Water is necessary to life on earth.
All organisms contain water and require that water to be relatively pure.
Plants and animals cannot survive if their water contains toxic chemicals or harmful microorganisms. Water pollution can kill large numbers of fish, birds, and other animals, in some cases killing all members of a species in an affected area. Major Types of Pollutants include but are not limited to chemical, biological, or physical materials that degrade water quality. Hazardous wastes are chemical wastes that are either poisonous, capable of producing explosive or toxic gases, highly corrosive, or flammable. When improperly treated or stored, hazardous wastes can pollute water supplies.