Making sure people have clean water to drink is an important step towards public health.
In the past, public health management of supplies relied largely on monitoring the quality of the water produced by individual water suppliers to check that it complied with the Drinking-water Standards for New Zealand (DWSNZ).
While monitoring is always important, water safety plans (formerly known as public health risk management plans) for drinking-water supplies provide the additional benefit of reducing the likelihood of contaminants entering supplies in the first place. By the time monitoring shows that contaminants are present, something has already gone wrong and a hazard is already present in the water.
Water safety plans encourage the use of risk-management principles during treatment and distribution so that monitoring is not the only water quality management technique used and further reducing the risk of contamination.
To help you create and operate a water safety plan for your drinking-water supply a set of model Water Safety Plan Guides has been prepared by the Ministry of Health. Table 1 sets out the information contained in the guides that will help you prepare a water safety plan.
This overview document also suggests how to prepare and operate a plan. It helps you understand the information contained in the model guides and how this information can be used. Table 1 tells you what information is contained in the guides.
You may wish to use the information given here and in the guides, or you may prefer a different approach. You do not have to prepare your plan using the guides, nor do you have to follow the steps for preparing them described in this document.
Your plan needs to show how you will reduce risks to public health from drinking-water. It should identify the situations that may lead to contamination and the actions necessary to protect the public.
In the guides we have tried to identify all the events that might lead to contaminants reaching the public, but some events – and their causes and preventive measures – may have been overlooked. When preparing your own plan, it is important that you identify and include possibilities not mentioned in the guides.