California ICC UST Inspector Practice Exam

Which of the following markings is NOT required on the exterior surface of an underground tank?

1. Width of interstitial space

2. Design pressure in psi

3. Usable capacity in gallons

4. Identity of manufacturer

The correct answer is: Width of interstitial space

The correct choice indicates that the width of the interstitial space is not a required marking on the exterior surface of an underground tank. The markings mandated for these tanks are specifically aimed at conveying critical information related to safety, capacity, and compliance with regulations. The design pressure in psi is an important safety feature. It helps ensure that the tank is operated within its structural limits and informs inspection personnel of the tank's specifications, thus aiding in preventing overpressure situations. Usable capacity in gallons provides crucial information for both operation and environmental safety. It allows operators to manage the contents effectively and ensures that the tanks are not overfilled, which can prevent spillage and potential groundwater contamination. The identity of the manufacturer is included for regulatory and accountability purposes. This marking allows for tracking the tank's compliance with standards and facilitates communication in the event of a recall or safety notice. Given these required markings, it becomes clear that the width of the interstitial space, while important for other aspects of tank design and function, does not need to be visibly marked on the exterior, making it the correct answer to the question.