1. (a) Materials used in construction or repairs for an underground storage tank system must be applied in accordance with the manufacturer's written guidelines, an industry code, or engineering standard.
2. (b) All tanks must be tested and certified by the manufacturer before installation to demonstrate that the tanks were constructed in accordance with the applicable sections of the industry code or engineering standard under which they were built. For all tanks manufactured on or after July 1, 2026, the manufacturer must provide the owner with documentation confirming that the manufacturer has verified continuity within the tank interstice.
3. (c) Underground storage tank systems must be installed by persons meeting the requirements of sections 2632 and 2633, as applicable.
4. (d) All piping must be installed in accordance with manufacturer's installation procedures, or an industry code of practice developed in accordance with voluntary consensus standards if requirements are not specified by the manufacturer. Notwithstanding paragraphs (1) and (3) of section 2640(b), steel piping installed on or after January 1, 2026, must be constructed of a minimum factory coated black steel meeting ASTM A53, with minimum schedule 40 thickness if used for primary containment and minimum schedule 10 thickness if used for secondary containment.

5. (e) Underground storage tank systems must be installed, operated, and maintained in accordance with the manufacturer's specifications, industry codes, and engineering standards.

   1. (1) Tanks installed on or after January 1, 2027, must be anchored to prevent flotation using methods specified by the manufacturer, an industry code or engineering standard, or in accordance with an engineering specification approved by a state registered professional engineer.
   2. (2) Water used to ballast an underground storage tank during construction must be completely removed and properly disposed of to the satisfaction of the Unified Program Agency.
6. (f) Newly installed or repaired components must be tested in accordance with article 6. Underground storage tank systems that fail testing must be repaired or closed in accordance with article 8.

7. (g) Within 30 days of an inspection by the Unified Program Agency or special inspector of an installation, the owner or operator must certify the installation of tanks and piping by submitting to the Unified Program Agency in the “UST Certification of Installation/Modification” data elements a certification that installation of the underground storage tanks and piping, including containment sumps, meets all the following conditions:

   1. (1) The installer has met the requirements set forth in section 2632;
   2. (2) The tank, any primary piping, and any secondary containment, was installed in accordance with applicable voluntary consensus standards and any manufacturer's written installation instructions;
   3. (3) All work listed in the manufacturer's installation checklist has been completed; and
   4. (4) The installation was inspected and approved by the Unified Program Agency, or if required by the Unified Program Agency, inspected and certified by a special inspector meeting the requirements of section 2634 with experience inspecting underground storage tank system installations.
8. (h) The owner or operator must comply with applicable release reporting requirements of article 7 before repairing an underground storage tank system.
9. (i) The owner or operator must determine whether the proposed repair is isolated to one component or is a global repair throughout the underground storage tank system. Before the repair is conducted, it must be demonstrated to the satisfaction of the Unified Program Agency that the repair will prevent releases due to structural failure or corrosion for the operational life of the system. An underground storage tank system must be repaired only after approval from the Unified Program Agency.
10. (j) Repairs to underground storage tank systems must be performed in accordance with the tank manufacturer's written guidelines, an industry code, or an engineering standard. If there is no specified method of repair, the component or tank must be properly closed as soon as practical in accordance with article 8.
11. (k) Single-walled spill containment structures in direct contact with backfill which require replacement must be replaced with secondarily contained spill containment.
12. (l) The Unified Program Agency only may approve a repair if it can be demonstrated that the underground storage tank is structurally sound, and the method of repair will prevent unauthorized releases due to structural failure or corrosion while the underground storage tank system is operational. Unified Program Agency approvals of any repair to the primary containment must be in writing.
13. (m) For non-integral secondary containment components using isolation for corrosion protection, if any portion of the isolation component has failed or is compromised, any repair must include confirmation of isolation from the backfill.

Note: Authority cited: Sections 25299.3 and 25299.7, Health and Safety Code. Reference: Sections 25284.1, 25290.1, 25290.2, 25291, 25292.1, 25296 and 25404, Health and Safety Code; and 40 CFR Sections 280.20, 280.21, 280.33 and 280.40-280.45.

History

1. Amendment filed 8-9-91 as an emergency; operative 8-9-91. Text remains in effect uninterrupted pursuant to Health and Safety Code section 25299.7 (Register 92, No. 14).

2. Editorial correction of printing errors in History 1 (Register 92, No. 43).

3. Amendment filed 4-5-94; operative 5-5-94 (Register 94, No. 14).

4. Editorial correction renumbering Histories (Register 99, No. 7).

5. Repealer and new section heading and section filed 10-28-2025; operative 1-1-2026 (Register 2025, No. 44).