1. (i) When a UST system is out-of-service, the facility must continue operation and maintenance of corrosion protection in accordance with section 613-3.2(b) of this Subpart, and any leak detection in accordance with section 613-3.3(a) and (b) of this Subpart. Subpart 613-6 of this Part must be complied with if a release is confirmed.
2. (ii) Leak detection required under section 613-3.3(a) and (b) of this Subpart is not required as long as the UST system is empty. (The UST system is considered empty when all materials have been removed using commonly employed practices so that no more than 2.5 centimeters [one inch] of residue remain in the system.) However, leak detection required under section 613-3.3(a) and (b) of this Subpart must resume consistent with the original schedule or upon resumption of delivery of petroleum into the UST system, whichever is later.

3. (2) When a UST system is out-of-service for a period of 3 to 12 months, the facility must also comply with the following requirements:

   1. (i) leave vent lines open and functioning; and
   2. (ii) cap and secure all other piping, ancillary equipment, and manways.

4. (3) When a UST system is out-of-service for more than 12 months, the facility must permanently close the UST system in accordance with subdivisions (b) and (c) of this section.

   (b) Permanent closure.

5. (1) At least 30 days before beginning permanent closure, a facility must notify the department of its intent to permanently close, unless such action is in response to corrective action. Within 30 days after permanent closure, a facility must submit a registration application to the department, in accordance with section 613-1.9(f) of this Part, indicating that the UST system has been permanently closed.

6. (2) To permanently close a UST system:

   1. (i) The facility must empty and clean it by removing all liquids and accumulated sludge. Every tank that is part of a UST system that is permanently closed must also be either removed from the ground or filled with an inert solid material (such as sand or concrete slurry). If an inert solid material is used, all voids within the UST must be filled. All connecting and fill lines must be disconnected and removed or securely capped or plugged. Manways must be securely fastened in place. One of the following codes of practice (refer to section 613-1.10 of this Part for complete citation of references) must be adhered to in order to comply with this subparagraph:

      1. (a) API RP 1604, March 1996;
      2. (b) API RP 2016, August 2001;
      3. (c) API RP 1631, June 2001; or
      4. (d) NFPA 326, 2010 edition.

   2. (ii) The facility must ensure that all scheduled deliveries to the UST system are terminated.

      (c) Records for permanent closure.

      The facility must maintain for three years records that are capable of demonstrating compliance with closure requirements under this Subpart. In addition, the facility must transmit a copy of the records to the department within 30 days after permanent closure.

(a) Out-of-service UST systems.

(1)