[Code of Federal Regulations] [Title 40, Volume 24] [Revised as of July 1, 2003] From the U.S. Government Printing Office via GPO Access [CITE: 40CFR280.73] [Page 473] TITLE 40--PROTECTION OF ENVIRONMENT AGENCY (CONTINUED) PART 280--TECHNICAL STANDARDS AND CORRECTIVE ACTION REQUIREMENTS FOR OWNERS AND OPERATORS OF UNDERGROUND STORAGE TANKS (UST)--Table of Contents Subpart G--Out-of-Service UST Systems and Closure Sec. 280.73 Applicability to previously closed UST systems. When directed by the implementing agency, the owner and operator of an UST system permanently closed before December 22, 1988 must assess the excavation zone and close the UST system in accordance with this subpart if releases from the UST may, in the judgment of the implementing agency, pose a current or potential threat to human health and the environment.