Definitions and Use of Terminology for Chlorine

Subsequent to the Council's advice on the “Procedure for Disinfection of Drinking Water in Ontario” (Disinfection Procedure), the Council became aware that the definitions and terminology used for chlorine, chlorination, free chlorine residual, combined chlorine residual, and total chlorine residual, as found in the Disinfection Procedure, O. Reg. 903, and O. Reg. 170, have not been applied consistently.

The Council also reviewed definitions and use of terminology for chlorine residuals from the American Water Works Association (AWWA) and the Canadian Environmental Law Association (CELA), and transmitted its final advice letter to the Minister of the Environment on April 10, 2006.

The Council feels that its advice on the definitions and application of terms relating to chlorine, once incorporated into regulatory and procedural amendments, will help to ensure consistency and clarity amongst all Ministry of the Environment regulations and documentation.

The Council transmitted its final advice letter to the Minister of the Environment on this issue on April 10, 2006.

 Click here to view the Council's advice.