1 COMMENTS AND RESPONSES State Implementation Plan Revision: Section 110(a)(2)(d)(i) for the Eight

- Hour Ozone and PM 2.5 National Ambient Air Quality Standards The public comment period began on September 15, 2007 and closed on October 16, 2007. A public h earing was held on October 16, 2007. Proof of publication is attached.

COMMENTATORS:
1. Anne R. Gobin, Chief Bureau of Air Management Connecticut Department of Environmental Protection 79 Elm Street Hartford, CT 06106

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COMMENTS: COMMENT: Pennsylvania has taken sincere efforts to support regional solutions to the ozone problem with its involvement in the Ozone Transport Commission and we are grateful to have your commitment to work with us to address gaps left by CAIR. We remain concerned that the emission reductions that will result from the Clean Air Interstate Rule (CAIR) will not satisfy the Clean Air Action Section 110(a)(D)(i) that states upwind from Connecticut, such as Pennsylvania, prohibit emissions in amounts that contribute sig

nificantly to nonattainment of the eight

- hour ozone standard in other states. EPA concluded that most of the 2010 projected peak ozone levels would be transported from upwind states. The regional summer season NOx emission reductions from CAIR provide ve ry little ambient peak ozone improvement in Connecticut. Levels of transport after CAIR implementation remain large enough that attainment may be difficult to achieve in Connecticut by June 2010, regardless of the level of in

- state emission controls. This creates uncertainty about Connecticut’s ability to attain the ozone standard by the required June 2010 deadline. EPA’s Phase 2 CAIR reductions in 2015 are inadequate to ensure healthy air quality in Connecticut. EPA’s CAIR data also indicate that a NOx budget more stringent than CAIR can be achieved at a reasonable cost compared to many control measures that are being pursued by Connecticut and other states. Additional cost effective reductions may also be realized by targeting emissions that occur on peak electric demand days in the summer months. (1)2

RESPONSE: The Department appreciates the commentator’s support of its efforts to reduce transported ozone precursors. The Department believes the Commonwealth is meeting its obligations under sectio n 110(a)(2)(D)(i) of the Clean Air Act (CAA) to include in its State Implementation Plan (SI P) adequate provisions prohibiting sources and other emissions activities in the Commonwealth from emitting any air pollutant in amounts that will “contribute signi ficantly ” to nonattainment in downwind states, like Connecticut. Beginning with the 2009 control period, EGUs in the Commonwealth will be subject to the federal Clean Air Interstate Rule (CAI R) Federal Implementation Plan (FIP). In the meantime, electric generating units (EGU)s and certain non

- EGUs are subject to the Commonwealth’s NOx Budget Trading Program, and the Department plans to present its final CAI R rulemaking to the Commonwealth’s Environmental Quality Board for approval in December, 2007. If the necessary approvals are timely

obtained, the final CAI R regulation should be published and effective earl y in 2008, at which time it will be submitted to EPA for inclusion in the Commonwealth’s SI P. On April 25, 2005, EPA published national findings that States had failed to submit SI Ps required under section 110(a)(2)(D) to address interstate transport with respect to the eight

- hour ozone and PM 2.5 NAAQS. 70 Fed. Reg . 21147. On May 12, 2005, EPA published the CAI R, which established emission reducti on requirements for affected upwind States under section 110(a)(2)(D)(i). 70 Fed. Reg . 25162. On April 28, 2006, EPA denied North Carolina’s Section 126 petition with respect to sources in States having an approved SI P meeting the CAI R emissions reductio ns requirements, and with respect to sources in States for which EPA promulgated a Federal Implementation Plan (FIP) with those same emission reductions requirements. In either case, EPA reasoned, there would no longer be a violation of the prohibition in section 110(a)(2)(D)(i). Since a violation of that prohibition is a condition precedent for granting a section 126 petition, EPA necessarily

denied the petition. 71 Fed. Reg . 25334

- 5. In addition, EPA interprets “significant contribution” under section 110(a)(2)(D) in the CAI R “to include both an emission component and a feasibility /cost

- effectiveness component, so that what is prohibited are specific levels of emissions which can feasibly be reduced in a highl y cost

- effective manner.” 71 Fed. Reg . 253 35. EPA states in its preamble to the CAIR FIPs that “adoption of a CAI R SIP (or EPA adopting a CAI R FIP) fully addresses” the section 110(a)(2)(D)(i) prohibition against significant contribution. Id. Recognizing that the Connecticut Department of Envi ronmental Protection asserts that implementing CAI R is inadequate to satisfy 110(a)(2)(D)(i), we note the other measures listed in Pennsylvania’s proposed section 110(a)(2)(D)(i) SI P that will also reduce downwind transport of ozone precursors.