California Code, Health and Safety Code - HSC § 101029

The sheriff of each county, or city and county, may enforce within the county, or the city and county, all orders of the local health officer issued for the purpose of preventing the spread of any contagious, infectious, or communicable disease. Every peace officer of every political subdivision of the county, or city and county, may enforce within the area subject to his or her jurisdiction all orders of the local health officer issued for the purpose of preventing the spread of any contagious, infectious, or communicable disease. This section is not a limitation on the authority of peace officers or public officers to enforce orders of the local health officer. When deciding whether to request this assistance in enforcement of its orders, the local health officer may consider whether it would be necessary to advise the enforcement agency of any measures that should be taken to prevent infection of the enforcement officers.