(a) At closure, the owner or operator must:
  (1) remove or decontaminate all brine product waste and waste residues, contaminated design and operating system components such as liners, dikes, storm water retention structures, brine product handling areas, and contaminated media; or
  (2) eliminate free liquids by removing liquid wastes or solidifying the remaining wastes and waste residues; stabilize remaining wastes to a bearing capacity sufficient to support final cover; and cover the brine evaporation pit with a final cover designed and constructed to:
    (A) provide long-term minimization of the migration of liquids through the closed impoundment;
    (B) function with minimum maintenance;
    (C) promote drainage and minimize erosion or abrasion of the final cover;
    (D) accommodate settling and subsidence so that the cover's integrity is maintained; and
    (E) be constructed of at least a three-foot layer of re-compacted soil with a hydraulic conductivity of no more than 1 x 10-7 centimeters per second (cm/sec).
(b) If some waste residues or contaminated materials are left in place at final closure, the owner or operator must comply with the following post-closure requirements:
  (1) maintain the integrity and effectiveness of the final cover including making repairs to the cap as necessary to correct the effects of settling, subsidence, erosion, or other events; and
  (2) prevent run-on and run-off from eroding or otherwise damaging the final cover.
(c) Additional post closure requirements may be added by the executive director as determined to be necessary to protect human health and/or the environment; including but not limited to, groundwater monitoring.
(d) The closure plan for the brine evaporation pit must include both a plan for complying with subsection (a)(1) of this section and a contingent plan for complying with subsection (a)(2) of this section, in case not all contaminated subsoils can be practicably removed at closure; and the owner or operator must prepare a contingent post-closure plan for complying with subsection (b) of this section, in case not all contaminated subsoils can be practicably removed at closure.
(e) Written notification must be provided to the executive director at least 90 days prior to conducting any facility closure activity.
(f) Within ten days after completion of final closure activities of a facility, the owner or operator shall submit to the executive director by registered mail the following:
  (1) a certification, signed by a licensed professional engineer, verifying that final facility closure has been completed in accordance with the approved closure plan. The submittal to the executive director shall include all applicable documentation necessary for certification of final facility closure; and
  (2) for a facility that does not require post-closure care, a request for voluntary revocation of the permit.

Source Note: The provisions of this §218.25 adopted to be effective October 16, 2008, 33 TexReg 8530