Owners and operators using interstitial monitoring must comply with the requirements of this section.
- (1) Standards. The interstitial monitoring system must be able to detect a leak through the inner wall of any portion of the tank or underground piping that routinely contains a regulated substance. 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.
- (2) Performance. Interstitial monitoring must be performed in accordance with the manufacturer's instructions and any conditions or limitations specified in the certification of the equipment.
[Statutory Authority: Chapter 90.76 RCW. WSR 18-15-083 (Order 16-02), § 173-360A-0655, filed 7/18/18, effective 10/1/18.]