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Underground Storage Tanks:

Underground Storage Tanks Underground Storage Tanks (USTs) are tanks or connective piping that have at least 10% of its volume below ground. UST's are potentially harmful because they can seep through the ground to the aquifer below, which may provide drinking water to the surrounding community. Rural communities are especially at risk due to a large reliance on groundwater as the primary drinking water source.

Petroleum products are the most common types of contaminants stored in UST's. Examples of these include diesel tanks on farms and gas stations. Hazardous substances may also be stored in UST's.

The following types of tanks do not have to meet federal UST regulations:
  • Farm and residential tanks of 1,100 gallons or less capacity holding motor fuel used for noncommercial purposes;

  • Tanks storing heating oil used on the premises where it is stored;

  • Tanks on or above the floor of underground areas, such as basements or tunnels;

  • Septic tanks and systems for collecting storm water and wastewater;

  • Flow-through process tanks;

  • Tanks of 110 gallons or less capacity; and

  • Emergency spill and overfill tanks.

Leaking underground storage tanks (LUST) are very common.

Contaminants of Concern:

Contaminants of concern are based on the type of substance, usually a liquid, being stored in the UST. Petroleum products (motor fuels, diesel) consist of the majority of UST's, however any number of hazardous substances may also be stored in UST's. Common contaminants of concern for petroleum substances include:
  • BTEX (crude oils high in BTEX: benzene, toluene, ethyl benzene, and xylene)

  • Ethyl benzene (high in gasoline)

  • Methyl tert-butyl ether (MTBE) (octane booster and clean air additive for gasoline)

  • lead
Any oil spill can pose a serious threat to human health and the environment, requires remediation that extends beyond your facility's boundary, and results in substantial cleanup costs. Even a small spill can have a serious impact. A single pint of oil released into the water can cover one acre of water surface area and can seriously damage an aquatic habitat. A spill of only one gallon of oil can contaminate a million gallons of water.

Implementing Solutions:

Please submit your experiences (successes/challenges) and tribal-specific documents to share on our website using the attached form.
Download Form


UST Program Tribal Directory (Contact List) [pdf]

Preventing Leaks and Spills at Service Stations: A Guide for Facilities [pdf]

UST Regulations Factsheet [pdf]

Petroleum Brownfields Opportunities [pdf]

Number of Active and Closed Underground Storage Tanks on Tribal Lands [pdf]

2010 Fiscal Year Update [pdf]

Report to Congress On UST Program In Indian Country [pdf]

Timber Lake LUST Site, Community Engagement, Cheyenne River Indian Reservation [pdf]


Underground Storage Tanks Program in Indian Country EPA's UST Office provides technical and financial support to tribal governments to prevent and cleanup petroleum releases from USTs:

EPA Preventing and Detecting UST Releases:

EPA UST Detecting Releases:

Publications Related to Underground Storage Tanks in Indian Country:

UST Policy and Guidance:

Leaking Underground Storage Tank Technical Policy and Guidance:

Community Engagement Resources for UST:

Idaho DEQ Storage Tank Guide:

ADEC Spill Prevention and Response Heating Oil Tank Guidance:

Related Pages:

Aboveground Storage Tanks


Contaminated Sites

Emergency Planning, Management, and Response

Federal Facilities

Hazardous Waste and Emergency Response Training Requirements

Oil Spill Response

For more information, please contact:
Todd Barnell, Program Manager
Tel: 928/523-3840
Email: Todd.Barnell@nau.edu

Jennifer Williams, Alaska Program Coordinator, Sr.
Tel: 928/523-0673
Email: Jennifer.Williams@nau.edu

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Last updated: July 10, 2015


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Northern Arizona University, South San Francisco Street, Flagstaff, Arizona 86011