Practical evaluation of inorganic contaminant presence in a drinking water distribution system after hydraulic disturbance

The accumulation of loose deposits in a drinking water distribution system (DWDS) is a potential risk for water quality. In this work, hydraulic disturbance was simulated in different areas of a large DWDS. The water quality features before and after the disturbance were compared, and the solid deposits captured from different experimental sites were characterized. The results showed that the hydraulic disturbance increased the water turbidity and color, which can be attributed to the re-suspension of iron and manganese oxide particulates. The concentrations of arsenic and lead increased after the disturbance, and a significant positive correlation was observed between the iron and arsenic concentrations. The solid deposits exhibited distinct characteristics in different sites based on the normal hydraulic conditions and pipe material. The main crystalline iron substances were goethite and pyrosiderite. The iron and arsenic contents in the deposits had a positive correlation with their concentrations in the disturbed water. The combination status of manganese, chromium, and lead in the deposits was different from that of arsenic.