Groundwater Pollution
• Pollution sources – from sewers, storage
• Slow flow, dilution, dispersion
• Low dissolved oxygen
• Fewer bacteria
• Cooler temperatures
• Long time scale for natural cleansing – Degradable wastes – organic matter
– Slowly degradable wastes – DDT
– Nondegradable wastes – lead, arsenic
• Protecting groundwater – prevention is best and least expensive