Carherine E. Heigel. Direcror Promotillg andprotecting tht, health o/,liJepub/icfind tbe /'JIIJiron1fll'l1t April 19,2016
Ms. Heather McTeer Toney Regional Administrator U.S

. EPA Region 4 Sam Nunn Atlanta Federal Center 61 Forsyth Street SW Atlanta, GA 30303-8909
Re: South Carolina Air Quality Implementation Plan
Dear Ms

. Toney:
The South Carolina Department ofHealth and Environmental Control (Department) is providing this letter to the U.S. EPA (EPA) to provide a written commitment under section 110(k)(4) ofthe Clean Air Act (Act) to take action to meet the requirement ofsection 11 0(a)(2)(D)(i)(II) ofthe Act. This section ofthe Act states that state implementation plans (SIPs) are required to contain adequate provisions to prohibit emissions from interfering with measures required to be in other states' SIPs to protect visibility. The Department is committing to adopt the measures described herein for the control ofair pollution and submit the SIP revision to the EPA no later than one year after the date ofthe EPA's conditional approval. South Carolina's anticipated schedule for the SIP revision is as follows:

• SIP revision out for public comment December 2016;

• Address comments received February 2017;

• Submit final SIP revision for approval April 2017. To meet the requirements ofsection 110(a)(2)(D)(i)(II) for visibility, a state may rely on a fully approved regional haze SIP or may demonstrate that other SIP measures ensure that emissions from within the state will not interfere with other air agencies' plans to protect visibility

. See Guidance on Infrastructure State Implementation Plan (SIP) Elements Under Clean AirAct Sections I IO(a) (I) and IIO(a)(2) (Sept. 13,2013). South Carolina's regional haze SIP is not fully approved because the EPA issued a limited approval and a limited disapproval ofthe SIP submitted by South Carolina on December 17, 2007, to address the requirements ofthe regional haze program. 77 Fed

. Reg. 33,642 (June 7, 2012); 77 Fed. Reg. 38,509 (June 28,2012). We note that the EPA's limited disapproval ofSouth Carolina's SIP was based on the regional haze SIP's reliance on the Clean Air Interstate Rule (CAIR), which at the time ofthe limited disapproval had been remanded by the U.S. Court ofAppeals for the D.C. Circuit. 77 Fed. Reg. 33,642 (June 7, 2012). The EPA's limited disapproval, therefore, was based on the Agency's conclusion that CAIR would remain in place only temporarily; other aspects ofthe regional haze SIP were approved

. SOT H C 1 \ }{ 0 L 1j\; A D £ PAR T MEN I 0 f H E i\ L T HAN DEN VIR 0 :'\i MENTAL COT R 0 L 2600 BI111 Street. • Columbia,SC 29201 • Phone:(803) 898-3432· \,'ww.scdhec.go\,To satisfy the requirement ofsection 11 0(a)(2)(D)(i)(II) related to visibility protection for the 2008 8-hour ozone National Ambient Air Quality Standards (NAAQS), 2010 nitrogen dioxide NAAQS, 2010 sulfur dioxide NAAQS, and 2012 fine particulate matter NAAQS, we intend to provide to the EPA a SIP revision that adopts provisions for participation in the Cross-State Air Pollution Rule ("CSAPR") annual NOx and annual S02 trading programs, including annual NOx and annual S02 budgets. Any adopted budgets would be at least as stringent as the budgets codified for South Carolina at 40 CFR 97.7l0(a) (annual S02 group 2 trading budgets) and 40 CFR 97.4 1 O(a) (annual NOx trading budgets), as promulgated in the Federal Register notice of June 12,2012 (77 Fed. Reg. 34,830). We will rely on this SIP revision adopting such budgets to submit a concurrent SIP revision that will satisfy the visibility requirements ofsection 11O(a)(2)(D)(i)(IJ) and EPA's corresponding guidance on those requirements. We commit to provide this concurrent SIP revision within the one-year period described above. This concurrent SIP revision will rely on either an analysis provided therein showing that emissions from sources in South Carolina will not interfere with the attainment ofthe reasonable progress goals ofother states or on a fully approved regional haze SIP relying on CSAPR. Ifthe concurrent SIP revision relies on a fully approvable regional haze SIP, we commit to provide this regional haze SIP to EPA within the one year period described above. Should you or your staffhave any questions or comments concerning this SIP revision proposal, please contact Rhonda Banks Thompson, Chiefofthe Bureau ofAir Quality (BAQ) at (803) 898-4391 or thompsrb@dhec.sc

.QOv

. Sincerely,

# ~Vl.~ Myra C. Reece Director ofEnvironmental Affairs South Carolina Department ofHealth and Environmental Control

ec: R. Scott Davis, Chief , Air Planning and Implementation Branch, EPA Region 4 Lynorae Benjamin, Chief , Air Regulatory Management Section, EPA Region 4 Brad Akers, Air Regulatory Management Section, EPA Region 4 Rhonda B. Thompson, Chief, Bureau ofAir Quality, SCDHEC Robert J. Brown, Director, Division ofAir Assessment and Regulation, BAQ, SCDHEC