CT Values Dan Lanteigne CRTPA AGM 2017 CT Values Dan Lanteigne

CRTPA AGM 2017 CT Values CT Values are an important part of calculating disinfectant dosage for the chlorination of drinking water. A CT value is the product of the concentration of a disinfectant (e.g. free chlorine) and the contact time with the water being disinfected. It is typically expressed in units of mg-min/L.

CRTPA AGM 2017 CT Values Chemical disinfection CT values are calculated by multiplying the disinfectant residual concentration (in mg ⁄ L) by the disinfectant contact time (in minutes). CT = Concentration (mg ⁄ L) × Time (minutes)

CRTPA AGM 2017 CT Values The goal of disinfection is the inactivation of microorganisms. This depends on: the microorganism, the disinfectant being used, the concentration of the disinfectant, the contact time, and the temperature and pH of the water.

CRTPA AGM 2017 CT Values https://www.youtube.com/watch?v=CB4glN76bEc

CRTPA AGM 2017 CT Values A log removal value (LRV) is a measure of the ability of a treatment processes to remove pathogenic microorganisms.

CRTPA AGM 2017 CT Values First Nations communities follow the Ontario drinking water guidelines. 3 log 99.9% on protozoa 4 log 99.99% on viruses

CRTPA AGM 2017 CT Values Depending on the treatment process, Ct values and source of water will dictate the log removal credit the process will be granted.

CRTPA AGM 2017 CT Values

CRTPA AGM 2017 CT Values Calculating CT values CT = Concentration of free chlorine (C mg/L) * contact time (T Minutes)

CRTPA AGM 2017 CT Values Essentially Ct values are used in conjunction with the treatment process to achieve the required log removal