In the state of California any significant release or threatening release of hazardous material requires immediate reporting to CUPA. As of 2008 CUPA implemented the Aboveground Petroleum Storage Act (APSA) that regulates facilities with above ground storage tanks with capacities of 55 gallons or more.
An aboveground storage tank is defined as an above ground storage tank or storage tank with a capacity to store 55+ gallons or petroleum that is substantially or completely above the surface of the ground.