It is widely known that water covers almost three-quarters of the Earth's surface. However, it is not widely known that more than 99 percent of Earth's water is unusable by humans and many other living things. Less than one percent of water which supports most of the forms of life we are familiar with. Unfortunately, that one percent of fresh water becomes more polluted every year. The pollutants that fill our waterways each year are largely unknown. Water pollution comes from a number of unique sources, such as industrial waste, urban storm-water, agricultural runoff, various household chemicals and even nuclear waste. Combining these points of pollution with the increase in global population results in a continuously decreasing amount of clean drinking water for plant and animal life on Earth and an increasing amount of polluted water.
The many sources of pollution, along with the over-pumping of rivers and groundwater have caused drinking water quality to decline nationwide. Agricultural run-off has caused chemical pollution that damages the delicate aquatic ecosystems. Industry has been responsible for chemical pollution by dumping toxic wastes into rivers and on land, thus damaging groundwater supplies by allowing toxins to seep through soil into underground reserves. In addition to chemical pollution, industry is also responsible for thermal chemical pollution, the process of water from rivers used in cooling practices being returned to the rivers many degrees hotter than when it was removed, again disrupting the ecosystem. Poor sanitation of human wastes in water has further polluted the freshwater supply. Almost all drinking water comes from the freshwater supply.
The heavy use of water has caused other environmental problems as well. Water mining, which is the pumping of groundwater faster than it can be replenished, has caused the water tables to drop. This rapid pumping has created huge sinkholes on the land surface in some areas. Overpumping in coastal areas like Florida has caused the water table to drop below sea level and has contaminated the freshwater with salty ocean water.
Overpumping of rivers for agricultural and personal use has caused some rivers like the Colorado to dry up before it reaches the ocean. This not only harms the ecosystems found around the rivers, but also prevents essential nutrients from rivers from entering the ocean, depriving fisheries of food and in turn hurting the ocean's food chain. The end result of this is a loss in biodiversity and interruption in the food chain. Irrigation of land with water from these rivers...