When a concrete or asphalt pad is used at grade, how far must the pad extend beyond the tank outline in all directions?

The requirement for a concrete or asphalt pad to extend beyond the tank outline is established to ensure proper containment and to minimize potential environmental hazards. Extending the pad by 1 foot in all directions from the tank signifies adherence to safety regulations and helps to provide an effective barrier against spills or leaks that could potentially harm the surrounding soil and water supply.

This spacing also facilitates easier access for maintenance and inspections, ensuring that there are no obstructions when managing the underground storage tank facilities. Additionally, the extension provides a margin for error during installation and everyday operation, reducing the chances of operational issues.

In contrast, other options either fall short in providing adequate coverage—potentially leading to uncontrolled leaks or spills—or may exceed what is deemed necessary according to established guidelines. The choice of 1 foot balances safety, regulatory compliance, and practical concerns effectively.