What is the function of outer casing in a well?

The outer casing in a well serves the critical function of preventing the walls of the well from collapsing, which is essential for maintaining the structural integrity of the well. The installation of casing provides a sturdy barrier against soil movement and erosion, ensuring that the well remains stable over time. This is particularly important in areas where soil conditions may be unstable or where there is a significant risk of cave-ins.

Additionally, the outer casing protects the well from contaminants present in the surrounding soil, which could compromise the water quality. It prevents surface water and other impurities from entering the well, thus maintaining the safety and purity of the water supply. Overall, the outer casing is fundamental to the well's durability and the safety of the water it delivers.

While promoting drainage and allowing water to flow freely are important aspects of well function, they do not directly relate to the primary role of the outer casing. Similarly, enhancing well depth falls outside the scope of what casing is intended for, as well depth is typically determined by drilling capabilities and the geological conditions encountered.