California UST System Operator Practice Test

"Interstitial space" in the context of underground storage tank (UST) terminology specifically refers to the space that exists between the inner and outer walls of double-walled tanks and piping. This design feature serves multiple critical functions, particularly in enhancing environmental safety and leak prevention.

The interstitial space allows for the detection of leaks from either the inner tank or pipe, as any liquid that enters this space can be monitored. This setup is integral to the secondary containment system, which is designed to prevent hazardous substances from escaping into the surrounding environment. By ensuring that any leaks are caught early, the interstitial space contributes to the protection of groundwater and surrounding ecosystems.

In an industry that demands high levels of safety and compliance, understanding the role of interstitial spaces helps operators maintain the integrity of UST systems and comply with state and federal regulations.