Which document must be maintained on-site and be available for review?

The requirement for maintaining specific documents on-site is crucial for compliance and operational efficiency within the context of underground storage tank (UST) systems. UST operating records and compliance documentation must be readily available for review because they provide essential information regarding the safe operation, inspection, maintenance, and regulatory adherence of the UST systems. These documents include details on leak detection, inventory records, and maintenance schedules, which are integral to ensuring that the UST systems are functioning within the legal and safety guidelines set forth by environmental and safety regulations.

Having these documents accessible on-site enables quick response to inspections by regulatory bodies and assists in demonstrating compliance with environmental safety standards. In contrast, other documents such as business financial records, employee training manuals, and invoices or sales receipts may not be obligatory for immediate review in the context of UST regulatory compliance, making them less critical in this specific scenario.