PRIVATE WATER SYSTEMS - Ground Water - Parts on an Aquifer

Parts of an Aquifer

Artesian Aquifer
an aquifer that has pressure built up inside. This pressure is the result of the recharge area of the aquifer being at a higher level than the rest of the aquifer region. The force of gravity pulls the higher water down which creates extra pressure inside the aquifer. This is why artesian wells flow by themselves; the pressure forces the water out of the well.

Confining Bed
a layer of ground that resists water penetration. This layer is typically finer textured and denser than above layers of soil. Confining beds can keep water from seeping to unreachable depths, but can also prevent water from reaching aquifers.

Consolidated Rock
rock that contains very few holes or cracks for water to get through. Unconsolidated rock is rock such as gravel. Consolidated rock can serve as a confining bed.

Deep Percolation
Deep percolation is the process of water flowing through permeable material at depth. This is similar to infiltration except that infiltration is generally though to occur in a downward direction, while deep percolation is generally assumed to occur laterally.

Evaporation
Evaporation is the process of water molecules gaining enough energy to convert from a liquid form into a gaseous form.

Evaporation Station
An evaporation station monitors the rate of evaporation.

Flowing Artesian Well
one that has penetrated into a artesian aquifer. Artesian aquifers have pressure built up within themselves. This pressure results from a portion of the aquifer being at a higher elevation as shown in the figure. The pressure is released when a well is bored into it. This causes the well to flow spontaneously.

Infiltration
Infiltration is the process of water moving down through the soil. Any pollutants dissolved in the water enter the soil and move toward the water table with the water. This is one way ground water is contaminated by surface water.

Non-Flowing Artesian Well
occurs when the pressure is not great enough to force the water out of the well. In this diagram, this is apparent because the flowing artesian well is at a lower elevation than the non-flowing artesian well

Observation Well
An observation well monitors the level of the water table in the ground.

Precipitation
Precipitation is the act of moisture falling from the clouds in any way or form. The precipitation could be in rain, snow, sleet, or hail.

Quality of Water Station
The quality of water and stream gaging stations record the quality of the water. They also monitor the water level and other water information.

Rain Gage
Rain gages are the devices used to measure the rainfall. Most rain gages used today can also be used to measure frozen precipitation as well.

Recharge Area
an area that allows water to enter the aquifer. The area is particularly vulnerable to any pollutants that could be in the water. If pavement is constructed over this area, less water can enter the aquifer. This could mean a water shortage to those people using the groundwater from the aquifer.

Runoff
Soil has a limit to how much water can infiltrate it over a certain amount of time. When the rate of precipitation is greater than the infiltration rate of the soil, water flows over the land. Plants, plant residue, and other debris on the land can help stop or slow the water flow and give it the opportunity to seep into the soil

Snow Course Survey
The snow course survey calculates the amount of snowfall in its area.

Springs
occur when the watertable is higher than the ground surface. Pressure forces the water out of the land at a weak point which creates the spring.

Surface Water Stream or Pond
is caused by a high water table. Also, a high watertable can result from a stream and pond in that area.

Transpiration
Plants take water from the soil to use in photosynthesis. Water vapor is then given off to the atmosphere.

Water Table Aquifer
aquifer that supports the watertable. The top limit to this aquifer is the watertable itself.

Vapors
Vapors are groups water molecules in gaseous form. When the vapors begin to condense around dust particles in the air, one can see the development as clouds. When enough condensation occurs, precipitation falls from the cloud

Water Table Well
a well that only extends down into the watertable aquifer

Water Table
the level at which the water stays. The very top of the zone of saturation. Water can also be found a few centimeters above this level water due to capillary action. In the presence of a pumping well, the watertable drops near the well. This situation is called drawdown. Under some conditions, a perched watertable may exist. This occurs when the water percolation is interrupted by another confining layer above the "main" one.

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