Water’s journey from land to sky & back again
Posted 09/15/11, by Skagit PUD | 0 Comment(s)
Would you be believe that your last drink of water could have once been used by a dinosaur?
Water on earth today has been here for millions of years. Because of the hydrologic cycle (water cycle), water moves from the earth to the air to the earth again. It changes from solid to liquid to gas, over and over again.
What is the water cycle?
The water cycle keeps the amount of total water on the globe constant. Water evaporates. Water from oceans, lakes, rivers, ponds, puddles, and other water surfaces evaporates to become clouds. The clouds make rain, snow, or sleet that falls to earth to make rivers and streams, some of which seeps into the ground to form groundwater. All of this water flows to the ocean to start the cycle over again. Before returning to the ocean, some of this water is taken for drinking water and then is discharged as wastewater. The cycle is never-ending.
Precipitation creates runoff that travels over the ground surface and helps to fill lakes and rivers. It also percolates or moves downward through openings in the soil to replenish aquifers under the ground. As we all know, some places such as the Pacific Northwest, receive more precipitation than others. These areas are usually close to oceans or large bodies of water that allow more water to evaporate and form clouds. Other areas receive less. Often these areas are far from water or near mountains. As clouds move up and over mountains, the water vapor condenses to form precipitation and freezes. Snow falls on the peaks.
What if the water cycle stopped?
Without it all life on earth would end. Without this never-ending cycle, plants would die. Underground sources would soon be emptied. Rivers, lakes and oceans would overflow and flood large areas of land. The whole ecologic cycle would end.Pollution of water sources
Water can be polluted with human and/or chemical wastes. Even deep underground aquifers can be polluted from the surface. For example, oil thrown on the ground or in the sewer can pollute water and is very hard to remove.
Everyone must do their part to keep water sources clean.
Public utilities must clean water very carefully. We test water and measure pollutants to make sure the water is safe. We can measure very small amounts of pollutants in bodies of water—parts per million, parts per billion, and even parts per trillion. The water that we deliver to people must meet strict rules of purity. It is hard to imagine but:
- One part per million would be equal to one drop in 10 gallons.
- One part per billion would be equal to one drop in 10,000 gallons.
- One part per trillion would be equal to one drop in 10 million gallons.
At Skagit PUD, we are committed to providing you the safest and most reliable drinking water possible. Each year we mail all of our customers a copy of the water quality report. The report explains where your water comes from, what it contains, and how it compares to Environmental Protection Agency (EPA) and state standards. For additional reports, see the link below or pick up a copy in our main lobby in Mount Vernon.