An underground storage tank (UST) is defined as any one or a combination of tanks that have 10 percent or more of their volume below the surface of the ground in which they are installed. This definition includes the tank, connected underground piping, underground ancillary equipment, and containment system. Further, this definition specifically pertains to UST systems that contain regulated substances such as solvents, methanol, and ethylene glycol (anti-freeze). State and local UST programs began submitting information about their tank populations in 1988. On the average approximately 30,000 new releases are reported each year.
In 1984, Congress directed the U.S. EPA to develop regulations underground storage tank systems. Many USTs are subject to both Federal and State regulations. EPA’s Office of Underground Storage Tanks developed the Federal Regulations which delegate UST regulatory authority to approved State programs. States with approved programs operate with the Federal regulations. There are currently 24 states with approved UST programs. In a few instances, Federal regulations prior to 1984 did not address underground storage tanks (UST) systems. The Resource Conservation and Recovery Act (RCRA) of 1976 regulated only tanks containing hazardous wastes, not tanks storing petroleum or hazardous products. The Clean Water Act (CWA) of 1972 required owners of large underground tanks (greater than 42,000 gallons) to take certain measures to prevent corrosion and to test tanks periodically. These requirements, however, applied only to those tanks that were potentially direct sources of pollution into navigable waters. Because releases from USTs generally contaminated only groundwater, and usually affect surface water only indirectly, the CWA could not be used as a general basis for regulating most USTs. The Comprehensive Environmental Response, Compensation, and Liability Act of 1980, commonly known as Superfund, authorized EPA to respond whenever a hazardous substance is released into the environment. Superfund, however, cannot be used to respond to releases from UST systems because petroleum is specifically excluded from the list of hazardous substances defined under CERCLA. The Office of Underground Storage Tanks (OUST) was created in 1985 as part of EPA’s Office of Solid Waste and Emergency Response (OSWER) to carry out the Congressional mandate to develop and implement a new regulatory program for UST systems. OUST has two divisions: The Policy and Standards Division and the Implementation Division. OUST is charged with developing regulations for UST systems in the areas of technical standards for tanks, financial responsibility, and state program approval. In 1986, Congress passed the Superfund Amendments Reauthorization Act (SARA) which amended Subtitle I to provide Federal funds for corrective actions on petroleum releases from UST systems. This amendment established the Leaking Underground Storage Tank Trust Fund, commonly known as the LUST Trust Fund. In 1988 EPA published the final technical regulations for tanks. On October 26, 1988, EPA published the finacial responsiblity regulations, indicating the minimum levels of insurance UST owners and operators need to ensure that they can take action in reponse to any leaks that occur from their UST systems and compensate anyone who is harmed by a release. Corrective action includes assessing the release and the extent of damage or danger to human health and the environment, determining what action is needed to repair any damage and remove contaminants, and taking the necessary remedial action.