Cal. Harbors and Navigation Code - HNC § 4160. Section 4160.
The board of supervisors of any county in which there is a port of entry or harbor, for which there is not otherwise provided quarantine regulations, may by an ordinance adopt the whole or any part of the provisions of Article 2 of Chapter 10 of Part 1 of Divison VI, of this code, appoint a board of health, or health officer, locate quarantine grounds when necessary, and provide for the enforcement of quarantine regulations.