Evaluation of drinking water quality in a water supply distribution network based on Grey correlation analysis

The lack of access to clean drinking water adversely affects public health and life expectancy in many developing countries. However, not all cities' drinking water can currently meet drinking water standards. Therefore, determining reasonable water quality changes and the influence of various factors on water quality is important for improving drinking water quality. The objective of this study was to develop a water quality evaluation method based on Grey correlation analysis by evaluating water quality variations using tap water monitoring parameters and analysing the main factors that influence water quality throughout the water distribution network. A comprehensive evaluation system based on the proposed method has been implemented in drinking water quality control for water supply networks in the city of Zhenjiang. The results show that the main influencing factors are different at different monitoring locations. The main factor is the residence time at approximately half of the monitored locations. For the remaining locations, the main factors are pipe age and pipe material. Based on the evaluation results of water quality in the pipe network, the pipeline can be replaced, beginning with locations 4 and 8 in Zhenjiang city and followed by the remaining locations.