Survey on hygienic status of rural centralized water supply projects in Dalian city 2010

Objective The study was performed in order to investigate the health status of centralized rural water supply projects in Dalian, and provide scientific basis for improving drinking water hygiene and safety in rural areas. Methods Surveys on the centralized water supply projects were carried out, and water quality test for rural centralized water supply projects was performed. Results The survey indicated that there were 2 110 rural centralized water supply projects associated with 1 004 943 people in Dalian. Water supply pattern was mainly the continuous water supply and the major water source was ground water from countryside concentrated supply water. Among the 520 samples tested, the qualification rate was 70.77 percent, water supply projects that had four qualified water samples accounted for 48.47 percent. The microbes and nitrate concentrations exceeded the national standard remarkably. The qualification rates for coli strains, nitrate concentration, heat resistant coli strains, and the total number of colony were 85.77%, 91.15%, 93.08%, and 94.62%, respectively. Conclusion The water disinfection facilities for rural central water supply projects were not adequate in Dalian. The qualification rate of water was low. The safety of drinking water has potential problems.