In this chapter: A term in §B of this regulation has the meaning indicated; and A term not defined in §B of this regulation has: The meaning given to the term in a relevant statute or COMAR 26.10.01 or 26.10.02; or If not defined in a relevant statute or COMAR 26.10.01 or 26.10.02, the meaning attributed by common use. Terms Defined. “AST” has the meaning stated in COMAR 26.10.01.02B. “AST system” has the meaning stated in COMAR 26.10.01.02B. “Certified inspector” includes one of the following individuals certified to perform an inspection on a shop-fabricated AST: An authorized inspector, as defined in COMAR 26.10.18.02B, with an adjunct certification, as specified in STI/SPFA SP001 “Standard for the Inspection of Aboveground Storage Tanks”; or A certified AST tank system inspector, as specified in STI/SPFA SP001 “Standard for the Inspection of Aboveground Storage Tanks”. “Double-walled AST” means an AST that: Is manufactured as a storage tank within a storage tank; and Has an interstitial space between the primary storage tank and secondary storage tank walls that allows for: Tightness testing of both storage tank walls; and Monitoring of the interstitial space for a release from the primary storage tank. “Elevated AST” means an AST that is not in direct contact with soil by either: Being raised above the surface of the ground or bottom of a vault using supports designed to secure and support the AST from collapse when containing oil; or Resting on a surface material that does not allow moisture penetration or corrosion, such as concrete or steel. “Existing” means the installation or construction of an AST, an AST system, or a secondary containment dike was complete before June 13, 2022. “External inspection” means a formal inspection of an AST conducted by a certified inspector in accordance with STI/SPFA SP001 “Standard for the Inspection of Aboveground Storage Tanks” to assess the condition of the AST to determine its suitability for continued service without entry into the AST interior. “Formal inspection” means a documented external inspection or internal inspection of an AST conducted by a certified inspector in accordance with STI/SPFA SP001 “Standard for the Inspection of Aboveground Storage Tanks”. Internal Inspection. “Internal inspection” means a formal inspection of an AST conducted by a certified inspector in accordance with STI/SPFA SP001 “Standard for the Inspection of Aboveground Storage Tanks” to assess the internal and external condition of the AST to determine its suitability for continued service. “Internal inspection” includes the requirements of an external inspection in STI/SPFA SP001 “Standard for the Inspection of Aboveground Storage Tanks”. Interstitial Space. “Interstitial space” means: The space in a double-walled AST between the primary and secondary storage tank walls; or The space in a double-bottom AST that provides an open or closed void to allow monitoring for a release between two storage tank bottoms. “Interstitial space” includes an interstice and an annular space. “Maximum working level” means the liquid level of a shop-fabricated AST that should not be exceeded during normal filling procedures and is below the activation level of any overfill prevention equipment. “New” means the installation or construction of an AST, an AST system, or a secondary containment dike was complete on or after June 13, 2022. Out-of-Service. “Out-of-service” means an AST system in which the owner, the operator, and the person in charge of the AST system has: Emptied the AST system of all oil and sludge; and Designated the AST system as out-of-service in accordance with Regulation .13 of this chapter. “Out-of-service” includes a change-in-service in which an AST system is emptied of all oil and sludge in order to store a non-oil product. “Overfill” means an occurrence when an AST is filled beyond the overfill level and may result in a spill, release, or discharge of oil. “Overfill level” means the maximum design capacity of a shop-fabricated AST as determined by the AST manufacturer. “Repair” means work necessary to maintain or restore an AST system to a safe operating condition using industry approved standards. Secondary Containment Dike. “Secondary containment dike” means a secondary containment system that confines a spill, release, or discharge of oil from an AST or piping within the secondary containment system. “Secondary containment dike” includes diking and a dike. “Secured area” means an area of an oil storage facility or oil handling facility where the owner, the operator, and the person in charge of the facility protects oil storage operations and oil handling operations from unauthorized access by: Providing appropriate security around an AST system, including fencing; Marking an AST system with the fire hazard category for the type of product stored; Posting “No Trespassing” signs; and Providing an adequate security lighting system to: Prevent acts of vandalism; and Assist in the detection of spills, releases, and discharges. “Shop-fabricated AST” means a welded carbon steel or stainless steel AST fabricated in a manufacturing facility, or an AST not otherwise identified as field-erected. “Vault” means an enclosure that: May be located above or below grade; Consists of four walls, a floor, and a top for the purpose of containing an AST; Allows for the inspection, repair, or maintenance of the vault and an AST; and Is not intended to be occupied by an individual for an extended period of time. “Vaulted AST” means an AST enclosed within a vault.