(a) The owner or operator of a Class I bedded salt cavern disposal well shall prepare, maintain, and comply with a plan for cavern closure that meets the following minimum requirements:(1) The owner or operator shall submit the plan as a part of the permit application and, upon approval, or approval with modifications by the executive director, such plan shall be a condition of any permit issued.(2) The owner or operator shall submit all proposed revisions to the plan and obtain any necessary permit amendments, as appropriate, over the life of the well and cavern.(3) The plan shall include, at a minimum, the following information:(A) Upon cessation of waste disposal, and before cavern sealing, the operator shall:(i) Conduct a gamma-density log to determine the cavern top, salt top and to check for fluid behind the casing.(ii) Conduct a sonar caliper survey on the storage cavern if no sonar has been run within the past five years. The owner or operator may use another similar proven technology designed to determine cavern configuration and measure cavern capacity as a substitute for a sonar survey.(B) All brine displaced from the well or flushed from waste lines during the plugging operation shall be managed and disposed of under applicable state and federal regulations.(b) The well shall be closed in accordance with §331.46 of this title (relating to Closure Standards).