Connecticut Department of



## ENERGY & ENVIRONMENTAL PROTECTION August 19, 2011 David Conroy, Chief, Air Programs Branch US EPA- New

England 5 Post Office Square- Suite 100 (Mail Code OEP05-2) Boston, MA02109-3912 Re: Addendumto the CAA §110(a)(2)(D)(i)(I) Portion ofConnecticut's Infrastructure Submittal for the 2006PM2,5 NAAQS Dear Mr. Conroy: On September 18, 2009, the Connecticut Department of Environmental Protection (now the Connecticut Department of Energy and Environmental Protection) submitted a determination that Connecticut's State Implementation Plan (SIP) adequately addressed the requirements of §§110(a)(1) and (2) of the CleanAir Act (CAA) for the 2006fine particulate matter (PMZ,5) national ambient air quality standards (NAAQS), demonstratingthat Connecticut's resources and authorities are adequate to implement, maintain, and enforce the NAAQS. Considering EPA's recent release of the Cross-StateAir Pollution Rule (CSAPR), Connecticut is submittingthis addendum

to our September 2009 submittal to clarify how Connecticut complies with §110(a)(2)(D)(i)(I) requirements, as described below . The §110(a)(2)(D)(i)(I) portion of the September 2009 submittal addresses the requirement that Connecticut prohibit any source or other type of emissions activity in the state from contributing significantly to nonattainment, or interfering with maintenance, of the NAAQS in another state. This portion of Connecticut's September 2009 submittal indirectly 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, EPA proposed the courtrequired replacement rule, which EPAcalled the Transport Rule.' EPA's modeling analysis conducted for the proposed Transport Rule supported EPA's conclusion at the time that Connecticut significantly contributed to nonattainment or interfered with maintenance of the 1996 24-hour PM2.5 NAAQS. After discussions with EPA Region 1 staff regarding the impact of the 2008 court decision upon the approvability of our September 2009 infrastructure submittal and the conclusions in the proposed Transport Rule, on January 7, 2011, Connecticut withdrew the §110(a)(2)(D)(i)(I) portion of the infrastructure submittal, as requested by EPA. I See, Federal Implementation Plans To Reduce Interstate TransportofFine particulate Matter and Ozone (75 FR 45210
. 79 ElmStreet " Hartford, CT 06106-5127 www .ct.gov/deep Affirmative ActionlEqual Opportunity EmployerMr . David Conroy

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On July 6, 2011, EPAfinalized CSAPR, which replaces CAIR. The results of EPA's analysis conducted for CSAPR differ fromthe results of the proposed Transport Rule.2 CSAPR requirements do not apply to Connecticut because the final rule's updated air quality modeling led EPAto conclude that Connecticut does not contribute significantly to nonattainment, or interfere with maintenance, of the 2006 PM2,5 NAAQS in another state.3 Therefore, based on EPA's modeling analysis and conclusions, we are resubmitting thesection of our September 18, 2009 infrastructure submittal that addresses interstate transport provisions of §110(a)(2)(D)(i)(I), certifying that Connecticut does not contribute significantly to nonattainment, or interfere with maintenance, of the 2006 PM2,5 NAAQS in any other state. Thank youfor your consideration ofthis clarification of the Connecticut's infrastructure certification for the 2006 PM2,5NAAQS. If you have any questions or comments concerning this matter, please contact me. Sincerely,

Anne Gobin Chief, Bureau ofAir Management

2EPAupdated its modeling platforms and modeling inputs in response to public comments received on the proposed Transport Rule and subsequent NODAs andperformed other standard updates. 3 EPA'smodeling also concludes that Connecticut does not significantly contribute significantly to nonattainmentor maintenance issues in other states forthe 1997 ozone and PM2 .5 NAAQS. Information about EPA's modeling for CSAPRis available on their CSAPRwebsite on thetechnical information and support documents page: http://www

.eva.pov/_crossstaterule/techinfo.html.