Question

How does groundwater become polluted?

Answer 1

Groundwater becomes polluted when contaminants on or near the surface leach down through soil and rock into aquifers, carrying chemicals, waste, and pathogens into the water table. Common causes include agricultural runoff (fertilisers and pesticides that add nitrates and toxic residues), sewage and failing septic systems, industrial discharges and leaking storage tanks (heavy metals, solvents and oil), and landfill leachate or natural mineral leaching (e.g., arsenic). Contaminated groundwater can persist for years and pose serious health risks.