Owners and operators using automatic tank gauging must comply with the requirements of this section.

(1) Standards. For the purposes of this method, automatic tank gauge systems must be able to:

(a) Detect at least a 0.2 gallon per hour leak rate from any portion of the tank that routinely contains a regulated substance with a probability of detection of at least 0.95 and a probability of false alarm of no more than 0.05;

(b) Measure tank liquid levels over the full range of the tank's height; and

(c) Measure water levels in the bottom of the tank.

(2) Performance. Leak detection tests must be performed in accordance with the manufacturer's instructions and any conditions or limitations specified in the certification of the equipment. Tests must be performed with automatic tank gauge systems operating in one of the following modes:

(a) In-tank static test mode. In this mode, testing must be performed at least once every thirty days; or

(b) Continuous in-tank leak detection mode. In this mode, automatic tank gauge systems must operate on an uninterrupted basis or operate within a process that allows the system to gather incremental measurements to determine the leak status of the tank at least once every thirty days.