42 U.S.C. § 300h–1 — State primary enforcement responsibility

(a) List of states in need of a control program. Within 180 days of December 16, 1974, the EPA Administrator must publish in the Federal Register a list of each state where, in the Administrator's judgment, a state underground injection control (UIC) program may be needed to keep underground injection from endangering drinking water sources. The Administrator can update this list over time. (b) State applications. (1)(A) Each listed state must, within 270 days after EPA issues a UIC regulation under section 300h (or within 270 days of being listed, if later), send the Administrator an application showing that the state (i) has adopted — after public notice and hearings — and will carry out a UIC program meeting the regulation's requirements, and (ii) will keep records and file reports on its UIC program as the Administrator requires. The Administrator may, for good cause, give a state up to another 270 days to submit its application. (B) Within 270 days after EPA amends a UIC regulation to add or change a requirement, each listed state must send the Administrator a notice showing its program meets the new requirement. (2) Within 90 days of receiving a state's application or notice, and after giving people a chance to comment, the Administrator must approve, disapprove, or partly approve and partly disapprove the state's program by rule. (3) If the Administrator approves the state's program, the state keeps primary enforcement responsibility for underground water sources until the Administrator rules that the state no longer meets requirement (i) or (ii) of paragraph (1)(A). (4) Before issuing any rule under paragraph (2) or (3), the Administrator must give the public a chance for a hearing. (c) EPA-run program for states without primary enforcement responsibility. If the Administrator disapproves a state's program, decides under (b)(3) that a state no longer qualifies, or a state misses its deadline to apply, the Administrator must — within 90 days — write a regulation (and may later revise it) setting up a federal program for that state that meets section 300h(b)'s requirements. That federal program cannot include requirements that interfere with (1) injecting brine or other fluids brought up during oil or gas production or gas storage, or (2) underground injection for secondary or tertiary oil or gas recovery — unless the requirements are truly needed to keep drinking water sources safe. This federal program only applies where the state doesn't already have an EPA-approved program covering the same ground. Before issuing this regulation, the Administrator must give the public a chance for a hearing. (d) "Applicable underground injection control program" — defined. This means either (1) the program (or its most recent amendment) that a state adopted and EPA approved under subsection (b), or (2) the program EPA wrote under subsection (c). (e) Primary enforcement responsibility by an Indian tribe. A tribe may take on primary enforcement responsibility for underground injection control, following EPA's regulations. The tribe's area doesn't need to have been on the subsection (a) list, and the tribe doesn't have to meet the 270-day deadline that applies to states. Until a tribe takes over, whatever UIC program already applies keeps applying. If there's no existing program for a tribe's area, the Administrator must write one under subsection (c) — consistent with section 300h(b) — within 270 days of June 19, 1986, unless the tribe gets approval to take over enforcement first.