What is the purpose of a leachate collection system in subsurface impounds?

A leachate collection system in subsurface impounds plays a crucial role in environmental protection, specifically aimed at preventing contamination of groundwater. Leachate is the liquid that percolates through waste materials and can absorb harmful contaminants. By collecting this leachate, the system ensures that potentially harmful substances are captured and managed properly, minimizing the risk of these pollutants infiltrating the groundwater aquifers.

This containment and management are vital because groundwater is a significant source of drinking water for many communities, and its contamination can lead to serious public health concerns, environmental damage, and costly remediation efforts. Therefore, the primary purpose of a leachate collection system is to safeguard groundwater quality by intercepting and managing leachate before it has the opportunity to reach and pollute aquifers.

The other choices serve different functions that do not align with the primary goal of leachate collection. For instance, while collecting excess water can be a benefit in some contexts, it does not specifically relate to the core function of preventing groundwater contamination. The treatment of air pollutants and draining rainwater are distinct processes not connected to the control of leachate within subsurface impoundments.