CT factor is a value derived to ensure drinking water is disinfected effectively. Disinfection standards require a disinfection concentration of 0.3 mg/L and a contact time of20 minutes at the first user on a public drinking water distribution system, or an equivalent CT of 6. Each individual drinking water system will have a unique CT, therefore it is important to know how to perform the calculation. The CT Factor calculator and user guide, located below, will assist in the calculation of the CT Factor for a public drinking water system.

• CT Factor Calculator (34 KB)
• CT Factor Calculator User Guide (364 KB)

For further assistance on the use of the CT Factor Calculator, contact the following: