California Code, Health and Safety Code - HSC § 25270.5

(a) Except as provided in subdivision (b), at least once every three years, the UPA shall inspect each storage tank or a representative sampling of the storage tanks at each tank facility that has a storage capacity of 10,000 gallons or more of petroleum. The purpose of the inspection shall be to determine whether the owner or operator is in compliance with the spill prevention control and countermeasure plan requirements of this chapter.

(b) The UPA may develop an alternative inspection and compliance plan, subject to approval by the secretary and the office.

(c) An inspection conducted pursuant to this section does not require the oversight of a professional engineer. The person conducting the inspection shall complete and pass the initial aboveground storage tank inspector training program. The curriculum of the aboveground storage tank inspector training program shall focus on the spill prevention control and countermeasure plan provisions and safety requirements for aboveground storage tank inspections.