Clay liners are impermeable barriers made from compacted clay, commonly used in environmental engineering. They are designed to prevent the movement of liquids, such as water or hazardous waste, through soil layers. This makes them essential in landfill construction and containment systems, where they help protect groundwater from contamination. These liners are typically installed beneath waste materials or storage facilities. The clay's natural properties, including its ability to swell when wet, enhance its sealing capabilities. Proper installation and maintenance of clay liners are crucial for ensuring their effectiveness in environmental protection and compliance with regulations related to waste management and groundwater safety.