California Code of Regulations (Cal. Code Reg.): Title 22 – Social Security > Cal. Code Reg. §65529. Public Pool Disinfection
(a) Public pools, when open or in use, shall be disinfected continuously by a chemical that imparts a disinfectant at concentrations consistent with subdivision (b) of this section. If halogens other than chlorine are used, residuals of equivalent strength shall be maintained.
(b) The minimum and maximum concentrations of disinfectant residuals in public pool water shall be:
Free – Chlorine Residual Bromine Residual
Without CYA With CYA
Min Max Min Mix Min Max
Public Pools* 1.0 ppm 10.0 ppm 2.0 ppm 10.0 ppm 2.0 ppm —
Wading Pools, and Spray Grounds 3.0 ppm 10.0 ppm 3.0 ppm 10.0 ppm 4.0 ppm —
CYA = cyanuric acid; Min = minimum; Max = maximum; ppm = parts per million.
*This includes all public pools except spas, wading pools, and spray grounds.
(c) In addition to the requirements in subdivisions (a) and (b), a spray ground and water features with an ultraviolet light disinfection system shall be disinfected continuously at a minimum of 40 mJ/cm<2> by the ultraviolet light disinfection units while the spray ground and water features are in use. If the ultraviolet dosage rate drops below 40 mJ/cm<2> the operator shall close the spray ground and water features.
(d) The enforcing agent may accept other disinfecting materials or methods after the pool operator has demonstrated to the enforcing agent that the materials or methods provide a readily measurable disinfectant residual in the public pool. The pool operator shall demonstrate to the enforcing agent that such materials or methods are at least as effective as the required chlorine concentration and do not have adverse physiological effects on pool users.
(e) The pool operator shall maintain a test kit for measuring the disinfectant residual, pH, and, if used, cyanuric acid concentration at the public pool. This test kit shall be available for use by the pool operator and the enforcing agent at all times the public pool is in use. The chlorine or bromine test kit shall be the diethyl-p-phenylenediamine (DPD) type or otherwise be capable of testing free-halogen residual. Chlorine test kits shall be capable of testing for free chlorine and total chlorine.