GSA effectively manages underground storage tanks in accordance with EPA, applicable state and local regulations.

An underground storage tank (UST) is used to store petroleum or other hazardous substances and has 10% or more of its volume underground. The majority of UST's store petroleum products. Less than 3% of UST's store hazardous substances.

Inhaling high concentrations of petroleum from leaking underground storage tanks can affect the heart and the lungs, especially in children, the elderly, and individuals with existing heart or lung conditions.

Gaseous leaks from underground storage tanks have the potential to cause hazards to the environment due to explosions or fires.

Petroleum leaks can contaminate groundwater, surface water and soils.

The underground storage tank program implementation has been delegated by the EPA to state agencies in 28 states and the District of Columbia. In the remaining states, EPA implements the Federal UST program.

GSA's Public Buildings Service (PBS), determines and maintains an inventory of the owner of each regulated UST in its space. Other federal agencies that own or operate UST's within GSA's space are responsible for managing those UST's in compliance with federal, state and local regulations.

As of 1999, GSA, has brought all 50 UST's in its inventory into operational compliance with federal and state regulations.

GSA's UST program minimizes petroleum or other hazardous substance exposure to building occupants and the environment:

• Yearly site assessments are conducted to determine if there is a possible leakage from the tank system into the environment.
• Corrosion protection and spill/overfill preventive devices were installed on all tanks by 1998, as required by EPA regulations.
• Regulated tanks and piping 15 years old or older by 1994 have been replaced or upgraded.
• all regulated tanks installed by 1974 or before or of unknown age, are leak tested, closed or removed.