Aboveground Storage Tanks

An aboveground storage tank (AST) is a storage tank placed above the surface of the ground. Any stationary tank system that is not covered with earth or other material or any tank located entirely within a structure that can be visually inspected, such as a building or basement, is generally considered an AST. U.S. Postal Service facilities use ASTs to store fluid products and waste such as motor oil, gasoline and diesel fuel, heating oil, and antifreeze to operate and maintain sites, vehicles, and equipment. Postal Service facilities with ASTs must establish a routine maintenance and inspection program to monitor the condition of the AST and avoid releases into the environment.Our objective was to assess the Postal Service’s effectiveness at managing ASTs by reviewing ASTs active as of January 2022.