30 Tex. Admin. Code § 101.23
An owner or operator of any facility that is affected by any control requirement of TACB Regulations I, II, III, V, VII, and IX adopted on or after March 30, 1979, may, prior to compliance with such requirement, request the executive director to approve control of emissions from an alternate facility or from alternate facilities located on the affected property and owned or operated by or under the control of the owner or operator of the affected facility in lieu of compliance with the requirement as prescribed in the regulation, provided the alternate proposed controls are not required by any TACB rule, regulation, permit condition, board order or court order. The executive director shall approve control of emissions from alternate facilities if the applicant demonstrates that the alternate controls will yield, by the date specified in the rule, emission reductions that are substantially equivalent to the emissions reductions which would otherwise be required in terms of their quantity, character, air quality impacts including health and welfare effects, and area affected. Facilities which receive the executive director's approval of an alternate emissions control plan will be deemed to have complied with the otherwise applicable TACB rule. However, the executive director may, after notice and opportunity for public hearing, revoke the credit or authority for alternate controls if he determines that any of the prerequisites for approval of the alternate controls are no longer met or if further emission reductions are needed to meet the intent of the Texas Clean Air Act.
30 Tex. Admin. Code § 101.23