California ICC UST Inspector Practice Exam 2025 – Your All-In-One Guide to Exam Success!

The correct answer is based on understanding the requirements for overfill protection devices in underground storage tank (UST) systems. Overfill protection is crucial for preventing spills and ensuring safe operation during tank filling.

Option D does not align with the approved practices because it only activates an alarm when the tank reaches 98% capacity. While alarming is a component of safety measures, simply alerting at this high fill level does not facilitate an active preventive measure to avoid overfilling. The best practices advocate for systems that take action before the tank reaches such a critical point.

In contrast, the other options describe proactive measures that are part of the accepted overfill protection guidelines. They either restrict the flow into the tank or provide a mechanism for shutting off the flow before reaching a dangerous capacity, ensuring that overfilling is actively mitigated before it happens. Understanding these nuances is essential for effective compliance and safety in UST management.