(a) Except as provided by Subsection (b), this subchapter applies to the following persons:
(1) all large-quantity generators of hazardous waste;
(2) all generators other than large-quantity generators and conditionally exempt small-quantity generators; and
(3) persons subject to Section 313, Title III, Superfund Amendments and Reauthorization Act of 1986 (42 U.S.C. § 11023) whose releases exceed the levels established under § 361.503(b).
(b) The commission by rule shall establish one or more schedules for the application of the requirements of this subchapter to designated classes of persons described by Subsection (a). The schedule shall provide for the inclusion of all persons described by Subsection (a) on a date to be determined by the commission, and until that date this subchapter applies only to those persons designated by rule of the commission.

(c) This subchapter does not apply to a facility regulated by the Railroad Commission of Texas under § 91.101 or 141.012, Natural Resources Code.