California Code of Regulations (Cal. Code Reg.): Title 22 – Social Security > Cal. Code Reg. §65531. Public Pool Water and Indoor Air Quality Standards
(a) The pool operator shall maintain microbiological water quality standards in each public pool at the site as follows:
(1) Standard Plate Count (Heterotrophic Plate): The number of colony forming units (CFU) shall not exceed 200 colonies per milliliter.
(2) Total Coliform:
(A) If the multiple-tube fermentation method is used, the most probable number (MPN) shall be less than 2.2 per 100 milliliters.
(B) If the membrane filtration technique is used, the number of coliform organisms shall be less than one colony per 100 milliliters.
(C) If an enzyme substrate method including Idexx Colilert-18 is used, an MPN shall be less than or equal to one per 100 milliliters.
(b) Chemical quality of public pool water and indoor air quality at the public pool site and ancillary facilities shall not cause adverse physiological effects, such as irritation of the eyes, lungs, or skin of the pool users.