A wetland can be a swamp, a cattail marsh, a wet meadow, a riverside tree grove, or a bog or fen. Wetlands vary enormously in size. A wetland can cover thousands of square miles, like the Everglades. It can be a small prairie pothole or western playa measuring just a few hundred square feet-or a tiny wet patch no larger than the trunk of a car. Wetlands are often described as the kidneys of the ecosystem because they filter out harmful materials.
Marsh plants have the ability to purify the water and filter out toxic compounds.
State of the art water treatment facilities utilizing wetlands ecology have been built in some communities, harnessing Mother Nature's superb ability to purify the water. These wetlands treat 400,000 gallons of water every day. The fertilizers wash out of the soil and eventually empty into the Mississippi River, which drains about 40 percent of the entire United States. The chemicals are then carried down the river and into the Gulf of Mexico. There the chemicals cause algae to over-populate, stripping the water of oxygen and destroying organisms up and down the food chain.