Cal. Health & Saf. Code § 116775
The Legislature hereby finds and declares that the utilization of the waters of the state by residential consumers for general domestic purposes, including drinking, cleaning, washing, and personal grooming and sanitation of the people is a right that should be interfered with only when necessary for specified health and safety purposes or to protect the quality of the waters of the state. The Legislature further finds that variation in water quality, and particularly in water hardness, throughout the state often requires that onsite water softening or conditioning be available to domestic consumers to ensure their right to a water supply that is effective and functional for domestic requirements of the residential household, but that residential water softening or conditioning appliances shall be available only as authorized in this article.
Ca. Health and Saf. Code § 116775