AWWA ACE95284

Severn Trent Water Ltd supplies 8 million customers in the center of the UK, 99.8% of the supplied water is judged to meet the exacting European Community Drinking Water Standards but it has become increasingly clear that a significant portion of customers do not like the taste of tap water. To combat this problem Severn Trent investigated three areas of high complaint in detail and found three different problems. The paper describes the problems, the investigations and the solutions. Use of continuous chlorine monitoring in the distribution systems and on customers' premises was used to develop dynamic water quality models of the distribution network. These models were then used to examine alternative disinfection regimes. Solutions included switching to chloramination, rechlorination and stabilizing chlorine levels with a new sophisticated disinfection controller. In one area, Henley-in-Arden, Warwickshire, extensive customer research before, during and after remedial work to stabilize chlorine levels revealed differences between customers perceptions of water taste, and their views following drinking a sample of water. These problems of customers' perceptions are also described.