Health-based targets are measurable health, water quality, or performance objectives that are established
based on a judgement of safety and on risk assessments of waterborne hazards. The Guidelines for Drinkingwater
Quality (the Guidelines) describe four distinct types of health-based targets, applicable to all types of
hazards and water supplies:
• health outcome targets (e.g. tolerable burdens of disease);
• water quality targets (e.g. guideline values for chemical hazards);
• performance targets (e.g. log-reductions of specifi c pathogens); and
• specifi ed technology targets (e.g. application of defi ned treatment processes).
These targets are common components of existing drinking-water guidelines or standards that are used to
protect and improve drinking-water quality and consequently, human health. They provide benchmarks for
water suppliers and regulators to confi rm the adequacy of existing systems or the need for improvement. They
underpin the development of WSPs and verifi cation of successful implementation. Where required, healthbased
targets can be used to support incremental improvement by marking out milestones to guide progress
towards water safety and public health goals. This normally requires periodic review and updating of priorities
and targets. In turn, norms and standards should also be periodically updated.
Health-based targets should assist in determining specifi c interventions appropriate to delivering safe drinkingwater,
including control measures such as source protection and treatment processes.