[ ] On August 5, 2013, the EPA designated a portion of Warren County, Pennsylvania (hereafter the “Warren County NAA”), as nonattainment for the 2010 1-hour primary SO 2 NAAQS, effective October 4, 2013. The Warren County NAA consists of Conewango Township, Glade Township, Pleasant Township, and the City of Warren. Ultimately, Pennsylvania did submit an attainment plan SIP revision for the Warren County NAA on September 29, 2017. Maintenance Plan RequirementsSection 175A of the CAA sets forth the elements of a maintenance plan. [ ] Area source emissions were estimated based on the relative percentage of the Warren County population residing in the Warren County NAA and the resulting factor allocated the appropriate fraction of the County's total emissions to the Warren County NAA.