Primary disinfection is the means to provide adequate levels of inactivation of pathogenic micro-organisms within the treatment process. The effectiveness of chemical disinfectants is measured as CT, a function of disinfectant residual and contact time. The effectiveness of UV disinfection is determined through validation testing of each model and specific configuration of UV reactor proposed in the design, as described in R309-520-8.
Four disinfectants: chlorine, ozone, ultraviolet light, and chlorine dioxide are approved as primary disinfectants of drinking water.
Utah Admin. Code R309-520-4