Water Facts Man’s very existence depends on water. Water is the major basic commodity of our lives, it sustains all life and is crucial to our existence. Roughly 2/3 of our planet is water but less than 1% is drinking water, found in our freshwater lakes, streams and wells. Nature has its own method of purifying water called the Hydrologic Cycle, but “water is best as nature provides it,” is a common misconception. Practically all natural water needs refinement or treatment to make it safe to drink or more satisfactory to use.
Water Contaminants Contaminants pour into our water resources at a rate of 500,000 tons per day. The earth’s water supply cycle starts in the upper cloud layers. As it falls to the earth as rain or snow, it picks up impurities and gases from the atmosphere. Landing on earth, it seeps over and through the ground, dissolving earth minerals. Passing through limestone, it dissolves calcium and magnesium, the hardness minerals. Iron deposits impart iron to the water. Acidity and sediments are other water issues. Municipal water supplies come from surface reservoirs, such as lakes and rivers, or from underground reservoirs. Usually, municipalities chlorinate the water to make it safe to drink. Sediment is removed by filtration. Tastes and odors are reduced or eliminated. The water is conditioned to comply with certain specifications. However, hardness minerals, tastes and odors are not always reduced to the most desirable levels. Underground reservoirs provide our private water supplies. Because the water is raw and untreated, it can have varying amounts of hardness, iron, tastes, odors, acidity, or combinations of these. Different localities and water levels affect mineral content.
The Hydrologic Cycle The hydrologic cycle is the earth’s natural method of cleansing water. The earth, sun and atmosphere all work together imitating a distiller. It is the largest water purification system known to man. In this cleaning process, surface water evaporates from streams, lakes, etc. and rises to the sky in the form of vapor. The vapor condenses into clouds. When the condensation in the clouds are heavy enough, it falls to earth as rain, snow etc. About 70% of the water will evaporate again. The remaining 30% will replenish surface water. Throughout the hydrologic cycle, water changes from pure to impure and back to pure again.
- Evaporation Surface water is heated by sunlight and evaporates into vapor that ascends into the atmosphere. This is the purest naturally occurring water.
- Condensation When water vapor condenses in the atmosphere, it forms a cloud. The cloud becomes increasingly ‘dirtier’ by picking up impurities – usually in the form of dissolved gases. This atmospheric water is acidic and aggressive. ‘Acidic’ water tends to dissolve virtually all minerals it comes in contact with.
- Precipitation The acidic water returns to earth as precipitation (rain, snow, sleet, etc.).
- Infiltration The water picks up sediment and dissolved minerals as it seeps through the soil becoming hard, brackish and contaminated to varying degrees.
- Evaporation The water eventually heats again and the cycle repeats.