How long must UST records be retained after closure?

The correct choice indicates that records related to Underground Storage Tanks (USTs) must be retained for at least three years after the closure of the tank. This requirement ensures that necessary documentation remains accessible for reference and compliance verification, supporting the safe and regulated handling of any potential risks associated with former UST sites. Maintaining these records is critical during that period because it allows for oversight by regulatory bodies to ensure the proper decommissioning of tanks, as well as to assist in any remediation efforts that may arise if there were issues during the tank's operational life.

This three-year retention period aligns with best practices in environmental management, ensuring that there is sufficient time to address any lingering impacts or regulatory inquiries after the closure of a UST.