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What is a Petroleum Storage Tank?

This page defines petroleum storage tank, underground storage tank, aboveground storage tank, and petroleum product. These definitions can help determine if your facility is regulated.

Definitions of Petroleum Storage Tank Terms

petroleum storage tank (PST) is any one or combination of aboveground storage tanks, underground storage tanks, and all connecting underground pipes that contain petroleum products.

An underground storage tank (UST) is a storage tank and any connecting underground pipes used to contain a regulated substance, when the volume of the tank and connecting underground pipes is 10% or more beneath the surface of the ground.

An aboveground storage tank (AST) is a storage tank and any associated piping designed to contain petroleum products that is located above the surface of the ground or the floor of an underground structure (such as a basement or vault). ASTs are:

  • non-vehicular
  • made of non-earthen materials

petroleum product is a petroleum substance obtained from distilling and processing crude oil that is liquid at standard conditions of temperature and pressure, and capable of being used as a fuel for the propulsion of a motor vehicle or aircraft. Petroleum products include, but are not limited to:

  • motor and aviation gasoline
  • gasohol and other alcohol blended fuels
  • kerosene
  • distillate fuel oil
  • Number 1 and Number 2 diesel
  • biodiesel blended with Number 1 or Number 2 diesel

The definition does not include naphtha-type jet fuel, kerosene-type jet fuel, or a petroleum product destined for use in chemical manufacturing.

For specific rule language of these definitions, see Title 30, Texas Administrative Code, Chapter 334.2 .

More Information

See the following resources for more on PST rules and requirements:

TCEQ's Small Business and Local Government Assistance section offers free, confidential help to small businesses and local governments working to follow state environmental regulations. Call us at (800) 447-2827 or visit our webpage at