Establishment of risk assessment index system for quality of drinking water from centralized water supply in Shanghai city: a Delphi study

  Objective  To establish a risk assessment index system for evaluating the quality of drinking water from centralized water supplies in Shanghai city and to provide a basis for risk management of centralized drinking water supplies.

  Methods  A set of indexes for risk assessment of centralized drinking water supplies was primarily established based on literature study and pervious work experience. Then a two-round Delphi consultation was carried out among 81 professionals to screen and to determine the weight of the 58 indexes using fuzzy analytic hierarchy process.

  Results  For the two-round consultation, the positive coefficients for the professionals are 100% and the professionals′ determination factor, degree of familiarity, and authority coefficient are 0.456, 0.881, 0.669, respectively. The coordination coefficient for all the items is 0.186 and 0.429 at the first and the second round consultation and the two coefficients are of statistical significance (both P < 0.05).Finally, a comprehensive index system was established with 6 primary indexes and 41 secondary indexes.

  Conclusion  The water quality risk assessment index system established in this study is in line with the basic situation of centralized drinking water supplies in Shanghai city.