2015 Ozone NAAQS Infrastructure and Transport SIPs

Under the Clean Air Act (CAA) sections 110(a)(1) and 110(a)(2), each state is required to submit a state implementation plan (SIP) that provides for the implementation, maintenance, and enforcement of a revised primary or secondary NAAQS (National Ambient Air Quality Standard). CAA section 110(a)(1) and section 110(a)(2) require each state to make this new SIP submission within three years after the Environmental Protection Agency (EPA) promulgates a new or revised NAAQS. On October 26, 2015, EPA revised the eight-hour primary and secondary standards for ozone from seventy-five parts per million (ppm) to seventy ppm (80 FR 65292).

ADEQ currently has a program in place to satisfy these programmatic elements; however, ADEQ cannot begin implementing the 2015 ozone NAAQS in the state, except for PSD and nonattainment new source review, until it is adopted by the Arkansas Pollution Control and Ecology Commission (APC&EC). ADEQ filed APC&EC Regulation No. 19 with APC&EC to initiate a permanent rulemaking on September 14, 2018. APC&EC initiated the rulemaking on September 28, 2018. ADEQ proposed the 2015 ozone NAAQS infrastructure SIP concurrent with initiation of rulemaking by APC&EC to adopt the 2015 ozone NAAQS. APC&EC hosted a public hearing on November 16, 2018 to address proposed revisions to APC&EC Regulation 19, and ADEQ hosted a public hearing to address proposed revisions to the ozone NAAQS infrastructure SIP immediately following. The comment period for this rulemaking closed November 30, 2018. ADEQ has proposed a SIP revision to address transport obligations under Clean Air Act Section 110(a)(2)(D). ADEQ plans to finalize both the infrastructure and transport SIPs upon final adoption of the 2015 ozone NAAQS by APC&EC.