§ 150.487 EXISTING UNDERGROUND STORAGE FACILITIES.
   (A)   Storage tanks. The tank shall be tested using a precision test which is capable of measuring a quantitative leak rate and which controls, eliminates, measures or otherwise takes into account changes in the coefficient of expansion of the liquid due to temperature changes, containment system deformations due to pressure changes, evaporative losses, and other relevant variables during the course of the test, as discussed in the National Fire Protection Association Pamphlet 329, "Recommended Practices for Handling Underground Leakage of Flammable and Combustible Liquids," as amended. Such testing shall prove the integrity of an underground storage tank according to the following schedule:
 
Tankage
Test Frequency
0 to 5 years old
On the fifth year
6 to 10 years old
Every two years
 
   (B)   Piping. The piping shall be tested using a precision test method capable of detecting both pressure and volume changes during testing and in accordance with the following:
      (1)   Suction and gravity flow piping systems shall be tested using a precision test method capable of detecting a leak rate of at least 0.05 gallons per hour;
      (2)   Pressure pumped piping systems fitted with approved continuous line pressure leak sensors capable of restricting the flow of product in the delivery system when a leak is detected shall be precision tested on the same schedule as the tank to which they are attached. Pressure pumped piping systems shall be tested using a precision test method capable of detecting a leak rate of at least 0.01 gallons per hour; and
      (3)   Pressure pumped piping systems fitted with approved continuous line pressure leak sensors capable of completely shutting down the delivery system when a leak rate of at least 0.05 gallons per hour is detected shall be precision tested every three years. Pressure pumped piping systems shall be tested using a precision test method of detecting a leak rate of at least 0.01 gallons per hour.