What does the "witness zone" refer to in a landfill?

The term "witness zone" in the context of a landfill specifically refers to the section situated between the lower and upper flexible membrane liners. This area is crucial for the integrity of landfill operations as it serves as a monitoring space for any potential leaks or failures in the liners. The configuration and purpose of the witness zone allow for the collection of leachate that may seep between the liners, ensuring that any issues are detected promptly. Monitoring this zone is vital for maintaining environmental protection standards, as it helps in assessing the performance of the landfill liners and reducing the risk of contamination. Thus, identifying the witness zone as the space between these liners accurately captures its role in landfill management.