What type of material is preferred for well casing to protect groundwater?

Steel is the preferred material for well casing to protect groundwater primarily because of its strength and durability. Steel casings provide a robust barrier that can withstand external pressures and is resistant to various environmental conditions. This material effectively prevents contaminants from entering the aquifer, which is crucial for maintaining the quality of the groundwater.

Steel also has a long lifespan compared to other materials and can be welded to ensure a secure fit, minimizing the risk of leaks. Additionally, the smooth surfaces of steel facilitate easy cleaning and maintenance of the well, further helping to protect the groundwater from potential pollutants.

While other materials like plastic and concrete have their uses in certain situations, they may not offer the same level of structural integrity and resistance to corrosion over time that steel provides, which is often essential in maintaining a safe and reliable water source. Wood, on the other hand, is not durable in the long term and can degrade or become a pathway for contaminants, making it unsuitable for this purpose.