4.3.1 Double-wall UST Systems
These systems are equipped with double-wall tanks or double-wall piping, or both.
Double-wall UST Systems must have a means for detecting a release from the inner wall of the double-wall tank or piping. The leak detection method must be able to detect a leak rate of 0.2 gallons per hour (GPH) (place the mouse over the gas tank image).
There are four primary methods for detecting a leak:
1. Brine solution