A supply tank exceeding how many gallons must be installed on the lowest floor?

The correct answer reflects the safety regulations concerning the installation of fuel supply tanks. In many jurisdictions, including regulations applicable in Maine, a supply tank that exceeds 60 gallons must indeed be installed on the lowest floor of a building. This requirement is primarily focused on minimizing the risk of potential leaks or spills that could occur from larger tanks, which can pose significant risks to both the environment and property.

By positioning larger tanks on the lowest floor, the likelihood of harmful substances contaminating the ground or entering occupied spaces is reduced. Additionally, this regulation helps ensure safety in areas where fuel systems are installed, making it easier to access the tank for maintenance and reducing hazards from fuel odors or accidental overflows. Therefore, the emphasis on the 60-gallon threshold is grounded in regulations that prioritize safety in fuel storage practices.