Leaking Underground Storage Tanks

Developed by Joe Ryan, University of Colorado

Overview
Contaminants

Federal
UST Legislation
State Support
Cleanup Status
UST Definitions

LUST Anatomy
Corrosion
Leaks
Site Character
Remediation
   Source
   Groundwater
New Tanks
   Installation
   Monitoring

Anatomy of a LUST

Typical Gasoline Station Layout

Under a typical gas station are four or five tanks, one each for three grades of gasoline, one for diesel fuel, and one for waste oil. The tanks are filled by tank trucks. "Product" is delivered to the pumps by a system of pipes. Operation of the storage and delivery system is the responsibility of the station operator.

Corrosion

Most of the tanks installed after World War II through the 1980s were bare steel tanks with no defense against corrosion. Corrosion, the oxidation of iron metal to ferric iron, or rusting, of steel tanks occurs by various processes. Chemically, oxidation is the loss of electrons from the iron metal. Some nearby material must be available to accept the electrons lost by the iron metal for oxidation to occur. Some of the possible electron acceptors are portrayed in the images below.

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The EPA provides information about operating and maintaing USTs.

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