Underground piping that routinely contains regulated substances must be installed and monitored for releases in a manner that meets the following requirements:

1. (1) Pressurized piping.

   1. (A) Piping that conveys regulated substances under pressure must be equipped with an automatic line leak detector installed and operated in accordance with this Chapter.
   2. (B) New installations and facilities replacing a piping system must have at least one (1) sump sensor, float or similar mechanical device for each tank system, located at the bottom of the lowest piping gradient sump. The interstitial area of the piping must be open inside the sumps to allow fuel to drain into the sumps in the event that a leak occurs. Sensors must be mounted at the bottom of the sump(s) and accessible for testing.
   3. (C) Underground pressure piping from a master dispenser to a satellite dispenser must be designed and installed so that the satellite piping is tested by the automatic line leak detector. An annual line tightness test performed by a licensed tester is required on the satellite underground piping.
2. (2) Suction piping. New installations and facilities replacing a piping system must have at least one (1) sump sensor, float or similar mechanical device for each tank system, located at the bottom of the lowest piping gradient sump. The interstitial area of the piping must be open inside the sumps to allow fuel to drain into the sumps in the event that a leak occurs. Sensors must be mounted at the bottom of the sump(s) and accessible for testing.

3. (3) Methods of release detection for pressurized piping. Each method of release detection for underground pressurized piping must be performed in accordance with the following requirements:

   1. (A) Automatic mechanical line leak detectors and annual line tightness testing:

      1. (i) Methods which alert the owner and/or operator to the presence of a leak by restricting or shutting off the flow of regulated substances through piping or by triggering an audible or visual alarm may be used only if they detect leaks of three (3) gallons per hour at ten (10) psi line pressure within one (1) hour.
      2. (ii) An annual test of the operation of the leak detector must be conducted by a licensed tester by simulating a leak in accordance with the manufacturer's requirements.
      3. (iii) Automatic line leak detectors installed on or after September 22, 1991 must be capable of detecting the leak rate with a probability of detection of 0.95 and a probability of false alarm of 0.05.
      4. (iv) A hydrostatic line tightness test must be performed annually by a licensed tester.

   2. (B) Sump sensors with automatic line leak detectors

      1. (i) Double walled piping with sump sensors, floats or similar mechanical devices at each dispenser, transition and tank sump may be used in lieu of annual line tightness testing except at marinas where a line tightness test is required by April 1st of each year.
      2. (ii) The sump sensors, floats or other mechanical devices used must be tested annually by a licensed tester. This test must be scheduled in the established online format prior to testing. Sensors status and alarm history reports must be printed and retained or an interstitial monitoring form used every thirty (30) days.
      3. (iii) An annual function test of the operation of the leak detector must be conducted by a licensed tester by simulating a leak in accordance with the manufacturer's requirements.

   3. (C) Electronic line leak detection. A certified electronic line leak detector may be used in lieu of a mechanical line leak detector and annual tightness test only if:

      1. (i) The system is capable of detecting and tests for a leak of three (3) gallons per hour before or after each operation of the submersible turbine pump; and
      2. (ii) The system is capable of detecting and tests for a leak of 0.2 gallons per hour at least once every thirty (30) days; and
      3. (iii) The system is capable of detecting and tests for a leak of 0.1 gallons per hour annually; and
      4. (iv) The system must be function tested annually by a licensed tester by simulating a leak in accordance with manufacturer's specifications. If the system has printer capabilities, attach the electronic line leak detector printout documenting the system shutdown or alarm when tested.

4. (4) Methods of release detection for suction piping. Each method of release detection for underground suction piping must be performed in accordance with the following requirements.

   1. (A) Sump Sensors

      1. (i) Double walled piping with sump sensors, floats or similar mechanical devices at each dispenser, transition and tank sump may be used in lieu of annual line tightness testing except at marinas where a line tightness test is required by April 1st of each year.
      2. (ii) The sump sensors, floats or other mechanical devices used must be tested annually by a licensed tester. This test must be scheduled in the established online format prior to testing. Sensors status and alarm history reports must be printed and retained or an interstitial monitoring form used every thirty (30) days.
   2. (B) Annual Line Tightness Testing. A hydrostatic line tightness test must be performed annually by a licensed tester.

Amended and renumbered from 165:26-2-56 at 23 Ok Reg 2297, eff 7-1-06

Amended at 25 Ok Reg 2187, eff 7-11-08

Amended at 32 Ok Reg 794, eff 8-27-15

Amended at 35 Ok Reg 1010, eff 10-1-18

Amended at 41 Ok Reg, Number 23, effective 10-1-24