How far below the manhole lid should the top of the fill cap be installed?

The top of the fill cap should be installed 4-6 inches below the manhole lid to ensure proper functionality and safety of the underground storage tank (UST) system. This specific distance helps prevent any potential issues related to overflow or spillage. By maintaining this height, it also allows for easier access when refueling and ensures that any vapors can vent appropriately without risking ignition or other hazards. Proper installation according to these measurements is essential for compliance with regulations while helping to mitigate environmental risks.