Section 49.121 - Introduction(a)What is the purpose of the "General Rules for Application to Indian Reservations in EPA Region 10"? These "General Rules for Application to Indian Reservations in EPA Region 10" establish emission limitations and other requirements for air pollution sources located within Indian reservations in Idaho, Oregon, and Washington that are appropriate in order to ensure a basic level of air pollution control and to protect public health and welfare.(b)How were these "General Rules for Application to Indian Reservations in EPA Region 10" developed? These "General Rules for Application to Indian Reservations in EPA Region 10" were developed in consultation with the Indian Tribes located in Idaho, Oregon, and Washington and with input from the public and State and local governments in Region 10. These general rules take into consideration the current air quality situations within Indian reservations, the known sources of air pollution, the needs and concerns of the Indian Tribes in that portion of Region 10, and the air quality rules in adjacent jurisdictions.(c)When are these "General Rules for Application to Indian Reservations in EPA Region 10" applicable to sources on a particular Indian reservation? These "General Rules for Application to Indian Reservations in EPA Region 10" apply to air pollution sources on a particular Indian reservation when EPA has specifically promulgated one or more rules for that reservation. Rules will be promulgated through notice and comment rulemaking and will be specifically identified in the implementation plan for that reservation in Subpart M-Implementation Plans for Tribes-Region 10, of this part. These "General Rules for Application to Indian Reservations in EPA Region 10" apply only to air pollution sources located within the exterior boundaries of an Indian reservation or other reservation lands specified in subpart M of this part.