“Chlorine is a disinfectant added to drinking water to reduce or eliminate microorganisms, such as bacteria and viruses, which can be present in water supplies. The addition of chlorine to our drinking water has greatly reduced the risk of waterborne disease.” – Health Canada.
Chlorination—a contentious issue to say the least. This article seeks to provide you with an understanding of how the safety of drinking water works in Canada and where Port Clements fits in that picture.
There are several pieces of legislation that deal with public drinking water systems be they Federally via Health Canada, Provincially via the Drinking Water Protection Act or Regionally as authorized under the Public Health Act which gets relegated to the Health Authorities to implement via their Environmental Health Officers.
A couple of related quotes from Northern Health’s Website:
“The mission of the Public Health Protection Program is to protect the health of Northern communities through education and inspection strategies designed to reduce health risks to the public. “
Operators of water systems are required to complete training, monitor treatment equipment, report hazards and collect water samples, as part of maintaining a safe water system. Environmental Health Officers (EHOs) routinely inspect, assess and interpret sample results for water systems. EHOs assign hazard ratings to water systems during inspections. A low hazard rating generally means a system is well run and safe to drink. Water systems that are given a high hazard rating are generally placed on a boil water notice until the source of contamination is contained, adequate treatment is installed, treatment system is corrected or hazard is removed. Lack of treatment, interruption of treatment, microbiological or chemical contamination can result in a boil water notice or a do not use notice.”
Currently the Village of Port Clements is rated as “low” by Northern Health meaning we have good quality water. Our water permit states that:
“d) a free available Chlorine residual of not less than 0.2mg/l must be maintained within the distribution system.”
Health Canada has a publication out (June 2009) called the Guidelines for Canadian Drinking Water Quality—Guideline Technical Document—Chlorine. In the Executive summary it states:
“Disinfection is an essential component of public drinking water treatment; the health risks associated with disinfection by-products are much less than the risks from consuming water that has not been adequately disinfected. Free chlorine concentrations in most Canadian drinking water distribution systems range from 0.04 to 2.0mg/l.”
Therefore at a rating of 0.2mg/l we are on the low side of treatment requirements here in Port Clements. Chlorine residual requirements are determined by the Environmental Health Officers and vary from municipality to municipality within provinces based on system-specific requirements. The World Health Organization (WHO) has recommended that areas with little risk of cholera or related outbreaks should maintain a free chlorine residual range of 0.2 to 0.5mg/l. We are on the very bottom range of this recommendation.
It is not necessary to further filter water at private residences but if individuals prefer to remove the residual chlorine there are a variety of filter systems available that can be added to your entire system or just at one tap. However, if you use a filter make sure you change it regularly or you could actually cause the water to become contaminated. Alternatively, chlorine will evaporate from the water if left standing for 2-3 hours in open air and sunlight or 48 hours if refrigerated. Also adding citrus fruit or vitamin C will cause chlorine to evaporate in approximately one hour