California Enforcement of Single-Walled Tank Regulations
On January 22, 2025, the California State Water Resources Control Board (SWRCB) issued updated enforcement guidance regarding the mandatory phase-out of single-walled underground storage tank (UST) systems, reinforcing a critical compliance deadline that UST owners and operators cannot afford to miss.
Under California Health & Safety Code Section 25292.05, all single-walled UST systems—including associated piping—must be permanently closed by December 31, 2025. Closure can be completed by physical removal or, where approved by a Unified Program Agency, closure-in-place.
Examples of tank red tag notices
What’s at Stake?
After the deadline, non-compliant UST systems cannot legally remain in operation. Enforcement actions may include:
Red tags preventing fuel deliveries,
Administrative penalties of $500 to $5,000 per tank, per day (per Section 25299), and
Potential additional regulatory or legal consequences.
SWRCB’s latest communication emphasizes that local agencies and inspectors are expected to take a proactive, no-leniency stance when enforcing these requirements.
Industry-Wide Challenges Prompt Legislative Response
With over 9 months remaining until the deadline, many operators are already facing significant roadblocks to compliance:
High demand for licensed UST contractors, often having limited availability;
Long permitting processes in some jurisdictions.
In response to these industry-wide challenges, California Assembly Member Diane Papan introduced Assembly Bill (AB) 626 on February 13, 2025.
AB 626: A Pathway for Good-Faith Compliance
AB 626 aims to protect operators who have taken meaningful steps to comply with the 2025 UST closure mandate but face unavoidable delays beyond their control.
Under the bill, UST owners/operators would not be subject to penalties if the following conditions are met:
A complete application for all required permits to upgrade or remove UST systems has been submitted by December 31, 2025.
Documented delays are outside the operator’s control (e.g., contractor shortages, equipment lead times).
The existing UST system continues to operate in full compliance with all other applicable environmental and safety regulations.
The operator submits a formal written request for deadline relief to the local enforcement agency, including evidence of good-faith compliance efforts and causes of delay.
Local agencies would then have 60 days to review and respond to these requests.
🛑 Important Note: AB 626 is currently proposed legislation and has not yet been enacted. Operators should not assume penalty relief until formal approval and guidance are issued by the state.
How Pinnacle Can Help
The countdown is on, and the time to act is now. At Pinnacle, we work closely with UST owners, operators, and environmental managers across California to:
Work with the environmental consultant who pulls the tanks to ensure a claim is filed timely if a release is discovered during the process.
Manage the claim process, start to finish, should remedial actions be required.
Draft and submit the formal written request for deadline relief should AB 626 become law.
Whether you’re in the early planning stages or already navigating project backlogs, we’re here to help.
📞 Need assistance navigating the 2025 deadline?
Contact us today to connect with our environmental compliance team.
📄 For full details, you can view the SWRCB’s official statement [linked here] or in the comments section of our related LinkedIn post.