Closure and postclosure care

1. At closure of a tank system, the owner or operator shall remove or decontaminate all waste residues, contaminated containment system components (liners, etc.), contaminated soils, and structures and equipment contaminated with waste, and manage them as a hazardous waste, unless subsection 4 of section 33.1-24-02-03 applies. The closure plan, closure activities, cost estimates for closure, and financial responsibility for tank systems must meet all of the requirements specified in sections 33.1-24-05-59 through 33.1-24-05-88. 2. If the owner or operator demonstrates that not all contaminated soil can be practicably removed or decontaminated as required in subsection 1, then the owner or operator shall close the tank system and perform postclosure care in accordance with the closure and postclosure care requirements that apply to landfills under section 33.1-24-05-180. In addition, for the purposes of closure, postclosure, and financial responsibility, such a tank system is then considered to be a landfill, and the owner or operator shall meet all the requirements for landfills specified in sections 33.1-24-05-59 through 33.1-24-05-88. 3. If an owner or operator has a tank system that does not have secondary containment that meets the requirements of subsections 2 through 6 of section 33.1-24-05-106 and has not been granted a variance from the secondary containment requirements in accordance with subsection 7 of section 33.1-24-05-106, then: a. The closure plan for the tank system must include both a plan for complying with subsection 1 and a contingent plan for complying with subsection 2; b. A contingent postclosure plan for complying with subsection 2 must be prepared and submitted as part of the permit application; c. The cost estimates calculated for closure and postclosure care must reflect the cost of complying with the contingent closure plan and the contingent postclosure plan, if those costs are greater than the costs of complying with the closure plan prepared for the expected closure under subsection 1; d. Financial assurance must be based on the cost estimates in subdivision c; and e. For the purposes of the contingent closure and postclosure plans, such a tank system is considered to be a landfill, and the contingent plans must meet all of the closure, postclosure, and financial responsibility requirements for landfills under sections 33.1-24-05-59 through 33.1-24-05-88.