California ICC UST Inspector Practice Exam

What is the required design for a secondary containment system that is not integral to the primary containment?

1. Must contain 100 percent of the largest primary container

2. Must contain 110 percent of the largest primary container

3. Must contain 150 percent of the largest primary container

4. Must contain 50 percent of the largest primary container

The correct answer is: Must contain 150 percent of the largest primary container

The design requirement for secondary containment systems that are not integral to the primary containment is to ensure they can effectively manage potential leaks or spills from the primary container. The correct value is to contain 150 percent of the largest primary container because this provides an added safety margin. In the event of a failure of the primary containment system, the secondary containment should be capable of fully holding not just the volume of the contents of the largest primary container but also an additional buffer to accommodate any unforeseen factors, such as precipitation or additional spillage. This 150 percent containment requirement reflects best practices in environmental protection by ensuring that even in worst-case scenarios, the containment system can prevent any release of hazardous materials into the environment, thus protecting soil and water resources. By exceeding the volume of the primary container, this design effectively mitigates risks associated with leaks and increases the overall safety of the handling and storage of substances. The other options do not provide the necessary safety margin required under regulations for secondary containment systems. Containing only 100 percent or 110 percent of the largest primary container may not be sufficient to handle potential overflows or additional leaks beyond the primary container's total volume. Therefore, these lower percentages do not meet the standards necessary to ensure maximum protection against environmental contamination.