DEVAL L f'ATriICK

GOVCrnor F21CHAnD K SULLIVAN in. S Iuurol,~Iry TIMOTHY P MUiiRM KENNETH L. KIMMELL Lujuur3nant Governor CommioLiuner August 19, 2011 David Conroy, Chief, Air Programs Branch US EPA- New

England 5 Post Office Square- Suite 100(Mail Code OEP05-2) Boston, MA 02109-3912 Re: SIP Submittal Addressing Massachusetts' Obligations Under §§110(a)(1) and (2) of the CleanAir Act - Addendum to §110(a)(2)(D)(i)(I) portion of the Infrastructure SIP certification for 2006 PM2,5 NAAQS Dear M\onroy: On September 21, 2009, the Massachusetts Department of Environmental Protection (MassDEP) submitted Massachusetts' Infrastructure State Implementation Plan (SIP) certification for adoption into the Massachusetts' SIP. The Infrastructure SIPcertified that Massachusetts meets the required elements of §§110(a)(1) and (2) of the Clean Air Act and demonstrated that Massachusetts' resources and authorities are adequate to implement, maintain, and enforce the 2006 24-hour National Ambient Air Quality Standards (NAAQS) for PMZ.5. The §110(a)(2)(D)(i)(I) portion of the submittal addresses the requirement that Massachusetts prohibit any source or other type of emissions activity in the state fromcontributing significantly to nonattainment, or interfering with maintenance, of the NAAQS in another state. This portion of Massachusetts' submittal referenced EPA's 2005 Clean Air Interstate Rule (CAIR) and the associated State program . However, a December 2008 court decision vacated CAIR, but kept CAIR requirements in place temporarily while directing EPA to issue a replacement rule. On August 2, 2010, EPAproposed the Transport Rule,' The analysis conducted for the proposed Transport Rule supported the conclusion at the time that Massachusetts significantly contributed to nonattainment or interfered with maintenance of the 2006 PM2 .5 NAAQS

. After discussions with EPA Region 1 staffregarding the impact of the 2008 court decision on the approvability of our September, 2009 Infrastructure SIPand the conclusions in the proposed Transport Rule, in Commonwealth of Massachusetts Executive Office of Energy &Environmental Affairs 

# Department of Environmental Protection One Winter Street Boston, MA 02108" 617-292-5500

1 See, Federal Implementation Plans To Reduce Interstate Transport of Fine particulate Matter andOzone (75 FR 45210 . This information Is available In alternate format . Call Michelle Waters-Ekanem, Diversity Director, at 617-282-5751 . TDD# 1-866-639-7622 or 1-617-674-6868 MassDEPWebsite: www .mass.govldep Printed on Recycled Paperour January 13, 2011 letter to you, Massachusetts withdrew the §110(a)(2)(D)(i)(I) portion of the Infrastructure SIP submittal . On July 6, 2011, EPAfinalized the Cross-State Air Pollution Rule (CSAPRor Transport Rule), which replaces CAIR. The results of the analysis conducted for the final CSAPRdiffer fromthe results of the proposed Transport Rule.2 The CSAPRprovisions do not include Massachusetts because updated EPAair-quality modeling supports EPA's conclusion that Massachusetts does not contribute significantly to nonattainment, or interfere with maintenance, of the 2006 PMZ,5 NAAQS (or of the 1997 ozone or PM2 .5 NAAQS) in another state.3 Therefore, we are resubmitting that section of our September, 2009 Infrastructure SIPthat addresses interstate transport and §110(a)(2)(D)(i)(I), and certifying that Massachusetts does not contribute significantly to nonattainment, or interfere with maintenance, of the 2006 PM2,5 NAAQS (or of the 1997 ozone or PM2,5NAAQS) in any other state based on air-quality modeling performed for CSAPR . Thank you for your consideration of this clarification of the Massachusetts Infrastructure SIP certification for the 2006 PM2,5NAAQS . Ifyou have any questions or comments concerning this matter, please contact Eileen Hiney (617-292-5520 ; Eileen.Hineycnt.state.ma.us.) Sincerely, ,---- . ( Nancy L. Seidman Deputy Assistant Commissioner for Climate Strategies Bureau ofWaste Prevention

2 EPAupdated its modeling platforms and modeling inputs in response to public comments received on the proposed Transport Rule and subsequent NODAs and performed other standard updates. 3 Information about EPA's modeling for CSAPRis available on their CSAPRwebsite on thetechnical information and support documents page: http://wwwepa yov/crossstaterule/techinfo html .