainment and are not contributing to nearby violations. Additionally, the EPA intends to designate as 

"unclassifiable" those areas where the EPA cannot determine based on available information whether 

the area is meeting the NAAQS or where EPA has not determined that the area contributes to a nearby 

Printed on Recycled Paper 
violation. At this time, the EPA is proceeding with intended initial area designations using qualityassured, ce1iified air quality monitoring data from 2011 to 2013. 

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

reducing PM2.s air pollution. Cunent and upcoming federal standards and safeguards - including 

pollution reduction rules for power plants, vehicles, and fuels - will ensure steady progress to reduce 

PM2.5-forming 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 2012 

annual PM2.s NAAQS. Should you have any questions, please contact me, or have your staff contact 

Kerry Drake of my staff at 415-94 7-4157, or drake.keny@epa.gov. 

Sincerely, 

cc: Eric Palacios, Administrator, Guam Environmental Protection Agency