Tex. Natural Resources Code § 134.102

(a) The commission may grant a variance from the contemporaneous reclamation requirement of Section 134.092(a)(16) for specific areas within the reclamation plan to permit underground mining operations before reclamation if:

(1) the applicant proposes to combine surface mining operations with underground mining operations to assure maximum practical recovery of the coal resources; and

(2) the commission finds in writing that:

(A) the applicant has presented, as part of the permit application, specific, feasible plans for the proposed underground mining operations;

(B) the proposed underground mining operations are necessary or desirable to assure maximum practical recovery of the coal resource and will avoid multiple disturbances of the surface;

(C) the applicant has satisfactorily demonstrated that:

(i) the plan for the underground mining operations conforms to requirements for underground mining in the jurisdiction; and

(ii) permits necessary for the underground mining operations have been issued by the appropriate authority;

(D) the applicant has shown that the areas proposed for the variance are necessary for implementing the proposed underground mining operations;

(E) substantial environmental damage, either on or off the site, will not result from the delay in completing reclamation as required by this chapter; and

(F) provisions for the off-site storage of spoil will comply with Section 134.106.

(b) Liability under the bond filed by the applicant with the commission under Section 134.121 must extend for the duration of the underground mining operations and until Sections 134.092 through 134.106 and Sections 134.128 through 134.134 have been complied with.

(c) The commission must adopt specific rules to govern the granting of a variance under this section and may impose additional requirements it considers necessary.

(d) The commission shall review a variance granted under this section not later than the third anniversary of the date the permit is issued.