Division of Water Quality – Underground Storage Tank Program

An underground storage tank (UST) is defined by law as "any one or combination of tanks, including pipes connected thereto, that is used for the storage of hazardous substances and that is substantially or totally beneath the surface of the ground" (certain exceptions apply).

The purpose of the UST Program is to protect the public health and safety, and the environment from releases of petroleum and other hazardous substances from USTs. There are four program elements:

  • Leak Prevention
    The Leak Prevention Program element includes requirements for tank installation, construction, testing, leak detection, spill containment, and overfill protection. Certified Unified Program Agencies (CUPAs) are the implementing agencies for the Leak Prevention program element. To find out which Unified Program Agency is responsible for your facility, see the Unified Program Regulator Directory.
  • Cleanup
    Cleanup of leaking tanks often involves a soil and groundwater investigation and remediation, under the direction of a regulatory agency. Responsible parties (RPs) who believe cleanup at their site is complete and are denied case closure by the regulatory agency, may consider filing a closure petition.
  • Enforcement
    The State Water Resources Control Board provides assistance to local agencies enforcing UST requirements.
  • Tank Tester Licensing
    Tank integrity testing is required by law, must meet the requirements of the State Water Resources Control Board, and must be conducted by State licensed tank testers.

Proposed Closure of Underground Storage Tank Cases

Quick Links

In addition, Geotracker is an important mainstay of the program. Finally, the UST Cleanup Fund is an independent but related State Water Resources Control Board program.

For UST vapor recovery information, visit the Air Resources Board Website.Click Here to Link to California Resources Air Board