EPA is approving State Implementation Plan (SIP) revisions submitted by the State of New Hampshire. This action consists of approving regulations in New Hampshire, as well as a case-specific order and two emission quantification protocols for Public Service of New Hampshire (PSNH). The regulations and order are part of a regional nitrogen oxide ( NO<INF>X</INF>) reduction program designed to reduce stationary source NO<INF>X</INF> emissions during the ozone season in the Ozone Transport Region (OTR) of the northeastern United States. Section 184(a) of the Clean Air Act defines the OTR as the States of Connecticut, Delaware, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont, and the Consolidated metropolitan Statistical Area that includes the District of Columbia. These SIP revisions were submitted pursuant to section 110 of the Clean Air Act (CAA).