The Environmental Protection Agency (EPA) is taking final action to approve the state implementation plan (SIP) revision submitted on March 9, 2017 by the Connecticut Department of Energy and Environmental Protection (CT DEEP) addressing the nonattainment new source review (NNSR) requirements for the 2008 8-hour ozone National Ambient Air Quality Standard (NAAQS). The SIP revision addresses both of Connecticut's ozone nonattainment areas for the 2008 ozone NAAQS; the Greater Connecticut area and the Connecticut portion of the New York-N. New Jersey-Long Island, NY-NJ-CT area. The Connecticut portion of the New York-N. New Jersey-Long Island, NY-NJ-CT ozone nonattainment area consists of Fairfield, New Haven, and Middlesex counties. The Greater Connecticut nonattainment area includes the rest of the State. This action is being taken pursuant to the Clean Air Act (CAA or Act) and its implementing regulations.