Aquifers

Groundwater is water that flows or seeps downward and saturates soil or rock, supplying springs and wells. Groundwater often begins as precipitation and soaks into the ground where it is stored underground in rock crevices and in the pores of geologic...
The beginning of a drought is difficult to determine. Several weeks, months, or even years may pass before people know that a drought is occurring. The end of a drought can occur as gradually as it began. Dry periods can last for 10 years or more. During...
The depth to the water table can change (rise or fall) depending on the time of year. During the late winter and spring when accumulated snow starts to melt and spring rainfall is plentiful, water on the surface of the earth infiltrates into the ground...
A well is said to have gone dry when water levels drop below a pump intake. This does not mean that a dry well will never have water in it again, as the water level may come back through time as recharge increases. The water level in a well depends on a...
A confined aquifer is an aquifer below the land surface that is saturated with water. Layers of impermeable material are both above and below the aquifer, causing it to be under pressure so that when the aquifer is penetrated by a well, the water will...
An aquifer is a geologic formation that can store and transmit water to wells, springs and some streams. An aquifer is more like a sponge than an underground river: geologic materials have connected pores that allow water to move from one space to...
Artesian well water is water from a well that taps an aquifer that is 'confined'. This aquifer is water-bearing rock below ground that is surrounded by other rock or material that does not allow water to pass through. So, the water in this aquifer is...
NAWQA findings indicate that MTBE is most frequently detected in ground water underlying urban areas in comparison to agricultural and mixed land-use settings. MTBE was detected in about 14 percent of wells sampled in urban areas. In addition, incidence...
Devils Hole is a tectonic cave developed in the discharge zone of a regional aquifer in south-central Nevada. The walls of this predominantly subaqueous cavern are coated with dense vein calcite. The stable isotopic content of the calcite provides a 500,...