Objective To understand and analyze the sanitary, quality, safety and dynamic change of centralized water supplies in rural areas of a city in 2012—2014, and to provide information for local government to ensure drinking water safety.

Methods The data of water quality were retrieved from the National Disease Control Information System. The information on centralized water supplies was collected from the literature review and on-site survey. Water samples were collected and examined according to the Standard Examination Methods for Drinking Water (GB/T 5750-2006) and the results were evaluated based on the Standard for Drinking Water Quality (GB 5749-2006).

Results A total of 666 centralized water supplies were monitored in 2012—2014 in the city. The number of water supplies with ground water as sources accounted for 65.62% (437/666). The number of water supplies with conventional water treatment accounted for 23.57% (157/666) and those without any water treatment accounted for 54.65%.The overall qualified rate of rural centralized water supplies was 44.13%. The qualified rates of finished water and terminal piped-water were declined year by year (linearity and linearity combination χ²=9.597, P < 0.05).The qualified rate of finished water and terminal piped-water from ground water source were higher than those from surface water source. The qualified rates of rural water supplies in dry seasons were better than those in wet seasons. The qualified rates of finished water and terminal piped-water with conventional treatment were 82.80% and 80.95%, respectively, and the qualified rates of finished water and terminal piped-water without any treatments were 19.78% and 13.65% respectively. The qualified rate of total coliforms was 46.79% and the qualified rate of heat-resistant coliform was 52.30%.

Conclusions Water purification and disinfection facilities for central water supplies in rural areas of this city were insufficient. The qualified rate of finished water and terminal piped-water were decreased year by year. The major reason was microbial contaminants exceeded the standard limits. As a result, there was a high risk of water-borne infection diseases in rural areas of this city.