Air Plan Approval; Connecticut; Infrastructure State Implementation Plan Requirements; Prevention of Significant Deterioration Permit Program Revisions

The Environmental Protection Agency (EPA) is approving elements of a State Implementation Plan (SIP) submission from Connecticut regarding the infrastructure requirements of the Clean Air Act (CAA or Act) for the 2012 fine particle (PM<INF>2.5</INF>) National Ambient Air Quality Standards (NAAQS), and a SIP submission addressing interstate transport requirements of the CAA for the 2006 PM<INF>2.5</INF> NAAQS. In addition, we are approving one statute included in the SIP for the 2012 PM<INF>2.5</INF> NAAQS. The infrastructure requirements are designed to ensure that the structural components of each state's air quality management program are adequate to meet the state's responsibilities under the CAA. The EPA is also approving revisions to the SIP submitted by Connecticut on October 18, 2017, satisfying Connecticut's earlier commitment to adopt and submit provisions that meet certain requirements of the federal Prevention of Significant Deterioration (PSD) permit program. In addition, we are converting the June 3, 2016 conditional approval to full approval for elements of Connecticut's infrastructure SIP regarding PSD requirements to treat nitrogen oxides (NO<INF>X</INF>) as a precursor to ozone and to establish a minor source baseline date for PM<INF>2.5</INF> emissions for the 1997 and 2006 PM<INF>2.5</INF>, 1997 and 2008 ozone, 2008 lead, 2010 nitrogen dioxide, and 2010 sulfur dioxide NAAQS. This action is being taken under the Clean Air Act.