Section 173-360-810. Secondary containment of tanks.

(1) Applicability. Tanks installed or replaced after October 1, 2012, must be secondarily contained and monitored for releases in accordance with the requirements in this section.

(2) Secondary containment. In addition to meeting the requirements in WAC 173-360-305(1), tanks must meet the secondary containment requirements in this subsection.

(a) Performance standards. Tanks must be double-walled. Double-walled tanks must be designed, constructed, and installed to:

(i) Contain any regulated substances leaking from the primary space (through the inner wall) within the interstitial space until they are detected and removed;

(ii) Prevent the release of regulated substances into the environment throughout the operational life of the UST system; and

(iii) Allow for interstitial monitoring.

(b) Codes of practice. Double-walled tanks must be designed and constructed in accordance with a code of practice developed by a nationally recognized association or independent testing laboratory. The following codes of practice may be used to meet this requirement:

(i) Underwriters Laboratories, Standard 58, "Standard for Safety for Steel Underground Tanks for Flammable and Combustible Liquids";

(ii) Underwriters Laboratories, Standard 1316, "Glass-Fiber-Reinforced Plastic Underground Storage Tanks for Petroleum Products, Alcohols, and Alcohol-Gasoline Mixtures";

(iii) Underwriters Laboratories, Standard 1746, "Standard for External Corrosion Protection Systems for Steel Underground Storage Tanks";

(iv) Steel Tank Institute, Standard F841, "Standard for Dual Wall Underground Steel Storage Tanks"; or

(v) Steel Tank Institute, Specification F922, "Specification for Permatank®."

(3) Release detection. Double-walled tanks must be monitored interstitially for releases at least every thirty days in accordance with WAC 173-360-345 (6)(h)(i). Methods that continuously monitor the interstitial space using a vacuum, pressure, or a liquid must be able to detect a breach in both the inner and outer walls.

[Statutory Authority: Chapter 90.76 RCW. WSR 12-17-041 (Order 08-08), § 173-360-810, filed 8/8/12, effective 10/1/12.]

Chapter 90.76 RCW. WSR 12-17-041 (Order 08-08), § 173-360-810, filed 8/8/12, effective 10/1/12.

Rules

173-360-305,173-360-345,