(a) If the executive director determines that a facility is eligible for listing on the state registry, a person may not perform at the facility any partial or total removal activities except as authorized by the executive director in appropriate circumstances after notice and opportunity for comment to all other potentially responsible parties. The commission may adopt rules determining what constitutes an appropriate circumstance to take removal action under this subsection. Authorization by the executive director to conduct a partial or total removal action does not constitute:
(1) a final determination of the party’s ultimate liability for remediation of the facility; or
(2) a determination of divisibility.
(b) If the facility is determined to be eligible for listing on the state registry, the owner or operator of the facility must provide the executive director with written notice of any substantial change in use of the facility before the 60th day before the date on which the change in use is made. Notice of a proposed substantial change in use must be in writing, addressed to the executive director, sent by certified mail, return receipt requested, and include a brief description of the proposed change in use. A substantial change in use shall be defined by rule and must include actions such as the erection of a building or other structure at the facility, the use of the facility for agricultural production, the paving of the facility for use as a roadway or parking lot, and the creation of a park or other public or private recreational use on the facility.

(c) If, within 30 days after the date of the notice, the executive director determines that the proposed substantial change in use will interfere significantly with a proposed or ongoing remedial investigation/feasibility study or similar study approved by the executive director or expose the public health and safety or the environment to a significantly increased threat of harm, the executive director shall notify the owner or operator of the determination. After the determination is made and notification given, the owner or operator may not proceed with the proposed substantial change in use. The owner or operator may request a hearing before the commission on whether the determination should be modified or set aside by submitting a request not later than the 30th day after the receipt of the executive director’s determination. If a hearing is requested, the commission shall initiate the hearing not later than the 45th day after the receipt of the request. The hearing shall be conducted in accordance with Chapter 2001, Government Code. The executive director’s determination becomes unappealable on the 31st day after issuance if a hearing is not requested.