UST Closure

State Water Board Evaluation staff will select facilities with UST closures, closures in place, and temporary closures as part of the facility file request. The evaluation staff will confirm that the CUPA has completed the following UST closure requirements:

Permanent Closure (UST Removal or Closure in Place)

  • Received documentation of proper disposal for residual liquids, solids, or sludges removed from the owner and operator
  • Received documentation of tanks being filled with an inert solid from the owner and operator
  • Received documentation of proper disposal of the removed USTs from the owner and operator
  • Provided the UST Closure Notification Letter to the owner and operator
  • Issued a closure plan and permit to the owner and operator
  • Received soil sample results and analysis from the owner and operator
  • Uploaded all preliminary written reports, soil sample results and analyses, and other closure data to the GeoTracker portal

Note: If the CUPA has not had a UST closure during the evaluation period, the evaluation staff will still request for the closure procedures.

Temporary Closure

  • Received documentation of proper disposal for residual liquids, solids, or sludges removed from the owner and operator
  • Issued a temporary closure plan and permit, indicating the permit approval date to the owner and operator
  • Ensure inspections were conducted by the owner and operator every three months to verify that temporary closure measures remain in place
  • If an extension was granted, received results of the site assessment from the owner and operator

CERS and Report 6

The evaluation staff review CERS to ensure the USTs have been properly closed out.

  • Permanent Closure
    • Evaluation staff use the UST Facility Search report available in CERS to check for the following:
      • Column H (Owner or Operate UST) is "N"
      • Column J (UST Reporting Requirement) is "Not Applicable"
      • Column N (UST Permanently Closed Date) includes a date
  • Temporary Closure
    • Evaluation staff review the Tank Information page to confirm that "Temporary UST Closure" is listed under "Type of Action"
    • Evaluation staff verify that the CUPA accurately reports all temporary closures in Report 6

GeoTracker

Evaluation staff verify that the CUPA has submitted all required closure documentation, including sampling results, to the GeoTracker System Removal or Unauthorized Release Reporting portal within 60 days of receiving the closure documents.

Closure Requirements Updates

Amended UST Regulations became effective on January 1, 2026. Evaluation staff will verify that samples are collected a minimum of two feet into native soil immediately beneath:

  • Each end of the tank
  • The midpoint of each tank with a capacity greater than 12,000 gallons
  • Each internal bulkhead of compartmented tanks
  • All hazardous substance piping at 20 linear-foot intervals, with additional samples collected at each change in direction for rigid piping
  • Each dispenser

CUPAs must contact their Cleanup Oversight Agency prior to sampling to ensure that all required constituents, based on tank contents, are included in the analysis. Additionally, specific timeframes now apply to the closure process. The flow chart below provides a general overview of the required timelines for closure activities.

Chart

UST Closure Statute and Regulation Code Sections:

  • CCR, Title 23, Chapter 16, Sections 2680 and 2681
  • HSC, Chapter 6.7, Section 25298