What is a Water Safety Plan ?
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The
2004 revision of the WHO Guidelines for Drinking-water Quality follow a
profoundly different approach for ensuring drinking-water safety: They
emphasise that it focussing on compliance to guideline values or standards in
finished water is not sufficient to ensure safety. Rather, safety is attained
through stringent process control from catchment to consumer. The new
paradigm of a systematic approach to this is the Water Safety Framework, of
which Water Safety Plans are a
central element. They are specifically developed for the individual water
supply and aim to 1.
identify and analyse
the hazards that may potentially occur, and to assess the health risk they may present as well as the system’s performance in controlling
these risks at the barriers in the catchment, in the water-body and at the
offtake, in drinking-water treatment, in distribution networks and in
households; 2. for the hazards
identified as presenting a significant risk to define control measures and to monitor the efficacy of their performance
continuously with a monitoring system that
effectively indicates performance. This includes defining critical limits for monitoring
results and corrective action to
take immediately if values are outside these critical limits; |
- document
these steps and validate
the whole system at regular intervals, i.e. to assess whether the risk
assessment is still adequate, the system’s design includes control of all
relevant risks, and performance of the whole system is satisfactory.
The Water Safety Plan concept focuses attention on risk assessment and on process control. It is an operational
system of quality management. This structured,
systematic approach to process control is particularly useful for managing cyanotoxin
risks.
The Water Safety
Framework proposed by WHO is based on defining the public health targets –
typically a task for governments and public authorities – as well as
independent surveillance of water quality and of supply systems. This includes
the familiar monitoring of compliance to guideline values or standards, and in
this context such values for cyanotoxins have their role. They may also be used
to define the quality target that the system should meet. The new WHO
Guidelines for Drinking-water Quality now call this surveillance step “verification” in order to clarify that
its primary purpose is an overall check that the system is adequately designed
to control the hazards, and that process control is working.
Further
Information:
·
http://www.who.int/water_sanitation_health/dwq/guidelines/en/ (download chapter 4 specifically for guidance
on WSP)
·
Book chapter on applying the WSP concept to cyanotoxin management
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Chorus,
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