air and water chapter 5 section 2 the water supply
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Air and Water Chapter 5Section 2The Water Supply
Main IdeasMost of Earths water about 97% is salt water.
People and many other organisms require fresh water to carry out their life processes.
Although there are some natural sources of water pollution, most pollution is the result of human activities. Agriculture, industry, construction, and mining all produce wastes that can end up in water.
Water a Limited Supply of the fresh water on Earth is in the form of ice.
Many areas do not have fresh water available to them. They draw their water from hundreds of kilometers away.
Most fresh water is located in ice caps
Key TermsGroundwater: Water stored in underground layers of soil and rock.Drought: A period of less rain than normal.Water pollution: A change to water that has a harmful effect.Sewage: The water and human wastes that are washed down sinks and toiletsFertilizer: A chemical that provides nutrients to help crops grow better.Pesticide: A chemical that kills crop=destroying organisms.Sediments: Particles of rocks and sand.
Water PollutionWater Pollution is any change to water that has a harmful effect on people or other living organisms.Even treated sewage can pollute.Fertilizers and Pesticides can pollute nearby waters such as rivers.
ReviewWhy isnt most of the water on Earths surface available for people to use?Most water on Earth is salty, and much of the fresh water is ice.Name four types of human activities that can be sources of water pollution.Agriculture, industry, construction, mining.
ReviewWhy can finding the source of water pollution be difficult?The source can be far from the pollution. Pollutants can dissolve and move throughout a body of water. Sources can be hidden underground.What is sewage? Why should it be treated before being released into the environment?Sewage is the water and human wastes that are washed down sinks and toilets. It contains disease causing organisms that can mix with water used for drinking or swimming, and make people ill.