Which term describes the liquid that drains from landfills and can carry pollutants into groundwater?

• A. Rainwater carrying 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 drains from landfills. It forms when water—usually rain—percolates through waste, dissolving and carrying a mix of contaminants such as organic compounds, metals, salts, and other chemicals. This polluted liquid can migrate through soil and reach groundwater, potentially contaminating drinking-water sources. To prevent this, landfills use liners and leachate collection systems to capture and treat it before it can reach groundwater. The other descriptions refer to different processes: rainwater runoff carrying nutrients into surface waters, groundwater discharging back to surface water, and air pollutants dissolving in water, none of which describe the liquid produced by landfills.