California ICC UST Inspector Practice Exam

Which of the following is an example of secondary containment?

1. Single-walled tanks

2. Buried leak detection systems

3. Dikes or sumps

4. Excavation of tank systems

The correct answer is: Dikes or sumps

Secondary containment refers to systems designed to prevent the escape of hazardous materials into the environment in case of a leak or spill. It serves as a secondary barrier to contain substances that could potentially escape from a primary containment system. Dikes or sumps are recognized as effective forms of secondary containment. Dikes, which are raised barriers, are constructed around storage tanks or hazardous materials to contain any potential leakage. Similarly, sumps can capture liquids that spill, preventing them from reaching the ground or water sources. Together, these systems help to ensure environmental safety by managing spills before they can cause damage. In contrast, single-walled tanks do not provide any secondary containment, as they lack an outer layer to contain spills. Buried leak detection systems are primarily designed to detect leaks but do not serve as a means of containment themselves. Excavation of tank systems refers to the physical removal of tanks, which does not involve any containment mechanism for leaks or spills. Thus, the most fitting example of secondary containment from the options provided is dikes or sumps.