Groundwater

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Groundwater is water that is found in aquifers below the lands surface. Almost all water, besides ocean water and frozen water, is groundwater. It can be found as deep as thirty thousand feet below the surface.[1] Aquifers have an immense amount of groundwater in them. There is a hundred times more water in the ground than in other areas like lakes. If groundwater is found in shallow areas it could be only a few hours old. If it is found farther down, it could a century old or more.[2]

Groundwater Uses

Groundwater has many uses. Farmers use set up irrigation systems and use water from the ground to irrigate crops. Cities and water departments withdraw it for public use. It is necessary for people who self-provide to use groundwater. It is also used by fire fighters, to fill swimming pulls, and in mining facilities.[3]

What is an Aquifer?

This is an image of groundwater and different ways it gets contaminated.

An aquifer, according to the Miriam Webster dictionary, is a “water-bearing stratum of permeable rock, sand, or gravel” and they can be found a few hundred feet below the surface."[4]

How Groundwater Works

Groundwater is kept within the “interconnected openings of saturated rock beneath the land surface.”[4] It is possible for rain water to seep into the ground. When water seeps it enters an unsaturated zone, which contains water and air. The root zone, the upper part, helps plants grow. Below this zone there is an attraction between water and rocks. Water then clings onto the surface of rock particles. The water flows from the unsaturated zone into a saturated zone and all openings in the rocks are filled with water.[4] This water is known as groundwater and it is held in aquifers.

The upper surface of a water table rises and falls freely because groundwater does not fill up the entire aquifer. Groundwater can leave an aquifer by being discharged. Unconfined aquifers can become contaminated and a confined aquifer occurs between impermeable material and the water cannot move. Confined aquifers enter a recharge zone when they are exposed to the surface, they then become unconfined. Aquifers get refilled through recharge, which is part of the hydrologic cycle. When the discharge of groundwater exceeds the recharge rate there is a over withdrawal.[5]

Gravity helps groundwater move as long as it is not confined by impermeable rock. Groundwater can also naturally flow downhill. However it ends up moving, it moves very slowly. It only moves a few inches a year.[5] It can also leave an aquifer by being pumped. Groundwater that is in a confined aquifer moves by pressure.[4]

Groundwater Issues

Depletion

Groundwater depletion is defined as “long-term water-level declines caused by sustained groundwater pumping.”[6] People pump water out of the ground faster than it can be replenished. If this continues, there won’t be any groundwater left. The water table will begin to lower, water in streams and lakes will lower, and the water quality will worsen. Lowering of the water table has taken place in the southwest, high plains, arid regions, and parts of the cost.[6]

Contamination

Groundwater can be contaminated naturally or by humans. Microorganism, radionuclides, heavy metals, and chemicals can naturally contaminate it.[7] Humans can contaminate it by littering, spilling chemicals, septic tanks discharges, and various forms of waste.[7] Chemicals can reach groundwater by moving downward with percolating water. Underground petroleum tanks are also dangerous. Dissolved chemicals can get into groundwater and be transported. Groundwater can enter lakes, rivers, oceans, and so on through discharge and if there was any sort of chemicals in groundwater the pollution could spread.[8] It can also be contaminated by saltwater intrusion.[1] One of the major substances that contaminate groundwater is nitrate. Nitrate is the primary form of nitrogen beneath agricultural lands. It can sink into the ground, reach groundwater, and stay there and accumulate for years. Nitrate does not affect adults however, if an infant drinks water with nitrate it can create low oxygen levels in the blood and kill them. This is why there is a regulation that says only 10 milligrams of nitrate as nitrogen can be in a liter. Nitrate contamination depends on the land surface and how vulnerable an aquifer is.[9] Once groundwater is contaminated it is hard to purify.[1]

Food Depletion

NASA states that diminishing groundwater can lead to a major loss in our food supply.  In fact, some areas have already been experiencing this. California has been losing 15 cubic kilometers of water per year since 2011.[10] This is partially due to the pumping of groundwater; people are using too much water and it can’t keep up with the demand. Since a large portion of our food is from irrigated farmland and the water is depleting, our food supply depletes as well. James Famigiletti believes that this depletion could lead to an international violent conflict. To prevent this, we must find sustainable ways of living and efficient agricultural practices.

Protecting Groundwater

Water needs to be treated by the federal quality standards. To prevent the water from being contaminated in the first place humans must protect it from chemical spills and hazardous substance.[7] Humans must use water wisely, stop littering, use water in more efficient ways, stop taking long showers, and so on. We should ACT which means to acknowledge the causes of preventable groundwater contamination, consider which apply to you, and take action to prevent groundwater contamination.[7]

See also

Other closely related articles in this wiki include:

References

  1. 1.0 1.1 1.2 [1]Oskin, B. (2015, January). What is Groundwater? Retrieved September 8, 2016
  2. [2]Perlman, H. (2016, May). Groundwater, USGS Water Science School. Retrieved September 8, 2016
  3. [3]Perlman, H. (2016, May). Groundwater Use, the USGS Water Science School. Retrieved September 8, 2016
  4. 4.0 4.1 4.2 4.3 [4]Groundwater & Aquifers | FracFocus Chemical Disclosure Registry (2016). Retrieved September 23, 2016
  5. 5.0 5.1 [5] Breslow, L. (2002). Gale Virtual Reference Library - Document - Groundwater. Retrieved October 7, 2016
  6. 6.0 6.1 [6]Perlman, H. (2016, May). Groundwater depletion, USGS water science. Retrieved September 8, 2016
  7. 7.0 7.1 7.2 7.3 [7]Treyens, C. (2016). Protect Your Groundwater Day - National Groundwater Association. Retrieved September 23, 2016
  8. [8]Salvage, K. M. (2004). Groundwater. In R. M. Stapleton (Ed.), Pollution A to Z (Vol. 1, pp. 243-245). New York: Macmillan Reference USA. Retrieved September 23, 2016
  9. [9]Nolan, B., Ruddy, B., Hitt, K., & Helsel, D. (1998, January). National look at nitrate contamination of Ground Water. Retrieved September 16, 2016
  10. [10]Lilley, J. (2014, November). NASA warns: Global groundwater crisis could lead to food supply collapse. Retrieved September 8, 2016


External links

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