What is the main environmental concern addressed by landfill liners?

Landfill liners are designed primarily to protect groundwater from contamination caused by leachate, which is a liquid that results from the decomposition of waste materials within the landfill. When organic and inorganic materials break down, they can release harmful substances, including heavy metals, chemicals, and pathogens. If this leachate were to escape from the landfill and seep into the surrounding soil and groundwater, it could pose significant health risks to nearby communities and ecosystems.

Thus, the main function of landfill liners, which are typically made of synthetic materials or clay, is to create a barrier that prevents leachate from infiltrating into the subsurface environment. By effectively doing this, landfill liners play a critical role in safeguarding one of our most precious resources—groundwater—ensuring that it remains clean and accessible for human use and environmental health.

While other concerns like fire hazards and land use are important, they do not directly relate to the fundamental purpose of landfill liners in protecting the environment.