Effects Of Water Sources Switching On Water Quality In Drinking Water Distribution System

"Red water" phenomenon occurs in regions with low alkalinity and low water hardness. It also happened in the tips of water distribution system in which water velocity is low and stagnant time is long. When water sources and thus water quality change, the phenomena become serious. Water quality tests prove that in the "red water" accident, water quality worsens and the turbidity, color, and total iron increase, which interfere with people's life.The paper research difference of water impact from different pipeline sources by the network laboratory simulating, and preliminarily analyze the reason of water switch caused "Red Water", based on the background of partly "red water" phenomenon in the periods of water resource switch in Chinese North city. According to the research, The repair capacity of pipeline which water is red is poor, and the "red water" phenomenon is still existed even the water resource switch back. However, the pipeline which does not have "Red Water" phenomenon when water switch still keep intact even long time switching to new sources of water, which shows strong adaptability for water switch. The difference of corrosion layer in pipe inner surface may be the reason which leads to different water switch adaptability for divergent regions pipe network. The pipe inner layer dirt is loose state which inclined to occur "Red Water" phenomenon, and the dense inner dirt as protect hardly leads to the phenomenon mentioned above. Besides this, the composition of fouling layer is also different.