Why Are UST Systems Regulated?
As of March 2014, 517,317 releases have been reported from UST systems. For state-by-state data (reported semi-annually) such as the number of active and closed tanks, releases reported, cleanups initiated and completed, inspections, and facilities in compliance with UST requirements, go to the UST Performance Measures.
These releases have been caused by leaks, spills, and overfills from UST systems. These releases can threaten human safety and health as well as the environment because UST systems contain hazardous and toxic chemicals. Fumes and vapors can travel beneath the ground and collect in areas such as basements, utility vaults, and parking garages where they can pose a serious threat of explosion, fire, and asphyxiation or other adverse health effects.
Gasoline, leaking from service stations, is one of the most common sources of groundwater pollution. Because approximately one-half of the population of the United States relies on groundwater as their source of drinking water, groundwater pollution is a serious problem. Many municipal and private wells have been shut down as the result of contamination caused by releases from UST systems.
Preventing and cleaning up releases are the two primary goals of the programs that regulate USTs. Cleaning up petroleum releases is difficult and usually expensive; it is easier and less costly to prevent releases before they happen. The old adage of "an ounce of prevention being worth a pound of cure" is particularly relevant to UST systems.