Prior to closing a UST, the owner/operator must ______________.

• A. not remove or fill
• B. remove all contents
• C. secure the area
• D. perform a final survey

Answer: (A)

When closing an underground storage tank, you want to avoid altering what’s inside or the tank’s condition before the closure is completed. Not removing contents and not filling the tank prior to final closure keeps the tank in its original state, which helps prevent spills or disturbances that could mask or create contamination pathways. This preservation supports an accurate final survey and proper documentation of the closure. Securing the area and performing a final survey are important steps in the overall process, but the specific pre-closure requirement emphasized here is to refrain from removing liquids or adding fill before closure is finished.