Surveillance on Rural Drinking Water Safety Project in Yunnan in 2008－2013

Objectives In order to understand the sanitary situation and variation on the quality of rural drinking water and to provide scientific data for improving the water quality and preventing water-borne diseases.

Methods The basic situation of water supplies in rural drinking water safety projects was investigated and water samples were collected according to the National Sanitary Surveillance Scheme for Rural Drinking Water Projects. All input data were verified by the National Disease Control Information System, and were downloaded and analyzed with SPSS 16.0.

Results A total of 10 648 water safety projects were surveyed in 2008-2013. The daily water supply capacity in 84.82% of projects was equal or less than 200 m³, and completed treatment facilities were provided only in 9.42% of projects, and which was increased year by year(χ²=84.04, P < 0.01). Eighteen indexes were detected for 42 592 water samples, the quality of only 8 828 (20.73%) water samples reached the standard for drinking water in China, but the qualified rate increased year by year (χ²=5.87, P < 0.05). The qualified rate of treated water was higher than tap water (χ²=7.43, P < 0.01), the qualified rate in dry period was higher than that in wet period (χ²=691.60, P < 0.01); the qualified rate of water original from surface water as water source was higher than the water original from underground water as water source (χ²=17.31, P < 0.01), the qualified rate of completely treated water was higher than the water treated by other ways (χ²=3 382.78, P < 0.01), the qualified rate of water disinfected by liquefied chlorine was higher than other disinfectants (χ²=4 126.54, P < 0.01), the qualified rate of water was improved with the increase of daily water supply capacity (χ²=2 194.72, P < 0.01). The items for the qualified rate lower than 90% were total coli forms, visible substances, total bacteria counts and turbidity in 18 examined indexes.

Conclusions The daily water supply capacity of most projects in this study was in a small-scale, the ways of water treatment were improved year by year, however, the proportion of completed treatment was still very low. The qualified rate of water increased year by year, but still lower than the average value of the whole nation, mainly due to the lower qualified rate on microbial indexes and general sensory characteristics.