Objectives To understand the quality of source water after phytoplankton blooms in Lushui Reservoir, to provide safe and sanitary drinking water for urban residents.

Methods According to the Standard Examination Methods for Drinking Water (GB/T 5750-2006), the source water from Lushui Reservoir and the drinking water purified by the water supply company were collected; 31 routine tests and 31 unconventional detections were done.

Results Besides the pH(9.41) of the source water was a little higher than the standard limit, the containment of mercury was less than 0.001 mg/L (corresponding to standard Ⅳ), cadmium was less than 0.0025 mg/L (corresponding to standard Ⅱ), total nitrogen was 4.51mg/L (exceeding the standard Ⅴ, the maximum value was 2.0 mg/L), and ammonia nitrogen was 0.41 mg/L (corresponding to standard Ⅱ), and all the other items were corresponding to standard Ⅰ. The quality of all items in purified water was corresponding to the sanitary standard for drinking water except the chrominance, turbidity and pH.

Conclusions The quality of drinking water in urban areas of Chibi city was totally corresponding to the sanitary standard for drinking water, which can ensure the safety of drinking water for urban residents. However, further protection of water sources and keep it from being polluted is needed.