What is the required duration for leaving vent lines open and functioning for USTs in temporary closure?

The requirement for leaving vent lines open and functioning during the temporary closure of underground storage tanks (USTs) is that they must remain open for a minimum duration of three months. This duration ensures that any vapors or gases that may accumulate within the tank or venting system can safely escape, preventing potential pressure build-up that could compromise the integrity of the UST or its system. Maintaining the vent lines in this state is crucial for regulatory compliance and for protecting the environment from potential leaks or releases during the closure period.

By adhering to this requirement, operators help to ensure that the UST system remains safe and functional throughout the temporary closure, minimizing risks not only to the equipment but also to the surrounding area.