Health and environmental policy issues in Canada: the role of watershed management in sustaining clean drinking water quality at surface sources

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Abstract

Sustaining clean and safe drinking water sources is increasingly becoming a priority because of global pollution. The means of attaining and maintaining clean drinking water sources requires effective policies that identify, document, and reduce watershed risks. These risks are defined by their potential impact to human health. Health and risk are, therefore, indelibly linked because they are in part defined by each other. Understanding pathogen ecology and identifying watershed sources remains a priority because of the associated acute risks. Surface water quality changes resulting from inputs of human waste, nutrients and chemicals are associated with higher drinking water risks. Nutrient input can increase primary production and the resulting increase of organic matter results in greater disinfection by-product formation or requires greater treatment intensity. Many drinking water disease outbreaks have resulted from breaches in treatment facilities, therefore, even with greater treatment intensity poor source water quality intrinsically has greater associated health risks. Government and international agencies play a critical role in developing policy. The goal of maintaining water supplies whose availability is maximized and risks are minimized (i.e. sustainable) should be a vital part of such policy. Health risks are discussed in the context of a multi-barrier perspective and it is concluded that both passive (protection) and active (prescriptive management) management is necessary for sustainability. Canadian aboriginal water systems, British Columbian water policy and US EPA policies are given as examples. The basis for developing effective policies includes a strong reliance on sound science and effective instrumentation with careful consideration of stakeholders' interests. Only with such directed policies can the future availability of clean drinking water sources be ensured.

Introduction

Nowhere does the link between human health and the environment manifest itself more strongly than our reliance on fresh clean drinking water. Management and treatment of waste generated from human activities including industrialization, agriculture, logging, and urbanization, have largely been insignificant in preventing pollution from affecting surface water quality on both local and global scales (Abu-Zeid, 1998). All levels of governments (local, provincial/state, and federal) bear the responsibility for setting policies to ensure the protection of our water resources and for providing instruments for the attainment of these policies. The policies of governments and international agencies directly impact environmental and human health, and the economic, social and cultural facets of our lives. Water resource management should be based on our scientific understanding of health and environmental risks, associated financial costs, and societal acceptance of these risks and costs.

Canada is bestowed with an estimated 9% of the world's renewable supply of fresh water and lakes account for roughly 7.5% of its inland surface area (Can., Gov., 2001). These surface sources, for example, provide at least three quarters of British Columbian (BC) residents with their drinking water (BC Auditor General, 1999). Given its natural abundance Canadians are accustom to water that is both plentiful and inexpensive. On a per capita basis Canadians use water at one of the highest rates in the world, while paying the least amount for it (McKanna, 2000). Despite having a wealth of water, drinking water sources are usually proximately located to areas they supply. Thus, impacts of industrialization, agriculture, and urbanization are closely linked to drinking water supplies. It is a critical goal to create a sustainable framework for human utilization of the environment and specifically for the protection of drinking water supplies so as to ensure human and environmental health.

Challenges toward achieving sustainable water supplies include a lack of recognition for the role of strong watershed management and discontinuity between policy makers, policy instrumentation, managers and scientists. The goal of this paper is to demonstrate the need for strong policies to direct source water management and the critical role of integrating the traditionally unique areas of policy, management, health and the environment. Given its sensitivity to both short- and long-term pollution, and its prevalence in Canada and elsewhere as a source supply, we examined health and environmental implications of policy regarding surface-sources of drinking water. Water quality is defined from a human health perspective and the major diseases and environmental risks to human health are outlined. From this perspective, Canadian and BC policies are reviewed and specific examples are given. The end of the paper builds on the requirements of sound scientific knowledge and strong policies by stressing the critical importance of effective policy instrumentation and sound risk management. We underscore the philosophy that many managers are acceding to, that drinking water quality issues need to evolve from a strict treatment-based approach (of both raw drinking water and sewage treatment) toward a watershed management approach (Aust. NHMRC, 2002). Only then can we ensure the short and long-term attainment of cost effective, high quality drinking water (Foran et al., 2000).

Section snippets

Water quality

Herein, surface-source water is defined as untreated or unfiltered (i.e. raw) water from lakes, streams, and rivers that water utilities or individuals use for drinking. Finished water is that which is delivered to consumers after receiving treatment. Usually, minimum treatment includes disinfection. Quality drinking water is ultimately defined as that which is safe for drinking and cooking (Gadgil 1998). Subjectivity associated with such a holistic definition has led to the functional

Health and water quality

The relationship between surface-source and finished water quality, in its simplest form, is that cleaner source water requires less intense water treatment and has lower associated acute and chronic health risks. Common health risks of drinking water include enteric pathogens, disinfection by-products (DBPs), chemical contamination, and other toxic compounds, such as those produced by cyanobacteria. The importance of identifying and breaking pathogen cycles to prevent waterborne illnesses was

Background—Canadian and BC water policy

The process of establishing safeguards and guidelines necessary for the continued attainment of high drinking water quality primarily depends on government policy. Policies are instruments through which governments can wield their power and provide directives for action (Elmore, 1987), such as establishment of specific procedures and rules, which in turn are used by regional, and local governments and water purveyors. Policies should be based on the best available information and result in

Risk assessment and cost

Health risks associated with drinking water can be reduced to the following equation: risk equals the likelihood of an event occurring (probability) multiplied by the consequence (the measurable effect). Health risks of contracting a disease from untreated drinking water is high in probability and high in consequence, whereas health risks of contracting a disease from disinfected water are lower in probability and, in the immunocompetent, lower in consequence. Drinking water that is free of

Role of science

Implicit in this paper is the requirement for sound science in all aspects of drinking water management. For example scientific studies form the basis of treatment development, setting MCLs/MACs and understanding source water and watershed ecology. The effectiveness of management and policy development is dependent upon a concerted scientific effort to understand all aspects of drinking water systems. Sound science forms the basis of the legitimacy, equitability and legality of implementing

Conclusion-health, policy and the environment

Ultimately drinking water management must be based on sound science, strong policy, effective policy instrumentation and a clear understanding of risk. The current crux of quality drinking water focuses on the end product, however, water quality is a consequence of water source, treatment, and distribution. The attainment of safe drinking water should employ several strategies (Table 2).

Ideally drinking water protection should focus on raising the quality of source water rather than increasing

Acknowledgements

We thank Stewart Irwin (Victoria BC, CRD Water Department), Jim Edmundson (Alaska Fish and Game), Rick Nordin (formerly MELP, currently University of Victoria) and Shaun Peck (Ministry of Health Planning, BC) for their helpful criticism and insightful suggestions. This project was funded by an NSERC Industrial Research Grant to A. Mazumder.

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