Safe drinking-water management must consider drinking-water quality, acceptability and quantity in the context of public health protection. In this manual, the term “safety” encompasses these three elements. Although the principles in this manual can be broadly applied to all types of drinking-water supplies, the guidance is primarily intended for piped water supplies that are professionally managed (by a water supplier or equivalent management entity).The guidance may be applied to existing drinking-water supplies, or adapted for water supplies that are in the planning stage before construction.