Water is a precious resource. Roughly two thirds of the Earth's surface is water; however, less than one percent of that water is fresh, usable water. Water is often referred to as the universal solvent because it dissolves virtually everything it touches.
Water exists on earth as a solid (ice), liquid or gas (water vapour). Oceans, rivers, clouds and rain, all of which contain water, are in a frequent state of change (surface water evaporates, cloud water precipitates, rainfall infiltrates the ground, etc.)
However, the total amount of the earth's water does not change. The circulation and conservation of earth's water is called the "hydrologic cycle". Water starts out in the clouds as soft and of high quality. As water precipitates in the form of rain, snow, sleet or hail, it begins to pick up dust, pollen, chemical pollutants and carbon dioxide.
In fact, as water absorbs carbon dioxide, it forms carbonic acid. As this slightly acidic water reaches the ground, it picks up decayed vegetation, farm fertilizers, urban runoff, and bacteria as well as herbicides and pesticides. Then, when water percolates through the ground, it dissolves calcium, magnesium, iron and metals that may be present such as lead, mercury or cadmium. So by the time the water reaches your tap, it can contain some elements that may create problems in the home such as stubborn hard water stains.
No comments:
Post a Comment