It would seem that a solution to the problem of protecting the groundwater supply would be to replace an underground storage tank (UST) with an aboveground storage tank (AST) to make leaks visible and eliminate the need for costly UST leak-detection systems.
But when it's located underground, the vulnerability of a tank to vehicular impact or even gunfire is virtually nil. In addition, both the tank owner and regulators have to be assured of the tank's fire protection in case a tank is overfilled and the spillage ignites.
Precast concrete producers have reacted to the regulatory demands placed on their customers who store fuel by marketing aboveground "super tanks" that address concerns about groundwater, air quality, impact, and fire safety. These "super tanks" actually use a steel tank but also offer secondary containment, insulation, and an outer concrete shell.
In 1988 the Environmental Protection Agency (EPA) mandated that UST owners comply with new standards for corrosion resistance, leak detection, and spillage and overfill protection by the end of 1998. Until 2000, the replacement market for ASTs boomed.
Now the market for concrete-encased ASTs has shifted from replacement to new construction. To be successful in creating customer value, the producer has to make a real commitment to the petroleum industry and create an entire division for the product.
Raising fuel storage above ground gives the producer a chance to market architectural concrete finishes. Both the internal steel tanks and the ASTs as a whole require a greater variety of tests to ensure that the tanks get UL listings for fire, air quality, and impact protection.
The article includes a list of licensors for whom precasters can manufacture tanks.
The article also includes information about franchising unattended gas stations that use ASTs.