An owner and an operator of a UST system, an underground farm tank, an underground residential tank, and an underground residential heating oil tank shall have a permanent closure or change-in-service of a storage tank system performed by or under the supervision of a certified UST system technician or remover. An owner, an operator, and a person in charge of a UST system shall conduct a permanent closure or change-in-service of a storage tank system in accordance with the following documents: API Recommended Practice 1604 “Closure of Underground Petroleum Storage Tanks”; and PEI/RP 1700 “Recommended Practices for the Closure of Underground Storage Tank and Shop-Fabricated Aboveground Storage Tank Systems”. Notification. Unless a permanent closure or change-in-service of a UST system is performed in response to a corrective action, an owner, an operator, and a person in charge of a UST system shall notify the Department of a planned permanent closure or change-in-service of the UST system by submitting a notification: In writing on a form provided by the Department; and At least 30 days before beginning the permanent closure or change-in-service, or within another reasonable time period determined by the Department. An owner and an operator of a UST system shall confirm a planned permanent closure of a UST system with the Department 48 hours in advance of beginning the permanent closure. An owner and an operator of a UST system shall perform an assessment of the excavation zone, as required under Regulation .03 of this chapter: After notifying the Department of a planned permanent closure or change-in-service of the UST system; and Before completion of the permanent closure or change-in-service of the UST system. In accordance with COMAR 26.10.03.09, an owner, an operator, and a person in charge of a UST system that was permanently closed or underwent a change-in-service shall amend the registration for the UST system after the permanent closure or change-in-service of the UST system is complete. Permanent Closure. When a UST system is permanently taken out-of-service, an owner and an operator of a UST system shall permanently close the UST system by: Removing the UST system from the ground; or If approved by the Department, abandoning the UST system in place. Unless otherwise directed by the Department, an owner, an operator, and a person in charge of a UST system requesting to abandon the UST system in place shall provide the Department with a report signed by a professional engineer that confirms the permanent closure of the UST system by removal would have an adverse effect on a building foundation or other important structures or utilities within the immediate vicinity of the excavation zone. To permanently close a UST system by removal or abandonment in place, an owner, an operator, and a person in charge of a UST system shall take the following actions: Immediately before closing the UST system, empty and clean the UST and piping by removing all flammable, combustible, and other liquids and accumulated sludge from the UST system; Unless otherwise directed by the Department, disconnect and remove all emptied lines; Remove all aboveground portions of vent lines and cap the remaining lines at their bases; and Remove all regulated substances, sludge, and soil contaminated with a regulated substance found during the UST system closure for treatment or disposal in compliance with applicable federal, State, and local laws. If a UST system is permanently closed by removal, an owner, an operator, and a person in charge of a UST system shall take the following actions: Purge all explosive vapors from the UST prior to removal from the excavation zone; Monitor the UST with an appropriate meter for vapors before and during removal of the UST from the excavation zone; Once the UST system has been removed from the excavation zone: Retest the UST for flammable vapors and, if necessary, purge all remaining explosive vapors; and Make holes or openings in the UST to render it unfit for further use; If the operation poses a threat to public safety, do not crush or cut up the UST on-site; Dispose of the UST system materials at a location acceptable to the Department; and Fill the former UST system excavation zone to grade with an appropriate fill material. If a UST system is permanently closed by abandonment in place, an owner, an operator, and a person in charge of a UST system shall take the following actions: Do not fill the UST through a fill or vent pipe; Provide proper openings by excavation, or other means, on the UST to facilitate cleaning and filling the UST; Completely fill the UST with a solid, inert, and flowable material so there are no voids in the UST; Dispose of any removed UST system materials at a location acceptable to the Department; and Fill any excavated areas to grade with an appropriate fill material. Change-in-Service. When an owner and an operator of a UST system chooses to store a nonregulated substance in a UST system, the owner and the operator of the UST system shall: Notify the Department of the planned change-in-service of the UST system in accordance with §C(1) of this regulation; Before completing the change-in-service, perform a site assessment in accordance with Regulation .03 of this chapter; and To conduct the change-in-service, empty and clean the UST and piping by removing all flammable, combustible, and other liquids and accumulated sludge from the UST system.