① Due to the improvement of the degree of urban industrialization, industrial pollution of groundwater is caused;
② The aging of the water supply pipeline and the secondary pollution of the drinking water caused by the high-rise water storage tank;
③ The tap water is chemically polluted due to the addition of medicines for disinfection and residual liquid chlorine. Drinking unclean water for a long time can lead to various diseases, such as: high water hardness can lead to gallstones and kidney stones; chlorine and some heavy metals are the main causes of cancer. According to statistics from the Residential Health Organization, 80% of the diseases are related to drinking water. With the improvement of people's living standards, water has become a profitable commodity, and the emergence of water-making machines makes it more convenient for people to drink high-quality water.