(3) Requirements for Tanks.

1. (a) Tanks (except tanks used to supply regulated substance to emergency engines) installed on or after January 1, 1989, and tanks used to supply regulated substance to emergency engines installed on or after January 2, 2015, shall be equipped with a system that continuously monitors interstitial space.

   1. 1. The interstitial monitors shall be installed and operated in accordance with the manufacturers' specifications.
   2. 2. The system shall comply with 310 CMR 80.26(3).
   3. 3. The interstitial monitoring shall detect leakage through the inner wall of any tank.
   4. 4. For UST systems using continuous vacuum, pressure, or hydrostatic methods (including brine systems) of interstitial monitoring, the method shall be capable of detecting a breach in the inner and outer walls of the tank.

2. (b) Tanks, except tanks used to supply regulated substance to emergency engines, installed before January 1, 1989, shall be equipped with at least one of the leak detection methods listed 310 CMR 80.19(3)(b)1. through 4. No later than October 13, 2022, tanks used to supply regulated substance to emergency engines that were installed before January 2, 2015, shall be equipped with at least one of the leak detection methods listed at 310 CMR 80.19(3)(b)1. through 4.

   1. 1. A system that continuously monitors interstitial space.

      1. a. The sensors shall be installed in accordance with the manufacturers' specifications.
      2. b. The system shall comply with 310 CMR 80.26(3).
      3. c. The interstitial monitoring shall detect leakage through the inner wall of any tank.
   2. 2. An in-tank monitoring system that is used to test the tank at least once a month over the continuous period of time prescribed by the manufacturer's specifications to determine if there is a release or leakage. If the manufacturer's specifications do not prescribe a continuous period of time, the continuous period of time shall be six hours. The system shall be capable of detecting a release or leakage of 0.20 gallons per hour with the probability of detection of 0.95 and a probability of false alarm of 0.05 as determined by an independent testing laboratory using the U.S. Environmental Protection Agency Standard Test Procedures for Evaluating Leak Detection Methods (EPA-510-B- 19-002, May 2019) or other equivalent test procedures and complies with 310 CMR 80.26(4).
   3. 3. A continuous in-tank monitoring system installed and operated in accordance with the manufacturers' specifications that is capable of detecting a release or leakage of 0.20 gallons per hour with the probability of detection of 0.95 and a probability of false alarm of 0.05 as determined by an independent testing laboratory using the U.S. Environmental Protection Agency Standard Test Procedures for Evaluating Leak Detection Methods (EPA-510-B-19-002, May 2019) or other equivalent test procedures and complies with 310 CMR 80.26(5).

   4. 4. An in-tank monitoring system installed, operated and maintained by a qualified person with inventory data analysis conducted by a trained statistical inventory reconciliation (SIR) vendor. The SIR testing or monitoring methods shall meet the following requirements:

      1. a. Report a quantitative result with a calculated leak rate;
      2. b. Be capable of detecting a release or leakage of 0.20 gallons per hour with the probability of detection of 0.95 and a probability of false alarm of 0.05 as determined by an independent testing laboratory using the U.S. Environmental Protection Agency Standard Test Procedures for Evaluating Leak Detection Methods (EPA/530/UST- 90/006 510-B-19-002, May 2019) or other equivalent test procedures;
      3. c. Use a threshold that does not exceed ½ the minimum detectible leak rate; and
      4. d. Comply with U.S. Environmental Protection Agency Standard Test Procedures for Evaluating Leak Detection Methods (EPA 510-B-19-004, May 2019) or other equivalent test procedures and with 310 CMR 80.26(6).

3. (c) Until October 13, 2022, tanks used to supply fuel to emergency engines installed before January 2, 2015 shall comply with at least one of the following leak detection methods:

   1. 1. Leak detection requirements at 310 CMR 80.19(3)(b)1., 2. 3. or 4.;
   2. 2. If the tank has a capacity of 1000 gallons or less, weekly tank gauging in accordance with 310 CMR 80.26(7); or
   3. 3. If the tank has a capacity of more than 1000 gallons, monthly tank gauging in accordance with 310 CMR 80.26(8), and conduct an annual tightness test in accordance with 310 CMR 80.32.

4. (d) Owners and Operators of field-constructed tanks with a capacity greater than 50,000 gallons capacity may use one of the following methods of leak detection for each tank to satisfy the requirements of 310 CMR 80.19(1):

   1. 1. Conduct an annual bulk tank tightness test that can detect a release or leakage at 0.5 gallon per hour;
   2. 2. Use an in-tank monitor to perform leak detection at least every 30 days that can detect a release or leakage of less than or equal to one gallon per hour. This method shall be combined with a bulk tank tightness test that can detect a release or leakage of 0.2 gallon per hour and be performed at least every three years; or
   3. 3. Use an in-tank monitor to perform leak detection at least every 30 days that can detect a release or leakage of less than or equal to two gallons per hour. This method shall be combined with a bulk tank tightness test that can detect a release or leakage of 0.2 gallon per hour and be performed at least every two years.
   4. 4. Perform inventory control (conducted in accordance with Department of Defense Directive 4140.25; ATA Airport Fuel Facility Operations and Maintenance Guidance Manual; or equivalent procedures) at least every 30 days that can detect a release or leakage equal to or less than 0.5% of flow-through; and perform a tank tightness test that can detect a release or leakage of 0.5 gallon per hour at least every two years.
   5. 5. Maintain records of the testing conducted according to 310 CMR 80.19(3)(d) in accordance with 310 CMR 80.36.

(4) Requirements for Piping.

1. (a) UST systems installed on or after May 28, 1999 shall have the following requirements for regulated substance piping, except European suction systems and single-walled siphon lines between tanks:

   1. 1. All regulated substance piping shall have a system that continuously monitors interstitial space as follows:

      1. a. Sensors shall be installed in the sump in accordance with the manufacturers' specification. If there is no manufacturer’s specification, the sensors shall be placed at the lowest point in the sump.
      2. b. The system shall comply with 310 CMR 80.26(3).
      3. c. The system shall detect regulated substance in a sump that leaked through the inner wall in any portion of the piping that routinely contains regulated substance.
   2. 2. In addition to complying with 310 CMR 80.19(4)(a)1., pressurized piping systems shall be equipped with an automatic line leak detector that accurately detects a release or leakage of three gallons per hour at ten p.s.i. in line pressure within one hour with the probability of detection of 0.95 and probability of false alarm of 0.05. At UST facilities that are staffed 24 hours per day, seven days per week, 365 days per year, an automatic line leak detector may also be a continuous alarm that alerts staff when there is regulated substance or pressure loss in a pressurized product line of a pressurized pumping system.
   3. 3. European suction systems and siphon lines between tanks are not required to have leak detection.

2. (b) UST Systems installed between January 1, 1989 and May 28, 1999 shall have the following requirements for regulated substance piping, except European suction systems and single-walled siphon lines between tanks:

   1. 1. Owners or Operators of all regulated substance piping shall implement one of the following methods of leak detection:

      1. a. A system that continuously monitors interstitial space in accordance with 310 CMR 80.19(4)(a)1.; or
      2. b. Quarterly visual inspections of secondary containment ports and conduct of an annual tightness test of the product piping line in accordance with 310 CMR 80.32; or
      3. c. An in-tank monitoring system that is maintained by a qualified person with inventory data analysis conducted by a qualified statistical inventory reconciliation

      4. (SIR) vendor. The SIR testing or monitoring methods shall:

         1. i. Report a quantitative result with a calculated leak rate;
         2. ii. Be capable of detecting a release or leakage of 0.20 gallons per hour with the probability of detection of 0.95 and a probability of false alarm of 0.05 as determined by an independent testing laboratory using the U.S. Environmental Protection Agency Standard Test Procedures for Evaluating Leak Detection Methods (EPA 510-B-19-0002, May 2019) or other equivalent test procedures;
         3. iii. Use a threshold that does not exceed ½ the minimum detectible leak rate; and
         4. iv. Comply with U.S. Environmental Protection Agency Standard Test Procedures for Evaluating Leak Detection Methods (EPA 510-B-19-004, May 2019) or other equivalent test procedures and with 310 CMR 80.26(6).
   2. 2. In addition to complying with 310 CMR 80.19(4)(b)1., pressurized piping systems shall be equipped with an automatic line leak detector that accurately detects a release or leakage of three gallons per hour at ten p.s.i. in line pressure within one hour with the probability of detection of 0.95 and probability of false alarm of 0.05. At UST facilities that are staffed 24 hours per day, seven days per week, 365 days per year, an automatic line leak detector may also be a continuous alarm that alerts staff when there is regulated substance or pressure loss in a pressurized product line of a pressurized pumping system.
   3. 3. European suction systems are not required to have leak detection.

3. (c) UST Systems installed before January 1, 1989 shall have the following requirements for regulated substance piping, except European suction systems and single-walled siphon lines between tanks:

   1. 1. Owners or Operators of all regulated substance piping shall implement one of the following methods of leak detection:

      1. a. A system that continuously monitors interstitial space in accordance with 310 CMR 80.19(4)(a)1.; or
      2. b. Quarterly visual inspections of secondary containment ports and conduct an annual tightness test of the product piping line in accordance with 310 CMR 80.32; or
      3. c. An in-tank monitoring system that is maintained by a qualified person with inventory data analysis conducted by a trained statistical inventory reconciliation

      4. (SIR) vendor. The SIR testing or monitoring methods shall:

         1. i. Report a quantitative result with a calculated leak rate;
         2. ii. Be capable of detecting a release or leakage of 0.20 gallons per hour with the probability of detection of 0.95 and a probability of false alarm of 0.05 as determined by an independent testing laboratory using the U.S. Environmental Protection Agency Standard Test Procedures for Evaluating Leak Detection Methods (EPA 510-B-19-002, May 2019) or other equivalent test procedures;
         3. iii. Use a threshold that does not exceed ½ the minimum detectible leak rate; and
         4. iv. Comply with U.S. Environmental Protection Agency Standard Test Procedures for Evaluating Leak Detection Methods (EPA 510-B-19-004, May 2019) or other equivalent test procedures and with 310 CMR 80.26(6).
      5. d. For single-walled pressurized piping systems and single-walled gravity piping systems, conduct an annual tightness test in accordance with 310 CMR 80.32; or
      6. e. For Non-European suction systems that do not have secondary containment, conduct an annual tightness test in accordance with 310 CMR 80.32.
   2. 2. In addition to complying with 310 CMR 80.19(4)(c)1., pressurized piping systems shall be equipped with an automatic line leak detector that accurately detects a release or leakage of three gallons per hour at ten p.s.i. in line pressure within one hour with the probability of detection of 0.95 and probability of false alarm of 0.05. At UST facilities that are staffed 24 hours per day, seven days per week, 365 days per year, an automatic line leak detector may also be a continuous alarm that alerts staff when there is regulated substance or pressure loss in a pressurized product line of a pressurized pumping system.
   3. 3. European suction systems are not required to have leak detection.