2019 California Standards for Accessible Design Guide (effective January 1, 2020 with July 1, 2021 amendments)

101.4.3 Plumbing.

The provisions of the California Plumbing Code shall apply to the installation, alteration, repair and replacement of plumbing systems, including equipment, appliances, fixtures, fittings and appurtenances, and where connected to a water or sewage system and all aspects of a medical gas system. The provisions of the California Plumbing Code shall apply to private sewage disposal systems.