Water Pollution

Water Pollution

Water pollution is increasingly becoming a large problem that we as humans need to confront. Water is our most valuable resource. Just think of how much we humans are dependent upon clean water. Water is way more valuable than gold, what can you go a day, week, year with out, gold or water? Besides the fact that we drink the water, we use it for irrigation of farm fields, cooking, washing clothes, flushing toilets, etc. and every industrial process requires water to function. Everyone knows that the Earth's surface is covered by 70% water, so why fuss of protecting water? Only 3% of all water is fresh and drinkable and of that 3%, 75% is frozen, which leaves a grand total of only 1% of the Earth's surface water that is readily available for consumption. After taking that fact into account, one can see why the conservation and protection of our remaining water supply is so vital. Before water pollution can be stopped, the sources of the pollution must be known.

The major sources of water pollution are organic pollution, agricultural pollution, runoff, toxic waste, and thermal pollution. Organic pollution is becoming more and more pressing on the environment, because of the growing population of the world. It's a simple concept, the more people there are in one area, the more waste they will produce. For example, in a city there are so many people that the sewage plants and the environment can't take care of all of the waste and function in its usual manner. The sewage plants do their best, but the secondary discharge that gets into the water supply causes great problems. The excess waste acts as a fertilizer or food source for algae and the growth rate is uncontrollable. Everyone has been in a lake where there is a lot of dead algae on the shore and the water is clouded with algae. This situation is known as eutrophication, where algae growth is out of control and the water becomes oxygen depleted. There are natural cycles of eutrophication in the spring and fall, but the body of water can deal with those amounts. When excess waste is added to the water the body of water can no longer control the growth of the algae and the water soon becomes algae ridden and oxygen depleted. The water becomes oxygen depleted, because the dead algae goes to the bottom and uses the oxygen in the deeper water to decompose, but if there is too much dead algae all the oxygen is depleted. Oxygen from the surface doesn't reach the bottom, because the warmer water is less dense than the deeper cooler water, therefor the warmer water floats on the colder water and they never mix, much like oil and water. Soon the dead algae piles upon itself and makes the lake shallower, until it totally fills in and dries up.

Eutrophication effects all bodies of water, great and small. In the summer of 1971 at the Chicago South Water Filtration Plant on the coast of Lake Michigan, the filters were clogged with so much algae it had to be removed by hand. In the winter the turbidity(sediment in the water) was so high that the water wasn't drinkable. In a third case, the water smelled and tasted like dead fish and huge amounts of chlorine had to be added to make the water drinkable. If eutrophication can happen in lakes like Lake Michigan and Lake Erie, than no lake is safe. When eutrophication become extreme the water isn't usable any more. To stop the eutrophication of our lakes we need to devise a better system to treat sewage so it can be reused or released back into the environment without a catastrophic reaction. Currently there are some new systems that take raw sewage and convert it into usable water through biological means. The plant takes the water and feeds it to various plants. The nutrients are taken from the waste and used to grow plants. The excess water becomes clean after a four day operation. This idea is like controlled eutrophication where the plants are feed the excess nutrients to get plant growth instead of algae growth. This has only be attempted on a small scale. In the future if this could be done on a large scale the plants that are feed the waste to clean the water could be used as a food source. This idea isn't very new, infact, it is millions of years old. Basically the new sewage plant is an artificial wetland.

A wetland as defined by the American Heritage Dictionary, "a lowland area, such as a marsh or swamp, that is saturated with moisture, especially when thought of as the natural habitat for wildlife." Wetlands perform a very important function in nature. First off they provide habitat for a high percentage of endangered and threatened species of plants and animals. The survival of the species depends upon the survival of the wetland. When wetlands are reduced the population of water foul, fish, and animals reduces drastically. Not only are they just a home for the animals, they serve as a purification system. Water moves slowly through the wetland and the soil and the plants pick up the nutrients and contaminants and clean the water. They serve as a large filter, dirty water passes into the wetland and clean water is the final result. Wetlands also serve as water retention and flood prevention areas. If there were no wetlands all the water that is in the wetlands and the rain and snow would flood into our cities and neighborhoods. All the excess water is held in the wetlands were it is purified and slowly dispersed. Wetland act as an erosion control along coastlines and prevent wind erosion. They also safeguard that the soil will keep its nutrients. Wetlands are economically important also. Over 95% of the fish and shellfish that the US commercial industry harvest are dependent on the wetlands. Sport fishermen spend large amounts of money on fishing equipment and licensees. Valuable timber is harvested from the many forested wetland. Fur bearing mammals and alligators are harvested in wetlands. The vegetation of the wetlands can also be harvested. The US hasn't taken advantage of this option yet, but other countries such as China do. As one can see there are countless reasons for the preservation of wetlands. Wetlands need to be protected and preserved for the future. Another type of water pollution is one most people don't really think about, runoff.

Rainfall, snowmelt and irrigation cleanse the surface of the Earth. Any pollutants that are on the ground will eventually come in contact with water. So what? The water is just cleaning the streets and everything it comes in contact with, right? Wrong, the water picks up everything that is in it's