Section 30.699 - Closure and Post-closure Care(1) At closure of a tank system, the owner or operator shall remove or decontaminate all waste residues, contaminated containment system components, contaminated soils, and structures and equipment contaminated with waste, and manage them as hazardous waste, unless the conditions of 310 CMR 30.141 are met. The owner or operator shall be in compliance with all requirements for a closure plan, closure activities, cost estimates for closure, and financial responsibility for tank systems as set forth in 310 CMR 30.580, 30.590, and 30.900.(2) If the owner or operator demonstrates that not all contaminated soils can be practicably removed or decontaminated as required in 310 CMR 30.699(1), then the owner or operator shall close the tank system and perform post-closure care in accordance with the closure and post-closure care requirements that apply to landfills ( 310 CMR 30.633) . In addition, for the purposes of closure, post-closure, and financial responsibility, such a tank system is considered to be a landfill, and the owner or operator shall meet all of the requirements for landfills specified in 310 CMR 30.580, 30.590 and 30.900.(3) If an owner or operator has a tank system that does not have secondary containment that meets the requirements of 310 CMR 30.694, then: (a) The closure plan for the tank system shall include a plan for complying with 310 CMR 30.699(1) and a contingent plan for complying with 310 CMR 30.699(2).(b) A contingent post-closure plan for complying with 310 CMR 30.699(2) shall be prepared and submitted as part of the permit application.(c) The cost estimates calculated for closure and post-closure care shall reflect the costs of complying with the contingent closure plan and the contingent post-closure plan, if those costs are greater than the costs of complying with the closure plan prepared for the expected closure under 310 CMR 30.699(1).(d) Financial assurance must be based on the cost estimates in 310 CMR 30.699(3)(c).(e) For the purpose of the contingent closure and post-closure plans, such a tank system is considered to be a landfill, and the owner or operator shall be in compliance with all requirements for all of the closure, post-closure, and financial responsibility requirements for landfills under 310 CMR 30.580, 30.590, and 30.900.Amended by Mass Register Issue 1278, eff. 1/16/2015.