Underground Storage Tanks

Last Updated 6/13/17

Issue: An underground storage tank (UST) is a tank or combination of tanks, including pipes connected to the tank, that is used for the storage of hazardous substances and that is substantially or totally beneath the surface of the ground. Until the mid-1980s most USTs were made of bare steel, which is prone to corrode over time (30-50 years) and allow UST contents to leak into the environment. The boom in automobile sales following World War II was closely followed by the construction of thousands of gasoline stations across the country. At these stations, bare steel tanks were installed underground to store gasoline, which are likely to corrode over time and allow UST contents to leak into the environment.

According to the Environmental Protection Agency (EPA), there are approximately 570,000 USTs nationwide that store petroleum or hazardous substances. The greatest potential threat from a leaking UST is contamination of groundwater, the source of drinking water for nearly half of all Americans. EPA works with its state, territorial, and tribal partners to prevent and clean up releases from UST systems.

Overview: Congress passed a series of laws in the mid-1980s to address a nationwide problem of leaking USTs. In 1984, Congress established a leak prevention, detection, and cleanup program through amendments to the Solid Waste Disposal Act. The Hazardous and Solid Waste Amendments of 1984 created a federal program to regulate USTs containing petroleum and hazardous chemicals to limit corrosion and structural defects and thus minimize future tank leaks. The UST program is to be administered primarily by states

In 1986, Congress passed the Superfund Amendments and Reauthorization Act (SARA) in response to a chemical disaster in Bhopal, India where methyl isocyanate gas leaked from a tank. The disaster killed or injured more than 1,000 people and focused worldwide attention on the possibility that accidents at facilities handling hazardous chemicals could harm neighboring communities. The SARA authorized the EPA to respond to petroleum spills and leaks and required owners and operators of USTs to ensure corrective action is completed when a tank is in need of repair, or removal, when it is necessary to protect human health and the environment. It is also recommended that above-ground storage tanks are used whenever possible.

In addition, the SARA directed the EPA to establish financial responsibility requirements for UST owners and operators to cover costs of taking corrective action and to compensate for bodily injury and property damage caused by leaking tanks. The law required owners and operators of USTs to demonstrate that they have an EPA-approved source of funds to pay clean-up costs and to compensate third parties for injury to their property or themselves if a release occurs.

Status: The financial responsibility regulations allow UST owners and operators to choose from a variety of financial mechanisms to comply with the regulations. One of these financial mechanisms is the use of insurance. A list of known insurance providers for UST owners and operators is available on the EPA website. Title 40 CRF Section 280.97(a) specifically provides that an owner or operator may satisfy the financial responsibility requirements by obtaining liability insurance that conforms to the requirements of this section from a qualified insurer or risk retention group. Additional mechanisms for UST owners and operators include: obtain guarantees, surety bonds, or letters of credit; qualification as a self-insurer; or participation in an EPA approved state financial responsibility program.