How are GCLs typically used in landfill operations?

Geosynthetic Clay Liners (GCLs) are widely utilized in landfill operations primarily for their effectiveness in controlling leachate migration, providing hydraulic barriers, and assisting in waste containment. Specifically, GCLs serve dual functions as both bottom and side slope liners, as well as components of the cover system.

Utilizing GCLs as bottom and side slope liners is critical in establishing a protective layer that helps prevent leachate, which can contain hazardous substances, from seeping into the underlying soil and groundwater. This function is vital for environmental protection and regulatory compliance. Additionally, GCLs can be used in the final cover systems, where they help to manage water infiltration and minimize erosion, contributing to the long-term stability of capped landfill areas.

The other options do not fully capture the primary and practical applications of GCLs in landfill operations. For example, while GCLs can be part of a cover system, their roles extend beyond just that. They are not solely employed as bottom liners nor are they used for fencing or as temporary construction structures, which diminishes their intended purpose in sustainable landfill management.