Municipal Affairs and Environment

CT Factor Calculator

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.

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

Genny DeCoste

Environmental Scientist
PO Box 8700
Confederation Building, West Block, 4th Floor
St. John’s NL A1B 4J6
Tel: (709) 729-2558
Fax: (709) 729-0320

Chris Blanchard

Environmental Scientist
PO Box 2006
Sir Richard Squires Building, 9th Floor
Corner Brook NL A2H 6J8
Tel: (709) 637-2034
Fax: (709) 637-2541


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