Owners and operators using other methods, or combinations of methods, of release detection must comply with the requirements of this section.

(1) Standards. Other release detection methods must:

(a) Be able to detect a 0.2 gallon per hour leak rate or a release of one hundred fifty gallons within a thirty-day period from any portion of the tank or underground piping 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; or

(b) Be approved by the department. To be approved, owners and operators must demonstrate the other method is able to detect a leak as effectively as any of the following methods. In comparing methods, the department will consider the size of release that can be detected and the frequency and reliability of detection. Owners and operators must comply with any additional requirements imposed by the department on its use to ensure protection of human health and the environment:

(i) Automatic tank gauging (WAC 173-360A-0630);

(ii) Tank tightness testing (WAC 173-360A-0635);

(iii) Monthly automatic electronic line leak detection (WAC 173-360A-0645);

(iv) Line tightness testing (WAC 173-360A-0650);

(v) Interstitial monitoring (WAC 173-360A-0655);

(vi) Vapor monitoring (WAC 173-360A-0660);

(vii) Groundwater monitoring (WAC 173-360A-0665); or

(viii) Statistical inventory reconciliation (WAC 173-360A-0670).

(2) Performance. Other release detection methods must be performed in accordance with the manufacturer's instructions, any conditions or limitations specified in the certification of the method or equipment, and any additional requirements imposed by the department.