California ICC UST Inspector Practice Exam 2026 – Your All-In-One Guide to Exam Success!

In the context of permanent Underground Storage Tank (UST) closure, the chosen answer is accurate because regulatory requirements generally dictate that certain actions are necessary, even in the absence of visible evidence of leaks. This includes soil and groundwater sampling to ensure that no contamination exists, as unmonitored leakage could still occur without visible signs.

This sampling is a critical part of the closure process to confirm that any potential environmental impact has been evaluated and addressed. Regulatory authorities typically require this to ensure compliance with environmental protection standards.

The other options reflect requirements that are indeed typically true. Submitting an approval proposal 30 days in advance allows for adequate time for regulatory review before closure activities begin. The 90-day cessation and application closure period allows for the determination and assessment of potential contamination after the tank has been taken out of service. Lastly, the exemption for USTs filled with inert materials before 1984 indicates a specific regulatory provision recognizing the lower risk profile of these tanks.

Together, these requirements help ensure environmental safety and adherence to regulations during the closure of USTs.