In order to comply with provincial regulations, on October 27, 2011 PUC changed the method used for providing disinfection in the water distribution pipes. Prior to this date, we used chlorine combined with ammonia to form chloramine. This method is known as ‘Chloramination’.
On October 27th we turned off the ammonia and continued with only the chlorine. This is generally known as using ‘free chlorine’ (i.e. chlorine alone) and is the most commonly used method of providing distribution piping residual disinfection all around the world. This method is known as ‘Chlorination’.
Since switching to free chlorine, PUC now uses 30% less chlorine and has eliminated the past addition of about 16 tonnes of ammonia per year to the city’s drinking water.
Various communications and presentations have been provided to PUC customers both before and after the change. These documents are available here.
Water Quality Improvement Strategy announced February 3, 2014 - Click Here for details