August 19,2014 

### UNITED STATES ENVIRONMENTAL PROTECTION AGENCY Region 1 5 Post Office Square, Suite 100 Boston, MA 02109-3912

The Honorable Paul LePage Governor ofMaine 1 State House Station Augusta, Maine 04333
Dear Governor LePage: Thank you for your recommendation dated October 18, 2013 of air quality designations for the 20 12 revised primary annual fine particle (PM2
.s) National Ambient Air Quality Standard (NAAQS) throughout Maine. I appreciate the information Maine shared with the U.S. Environmental Protection Agency as we move forward to improve PM2.s air quality. This letter is to notify you ofthe EPA's preliminary response to Maine's recommendation and to inform you of our approach for completing the initial area designations for the 2012 revised primary annual PM2 .s standard. 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**(~g/m )**  to 12.0**~g/m ;**  retained the existing 24-hour PM2
.s standard at 35**~g/m ;**  retained the existing 24-hour PM10(coarse particle) standard at 150**~g/m ;**  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 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 ho spital admissions and emergency department visits, and development and exacerbation of chronic respiratory disease. 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 commonsense approach that improves air quality and minimizes the burden on state, local, and tribal governments . As part ofthis routine process, the EPA i s working with the states and tribes to identify areas in the country that meet the standards and those th at need to take steps to reduce PM2.s air pollution
. Within one year ofpromulgating a new or revised air quality standard, the Clean Air Act requires the Governor of each state to submit to the EPA a list of all areas in the state, with a designation recommendation for each area. As a first step in implementing the 2012 annual PM2. s standard, Governors were to s ubmit their designation recommendations, including appropriate area boundaries, by December 13, 2013.2 As required by the Clean Air Act, the EPA then promulgates designations for all areas across the country . The EPA designates an area as "nonattainmen t " 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, but for which 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 E PA has not determined that the area contributes to a nearby violation. At this time, the EPA is proceeding with intended initial area designations using quality-assured , certified air quality monitoring data from 2011 to 2013. We have considered the annual PM2
.s designation recommendations submitted by Maine on October 18, 2013 and have reviewed the relevant technical information, including 2011

- 2013 air quality data. These data do not indicate any vio latio n of the 2012 annual PM2
.s NAAQS in Ma ine or cont ribution to any nearby area. Accordingly, the E PA intends to designate the entire state of Maine as unclass ifiable/attainmcnt. 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 consider ing the additional information we receive, the EPA plans to promulgate final annual PM2.s des ignations in December of 2014. The EPA is committed to working with the states and tribes to share the responsibility ofreducing PM2 .5 air po ll ution
. Current and upcoming federal standards and safeguards

- including pollution reduction rules for power plants, vehi cles, and fuels- will ensure steady progress to reduce PM2. sforming pollut ion and will protect publi c 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 standard
. Should you have any questions , p lease do not hesitate to contact me, or have your staff contact Alison Simcox of my stafT at 617-918

- 1684 or simcox.a l ison@epa.gov.

cc: Patricia Aho, ME DE P Commiss ioner Marc Cone, Director, Bureau ofAir Quality

# 116 1**urt s**  Spalding, Regional Administrator, EPA New Engla nd.

Janet G. McCabe , Acting Assistant Administrator for Air and Radiation Stephen D. Page , Director, Office ofAir Quality Planning and Standards