California Code, Business and Professions Code - BPC § 6703.1

“Supervision of the construction of engineering structures” means the periodic observation of materials and completed work to determine general compliance with plans, specifications, and design and planning concepts.  However, “supervision of the construction of engineering structures” does not include responsibility for the superintendence of construction processes, site conditions, operations, equipment, personnel, or the maintenance of a safe place to work or any safety in, on, or about the site.

For purposes of this subdivision, “periodic observation” means visits by an engineer, or his or her agent, to the site of a work of improvement.