The zone immediately below the land surface where the pores contain both water and air, but are not totally saturated with water. Plant roots can capture the moisture passing through this zone, but it cannot provide water for wells. Also known as the unsaturated zone.
An underground geological formation able to store and yeild water.
Cone of depression
The zone around a well in an un confined aquifer that is normally saturated but becomes unsaturated as a well is pumped, leaving an area where the water table dips down to form a cone shape. The shape of the cone is influenced by porosity and the water yield or pumping rate of the well.
Geologic material with little or no permeability or hydraulic conductivity. Water does not pass through this layer or the rate of movement is extremely slow
The loss of water from surface water reservoirs or grounwater aquifers at a rate greater than that of recharge.
An outflow of water from a stream, pipe, groundwater aquifer, or watershed; the opposite of recharge.
A lowering of the groundwater level caused by pumping.
The time required for a volume of groundater to move between points. Typically groundwater moves very slowly- sometimes as little as inches per year
Water found in the spaces between soil particles and cracks in rocks underground (located in the saturation zone).
Groundwater is a natural resoource that is used for drinking, recreation, indusry, and growing crops.
Groundwater under the direct influence (UDI) of surfacee water
A groundwater source locatid close enough to nearby surface water, such as a river or lake, to receieve direct surface water recharge. Since a portion of the groundwater source’s recharge is from surface water, the groundwater is at risk of contamination from pathogens such as Giardia lamblia and viruses which are not normally found in groundwater.