Underground Storage Tank System Management

1. (a) Applicability and partial exemptions

   1. (1) Applicability Owners and operators of the following types of UST systems shall comply with the requirements of this section:

      1. (A) UST systems used solely for storing heating oil for heating on the premises where stored; and(B) Farm UST systems or former farm UST systems of 1,100 gallons or less capacity used for storing motor fuel that is not re-sale.

   2. (2) Partial Exemptions.

      1. (A) An UST system which satisfies all of the following criteria is exempt from subsections (d) and (h) of this section:

2. (i) The capacity of the UST associated with such system is less than 2,100 gallons;

   1. (ii) The sole intended use of the oil or petroleum liquid is for heating on the premises where stored; and(iii) The UST is double walled and installed on or after October 1, 2003.
   2. (B) An UST system which satisfies both of the following criteria is exempt from subsection (g)(9) of this section:
3. (i) The sole intended use of the oil or petroleum liquid is for heating on the premises where stored; and(ii) The UST associated with such system is single-walled and installed prior to October 1, 2003.

4. (b) DefinitionsWhen used in this section, the following terms shall have the following meanings:

   1. (1) “Abnormal loss or gain” means an apparent loss or gain in liquid exceeding 0.5 percent of (A) the volume of product used or sold by the owner or operator during any 7 consecutive day period, or (B) the volumetric capacity of the tank; whichever is greater, as determined by reconciliation of inventory measurements made in accordance with subsection (g) of this section;
   2. (2) “Closure” means removing an UST from the ground or rendering an UST permanently unusable (with or without any connected piping) or removing or rendering permanently unusable more than 50 percent of the piping associated with an UST, and for either tank or piping, as applicable, performing the assessment required by subsection (j) of this section;
   3. (3) “Commissioner” means the Commissioner of Energy and Environmental Protection or the commissioner’s designee;
   4. (4) “Department” means the Connecticut Department of Energy and Environmental Protection;
   5. (5) “Dispenser” means equipment located above ground that delivers oil or petroleum liquid transferred to a point of use outside the UST system;
   6. (6) “Failure” means a condition which can or does allow the uncontrolled passage of liquid into or out of any portion of an UST system, including, but not limited to, the primary or secondary containment system;
   7. (7) “Failure determination” means an evaluation to determine whether a failure has occurred using any test that takes into consideration the temperature coefficient of expansion of the product being tested as related to any temperature change during the test, is capable of detecting a loss of 0.05 gallons per hour, and is conducted in accordance with a code of practice or other standard developed by a nationally recognized association or independent testing laboratory;
   8. (8) “Farm” means a tract of land devoted solely to the commercial production of crops or raising of animals, including, but not limited to, fish, and associated residences and improvements, including fish hatcheries, rangeland and nurseries with growing operations;
   9. (9) “Flammable liquid” means a flammable liquid as determined in accordance with NFPA 30 and having a flash point below 100 degrees Fahrenheit (37.8 degrees centigrade) and having a vapor pressure not exceeding 40 pounds per square inch (absolute) (2,068 millimeters mercury) at 100 degrees Fahrenheit (37.8 degrees centigrade);
   10. (10) “Life expectancy” means the time frames specified in subsection (h) of this section;
   11. (11) “Liquid” means any fluid, including, but not limited to, oil and petroleum fluids;
   12. (12) “NFPA” means National Fire Protection Association;
   13. (13) “Nonresidential” means, when referring to an UST system, an UST system which serves any commercial, industrial, institutional, public or other building, including, but not limited to, hotels and motels, boarding houses, hospitals, nursing homes and correctional institutions, and residential buildings with greater than four living units;
   14. (14) “Oil or petroleum liquid” means oil or petroleum of any kind in liquid form including, but not limited to, used oil, waste oils, bio-fuel blends, and distillation products such as fuel oil, kerosene, naphtha, and gasoline;
   15. (15) “Operator” means the person or municipality in control of or having responsibility for the daily operation of an UST system;
   16. (16) “Owner”' means the person or municipality in possession of or having legal ownership of an UST system;
   17. (17) “Release” means any spilling, leaking, pumping, pouring, emitting, emptying, discharging, injecting, escaping, leaching, dumping or disposing of oil or petroleum liquids from any UST system, including but not limited to, into secondary containment, or into or onto anything, anywhere, except from the dispenser into a tank, container or similar device used to hold or contain oil or petroleum liquid, or as otherwise authorized by the commissioner;
   18. (18) “Residential building” means any house, apartment, trailer, mobile home, or other structure, composed of four living units or fewer, occupied by individuals solely as a dwelling;
   19. (19) “Tank” means a stationary object designed to contain, or that contains, an accumulation of oil or petroleum liquid and constructed of non-earthen materials including, but not limited to, concrete, steel, fiberglass, and plastic, that provide structural support;
   20. (20) “Underground storage facility” means a parcel of real property on which an UST or UST system is located;
   21. (21) “Underground storage tank” or “UST” means any one or combination of tanks (including underground pipes connected thereto) that is used or designed to contain, or that contains, an accumulation of substances referenced in subsections (a)(1)(A) and (a)(1)(B) of this section, and the volume of which (including the volume of underground pipes connected thereto) is 10 percent or more either beneath the surface of the ground or covered with earthen material;
   22. (22) “UST system” means a system of interconnected tanks, pipes, pumps, vaults, fixed containers and appurtenant structures, singly or in any combination, which is used or has been used for the storage, transmission or dispensing of oil or petroleum liquids, including any monitoring devices, and for which 10 percent or more of the volumetric capacity of the UST system is below the surface of the ground and that portion which is below the surface of the ground is not fully visible for inspection. “UST system” does not include residential underground heating oil storage tank systems;
   23. (23) “UST system component” means any of the following items associated with the use of an UST: an underground storage tank, connected piping, dispensers, spill buckets, containment sumps or release detection and release prevention equipment. “UST system component” does not include piping that does not routinely contain regulated substances or items associated with routine maintenance such as filters or o-rings;
   24. (24) “Under-dispenser containment sump” means containment underneath a dispenser system designed to prevent a release from the dispenser and piping within or above the under-dispenser containment sump from leaving the UST system.
5. (c) Releases prohibitedAn owner and operator shall ensure that there is no release of any water, substance or material, including, but not limited to, oil or petroleum liquids from an UST system.

6. (d) Notification requirements

   1. (1) The owner or operator of an UST system shall submit to the commissioner and the local fire marshal:

      1. (A) The annual notification required under section 22a-449(e) of the Connecticut General Statutes. Such notification shall be submitted within the time period specified by the commissioner on the department’s internet website. The time period shall be a minimum of 30 days and shall conclude not later than October 10 of each year; and(B) As applicable, notification of each of the following events within 30 days of such event:

7. (i) The installation of an UST system(ii) The permanent closure of an UST system(iii) Any change in information provided in any prior notification submitted to the commissioner and the local fire marshal in accordance with this subsection, including temporarily taking an UST system out of service.

   1. (2) Each notification required by this subsection shall be submitted by the owner or operator on forms furnished by and in a manner prescribed by the commissioner on the department’s internet website, including an electronic submission and shall contain all information prescribed by the commissioner. Each notification shall be accompanied by any fee as required by sections 22a-449(e) and 22a-449(h) of the Connecticut General Statutes and shall be deemed incomplete if not accompanied by the required fee.

8. (e) Design and constructionThe owner or operator of each UST system shall ensure compliance with the following requirements:

   1. (1) Tanks. Each tank that is part of an UST system shall:

      1. (A) Be properly designed and constructed in accordance with a code of practice developed by a nationally recognized association or independent testing laboratory, unless the commissioner has posted on the department’s internet website that use of such code of practice is unacceptable. In addition, the commissioner may post codes of practice deemed acceptable on the department’s internet website;
      2. (B) Be constructed of one of the following:

9. (i) Fiberglass-reinforced plastic;

   1. (ii) Steel coated with a factory applied suitable dielectric material approved by the manufacturer of such tank for the proposed use and is equipped with corrosion protection through the use of either:

   2. (I) Galvanic cathodic protection attached to the tank; or (II) An impressed current cathodic protection system that allows the owner or operator to determine whether such impressed current system is properly operating;

      1. (iii) Steel and clad or jacketed with a non-corrodible material; or(iv) A material or materials posted on the department’s internet website;
   3. (C) Be equipped with contact plates under all fill and gauge openings;
   4. (D) If installed on or after October 1, 2003, be a double-walled UST and have secondary containment that can fully contain oil or petroleum liquid leaked from the primary containment until the leak is detected and removed and the secondary containment shall prevent the release of oil or petroleum liquid from the tank at any time during the operational life of such tank; and(E) (i) If installed on or after October 1, 2003, but on or before August 5, 2025 shall continuously monitor the interstitial space of the tank using inert gas, liquid, a vacuum, electronic monitoring, or mechanical monitoring; and(ii) If installed after August 5, 2025, shall have continuous interstitial monitoring that monitors both primary containment and secondary containment such that the inner and outer walls are continuously monitored using technology such as inert gas, liquid, or a vacuum.

   5. (2) Piping. Piping that routinely contains oil or petroleum liquid and is part of an UST system shall:

      1. (A) Be properly designed and constructed in accordance with a code of practice developed by a nationally recognized association or independent testing laboratory, unless the commissioner has posted on the department’s internet website that use of such code of practice is unacceptable. In addition, the commissioner may post codes of practice deemed acceptable on the department’s internet website;
      2. (B) (i) If installed before May 7, 2025, be constructed of corrodible or non-corrodible material. If the piping is constructed of corrodible material, such piping shall not come in contact with the ground or any water unless such piping is:
      3. (I) Coated with a suitable factory applied dielectric material approved by the manufacturer of such piping for the proposed use; and(II) Equipped with galvanic cathodic protection attached to the piping, or an impressed current cathodic protection system that allows the owner or operator to perform a structure to soil voltage test of such system to determine whether such system is properly operating; and(ii) If installed on or after May 7, 2025, be constructed of a non-corrodible material, provided this requirement shall not apply to piping that does not come into contact with the ground or any water; and(C) If installed on or after October 1, 2003:
10. (i) Be double-walled with secondary containment that is capable of containing oil or petroleum liquid released from primary containment and prevent the release of oil or petroleum liquid from the piping at any time during the operational life of the UST system; and(ii) Be equipped with interstitial monitoring, that, at a minimum, has sensors at both ends of the piping run or a vacuum that provides continuous interstitial monitoring; and(D) For piping that conveys oil or petroleum liquid under pressure, be equipped with an automatic line leak detector capable of detecting the presence of a release of 3 gallons per hour at 10 pounds per square inch line pressure within 1 hour by restricting or shutting off the flow of oil or petroleum liquid through piping. The requirements of this subparagraph shall be applicable as follows:

11. (i) On May 7, 2025, for all piping that conveys oil or petroleum liquid under pressure installed on or after such date; and (ii) On August 5, 2025, for all piping that conveys oil or petroleum liquid under pressure installed before May 7, 2025.

    1. (3) Cathodic protection systems. All cathodic protection systems required by this subsection shall meet the specifications of the manufacturer of any component being protected and shall provide continuous corrosion protection.

    2. (4) Spill and overfill prevention equipment. Each UST system shall be equipped with the following:

       1. (A) Spill prevention equipment, such as a spill bucket, capable of containing the amount of oil or petroleum liquid in a transfer hose used to deliver oil or petroleum liquid to an UST when such hose is detached from the fill pipe. Spill buckets that are part of an UST system shall be liquid tight. No spill bucket shall be less than 5 gallons; and(B) Overfill prevention equipment that will alert the transfer operator when an UST is reaching its maximum capacity to prevent overfilling.

    3. (5) Containment sumps.

       1. (A) Under Dispenser Containment Sump. Except for UST systems that do not have a dispenser, each UST system shall comply with the following requirements:

12. (i) On or after May 7, 2027:

    1. (I) Each UST system installed shall be equipped with under-dispenser containment sumps that comply with the requirements specified in subparagraph (C) of this subdivision;

       1. (II) Each under-dispenser sump installed, replaced or repaired shall comply with the requirements specified in subparagraph (C) of this subdivision; and(ii) On or after May 7, 2027 no owner or operator shall use an UST system with a dispenser, unless such dispenser is equipped with an under-dispenser containment sump that complies with the requirements specified in subparagraph (C) of this subdivision.
    2. (B) Piping Containment Sump.

13. (i) Each UST system installed shall be equipped with piping containment sumps that comply with the requirements specified in subparagraph (C) of this subdivision;

    1. (ii) Each piping containment sump installed after May 7, 2025 shall comply with the requirements specified in subparagraph (C) of this subdivision; and(iii) On or after May 7, 2027, no UST system shall be used, unless such UST system is equipped with piping containment sumps that comply with the requirements specified in subparagraph (C) of this subdivision.
    2. (C) Each under-dispenser containment sump or piping containment sump, as applicable, shall:

14. (i) Prevent any liquid that may accumulate in such containment sump, including liquid from the piping or pump, and liquid from the dispenser from leaving the containment sump;

    1. (ii) Be capable of immediate visual inspection and provide immediate access to the components of such sump and the components contained therein;
    2. (iii) Be equipped with an alarm or other device such as a sensor that is capable of immediately alerting the owner or operator whenever any liquid, including precipitation, is present in any such sump. The alarm or other device shall:

    3. (I) Operate as intended:

       1. (II) Not be removed, disabled, or otherwise rendered inoperable; and(III) Be located at the lowest point within the containment sump so that any liquid present in such sump can be detected.

    4. (6) Dispensers. On or after May 7, 2027, all dispensers shall be equipped with the following:

       1. (A) A breakaway device compatible with the oil or petroleum liquid being dispensed that is installed in a vehicle fueling hose that separates when excessive pulling force is applied to the hose, including when a vehicle leaves the dispenser area with the nozzle from the fueling hose still in the vehicle fill pipe. When excessive pulling force is applied to such hose, a breakaway device shall prevent the flow of liquids from either section of the parted hose as well as protect the dispenser from damage; and(B) A shear valve or crash valve that, when fueling occurs under pressure, automatically shuts off the flow of fuel to the dispenser in the event of a fire inside the dispenser or a severe impact to the dispenser; and(C) A mechanism or a design for ensuring that a fuel dispensing hose is not on the ground when such hose is not in use.

15. (f) Installation

    1. (1) Installation Requirements. The owner or operator of each UST system shall ensure compliance with the following requirements:

       1. (A) All components of an UST system shall be installed, maintained, and repaired in accordance with a code of practice developed by a nationally recognized association or an independent testing laboratory and in accordance with the manufacturer’s specifications and instructions, unless the commissioner has posted on the department’s internet website that use of such code of practice is unacceptable. If the provisions of a code of practice or manufacturer instruction are inconsistent, the most stringent and protective requirement shall be applied.
       2. (B) All work listed in the manufacturer’s checklist for the installation of a tank or piping or a similar document from the manufacturer regarding installation of a tank or piping shall be completed and one of the following conditions shall be satisfied:

16. (i) The manufacturer has certified the installer, in writing, to install such equipment; or (ii) The installation has been inspected and approved, in writing, by a registered professional engineer licensed in the state of Connecticut and who has education and experience in UST and piping installation.

    1. (C) Within 30 days after completion of installation of an UST, the owner or operator shall submit to the commissioner, in a manner and on a form prescribed by the commissioner, a statement signed by the installation contractor certifying that the installation has been carried out in accordance with this subsection.

    2. (2) Installation Testing. The owner or operator of each UST system shall ensure compliance with the following requirements:

       1. (A) No UST system installed on or after May 7, 2025, shall contain any oil or petroleum liquid until testing has been conducted that demonstrates that there is no release or loss of any liquids from any component of such system. The person who performs the testing shall have the required qualifications to perform such testing and the owner or operator shall retain the results of such testing.
       2. (B) Any test conducted to satisfy the requirements of subparagraph (A) of this subdivision shall be performed in accordance with the manufacturer’s guidelines and standards. If there are no manufacturer’s guidelines or standards, the owner or operator shall perform such tests in accordance with an applicable method specified in an industry code or engineering standard. If there are no applicable manufacturer’s guidelines or standards, industry codes, or engineering standards, the owner or operator shall perform such tests using a test method that, before use, is approved in writing, by a registered professional engineer licensed in the state of Connecticut.
       3. (C) Notwithstanding subparagraph (B) of this subdivision, an owner or operator shall not use a test method to comply with subparagraph (A) of this subdivision if the commissioner has posted on the department’s internet website that use of such test method is unacceptable. In addition, the commissioner may post on the department’s internet website test methods deemed acceptable.

17. (g) Operation and maintenance requirementsThe owner or operator of each UST system shall comply with the following requirements:

    1. (1) Each UST system shall be made of materials that are compatible with any oil or petroleum liquid stored in such system. This requirement shall apply to the entirety of an UST system.

    2. (2) (A) The owner or operator of an UST system storing greater than 10 percent ethanol or greater than 20 percent biodiesel shall demonstrate to the commissioner upon request that such oil or petroleum liquid are compatible with the tank, piping, containment sumps, under-dispenser containment sumps, pumping equipment, release detection equipment, and spill and overfill equipment parts of an UST system using one of the following options:

       1. (i) Certification or listing of UST system equipment or components by a nationally recognized independent testing laboratory for use with such oil or petroleum liquid; or(ii) An affirmative statement of compatibility in writing from the equipment or component manufacturer that specifies the range of ethanol or biofuel blends with which the equipment or component is compatible.
       2. (B) Documentation demonstrating compliance with the requirements of subparagraph (A) of this subdivision shall be obtained by November 3, 2025 and maintained in accordance with subsection (g) of this section.
    3. (3) All corrosion protection systems shall be operated and maintained to continuously provide corrosion protection to the metal components of that portion of the tank and piping that routinely contain oil or petroleum liquid and are in contact with the ground or water. Such corrosion protections shall, at a minimum, be maintained continuously at least minus 0.85 volts, measured between the structure and a copper-copper sulfate electrode.
    4. (4) All cathodic protection systems which protect UST system components shall be tested annually using a structure to soil test voltage test. In order to pass the test, a reading of at least minus 0.85 volts measured between the structure and a copper-copper sulfate electrode shall be maintained.
    5. (5) Impressed current cathodic protection systems, in addition to subdivision (4) of this subsection, shall also be checked monthly to ensure that the system rectifier providing the source of current is operating properly. A monthly record of rectifier current and voltage output shall be maintained.

    6. (6) If any cathodic protection system malfunctions or fails to meet the structure to soil test voltage requirement specified in subdivision (4) of this subsection, the following requirements shall apply:

       1. (A) If such system achieved a passing test within the previous 5 years, the system shall be repaired as quickly as possible, but not later than 30 days from the date of discovery of the malfunction or failed test. If the repair cannot be done within this 30-day period, the owner or operator shall empty the tank of liquid to less than 1 inch not later than the end of this 30-day period and ensure that the system is repaired not later than 60 days from the date of discovery of the malfunction or failed test. If the system is not repaired within this 60-day period, the system shall be closed in accordance with subsection (j) of this section unless otherwise provided by the commissioner in writing.
       2. (B) If such system did not achieve a passing test within the previous 5 years, the UST system shall immediately be emptied to less than 1 inch and shall be closed in accordance with subsection (j) of this section.

    7. (7) (A) Except for a dispenser, no other component of an UST system shall be moved or relocated for use at another location, including another location at the same underground storage facility, without the prior written approval of the commissioner. An approval under this section may include any conditions the commissioner deems appropriate;

       1. (B) No tank or piping shall be moved or relocated from one location to another unless such tank or piping is in compliance with section 22a-449o of the Connecticut General Statutes. For purposes of this subdivision, the life expectancy of a tank or piping that routinely contains product relocated under this section shall be based on the date such tank or piping was originally installed, not the date such UST or piping was relocated; and(C) An owner or operator of an UST system shall not install or reinstall a dispenser from another location, including another location at the same underground storage facility, unless such dispenser is equipped with a containment sump that meets the requirements of an under-dispenser containment sump in accordance with subsection (e)(5) of this section.

    8. (8) Methods of Release Detection for Double-Walled Petroleum USTs. A double-walled UST shall use interstitial monitoring that complies with the requirements of this subdivision:

       1. (A) The owner or operator of a double-walled tank installed before October 1, 2003, shall perform release detection using any method that complies with the requirements of this subsection, provided that on or after May 7, 2027, such owner or operator shall use monitoring that complies with subparagraphs (B) or (C) of this subdivision.
       2. (B) For a double-walled UST installed on or after October 1, 2003, but before August 5, 2025, the release detection shall continuously monitor the interstitial space between the walls of the UST or conduct interstitial monitoring that complies with subparagraph (C) of this subdivision.
       3. (C) For a double-walled UST installed on or after August 5, 2025, the release detection shall continuously monitor the integrity of the walls of the tank for a potential failure of the primary and the secondary containment, including both the inner and outer walls of such tank, using technology such as systems that are hydrostatically monitored or under constant vacuum.

    9. (9) Methods of Release Detection for Single-Walled Petroleum USTs.

       1. (A) (i) For a single-walled UST system, the following information shall be recorded on a daily basis, the amount of oil or petroleum liquids used and received, and the level of water and product in the tank; and on a weekly basis, a reconciliation comparing these figures to determine whether an abnormal loss or gain has occurred;

          1. (ii) Separate records shall be maintained for each system of interconnected tanks and serving pumps or dispensers; and (iii) The owner or operator for each UST system shall review such records and attest to their accuracy by signing them, including by electronic signature, not later than 7 days after the recordation of such data.
       2. (B) Daily inventory measurements shall be made by gauge or gauge stick or by readout from a listed automatic monitoring device. Such measuring devices shall be calibrated in accordance with the manufacturer’s specifications and recommendations and be capable of measuring the level of product over the full range of the tank’s height to the nearest one-eighth of an inch. The oil or petroleum liquid inputs shall be reconciled with delivery receipts by measurement of the tank inventory volume before and after delivery. The measurement of any water level in the bottom of the tank shall be made to the nearest one-eighth of an inch at least once a day.
       3. (C) Daily inventory measurements do not need to be recorded on those days when an UST system is not in operation, except that if such period exceeds 15 consecutive days inventory measurements shall be recorded on every 15th day. A day on which product is delivered to the UST system shall be considered a day of operation.
       4. (D) The commissioner may require an owner or operator to perform a failure determination of any UST system for which daily inventory records are not maintained in accordance with this subsection.
       5. (E) When inventory reconciliation indicates an abnormal loss or gain which is not due to spillage, temperature variations or other known causes, the owner or operator shall immediately investigate and correct the source of the abnormal loss or gain. At a minimum, the owner or operator shall take as many of the following steps as necessary to confirm an abnormal loss or gain:

18. (i) When an inventory record error is not apparent, conduct a recalculation to determine abnormal loss or gain starting from a point where the records indicate no abnormal loss or gain;

    1. (ii) Perform a detailed visual inspection of those components of the UST system which are readily accessible for evidence of failure;
    2. (iii) Check the dispensers of the particular oil or petroleum liquid in question for proper calibration;
    3. (iv) Perform a failure determination on the piping system between the tank and dispensers in accordance with subsection (i) of this section; and(v) Perform a failure determination on the tank in accordance with subsection (i) of this section.
    4. (F) When an abnormal loss or gain is confirmed, the owner or operator shall immediately report the abnormal loss or gain to the commissioner in accordance with section 22a-450 of the Connecticut General Statutes and sections 22a-450-1 to 22a-450-6, inclusive, of the Regulations of Connecticut State Agencies, as soon as possible, but in no event later than 1 hour after the discovery of the release. The report shall be made using a telephone number specified by the commissioner or some other method for reporting UST releases specified by the commissioner on the department’s internet website.
    5. (G) Beginning November 3, 2025 and notwithstanding subparagraph (E) of this subdivision, a failure determination shall be conducted on all UST systems every 5 years until such systems reach their applicable life expectancy in accordance with subsection (h) of this section.

19. (h) Life Expectancy

    1. (1) No owner or operator of an UST system shall use or operate any tank or piping that routinely contains product beyond its life expectancy as determined in accordance with this subsection. Prior to the last day of the life expectancy of any such tank or piping, the owner or operator shall close such tank or piping in accordance with the closure requirements specified in subsection (j) of this section.
    2. (2) Life expectancy shall be 30 years from the date of installation of each tank or piping. No owner or operator of an UST system shall operate any tank or underground piping that routinely contains product beyond its life expectancy. If the installation date of an UST system component cannot be determined, such component(s) shall be permanently closed in accordance with subsection (j) of this section.
    3. (3) Life expectancy shall be 45 years for a double-walled tank or piping made of fiberglass-reinforced plastic, or any other non-metallic material and using continuous interstitial monitoring that monitors both the primary containment and secondary containment such that the inner and outer wall are continuously monitored using technology such as inert gas, or liquid, or under constant vacuum.
    4. (4) Any tank or piping whose date of installation is unknown shall be deemed beyond the life expectancy upon May 7, 2025 and shall be closed in accordance with subsection (j) of this section.
    5. (5) Notwithstanding the provisions of subdivisions (2) and (3) of this subsection, the period of life expectancy for either tanks or piping that routinely contains product, may upon request to the commissioner, or upon the commissioner’s own initiative, be modified by the commissioner. The commissioner may request any information the commissioner deems necessary in responding to such request. Any modification by the commissioner under this subsection may include any conditions the commissioner deems appropriate.

20. (i) Failures

    1. (1) An owner or operator of an UST system shall report any failure immediately, in accordance with section 22a-450 of the Connecticut General Statutes and sections 22a-450-1 to 22a-450-6, inclusive, of the Regulations of Connecticut State Agencies.

    2. (2) The owner or operator of an UST system at which a failure of any UST system component occurs shall immediately empty and discontinue the use of the failed UST system component and:

       1. (A) Remove or abandon such component within 90 days in accordance with procedures specified in subsection (j) of this section;
       2. (B) Repair such component within 60 days; or(C) Replace all damaged components in accordance with the design and construction requirements in subdivision (e) of this section.
    3. (3) The owner or operator of an UST system which releases oil or petroleum liquids without a permit issued pursuant to section 22a-430 of the Connecticut General Statutes shall immediately cease such release and reclaim, recover and properly dispose of the discharged liquid and any other substance contaminated by the release, restore the environment to a condition and quality acceptable to the commissioner, and shall otherwise repair all damage caused by the release, all to the satisfaction of the commissioner.
    4. (4) When a failure occurs at an UST system, the owner or operator shall ensure all of the system’s components are evaluated within 30 days to determine whether there are conditions similar to those that caused the failure. Within 10 days following such evaluation, the owner or operator shall notify the commissioner in writing of the methods and results of each such evaluation. If an additional failure is detected, the owner or operator shall act in accordance with this subsection.

21. (j) Closure of UST systems

    1. (1) An UST system or UST system component shall be closed in accordance with all applicable laws, regulations, codes, and standards, except for any code or standard identified by the commissioner on the department’s internet website as unacceptable for the closure of an UST system or UST system component.

    2. (2) At a minimum, the closure of an UST system shall comply with the following requirements:

       1. (A) The entire UST system is emptied and cleaned by removing all liquids and accumulated sludges.
       2. (B) After removal of such liquids and sludges:

22. (i) For each tank or UST not being closed in place, remove from the ground; or(ii) For each tank or UST being closed in place, prior to filling the UST with a solid inert material, conduct the requirements prescribed in subparagraphs (C) and (D) of this subdivision; and(iii) All piping shall be removed from the ground or capped.

    1. (C) An assessment shall be performed at the time of closure and shall include an evaluation of the presence of a release or potential release at all locations where contamination is most likely to be present at the underground storage facility. The selection of sample types, sample locations, and analytical methods, shall take into account the nature of the stored substance, the type of backfill, the depth to groundwater, the presence of rainwater or groundwater, and other factors appropriate for identifying the presence, or potential presence, of a release. Sample locations shall include, at a minimum:

23. (i) all sides and the bottom of the area where a tank has been removed or closed in-place;

    1. (ii) areas of staining, areas where holes or perforation in the removed tank are visible;
    2. (iii) areas where spill buckets, containment sumps, or dispensers were used; and (iv) in the case of piping undergoing closure, at least one sample is taken at every 10-foot interval of piping, but for intervals of less than 10 feet, at least one sample.
    3. (D) All sampling and analysis conducted in accordance with subparagraph (C) of this subdivision shall meet the following requirements:

24. (i) Sample collection and analysis shall comply with appropriate chain-of-custody procedures to ensure sample integrity and all samples shall be analyzed by a laboratory that is either certified by the Connecticut Department of Public Health or approved in writing by the commissioner; and (ii) All analytical data used shall be scientifically valid and defensible, with a level of precision, accuracy, and sensitivity commensurate with its intended use. All analytical data shall include an analytical data quality assessment and data usability evaluation prepared by individuals qualified to make such assessment or evaluation in accordance with the requirements in the remediation standard regulations adopted pursuant to section 22a-133k of the Connecticut General Statutes. If the commissioner determines that analytical data is not scientifically valid and defensible, or not of a sufficient level of precision, accuracy, and sensitivity to support the intended use of the data, the commissioner shall identify in writing the reasons for such conclusions and such data shall not be relied upon to demonstrate compliance with this section.

    1. (iii) All results of sampling performed under subdivisions (C) and (D) of this subsection shall be retained in accordance with subsection (l) of this section.

    2. (3) If at any time during closure a release is suspected or confirmed, the owner or operator shall:

       1. (A) Report the release in accordance with subsection (i)(1) of this section.
       2. (B) Investigate, remediate, and repair any damage caused by the release in accordance with subsection (i)(3) of this section.
       3. (C) Prepare and submit a closure report that, at a minimum, summarizes the assessment completed in accordance with subdivision (2)(C) of this subsection, provides the complete sample results and analytical data compiled as a result of such assessment, and provides a map showing the extent and concentration of all releases, including locations of samples.
    3. (4) If the activities undertaken pursuant to this subsection, or the report prepared pursuant to subdivision (3)(C) of this subsection regarding closure are not completed to the satisfaction of the commissioner, the commissioner shall notify the owner or operator in writing, identifying what the commissioner deems unsatisfactory, the reasons why and what additional actions are necessary. The owner or operator shall undertake any actions requested by the commissioner within 60 days after receipt of request or within such other time as the commissioner specifies.

25. (k) Transfer of UST system ownership, possession or controlNo owner or operator shall transfer ownership, possession or control of any UST system without full disclosure to the transferee of the status of the UST system’s compliance with this section at least 15 days prior to the transfer. Such disclosure shall include an up-to-date copy of the information submitted to the commissioner pursuant to subsection (d) of this section.

    1. (1) Recordkeeping. The owner or operator of an UST system shall maintain all records regarding each component of the UST system, including installation, operation, maintenance, compatibility, inspection, testing, calibration, release detection, repair, release or suspected release, closure, and any record or report required to demonstrate compliance with any requirement of this section, other than records relating to routine maintenance of such system which includes changing filters or lubricating parts.

    2. (2) The owner or operator of an UST system shall maintain the records described in subdivision (1) of this subsection:

       1. (A) At the underground storage facility during the operational life of an UST system component, except as may be provided for in section 22a-449q of the Connecticut General Statutes; and(B) At any location after the operational life of an UST system component. Such records shall be maintained and made available for inspection for one year beyond the operational life of such component.

    (l) Records

(Effective July 28, 1994; Amended May 31, 2012; Amended May 7, 2025)