Section 11-264-228 - Closure and post-closure care(a) At closure, the owner or operator must: (1) Remove or decontaminate all waste residues, contaminated containment system components (liners, etc.), contaminated subsoils, and structures and equipment contaminated with waste and leachate, and manage them as hazardous waste unless subsection 11-261-3(d) applies; or(2)(i) Eliminate free liquids by removing liquid wastes or solidifying the remaining wastes and waste residues;(ii) Stabilize remaining wastes to a bearing capacity sufficient to support final cover; and(iii) Cover the surface impoundment 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) Have a permeability less than or equal to the permeability of any bottom liner system or natural subsoils present.(b) If some waste residues or contaminated materials are left in place at final closure, the owner or operator must comply with all post-closure requirements contained in sections 11-264-117 through 11-264-120, including maintenance and monitoring throughout the post-closure care period (specified in the permit under section 11-264-117). The owner or operator must: (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;(2) Maintain and monitor the leak detection system in accordance with subparagraph 11-264-221(c) (2) (iv) and paragraph 11-264-221(c)(3) and subsection 11-264-226(d), and comply with all other applicable leak detection system requirements of this chapter;(3) Maintain and monitor the ground-water monitoring system and comply with all other applicable requirements of subchapter F; and(4) Prevent run-on and run-off from eroding or otherwise damaging the final cover.(c)(1) If an owner or operator plans to close a surface impoundment in accordance with paragraph (a)(1), and the impoundment does not comply with the liner requirements of subsection 11-264-221(a) and is not exempt from them in accordance with subsection 11-264-221(b), then: (i) The closure plan for the impoundment under section 11-264-112 must include both a plan for complying with paragraph (a)(1) and a contingent plan for complying with paragraph (a)(2) in case not all contaminated subsoils can be practicably removed at closure; and(ii) The owner or operator must prepare a contingent post-closure plan under section 11-264-118 for complying with subsection (b) in case not all contaminated subsoils can be practicably removed at closure.(2) The cost estimates calculated under sections 11-264-142 and 11-264-144 for closure and post-closure care of an impoundment subject to this subsection must include the cost of complying with the contingent closure plan and the contingent post-closure plan, but are not required to include the cost of expected closure under paragraph (a)(1).Haw. Code R. § 11-264-228
[Eff 6/18/94; comp] (Auth: HRS §§ 342J-4, 342J-31, 342J-34, 342J-35) (Imp: 40 C.F.R. §264 - 228)