Cal. Civ. Code § 37.111.1216

(1) A service building must be provided at each establishment that provides dependent unit designated sites unless the campground limits occupancy of individuals to 14 days or less. The service building is subject to the following requirements:
(a) the service building must be of permanent construction and equipped with lighting, handwashing sinks, toilets, and a janitorial sink;
(b) interior service building surfaces in plumbed areas must be smooth, nonabsorbent, and easily cleanable;
(c) showers, if provided, must have non-slip surfaces sloped to drain, provide warm water, not to exceed 120°F, and provide adequate ventilation;
(d) all windows, doors, and other openings must be screened or closed;
(e) the service building must be conveniently located within a radius of 300 feet from all sites designated for use by dependent units;
(f) the service building must be connected to approved water and wastewater treatment systems;
(g) the number and type of plumbing fixtures must be provided in accordance with Table I below. If a campground has more than 100 dependent unit designated sites, two additional toilets shall be provided for every additional 75 designated sites. The numbers may be either unisex toilet facilities or divided equally between separate men's and women's facilities.
TABLE I
# Dependent Unit Designated Sites
# Toilets
# Handwashing Sinks
1 - 15
2
2
16 - 30
4
4
31 - 45
6
6
46 - 60
8
8
61 - 80
10
10
81 - 100
12
12
(h) all equipment must be kept clean and in good repair. All showers, toilets, and handwashing sinks must be cleaned with disinfectant products regularly; and
(i) the service building must have hand cleaner, disposable towels or hot air dryers, and toilet tissue at all times of operation.
(2) All cooking shelters or other buildings must be cleaned after each day's use during the operating season.