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 public health and safety and the environment from releases of petroleum and other hazardous substances from tanks. 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 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.
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
- New! Technical UST Program Notifications
- New! Administrative UST Program Notifications
- New! Monthly CUPA UST Updates
- Adopted UST Regulation
- Unified Program Newsletter
- Public Record Information as Required by The Federal Energy Policy Act of 2005
- Revised Forms
- The Federal Energy Policy Act of 2005
- Enhanced Leak Detection (ELD) Notification
- UST Program ICC Certification and Training Guidance
- Inspectors – One-Stop-Shop
- EVR Multi-Agency Review Process
- Vacuum, Pressure, and Hydrostatic Monitoring Methods
For UST vapor recovery information, visit the Air Resources Board Website.
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- Report 6 and U.S. EPA TCR Performance Measures (11/16/18)
- Information on the Title 23 Federal Reconciliation Proposed Regulations (11/15/17)
- Removal of Single Walled USTs by 2025
- Unified Program Agency Evaluation Reports
- Compliance with California and Federal Underground Storage Tank Regulations
- Well Destruction and Waste Removal Fact Sheet
- EPA Evaluation of California UST Leak Prevention Program
- CERS FAQ Links
- Abandoned UST Initiative
- GW Impact – LUST/Site Cleanup Program Fact Sheet
- Information on Storage of Biodiesel
- New! California Underground Storage Tank Leak Prevention: January - December 2018 Semiannual Report
- New! California Underground Storage Tank Leak Prevention: January - December 2017 Annual Report
- California Underground Storage Tank Leak Prevention: Semiannual Report, January - June 2017
- Semi-Annual Agency Status Report (July 1, 2017 through December 31, 2017)
- Corrosion of Metal Components in USTs Storing Diesel and Gasoline-Ethanol Blends
- California UST Program – CUPA/PA Data Study
- U.S. EPA to Empty Fuel from Abandoned Underground Tanks at Former Gas Station in Fresno, April 2016
- Removal of Underground Storage Tanks in Fresno, CA (August 27, 2014)
- LTCP Checklist Validation and Case Transfer Project, Sullivan, January, 2014
- Cafe Camellia - Bellflower, CA – U.S. EPA Region 9 Success Story
- I-710 Corridor Site Assessments – U.S. EPA Region 9 Success Story
- California Impacted Municipal and Domestic Wells
- Study on Leaking Underground Storage Tanks in California, Tetra Tech, EMI, 2012