In the past, many agencies in Canada and around the world have relied heavily on compliance monitoring as the mechanism for managing drinking water quality and therefore protecting public health. Compliance monitoring relies on sampling small amounts of water in a drinking water system and testing those samples for the presence of known and quantifiable organisms or substances. This approach has major limitations, including the shortcomings of sampling and monitoring techniques; inadequate consideration of the range of factors that affect drinking water quality; and failure to provide an effective response to microbiological pathogens and contaminants without a prescribed numerical guideline value or established method of analysis.
The multi-barrier approach recognizes that the key to ensuring clean, safe and reliable drinking water is to implement multiple barriers which control microbiological pathogens and contaminants that may enter the water supply system. Although the multi-barrier approach to safe drinking water is not a new concept, water purveyors around the world are beginning to shift their focus from compliance monitoring to the more holistic approach.
Implementing management and operation practices to ensure these barriers are in place and working is generally the job of regulatory agencies and owners/operators of drinking water systems. However, regulatory agencies and operators can only carry out these responsibilities if they are provided with required tools (e.g., human and financial resources, training and education). With the right tools, they are able to implement barriers, monitor their effectiveness, undertake required regulatory inspections and communicate information to the public in a timely and transparent manner.
Canada has about 9% of the world's renewable freshwater. However, more than half of this water drains northward into the Arctic Ocean and Hudson Bay, making it generally unavailable to the 90% of the Canadian population who live within 300 kilometres of the country's southern border. This fact, coupled with recent outbreaks of waterborne disease in Walkerton, Ontario, and North Battleford, Saskatchewan, has led Canadians to recognize they must treat freshwater sources as a precious resource, rather than an over-abundant commodity, in order to continue to access clean, safe and reliable drinking water.
To this end, the Federal-Provincial-Territorial Subcommittee on Drinking Water (DWS) - which represents government departments with interests in drinking water quality (usually health and environment) at the federal, provincial and territorial levels - has developed this guidance document for managing drinking water supplies in Canada.
This document considers the factors that affect drinking water quality from the intake to the tap, regardless of whether the supply is public or private, large or small, urban or rural. It identifies key elements in a comprehensive drinking water program and sets out best management practices for drinking water purveyors, with a broader goal of re-instilling public confidence in Canadian drinking water systems. This document will be expanded in 2002 into a larger, more technical document for use by drinking water authorities and others directly responsible for ensuring the safety of Canada's drinking water supplies, such as drinking water treatment plant operators. As bottled water is regulated under the Food and Drugs Act, neither this document nor the expanded technical document will address bottled water.
The DWS recognizes that source water protection is an essential component of the overall management scheme for ensuring the quality of drinking water. However, because source water protection is beyond the scope of this group's work, this report will not discuss source water protection in detail. Source water issues are the focus of the guidance document being produced by the CCME Water Quality Task Group and will be incorporated in a joint document in 2002.