(a) The purpose of the regulations in this part is to establish procedures for the assessment, billing, and collection of charges for goods/services provided to non-Federal users.(b) The Assistant Secretary may sell or contract to sell to non-Federal users within, or in the immediate vicinity of an Indian Reservation (or former Reservation), any of the following goods/services if it is determined that the goods/services are not available from another local source or providing that goods/services is in the best interest of the Indian tribes or individual Indians. The goods/services include, but are not limited to:(8) Natural, manufactured, or mixed gas;(11) Garbage collections.