California ICC UST Inspector Practice Exam

Secondary containment is not required on suction piping which meets all of the following, EXCEPT?

1. A check valve is located directly below suction pump

2. Piping is sloped to drain back to a monitored sump

3. Operating under less than atmospheric pressure

4. Check valve located at tank bottom

The correct answer is: Check valve located at tank bottom

Secondary containment is a critical safety feature for underground storage tanks (USTs) to prevent any potential leaks or spills from contaminating the surrounding environment. In the context of suction piping, certain conditions can render secondary containment unnecessary. When analyzing the requirements for suction piping, it's important to understand the specific criteria that must be met. The presence of a check valve located at the tank bottom is not a valid reason to exempt suction piping from requiring secondary containment. The check valve's position is crucial to maintaining proper system integrity; however, having it at the tank bottom does not ensure that any potential leaks from the tank itself are contained. Instead, it simply prevents backflow into the tank. Conversely, the other scenarios describe situations where the dynamics of the piping and operational pressures mitigate the risks of a leak causing environmental harm. For instance, a check valve directly below the suction pump and piping sloped to drain back to a monitored sump both function actively to manage flow and prevent any leaks from spreading. Operating under less than atmospheric pressure further reduces the chance of leaks as this creates a vacuum that can help keep fluids from escaping. Thus, the requirement for secondary containment is not negated by having a check valve placed at the bottom of the tank, highlighting the importance