The purpose of the APSA Program is to protect public health, the environment and groundwater from potential contamination or adverse effects associated with unintended releases from the aboveground storage of petroleum-based hazardous materials and wastes.

An Aboveground Petroleum Storage Tank (AST) is defined in the California Health and Safety Code as “…a tank that has the capacity to store 55 gallons or more of petroleum and that is substantially or totally above the surface of the ground.”

All facilities that have ASTs (including 55 gallon drums) with an aggregate storage capacity of ≥1,320 gallons of petroleum are subject to APSA. APSA also regulates tank facilities with less than 1,320 gallons of petroleum if they have one or more stationary tanks in an underground area (TIUGA) with a shell capacity of 55 gallons or more of petroleum, and, in this case, only the TIUGAs are subject to APSA, although there are exceptions.