Various human activities causes water pollution. They include discharges from wastewater treatment plants, run-off from agricultural fields, storm water drainage etc. Pollutants contaminate water bodies.Chemical factories and various industries discharge toxic heavy melts such as Fe, Mn, Al and organic wastes into water.Domestic sewege and animal excreta contaminate water.All industrial and chemical discharges should be free from toxic metals before allowing them to enter water bodies. There should be regular checks for the concentration of these species. To prevent harmful chemicals from entering ground water, compost should be used instead of chemical fertilizers in gardens and agricultural fields.