[Construction of a quantitative rating scale for sanitary evaluation of rural centralized water supply projects].

Objective: To establish a quantitative scoring scale for sanitary evaluation of rural centralized water supply projects.

Methods: On the basis of qualitative research method, combined with literature search and current relevant standards, the initial evaluation framework and indicators of the quantitative rating scale for sanitary evaluation of rural centralized water supply projects were formulated; using the Delphi method, two rounds of consultation with 23 experts in relevant fields were conducted to determine the evaluation indicators; the weights of the evaluation indicators were calculated by the rank-sum-ratio method; and the weight coefficients were converted into evaluation scores by using the equivalent conversion method.

Results: The recovery rate of the questionnaire of the two rounds of Delphi expert consultation was 100%, and the positive coefficient of the experts was 100%, the authority coefficient of the experts was 0.89. In the two rounds of consultation, the Kendall coordination coefficients of the importance of the experts for the evaluation indicators were 0.23(χ~2= 354.77, P<0.001) and 0.46(χ~2= 726.15, P<0.001), and the Kendall coordination coefficients of the sensitivity were 0.25(χ~2= 388.00, P<0.001) and 0.40(χ~2= 626.90, P<0.001). After screening the indicators, 7 first-level, 21 second-level, and 42 third-level evaluation indicators were ultimately determined. The final weight was converted into equivalent values, and the risk assessment scores for the water source link, water distribution network link, regulating structure link, purification and disinfection link, water quality testing link, sanitary management link, and internal management link of the water plant in the first-level indicators were determined to be 44 points, 13 points, 11 points, 42 points, 14 points, 16 points, and 25 points, respectively, for a total score of 165 points.

Conclusion: Based on two rounds of Delphi expert consultation, a quantitative scoring scale for sanitary evaluation of rural centralized water supply projects was constructed.