Underground Storage Tank Enforcement

Most underground storage tank (UST) owners and operators voluntarily comply with applicable laws and regulations; however some do not comply due to lack of information, neglect or deliberate intent.

The State Water Resources Control Board (State Water Board) created the Underground Storage Tank (UST) Enforcement Unit to support enforcement of the UST Leak Prevention and Cleanup Programs, primarily by investigating violations of UST construction, monitoring, and cleanup requirements. These include violations such as: failure to monitor tanks and/or piping, failure to perform required testing, and tampering with leak detection devices. The State Water Board develops cases to refer to the State Attorney General’s office or other prosecutorial entities. In addition, the State Water Board has the authority to prosecute cases administratively.

The UST Enforcement Unit also supports enforcement of the California Tank Tester Licensing Program by enforcing the tank tester licensing requirements. These requirements are designed to ensure that certain types of tests on UST systems are performed only by qualified individuals. The State Water Board can take administrative enforcement action against licensed tank testers. There are approximately 85 licensed tank testers in California.

The UST Enforcement Unit works closely and develops partnerships with various local, state and federal agencies to conduct inspections, review data, and assist in or lead statewide UST investigations to achieve compliance of USTs and minimize threats to water quality and the environment.

  More information on the Underground Storage Tank Program.

  More information on the Underground Storage Tank Cleanup Fund.

  Please contact us if you have questions or need assistance.
Brian Taylor, UST Enforcement Supervisor
Email: Brian.Taylor@waterboards.ca.gov

UST Enforcement Unit's Fiscal Year Priorities

The Office of Enforcement's (OE) Underground Storage Tank (UST) Enforcement Unit will apply its resources to administer the programs described in the following sections.

Removal of Improperly Abandoned Tanks (RAT)

The RIAT program is an enforcement initiative targeted at improperly abandoned underground storage tanks (USTs) statewide. This initiative is a continuation of an effort that identified 327 improperly abandoned UST facilities in 2013 and successfully achieved compliance at 208 facilities of those facilities. In 2021 a second statewide assessment of improperly abandoned USTs showed that 149 improperly abandoned facilities still existed. Included in this list are 12 facilities which are in disadvantaged communities (DAC) within 1,000 feet of a municipal supply well. This subset of facilities was prioritized by the RIAT program for evaluation to determine the best means to obtain compliance. The prioritization of these sites in this manner aligns with the Water Boards’ commitment to Environmental Justice principles.

The visualization shows the locations of RIAT facilities in the project indicated by indigo points and 1,000-foot buffer zones around municipal wells in the RIAT facility vicinities. The colored polygons indicate land tracts assigned a DAC percentile score. Facilities within DAC scores exceeding 70 are prioritized for compliance actions. The goal of the project is to remove all improperly abandoned USTs from each facility. All facilities will be evaluated for RUST (Replacing, Removal or upgrading Underground Storage Tanks) funding eligibility.

To interact with the map please hover the cursor above any feature displayed in the map legend. Facilities on the map can be searched by city or zip code by clicking on the search icon at the top left of the map.

The number of facilities counted as “In Compliance on the bar graph title is an aggregate total of the categories in the bar graph. Closed facilities are those that have removed improperly abandoned USTs from the facility but have permitted USTs remaining on other portions of the property. The No Further Action Required facilities have removed improperly abandoned USTs with no evidence of a release. The UST(s) removed facilities have removed the improperly abandoned tanks but have not yet completed a cleanup or determined if there was a release. To locate the facilities categorized in the bar graph, click on the title below any bar. Click on an area outside the bar but within the graph to return the visualization to its complete appearance.

Single-Wall Underground Storage Tanks Closure Initiative

On or before December 31, 2025, underground storage tank (UST) owners or operators must permanently close a UST if it was designed and constructed before January 1, 1984, and does not meet the requirements of H&SC, section 25291(a)(1)-(6) or if it was designed and constructed before January 1, 1997, in accordance with H&SC, section 25291(a)(7). Specifically, UST Systems which do not have secondary containment and a continuous leak detection system do not meet the applicable requirement and will need to be closed on or before the December 2025 deadline. UST Systems which are out of compliance, cannot be operated, and could be red tagged by the Unified Program Agency (UPA) or the State Water Resources Control Board (State Water Board), preventing fuel deliveries and dispensing. Penalties for systems out of compliance are $500 to $5,000 per day per underground storage tank.

The UST Enforcement Unit has implemented the three-pronged Underground Single Wall Storage Tank Initiative to ensure that single wall UST systems are maintained and compliant with all applicable requirements leading up to the December 2025 deadline, or, if practical, are being considered for closure prior to that deadline. It is important that single wall UST systems in operation, leading up to the deadline, are maintained and operated appropriately to minimize the threat to water quality. Our Single Wall Tank Initiative consists of conducting inspections at three different sub-sets of facilities in the single wall underground storage tank macrocosm. These include emergency-generator, federal facility and abandoned single wall UST facilities. The objective is to elevate the awareness of the single wall UST owners of the impending closure deadline and ensure that single wall UST systems are closed appropriately by the required deadline. Additional information regarding available funding for the closure of single wall UST systems can be found here:

The visualization below maps the densities of single wall systems, by county, which must be permanently closed on or before December 31, 2025. Hover your cursor to display the selected county name and number of single wall USTs. The facility list was compiled using data from the California Environmental Reporting System. The map will be updated periodically to track the progress of this initiative.