What is a water safety plan?

The water safety plan (WSP) approach came to prominence in 2004 with the publication of the third edition of the World Health Organizationís Guidelines for Drinking-water Quality1. Essentially, all risks to the safety of the final water and the health of consumers from hazardous events likely to affect each drinking water supply system are assessed and, where necessary, controlled and monitored. Emphasis is placed on an inclusive and enduring systematic approach backed by thorough management and supporting procedures. For water suppliers the WSP approach builds on good practice already prevalent in the mature European water industry but it is applicable to any size of water supply, however small. It is the ideal practical approach for raising awareness of the risks that can affect small supplies and how they can be controlled.

The aim of a WSP is to ensure that a drinking water supply consistently produces safe drinking water that is acceptable to consumers. However, the scope and application of the WSP approach is often misunderstood for it should go much further than just hazard identification and risk assessment and control through catchment, treatment and distribution. It should envelop all operations linked to water supply including management and management procedures, training, internal and external communications, monitoring, laboratories, reporting and incident and emergency procedures. Obviously, the complexity and scope of the WSP approach will reflect that of the water supply system and will be much simpler for small supplies.

Benefits of the water safety plan approach

Traditionally the demonstration of the quality of water supplied to consumers has relied upon testing the water for a wide range of parameters after it leaves treatment or at the consumers tap. The drawback of this approach is that the water is likely to have been consumed before the results of analysis are known. Although developments in rapid and on-line analysis have gone some way to overcome this problem, relying solely on analysis to demonstrate the safety of water may allow insufficient time for remedial action to be taken to protect consumers. The WSP approach of comprehensive hazard identification, risk assessment and risk management puts emphasis on controlling risks where they arise putting less reliance on water treatment processes which can mean more sustainable solutions with reduced carbon footprints. Monitoring becomes more targeted towards demonstrating that the controls are working and WSP procedures should enable early identification of new or increased risks. Incidents and events should become more predicable and preventable. The inclusive WSP approach will enable stakeholders to better realise their responsibilities towards the safety of water supplies and enable consumers to have more confidence in the quality of their drinking water.

Developing a water safety plan

There is no one way to develop a WSP. Generally, for ease of acceptance within water suppliers, it should fit in with existing ways of working unless these are shown to be insufficient or to have the potential to introduce or fail to identify hazards to the safety of the water supply. A WSP should be developed for each water supply system. The simplest form of water supply system consists of four elements, catchment including the source water, treatment, distribution and consumers but other formats can be used. Development of a water safety plan by a water supplier will require the support of senior management both because there will be cost and time requirements and because without such support the approach will not get widespread staff acceptance. Below is an outline of the main points of a WSP. Much more detailed explanation and advice is available in, for example, the WHO Water Safety Plan Manual2 and, particularly for small supplies, a Scottish Government website3.

Water safety plans for small supplies

The above outline of WSP implementation may seem daunting for owners and users of small water supplies particularly where funding, expertise and human resources are limited but the main elements that they should apply will be the same albeit in a more simplified form. The best approach is to concentrate on the main points of identifying hazards and then mitigating risks in the most sustainable and cost effective method possible. For example, if cattle or sheep have access to a spring or stream used as a water supply, the hazard of faecal contamination would be immediately obvious from a site visit and would represent a significant risk to the safety of the water supply. The most effective sustainable control would not be occasional monitoring of the water for faecal bacteria; it would be prevention of animal access to the water by erection of a sturdy fence and the monitoring would be regular checking that the fence was intact and effective. Obviously not all hazards are so straightforward and external expertise and analysis will be required for help with those less easily detectable.

Water safety plans in regulations

A number of countriesí regulations for drinking water quality now specify a requirement for water suppliers to implement a risk assessment and risk management approach to the production and distribution of drinking water. These vary from a vague requirement for water safety plans to be implemented to very specific requirements as to how the approach should be carried out and reported. For regulations requiring WSP implementation to be effective it is essential that water suppliers understand the approach fully. This may mean that terms such as water safety plan, water supply system, risk assessment, operational monitoring, validation and verification need to be carefully defined or that the whole WSP approach needs to be described. Flexibility of approach is a key to WSP regulatory success and it is important that regulations do not become so prescriptive as to prevent water suppliers from developing approaches that work well for them. It is easier to draw up separate regulations for small supplies because, as was explained above, a simpler WSP approach is likely to be the most effective.

The water safety plan approach has both attractions and drawbacks for regulators. Seeing a water supplierís hazard identifications and risk assessments will give the regulator insight into how well the supplier understands and protects its systems. However with greater emphasis on targeted operational monitoring, compliance monitoring would be reduced making it more difficult for straightforward reports on percentage compliance and comparisons between suppliers. Where there is a regulatory requirement the regulator can become the external WSP auditor. This is not so easy when the best WSP approaches should be influencing every aspect of water abstraction, treatment and distribution but can work well if used selectively, for example, by assessing how well the approach was applied to an individual water treatment works, in dealing with consumer complaints or was followed during an incident.

Since the Drinking Water Seminar organised by the European Commission (EC) in October 2003, the EC has stated on several occasions that the water safety plan approach will be an important element to be considered in the forthcoming revision of the Council Directive 98/83/EC on the quality of water intended for human consumption (the Drinking Water Directive; DWD). Whilst still favouring the approach, the EC is struggling with some of the regulatory issues outlined above. How can it lay down in a directive a water safety plan approach that is acceptable and understandable to 27 member states? In principle it could be done quite easily with some definitions and perhaps one new article but some form of guidance document would be required to explain the WSP approach in more detail. Such guidance would be welcomed by many member states but as it is unlikely that it would have legal status would make DWD implementation more difficult. Another question is how could member states demonstrate DWD WSP implementation to the EC? A further problem for the EC is that any changes to the existing DWD have to be justified through cost and environmental appraisal. Whilst it is easy to see how the WSP approach will benefit both in theory, collecting actual evidence around Europe where there are different approaches and timescales is difficult because the WSP approach requires time to deliver benefits. Small supplies may be the key here as across the EC they have the worst water quality and, if resources are available, are the easiest to improve through risk management.

References and further reading

  1. Guidelines for Drinking-water Quality. Third Edition. Volume 1 Recommendations. World Health Organization, Geneva 2004. ISBN 9241546387
  2. Water Safety Plan Manual: step-by step risk management for drinking-water suppliers. World Health Organization, Geneva, 2009. ISBN 9789241562638
  3. Scottish Government Private Water Supplies website