Incorporating taste and odour problems in water safety plans

Many water companies are at least occasionally affected by unpleasant taste and odour (T&O) in drinking water. For decades, aesthetic water quality has been of secondary concern to water producers, with water safety being the primary focus. However, there has been a recent shift towards prioritising consumer satisfaction, encompassing not only services, but also water quality, including T&O issues, which can negatively impact the supplier's reputation. Starting to address a T&O problem until consumers' complaints become massive is too late and puts water producers under great stress to take effective action in a timely manner. Rather, a preventive approach is necessary. The most effective approach is to include T&O as a hazard to assess and manage in the context of developing a water safety plan (WSP) for the supply system. The development of a WSP provides an excellent platform for including the stakeholders needed to control the source of T&O events, as this often requires multistakeholder cooperation. Our review provides a comprehensive guide to addressing T&O occurrences and shows how this can be included in the framework and the steps of WSP development. It identifies supporting tools and illustrates the information given with a number of examples from water suppliers' practice.