On July 23, 1996, we proposed to revise regulations for both the approval and promulgation of implementation plans and the requirements for preparation, adoption, and submittal of implementation plans governing the NSR programs mandated by parts C and D of title I of the Clean Air Act (61 FR 38249). The NSR program includes the part C PSD and part D NAA NSR Programs. These regulations are contained in 40 CFR 51.165, 51.166, 52.21, 52.24 and part 51, appendix S. The proposed changes were commonly known as the NSR Reform package. They included baseline emissions, actual-to-future-actual methodology, establishment of PALs, Clean Units, PCPs, PSD applicability for HAPs, State selection of applicability options, and other changes. This FR Notice also included EPAs proposed action on CMA Exhibit B. Volume I of this document summarizes the written and oral comments that were submitted during the public comment period regarding the 1996 and 1998 FR Notices. For the topics that were covered in the 1998 NOA in addition to the 1996 Reform proposal (baseline emissions, actual-to-future-actual methodology, and PALs), there is a separate chapter for comments on each FR Notice. Volume I of this document includes all of the comments directly on the 1998 NOA that were received by the end of the public comment period. It also includes all of the public comments on areas of the 1996 Reform Proposal for which we have taken final action. (That is, baseline emissions, actual-to-future-actual methodology, PALs, Clean Units, PCPs, PSD applicability for HAPs, and State selection of applicability options). It does not include public comments on other aspects of the 1996 Reform Proposal. Volume I of this document also includes our responses to these comments. This comment summary and our responses provided input for the revisions made to the standards between proposal and promulgation.