Our living on earth depends on an ecological balance together with an atmosphere balance. This balance is placing our survival at risk.

One of the causes of this is the interaction between land and water, where water falls from the atmosphere, flows through air, drops in the soil, runs through it, makes puddles, vaporizes with the sun and gets back to the atmosphere. During all this process, it carries nutrients and chemicals that are filtered through the soil.

Water is a clear, colorless, odorless liquid, the most common substance on the earth's surface. This transparent liquid is vital for every living thing on our planet. It covers over 70% of its surface and is made up of oxygen and hydrogen. An Italian scientist, Stanislao Cannizzarro, established in 1860 a chemical formula of the water molecule of two atoms of hydrogen (H2) and one atom of oxygen (O).

Over 90% of the world's water is salt water, 3% is fresh water found in glaciers and polar ice caps, buried beneath the ground or suspended in the atmosphere as water vapor or steam. One fiftieth of 1% is found in lakes, ponds, rivers and streams.

The Great Lakes of North America comprise the largest surface fresh water system in the world. They contain 18% of the globe's supply of fresh water.

Water is described as polluted if the amount of, or kinds of, substances contained in it are likely to cause harm to humans, animals, or plants. Even by becoming too rich in nourishment, water can also be polluted. Environmental pollution is any discharge of material into water, or land, or air, that causes a change on the ecological balance that lowers the quality of life. The discharge of waste into waterways without consideration, has caused major disasters with water becoming so polluted as to become a problem. Biological, chemical, and physical material degrades the quality of the water and affects living organisms. Waste products have caused sewage problems because treatment facilities have not been done according to the needs. Pollutants cause water pollution problems. Excess dissolved solids make water not good for one to drink or to use it for crop irrigation.

Water is a powerful solvent, it stores heat and cold well. It conducts heat away from warm bodies much quicker than air does. It dissolves more solids than any other solvent, like dirt. The physical properties and the chemical properties make it act as a positively charge pole due to its hydrogen atoms that are attached to the oxygen atom, which acts as a negatively charge pole. This is described as "polarity of the molecules".

Water boils at 212 degrees (F) and freezes at 32 degrees (F). As water cools it contracts, though cooling it further causes it to expand; if it freezes it will expand even more. Once it is solidified (has become ice) it floats in liquid water.

Lakes can become aged by the over fertilization. Here in Chicago, at Lake Michigan, the interaction of microorganisms play an important role in maintaining the quality of the water. By the studies of the microscopic communities, the health of the water is determined. Certain plants and animals are considered biotic indicators because their presence or absence can tell whether the lake is healthy or not.

Life in water has brought other basic physiological and behavioral changes. In extreme cases where high oxygen consumption may cause an oxygen depression and fish may die and other organisms, too.

In USA thousands of untested chemicals are discharged into waterways that may go undetected for years, but if discovered may b very difficult to correct. Conventional pollutants can be treated with adequate treatment facilities. The government has now imposed discharge limits on industrial plants, requiring examination to certain chemicals.

The major source of pollution is fossil fuel and nuclear electric power, chemical and petrochemical producers. Also heated waters that are discharged into waterways cause ecological imbalance; because the heat causes the decrease of the water to hold dissolved oxygen. The first is affected on its reproduction.

Agricultural and mining waste are generally disposed of on the land from which they came. When not adequately contained, these wastes have caused the contamination of run off and receiving waters.

At the sea, there are some threats like in Australia 's Great Barrier Reef, where the world's largest living structure, 1,200 miles long, pollution is due to earth exploration. It is upsetting the balance of life to its 340 species of coral and hundreds of species of rare tropical fish and any organisms living there. the government has made more rules to protect the reef. So, humans and industrial waste are causing all this pollution. Clean up projects are debated by political leaders, though not too much is accomplished , our portable water supply is being affected. Pure water coming from streams must be filtered and treated to ensure that it is clean. filters are used but are very expensive or complex or energy intensive. Most small towns and rural areas are not up to using this method.

A substance called alum is being used. After extensive process water passes through a filter tank, chlorine and fluoride are added to kill any remaining disease germs. The chloride helps prevent cavities. In Indianapolis a plan was put into use recently to have water cleaned by a private company. This program saved the city millions of dollars.

NASA has been helping too, with their research for space travel, implementing space technology in solving waste water and water reuse problems. They are growing plants hydroponically using aquatic plant roots, bacteria and other microorganisms.

Aquatic plants as treatment is an excellent solution. One is the water hyacinths, also duckweed, calla lilies, etc. Though this can be done at tropical and subtropical climates, other plants are used in solder regions like bulrushes. This system is thought to be helpful in providing for our future generations while being useful for us today.

Bibliography

Branley, Franklin, Water for the World, New York, 1982.
Eisemberg, David, and Kauzmann, Walter, The Structure and Properties of Water, 1969.
Katz, Adrienne, Nature Watch: Exploring Nature With Your Children, Addison Wesley, New York, 1986.
Watson, Lyall, The Water Planet, 1988.
Yeager, Peter C., The Limits of the Law, The Public Regulations of Private Pollution, 1990.