For the purposes of developing or assisting in the development of any regulation, conducting any study, taking any corrective action, or enforcing the provisions of this subchapter, any owner or operator of an underground storage tank (or any tank subject to study under section
of this title that is used for storing regulated substances) shall, upon request of any officer, employee or representative of the Environmental Protection Agency, duly designated by the Administrator, or upon request of any duly designated officer, employee, or representative of a State acting pursuant to subsection (h)(7) ofsection
of this title or with an approved program, furnish information relating to such tanks, their associated equipment, their contents, conduct monitoring or testing, permit such officer at all reasonable times to have access to, and to copy all records relating to such tanks and permit such officer to have access for corrective action. For the purposes of developing or assisting in the development of any regulation, conducting any study, taking corrective action, or enforcing the provisions of this subchapter, such officers, employees, or representatives are authorized—
Each such inspection shall be commenced and completed with reasonable promptness.