1. A. 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.

2. B. 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:

   1. (1) API Recommended Practice 1604 “Closure of Underground Petroleum Storage Tanks”; and
   2. (2) PEI/RP 1700 “Recommended Practices for the Closure of Underground Storage Tank and Shop-Fabricated Aboveground Storage Tank Systems”.

3. C. Notification.

   1. (1) 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:

      1. (a) In writing on a form provided by the Department; and
      2. (b) At least 30 days before beginning the permanent closure or change-in-service, or within another reasonable time period determined by the Department.
   2. (2) 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.

   3. (3) 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:

      1. (a) After notifying the Department of a planned permanent closure or change-in-service of the UST system; and
      2. (b) Before completion of the permanent closure or change-in-service of the UST system.
   4. (4) 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.

4. D. Permanent Closure.

   1. (1) 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:

      1. (a) Removing the UST system from the ground; or
      2. (b) If approved by the Department, abandoning the UST system in place.
   2. (2) 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.

   3. (3) 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:

      1. (a) 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;
      2. (b) Unless otherwise directed by the Department, disconnect and remove all emptied lines;
      3. (c) Remove all aboveground portions of vent lines and cap the remaining lines at their bases; and
      4. (d) 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.

   4. (4) 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:

      1. (a) Purge all explosive vapors from the UST prior to removal from the excavation zone;
      2. (b) Monitor the UST with an appropriate meter for vapors before and during removal of the UST from the excavation zone;

      3. (c) Once the UST system has been removed from the excavation zone:

         1. (i) Retest the UST for flammable vapors and, if necessary, purge all remaining explosive vapors; and
         2. (ii) Make holes or openings in the UST to render it unfit for further use;
      4. (d) If the operation poses a threat to public safety, do not crush or cut up the UST on-site;
      5. (e) Dispose of the UST system materials at a location acceptable to the Department; and
      6. (f) Fill the former UST system excavation zone to grade with an appropriate fill material.

   5. (5) 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:

      1. (a) Do not fill the UST through a fill or vent pipe;
      2. (b) Provide proper openings by excavation, or other means, on the UST to facilitate cleaning and filling the UST;
      3. (c) Completely fill the UST with a solid, inert, and flowable material so there are no voids in the UST;
      4. (d) Dispose of any removed UST system materials at a location acceptable to the Department; and
      5. (e) Fill any excavated areas to grade with an appropriate fill material.

5. E. 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:

   1. (1) Notify the Department of the planned change-in-service of the UST system in accordance with §C(1) of this regulation;
   2. (2) Before completing the change-in-service, perform a site assessment in accordance with Regulation .03 of this chapter; and
   3. (3) 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.

Authority: Environment Article, §§4-402, 4-405, 4-407, 4-408, 4-410, 4-411, 4-411.1, 4-417, and 7-201 et seq., Annotated Code of Maryland

Effective date: February 4, 1991 (18:2 Md. R. 151)

Chapter revised effective November 4, 1996 (23:22 Md. R. 1498)

Regulation .01D amended effective June 29, 1998 (25:13 Md. R. 997)

Regulation .02F amended effective June 29, 1998 (25:13 Md. R. 997)

Regulations .01—.05 repealed and new Regulations .01—.05 adopted effective June 13, 2022 (49:12 Md. R. 642)