A FRAMEWORK FOR ASSURING THE QUALITY OF DRINKING WATER IN THE 21^st CENTURY

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October, 2001

(Summary and Key Principles)

This framework was developed in October 2001 at a workshop comprising a group of senior water-quality experts from the USA, Europe and Australia with backgrounds in regulation, water-supply operation, health, and research. The group reached a high level of consensus on the approach that they believe provides a good model from which to further discuss and develop the concepts amongst the worldwide water community.

The Goal: To provide good, safe drinking water that has the trust of consumers

Key Principles

• Good, safe drinking water can be provided only through an integrated approach from catchment to consumers’ taps.
• Such an integrated approach will require close cooperation and partnership between governments, water suppliers, health agencies, environmental agencies, land users, contractors, plumbers and consumers themselves.
• Transparency of the quality assurance process, including the derivation of standards, is vital for consumer confidence
• It is believed that a common framework for assuring drinking water quality can be developed, but this must:
  • Be based on best available scientific and medical advice
  • Place greater emphasis on proactive and prevention based quality management systems
  • Be sufficiently flexible to take account of different legal, institutional, cultural, and socio-economic situations in different countries

The Goal of Good, Safe Drinking Water Quality

The purpose of the framework is to deliver "good, safe drinking water quality." However, the precise definition of this could legitimately vary between countries and regions, depending on local circumstances. In any case, the framework must ensure the provision of water that has the trust of consumers and as a minimum be:

• Safe in both microbiological and chemical terms
• Acceptable to the consumers in terms of taste, odour, and appearance
• Reliable in terms of both quality and quantity

The Proposed Framework

The proposed framework is summarised in the diagram below. Key aspects are described in more detail in subsequent paragraphs

Responsibilities and Institutional Arrangements

The management of drinking-water quality from catchment to consumer is a complex process. The legal and institutional arrangements for this can only be established by government, but water suppliers have a pivotal role in the whole process. It is essential that effective mechanisms exist for the proper allocation of responsibility and to actively promote collaboration and knowledge-sharing between all stakeholders.

The Types of Control Proposed within the Framework

The framework envisages two types of control that together provide a flexible mechanism to assure good drinking-water quality. Each type of control will comprise a number of elements that can be used in different combinations depending on the precise legal, institutional, cultural, socio-economic, and hydrological factors in each country.

Key aspects of each type of control are summarised below:

Output Controls

Traditionally the verification of processes to ensure drinking-water quality has been managed by measuring the value or concentration of various parameters and comparing the results to predetermined norms, standards, or guidelines.

Such output control values will continue to play a critical role in assuring drinking water quality, but in the future there should be a much greater emphasis on the complementary use of Input Control Systems.

The number of parameters covered by statutory output standards should be kept to a minimum but with:

• A core set of parameters tailored to meet local needs
• Appropriate monitoring and reporting systems
• Use of suitable "indicator" microbiological and chemical parameters, where scientifically valid

The use of operational control parameters is essential to allow operators to monitor the effectiveness of treatment, e.g., chlorine residual to monitor disinfection and turbidity to monitor flocculation/filtration.

Output control values should be based on the protection of human health and consumer acceptability and not used as an indirect way to meet environmental goals in raw water.

Input Control Systems

There are three key elements of input control systems that underpin effective quality assurance:

• A system-wide risk-based assessment of safety from catchment to consumers' taps
• Identification of the most effective control points to reduce risk
• Effective operational, maintenance, and management plans to deal with both routine and abnormal operating conditions

Essential components of input control systems include:

• Measures to assess the effectiveness of the controls that have been put in place
• Independent third party verification of the effectiveness of the control system, which could form part of a regulatory system for drinking water quality but should not conflict with the management responsibilities of water suppliers and others

Other factors to be considered include:

• There would be value in the development of base criteria from which to derive input control systems for assuring drinking water quality.
• Wherever possible, water suppliers and other organisations should be encouraged to produce individually tailored risk based input control systems.
• An "off the shelf" standard package of typical input control systems would be beneficial for those organisations that do not have the capability or desire to derive tailored systems.

The Way Forward

Whilst there was a high degree of consensus among the participants in the workshop about the principles outlined in this paper, it was recognised that this is only the first small step in developing a much broader worldwide dialogue. For that reason the participants proposed the following:

• There should be widespread dissemination of this document through a variety of channels to further promote discussion of this topic.
• Pilot studies to test and refine the framework should be pursued in different countries.
• Areas identified where further technical and scientific research was necessary should be pursued through the appropriate water research and other organisations.
• A key part of assuring the quality of drinking water in the 21^st century is improved availability of information and data sources. Ways should be investigated for this to occur using modern web enabled electronic communication.
• Further practical seminars/workshops should be considered to share knowledge and review progress toward achievement of 21st-century quality assurance systems.

[Foundation note: To follow up on the conclusions of this 2001 workshop, a meeting is being planned for 2004 by the International Water Association. For more information, contact Andrew Speers at IWA at andrew.speers@iwahq.org.uk.]