A Water Safety Plan is a plan to ensure the safety of drinking water through a risk assessment and management process that considers all the points in water supply from the catchment to the consumer. It is a means of preventing and managing threats to a drinking water supply system, before anything goes wrong, taking into account all the stages of the supply process from the water catchment to the consumer.
What is a water catchment?
From Study Session 4 you know that the catchment is the area of land surrounding and sloping towards a river.
If the water quality assessed at the tap where people collect it or use it is found to be poor, it has the disadvantage that unsafe water may already have been consumed by the people served by the distribution system. The WHO has published recommended steps for drawing up a Water Safety Plan (Bartram et al., 2009) on which the following description is based. By using Water Safety Plans, the quality of the water is proactively managed so that poor-quality water does not reach consumers. Water Safety Plans also help to eliminate the causes of incidents that might disrupt the delivery of safe water to consumers. Incidents, in the context of water supply, means emergencies such as a burst pipe.
A Water Safety Plan considers all the stages in the supply of water, and therefore it involves:
- management of the catchment to prevent contamination of the source water
- removal or elimination of contaminants during treatment of the water
- prevention of contamination of the water after treatment (during distribution, storage and handling).
Water Safety Plans put the emphasis on controlling risks where they are likely to arise, rather than having a treatment plant deal with cases of contamination after they have occurred. Preventing a problem from occurring is much better than having it occur and then trying to minimise its impact.
While the primary focus in a Water Safety Plan is on the direct dangers facing safe water quality (such as the possibility of chemical or microbial contamination), the Plan has to be more wide-reaching, considering aspects such as potential for flood damage; the sufficiency of the source water and alternative supplies; availability and reliability of power supplies; the quality of treatment chemicals; the availability of trained staff; security; and the reliability of communication systems.