Section 173-360A-0635 - Tank tightness testing.Owners and operators using tank tightness tests must comply with the requirements of this section.
(1)Standards. Tank tightness tests must be able to detect at least a 0.1 gallon per hour leak rate from any portion of the tank up to the ninety-five percent full level or up to the product level limited by overfill prevention equipment while accounting for the effects of thermal expansion or contraction of the regulated substance, vapor pockets, tank deformation, evaporation or condensation, and the location of the water table. The tests must be able to detect the specified leak rate with a probability of detection of at least 0.95 and a probability of false alarm of no more than 0.05.(2)Performance. Tank tightness tests must be performed: (a) By or under the direct supervision of a service provider certified in accordance with Part 9 of this chapter; and(b) In accordance with the manufacturer's instructions and any conditions or limitations specified in the certification of the method or equipment.(3)Reporting. Tank tightness tests must be reported to the department within thirty days using the applicable checklist provided by the department. The checklist must be completed by the service provider.Wash. Admin. Code § 173-360A-0635
Statutory Authority: Chapter 90.76 RCW. WSR 18-15-083 (Order 16-02), § 173-360A-0635, filed 7/18/18, effective 10/1/18.