UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION IX 75 Hawthorne Street San Francisco, CA 94105-3901

The Honorable Eddie Baza Calvo Governor ofGuam 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 ofthe 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 ofGuam 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 of2014. As background, on December 14, 2012, the EPA promulgated a revised primary annual PM2
.sNAAQS (78 FR 3086, January 15, 2013)
. In that action, the EPArevised 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 ofsecondary PM standards. The EPA revised the primary annual PM2.s standard based on an integrated assessment ofan extensive body ofnew scientific evidence, which substantially strengthens our body ofknowledge 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 ofchronic respiratory disease. The EPA designates an area as "nonattainment" ifit is violating the 2012 annual PM2.s NAAQS or ifit is contributing to a violation ofthe 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 Paperviolation. 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 committedto working withthe states, tenitories and tribes to share the responsibility of reducing PM2.s airpollution. Cunent and upcoming federal standards and safeguards

- including pollution reduction rules for powerplants, vehicles, and fuels

- will ensure steadyprogress to reduce PM2.5-formingpollution and will protectpublic health in communities across the country. We look forward to a continued dialogue with you and your staffas we worktogetherto implement the 2012 annual PM2.s NAAQS. Should you have any questions, please contact me, or have your staffcontact Kerry Drake ofmy staffat 

### 415-947-4157, or drake.keny@epa.gov. Sincerely,

cc: Eric Palacios, Administrator, Guam Environmental Protection Agency