EPA is approving State Implementation Plan (SIP) revisions submitted by the State of New Hampshire. The revisions establish and require the implementation of the Clean Air Act Amendments (CAAA) of 1990 regarding New Source Review (NSR) in areas that have not attained the National Ambient Air Quality Standards (NAAQS) and areas within the ozone transport region (OTR). In addition, the revisions replace the existing definition of stationary source in New Hampshire's SIP with the plantwide stationary source definition. The intended effect of this action is to approve PART Env-A 610, "Additional Requirements in Nonattainment Areas and the New Hampshire Portion of the Northeast Ozone Transport Region." This action is being taken in accordance with the Clean Air Act (CAA).