The tap water supplied by the village should be taken from underground water instead of water from big rivers, which may be due to the following reasons: First, the mineral content in underground water is relatively low, the water source is relatively stable, it is not easy to be polluted, and it is more suitable for human consumption. Second, the water sources of large rivers often contain high pollution, bacteria and other ingredients. After passing through many towns, pollution may gradually accumulate to a higher level, making it difficult to meet the drinking water standard. Third, the village population density is relatively low, the required water supply is relatively small, and the environmental protection, health care and economic cost performance of groundwater are high. Finally, the choice of water source is actually a scientific decision, which needs to consider many factors and utilization benefits, and choose the appropriate water source and water supply mode according to the actual situation to ensure people's drinking safety.