Objectives MIn December 2015, the source of drinking water in Guangyuan city was contaminated with antimony in the upper stream of Jialing River. In order to understand the situation of contamination, the authes carried out emergency monitoring and take measures to reduce health hazards.

Methods Making emergency monitoring plan, conducting field investigation and laboratory examination.

Results The results of emergency monitoring found that the highest value of antimony in the contaminated raw water in Guangyuan was 0.019 3 mg/L. Three measures were taken to ensure the safety of drinking water in Guangyuan. To control the discharge of antimony from contaminated upstream source; to combine the water source for emergency with that discharge from Jialing River to reduce antimony concentration in drinking water. It found that the maximum rate to decrease antimony concentration after dilution was 59.6%; and to improve the water treatment process to reduce the concentration of the metal. The result of monitoring data indicated that the level of antimony could be reduced 0.015 3 mg/L to 0.001 3 mg/L by these processes. The level of antimony in the tap water after treatment was significantly lower than that in the source water (t=7.039, P < 0.001).

Conclusions The source of contamination and the level of antimony were identified through the field investigation and emergency monitoring. By way of the summary and statistics of emergency monitoring data, as wellas analysis and prediction of contamination trend, the sanitary condition and quality of water were grasped in an all-round way. Toke the emergent measures and analyzed the effectiveness in time, the contamination was controlled.