California ICC UST Inspector Practice Exam

At what level must an overfill alarm trigger an alert to the transfer operator?

1. 85%

2. 95%

3. 90%

4. 80%

The correct answer is: 90%

The overfill alarm is designed to provide an early warning to the transfer operator that the tank is nearing its capacity, allowing them to take action to prevent spillage or overfilling. The correct threshold for the overfill alarm is set at 90%. This is the level at which the alarm is activated to notify the operator that they need to stop filling the tank to avoid any potential for overflow. Setting the threshold at this level allows for a small margin of safety below the tank's actual capacity, providing sufficient time for the operator to respond adequately. In contrast, thresholds higher than 90%, such as 95%, would not provide timely alerts, which could lead to overfilling and environmental hazards. Similarly, a threshold set lower than 90%, such as 85% or 80%, would not offer the necessary warning if the tank is indeed close to full, resulting in potential operational issues. Thus, establishing the 90% threshold for the overfill alarm is critical for maintaining safety and compliance with regulations.