井水是农村广泛使用的水源。大口井的取水层一般是浅水层,是在地表以下第一个不透水层之上,是表层水下面较深的地下水。浅水层一般是由砂、砾石构成,其补给来源,除接受降水补给外,往往与河水互相补给。由于地层的渗滤作用,浅水在自然条件下,水质是比较清洁的,大部分悬浮物及微生物被滤除,因而水质物理性状较好,浊度小,细菌含量也比地面水和表层水少;但水流经地层时,溶解了 Well water is a widely used source of water in rural areas. The aquifer of the large well is generally a shallow aquifer, above the first impermeable layer below the surface of the earth, and is a deep groundwater below the surface water. Shallow water is generally composed of sand, gravel, and its sources of supply, in addition to receive precipitation recharge, often with the river water supply each other. As the formation of percolation, shallow water in natural conditions, the water quality is relatively clean, most of the suspended solids and microorganisms are filtered, so water physical properties better, less turbidity, bacterial content than the surface water and surface water less But when water flows through the formation, it dissolves