Guidance For Safe Drinking Water In Canada: From Intake To Tap

Commitment to the Drinking Water Program

In order to be effective and to ensure drinking water supplies are clean, safe and reliable, drinking water programs rely on the commitment of a wide range of stakeholders. In order to build public confidence in the system, these stakeholders - including government departments, industry, private sector companies, non-governmental organizations and the public - must work cooperatively without losing sight of the ultimate goal: the protection of public health. Policies at all levels related to the quality of drinking water should support public health goals, such as ensuring the microbiological safety of supplies.

Legislation and regulation

In Canada, drinking water has historically been considered a natural resource. As such, the legislative responsibility for providing safe drinking water to the public has long been considered a provincial/territorial responsibility. Most provinces and territories have adopted enforceable regulations to protect their source waters and to establish requirements for providing drinking water, including the certification of operators.

Interjurisdictional responsibility

As mentioned, the responsibility for regulatory oversight of public drinking water quality generally lies with the provincial and territorial governments, with the obligation to provide potable water resting with the purveyor. Within each jurisdiction, the authority responsible for drinking water is normally either the ministry of health or the ministry of environment (or both). On First Nations' lands, the responsibility is divided between First Nation Band Councils, Health Canada, Indian and Northern Affairs Canada, provincial authorities and the community itself. Areas of exclusive federal jurisdiction include national parks and on-board common carriers such as airplanes, trains, buses and marine vessels.

Each of these authorities must find ways to competently manage the water supplies in its jurisdiction. Authorities should also ensure consumers have access to information about their drinking water supply which may affect their health.

Scientifically-sound and implementable drinking water quality guidelines

For the past thirty years, the provincial, territorial and federal governments have collaborated through the DWS to establish the Guidelines for Canadian Drinking Water Quality. Provincial and territorial authorities are responsible for the implementation of these guidelines within their jurisdictions. At the federal level, the guidelines provide a benchmark against which drinking water quality can be measured on federal lands, such as in national parks or at border crossings.

The Guidelines for Canadian Drinking Water Quality set out the basic parameters that every water system (public, semi-public and private) should strive to achieve in order to provide the cleanest, safest and most reliable drinking water supply possible.

Guidelines are developed for microorganisms or chemical substances which meet the following criteria:

• exposure to the microorganism or substance could lead to adverse health effects; and
• it is frequently detected in, or could be expected to be found in, a large number of Canadian drinking water supplies; or
• the level at which it is detected, or could be expected to be detected, is of health significance.

.The most important drinking water guidelines deal with microbiological quality, to ensure that there is minimal risk of exposure to disease-causing organisms in drinking water. Turbidity is also considered a surrogate microbiological parameter because it is closely linked to the microbiological safety of drinking water.

Aesthetic and operational guidelines are also being developed. Aesthetic guidelines address those parameters which affect the consumer's acceptance of the water even though the substance in question is found at concentrations below which health effects may appear. These guidelines also address other characteristics of the water which may affect its taste, odour and colour.

All guideline values and supporting documentation are posted on Health Canada's water quality website (www.hc-sc.gc.ca/waterquality). Guidelines are re-assessed on an as needed basis.

Performance and design criteria

Authorities making decisions about treatment processes should select those that consistently provide potable and aesthetically-acceptable water to users. The microbiological safety of drinking water is a primary goal for public health. Therefore, barring system-specific exemptions, it is recommended that all drinking water supplies be disinfected. In addition, minimum treatment of all supplies derived from surface water sources and groundwater impacted by surface waters should include coagulation, sedimentation and filtration, or equivalent technologies.

It is also essential to develop comprehensive and scientifically defensible performance standards for those technologies that are economically affordable, effective, reliable and achievable. Treatment performance criteria are either narrative measures or numerical limits for a number of specific parameters which are required to meet a particular public health or environmental quality objective. At times, performance of available treatment technologies is limited, resulting in a less stringent drinking water quality guideline. Once new technology is available and is proven effective in achieving more stringent results, the guideline is modified.

Minimum criteria for design, construction (including materials) and operation should ensure public health protection and environmental quality objectives are met. Alternative approaches should only be used if it can be demonstrated these are better or equivalent ways of achieving the same objectives.

On-going infrastructure investment and maintenance programs

The costs of building, maintaining and operating infrastructure are very real. Assistance with funding for infrastructure projects is generally accessed through all three levels of government (municipal, provincial/territorial and federal), with each level contributing one third of the financial resources required to cover the cost of an approved project. On First Nation lands, Band Councils receive funding from Indian and Northern Affairs Canada.

It should be noted that a substantial portion of water supply infrastructure costs are borne by rate payers through normal water billing. While government "special funding" for water infrastructure is important, the user-pay model principle may better relate the true value of water to consumers.

That said, public health should be protected to the same degree regardless of the size of the community. For this reason, special consideration for additional funding support should be given to small systems in rural communities which have access to a much smaller municipal tax base than larger communities and which may not, therefore, be able to contribute their share of the capital cost of the project in question. For public health reasons, some small systems should be encouraged to amalgamate with municipal systems. Municipalities willing to take on ownership of these smaller systems should have access to financial assistance.

Faulty distribution systems are a significant cause of waterborne outbreaks. For example, a review of waterborne outbreaks in the United States from 1991 shows that 38.7% of outbreaks were caused by problems within the distribution system. For this reason, communities are strongly encouraged to have active cross-connection control programs in place, supported by municipal by-laws.

In addition, funding bodies should allocate resource s along health lines: infrastructure projects that have the greatest positive health impact should be given funding priority over those that will have minimal health effects. For instance, funding for drinking water treatment plant maintenance and upgrades which will have a positive public health impact should be given priority over the construction and maintenance of other infrastructure projects.

A secondary, but no less important, cost related to infrastructure maintenance and upgrading is ensuring that installers and designers are properly qualified. In order to ensure that they are, training or certification programs may need to be put in place.

Compliance monitoring and laboratory accreditation

Compliance monitoring should be carried out using various methods to ensure test results are accurate and reported properly. Each jurisdiction should have approval processes in place for selecting laboratories, or quality assurance/quality control (QA/QC) programs, for routine testing of drinking water samples for all relevant substances, especially those which indicate the microbiological quality of drinking water. Approved microbiological tests must be those developed for drinking water; methodologies for environmental sample analysis are not appropriate in this situation. Laboratories should be accredited to perform the specific analyses required. It should be noted that laboratories are not always accredited to do all types of water analyses.

Recent events have demonstrated that guaranteeing the safety of drinking water involves more than compliance monitoring. It is equally important that water treatment plants have standards for treatment and plant operation and that mechanisms are in place to ensure these standards are followed.

It is imperative that clear lines of communication be established between the laboratory, the agency operating the treatment plant and the regulator, so test results which may affect public health can be dealt with in an open, timely and effective manner. Ideally, the local health officer in each jurisdiction, or his or her designated official, would be one of the first points of contact for the laboratories to report any unacceptable water quality results.

Education of drinking water program staff

It is critical for all members of a drinking water program - whether elected officials (including municipal), regulators, scientific staff, utility operators or others - to have access to continuing education in this field.Appropriate training ensures staff are able to make effective decisions and have knowledge and understanding of the impact of their activities and decisions on the quality of the water.

Research and development

Drinking water programs must respond to on-going research into emerging issues, with an emphasis on the microbiological quality of drinking water from source to tap. Jurisdictions should engage in local research to determine site specific health concerns and how research in other jurisdictions is applicable locally.

Water purveyors and public health officials play an important role in research by collecting data about their water systems and the health of the community; they should be encouraged to participate in research activities. Health effects can sometimes be monitored by comparing these data to local hospital admittance records, medical billing records or sales of over-the-counter pharmaceuticals. Data collected help identify whether the contaminants or pathogens in question are entering the system or are a concern in Canadian drinking water supplies. These data may form the basis of new or revised public health policies.