Analysis of microorganism surveillence in rural centralized water supplies in Guangxi Province during 2008-2012

Objectives To investigate microbial contamination status of rural centralized water supplies in Guangxi Province and provide scientific basis for improving water quality of rural central water supplies. Methods Microbial indicators of water samples from 9 915 rural centralized water supply projects in Guangxi were tested according to the method of GB/T 5750-2006(Standard examination methods for drinking water).Results Among39 660 water samples, the qualified rate of wafer based on all microbial indicators was 39.30%. The qualified rate based on E.coli contamination indicator was 41.82% with the lowest among the three microbial indicators. The qualified rate of rural centralized supply water based on microbial indicators increased from 29.99% in 2008 to54.41% in 2012. The qualified rates of water quality were different because of different treatment process, different types of water sources and different water samples collected in flooding season or dry season(P0.01).Conclusions The qualified rate of centralized supply water based on microbial indicators is related to water source and treatment process. Thus we should strengthen the protection of water source and management of water purification and disinfection. At the same time,we should carry out health education of drinking water, to ensure drinking water safety of rural residents.