1. (a) Underground storage tank system integrity testing must meet the requirements of section 2651(d) and must be performed by a licensed tank tester in accordance with the manufacturer's written guidelines. Integrity test methods must account for the effects of thermal expansion or contraction, vapor pockets, primary containment deformation, evaporation or condensation, and the presence of liquid outside of the primary containment.

2. (b) Integrity testing must be performed after installation, replacement, or repair of underground storage tank primary containment components requiring excavation to access. Integrity testing must be performed prior to the system becoming operational:

   1. (1) Standard Integrity Test -- Type 1 underground storage tanks are subject to integrity testing capable of detecting a liquid release of 0.1 gallon per hour from any portion of the underground storage tank system primary containment with a probability of detection of at least 95 percent and a probability of false alarm no greater than five percent.
   2. (2) Enhanced Leak Detection Test -- Type 2 and Type 3 underground storage tanks are subject to integrity testing capable of detecting both vapor and liquid phase releases of 0.005 gallon per hour from any portion of the underground storage tank system primary containment with a probability of detection of at least 95 percent and a probability of false alarm no greater than five percent. The enhanced leak detection test cannot be performed until all ground penetrating work and surfacing has been completed.

Note: Authority cited: Sections 25299.3 and 25299.7, Health and Safety Code. Reference: Sections 25284.1, 25291, 25290.1, 25290.2 and 25292.4, Health and Safety Code; and 40 CFR Sections 280.43 and 280.44.

History

1. Repealer and new section filed 8-9-91; 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 of section heading, text and Note filed 4-5-94; operative 5-5-94 (Register 94, No. 14).

4. Amendment of subsection (c)(2) and repealer of subsections (c)(2)(A)-(B) filed 12-26-97 as an emergency; operative 12-26-97 (Register 97, No. 52). A Certificate of Compliance must be transmitted to OAL by 4-27-98 or emergency language will be repealed by operation of law on the following day.

5. Certificate of Compliance as to 12-26-97 order transmitted to OAL 4-22-98 and filed 6-2-98 (Register 98, No. 23).

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