What is the purpose of a landfill liner and a leachate collection system, and how do they protect groundwater?

• A. Liners prevent waste fluids from leaking; leachate collection conveys fluids to treatment, reducing groundwater contamination
• B. Liners prevent rainwater from entering the landfill; leachate collection stores waste fluids
• C. Liners increase leakage; leachate collection increases groundwater contamination
• D. Liners are cosmetic; leachate collection is irrelevant

Answer: (A)

The main idea here is that a landfill liner and leachate collection system work together to protect groundwater by containing and removing contaminated liquids generated in the waste. The liner acts as a barrier beneath the waste, preventing leachate from migrating into surrounding soil and groundwater. The leachate collection system sits above the liner and captures that liquid, moving it to treatment or storage so it isn’t allowed to seep out and contaminate the groundwater. This combination reduces the risk of groundwater contamination from the landfill.

Other descriptions miss the point: liners aren’t designed to prevent rainwater from entering the landfill, and leachate collection isn’t for storing fluids—it's for conveying them to treatment. The idea that liners increase leakage or that leachate collection is irrelevant is not consistent with how landfills are made to protect the environment.