AWWA WQTC65830

The Dublin San Ramon Services District (DSRSD) provides water, wastewater, and recycled water services for approximately 120,000 people living and working in communities east of the San Francisco Bay including Dublin, southern San Ramon, the Dougherty Valley, and Pleasanton. A wholesale water supplier, Zone 7 Water Agency (Zone 7), treats and provides all of the potable water to DSRSD. Water supplied to DSRSD consists of approximately 75% surface water (Sacramento San Joaquin Delta Water delivered via the South Bay Aqueduct and local runoff) and 25% local groundwater. At the time of the study, Zone 7 surface water underwent conventional water treatment and was disinfected with chloramines. Groundwater was also disinfected with chloramines. For some time, DSRSD customers have complained about tastes and odors in the drinking water. Consumer surveys in 2003 and 2004 quantified negative perceptions of drinking water quality, which were interpreted to be primarily associated with high hardness in groundwater sources. The purpose of this study was to conduct a quantitative taste test using consumers and three consumer focus group discussions to identify the characteristics of off-flavors in the water supplies, to determine what consumers like or dislike, and to recommend possible remedies. This paper describes the study approach, results, and implications of the findings. Includes reference, tables, figures.