Question

What causes groundwater pollution?

Answer 1

• Agricultural runoff: Pesticides, herbicides, and fertilizer salts (nitrates, phosphates) leach through soil into aquifers.
• Industrial discharges and wastes: Chemical effluent, heavy metals (lead, mercury, arsenic, etc.), and other toxic wastes can enter groundwater.
• Sewage and domestic waste/failing septic systems: Untreated or poorly treated sewage contaminates soils and groundwater.
• Leaking underground storage tanks and oil spills: Petroleum and lubricants seep into soil and groundwater.
• Mining and nuclear/radioactive wastes: Mining, tailings, and radioactive discharges can contaminate groundwater and the food chain.
• Air-pollution/acid rain effects: Acid deposition can mobilize heavy metals in soils that then leach into groundwater.
• Soil erosion and surface runoff carry contaminated sediments and wastes into recharge areas (including leachate from landfills and improper waste disposal).