Approval and Promulgation of the Northern Cheyenne Tribe's Tribal Implementation Plan; Northern Cheyenne Tribe; Open Burning Permit Program and Maintenance of the National Ambient Air Quality Standards

EPA is approving a Tribal Implementation Plan (TIP) submitted by the Northern Cheyenne Tribe (Tribe) on September 25, 2017, as described in our February 26, 2021 proposal. The TIP includes ambient air quality standards and provisions for an open burning permit program, enforcement and appeals, and emergency authority. These provisions establish a base TIP that is suitable for the Northern Cheyenne Indian Reservation and four tribal trust parcels at issue (Reservation), is within the Tribe's regulatory capacities, and meets all applicable minimum requirements of the Clean Air Act (CAA or Act) and EPA regulations. The effect of this action is to make the approved TIP federally enforceable under the CAA and to further protect air quality on the Reservation.