Leachate is best described as which of the following?

• A. Rainwater that carries nutrients into rivers.
• B. Liquid that drains from landfills and can carry pollutants into groundwater.
• C. Groundwater that returns to surface water.
• D. Polluted air dissolving in water.

Answer: (B)

Leachate is the liquid that forms when water percolates through waste in a landfill, dissolving and carrying away contaminants. This liquid can move through soil and reach groundwater if not properly contained, making it a major pathway for pollution. The description that fits best is the one that defines leachate as liquid that drains from landfills and can carry pollutants into groundwater. The other descriptions refer to different processes: rainfall washing nutrients into rivers describes nutrient runoff; groundwater returning to surface water describes baseflow or springs; and polluted air dissolving in water describes atmospheric deposition or gas exchange, not leachate.