# COMAR Title 26 — Department of the Environment

## Subtitle 10 — Oil Pollution Control and Storage Tank Management

### Chapter 10 — Out-of-Service UST Systems and Closure

**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

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

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

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

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

**Administrative History:** Regulations .01—.05 repealed and new Regulations .01—.05 adopted effective June 13, 2022 (49:12 Md.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

#### Regulation .01 Temporary Closure.

*COMAR 26.10.10.01*

A. When a UST system is temporarily closed, an owner and an operator of a UST system shall:

  (1) If a metal UST system, continue operation and maintenance of corrosion protection in accordance with COMAR 26.10.04.02;

  (2) Except as provided in §B(3) of this regulation, maintain a method of release detection in accordance with COMAR 26.10.05 and, if the UST system has a field-constructed tank or is an airport hydrant system, COMAR 26.10.12;

  (3) If a spill, release, or discharge is suspected or confirmed, comply with the reporting, investigation, and corrective action requirements in COMAR 26.10.08 and 26.10.09;

  (4) In accordance with COMAR 26.10.03.09, amend the registration for the UST system not later than 30 days following the temporary closure of the UST system; and

  (5) If a motor fuel, bulk oil storage, used oil, or hazardous substance UST system, perform the UST system inspections required in COMAR 26.10.03.10.

B. When a UST system is temporarily closed and the storage tank system is emptied by having all materials removed using commonly employed practices so that not more than 1 inch of residue or 0.3 percent by weight of the total capacity of the UST remain in the UST system, an owner and an operator of a UST system is not required to perform:

  (1) Operation and maintenance testing and inspections of spill and overfill prevention equipment, as required by COMAR 26.10.03.03;

  (2) Periodic operation and maintenance walkthrough inspections, as required by COMAR 26.10.04.03; and

  (3) Operation and maintenance testing and inspections of release detection equipment, as required by COMAR 26.10.05.

C. When a UST system is temporarily closed for 3 months or more, an owner and an operator of a UST system shall:

  (1) Leave the vent line open and functioning; and

  (2) Cap and secure all other lines, pumps, manways, and ancillary equipment.

D. When a UST system does not meet the performance standards for new UST systems in COMAR 26.10.03.01 or the upgrading requirements in COMAR 26.10.03.08, except for the requirements of COMAR 26.10.03.08F, and the UST system has been temporarily closed for more than 6 months, an owner and an operator of a UST system shall:

  (1) Permanently close the UST system in accordance with Regulations .02—.05 of this chapter; or

  (2) If the Department grants an extension, permanently close the UST system within the time period established by the Department and in accordance with Regulations .02—.05 of this chapter.

E. When a UST system meets the performance standards for new UST systems in COMAR 26.10.03.01 or the upgrading requirements in COMAR 26.10.03.08, and the UST system has been temporarily closed for more than 1 year, an owner and an operator of a UST system shall:

  (1) Permanently close the UST system in accordance with Regulations .02—.05 of this chapter; or

  (2) If the Department grants an extension, permanently close the UST system within the time period established by the Department and in accordance with Regulations .02—.05 of this chapter.

F. An owner and an operator of a temporarily closed UST system required to permanently close the UST system under §D or E of this regulation may apply to the Department for an extension to the required time period for completing the permanent closure by:

  (1) Completing a site assessment in accordance with the procedures in Regulation .03 of this chapter; and

  (2) Submitting a written site assessment report to the Department that includes, at a minimum, the following information:

    (a) The location of the UST system on the property;

    (b) The date the site assessment was performed;

    (c) A summary of any field test and the laboratory analytical results;

    (d) The name of the contractors who performed the work; and

    (e) All analytical data and laboratory reports.

#### Regulation .02 Permanent Closure and Changes-in-Service.

*COMAR 26.10.10.02*

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.

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) API Recommended Practice 1604 “Closure of Underground Petroleum Storage Tanks”; and

  (2) PEI/RP 1700 “Recommended Practices for the Closure of Underground Storage Tank and Shop-Fabricated Aboveground Storage Tank Systems”.

C. Notification.

  (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:

    (a) In writing on a form provided by the Department; and

    (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) 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) 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:

    (a) After notifying the Department of a planned permanent closure or change-in-service of the UST system; and

    (b) Before completion of the permanent closure or change-in-service of the UST system.

  (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.

D. Permanent Closure.

  (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:

    (a) Removing the UST system from the ground; or

    (b) If approved by the Department, abandoning the UST system in place.

  (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) 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:

    (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;

    (b) Unless otherwise directed by the Department, disconnect and remove all emptied lines;

    (c) Remove all aboveground portions of vent lines and cap the remaining lines at their bases; and

    (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) 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:

    (a) Purge all explosive vapors from the UST prior to removal from the excavation zone;

    (b) Monitor the UST with an appropriate meter for vapors before and during removal of the UST from the excavation zone;

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

      (i) Retest the UST for flammable vapors and, if necessary, purge all remaining explosive vapors; and

      (ii) Make holes or openings in the UST to render it unfit for further use;

    (d) If the operation poses a threat to public safety, do not crush or cut up the UST on-site;

    (e) Dispose of the UST system materials at a location acceptable to the Department; and

    (f) Fill the former UST system excavation zone to grade with an appropriate fill material.

  (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:

    (a) Do not fill the UST through a fill or vent pipe;

    (b) Provide proper openings by excavation, or other means, on the UST to facilitate cleaning and filling the UST;

    (c) Completely fill the UST with a solid, inert, and flowable material so there are no voids in the UST;

    (d) Dispose of any removed UST system materials at a location acceptable to the Department; and

    (e) Fill any excavated areas to grade with an appropriate fill material.

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) Notify the Department of the planned change-in-service of the UST system in accordance with §C(1) of this regulation;

  (2) Before completing the change-in-service, perform a site assessment in accordance with Regulation .03 of this chapter; and

  (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.

#### Regulation .03 Assessing the Site at Closure or Change-in-Service.

*COMAR 26.10.10.03*

A. Before applying for an extension for temporary closure or completing a permanent closure or change-in-service of a UST system, an owner and an operator of a UST system shall:

  (1) Perform a site assessment to determine if there is evidence of a spill, release, or discharge where contamination would most likely be present; and

  (2) In selecting sample types, sample locations, and measurement methods consider:

    (a) The method of closure;

    (b) The nature of the stored regulated substance;

    (c) The type of backfill;

    (d) The depth to groundwater; and

    (e) Other factors appropriate for identifying the presence of a spill, release, or discharge.

B. If contaminated soil, contaminated groundwater, free product, or vapor is discovered while performing the actions under §A of this regulation or by any other manner during a UST system closure or change-in-service activities, an owner, an operator, and a person in charge of a UST system shall:

  (1) Notify the Department within 2 hours of the discovery, as required in COMAR 26.10.08; and

  (2) Begin performing the response and corrective actions required in COMAR 26.10.09.

#### Regulation .04 Applicability to Previously Closed UST Systems.

*COMAR 26.10.10.04*

When directed by the Department, an owner and an operator of a UST system that was permanently closed before December 22, 1988 shall assess the excavation zone and close the UST system in accordance with this chapter if a spill, release, or discharge from the UST system may, in the judgment of the Department, pose a current or potential threat to human health and the environment.

#### Regulation .05 Closure Records.

*COMAR 26.10.10.05*

A. An owner and an operator of a UST system shall maintain records in accordance with COMAR 26.10.04.05 that demonstrate compliance with closure requirements under this chapter.

B. The owner and the operator of a UST system that took the UST system out-of-service or the current owner and operator of a property where the UST system was taken out-of-service shall:

  (1) Maintain the closure report required in §C of this regulation and the results of the site assessment required in Regulation .03 of this chapter for at least 5 years after completion of a permanent closure or change-in-service; and

  (2) Maintain the records specified in §B(1) of this regulation by:

    (a) Storing the records at the property; or

    (b) If the records cannot be stored at the property, submitting the records to the Department.

C. UST System Closure Report. An owner and an operator of a UST system that underwent a permanent closure or change-in-service shall submit to the Department a written UST system closure report:

  (1) Signed by the certified UST system technician or remover that performed the permanent closure or change-in-service;

  (2) Within 45 days of completing the UST system closure or change-in-service; and

  (3) That includes records documenting:

    (a) The permanent closure or change-in-service of the UST system was conducted in accordance with Regulation .02 of this chapter;

    (b) The site assessment was performed in accordance with Regulation .03 of this chapter; and

    (c) At a minimum, all of the following information:

      (i) The UST size;

      (ii) The location of the UST system on the property;

      (iii) The date of the UST system closure or change-in-service;

      (iv) The method used for the UST system closure or change-in-service;

      (v) A summary of the work performed;

      (vi) A summary of any field test and the laboratory analytical results;

      (vii) The name and certification number of the certified UST system technician or remover, and name of the contractors who performed the work;

      (viii) If permanently closed by removal, a receipt documenting proper disposal of the UST system;

      (ix) A receipt documenting proper treatment or disposal of excavated oil-contaminated soils;

      (x) All analytical data and laboratory reports; and

      (xi) Photographs of each UST system taken out-of-service and each excavation zone.

D. An owner and an operator of an underground farm tank, an underground residential tank, and an underground residential heating oil tank that does not meet the definition of a UST shall submit a written storage tank closure report in accordance with the requirements in §C of this regulation if:

  (1) A spill, release, or discharge occurred at the property that required the owner and the operator of the underground storage tank to notify the Department in compliance with COMAR 26.10.08 and 26.10.09; or

  (2) The Department directs the owner and the operator of the underground storage tank to submit a storage tank closure report.