What will happen to the water level in a well drilled into a confined aquifer?

What will happen to the water level in a well drilled into a confined aquifer?

Water movement in aquifers Groundwater in aquifers between layers of poorly permeable rock, such as clay or shale, may be confined under pressure. If such a confined aquifer is tapped by a well, water will rise above the top of the aquifer and may even flow from the well onto the land surface.

Does a confined aquifer interact with surface water?

In confined aquifers the groundwater is under pressure. If penetrated by a well, the water level in a confined aquifer will rise above the top of the aquifer. Because unconfined aquifers are exposed to the atmosphere, they may interact with surface water features, such as rivers and lakes.

What is confining the water in a confined aquifer?

It is confined in the sense that the groundwater in this aquifer is being held in by the silt bed above it. Confining beds are not very permeable, and water moves slowly through them, thus an elevated water pressure is maintained in the underlying confined unit.

How does a confined aquifer recharge?

A confined aquifer happens when water in porous layers is trapped by layers that are relatively impermeable, like granite or dense clay. A recharge zone usually occurs at a high elevation where rain, snowmelt, lake or river water seeps into the ground to replenish the aquifer.

How does a confined aquifer differ from an unconfined aquifer?

A confined aquifer is an aquifer below the land surface that is saturated with water. A water-table–or unconfined–aquifer is an aquifer whose upper water surface (water table) is at atmospheric pressure, and thus is able to rise and fall.

How are confined aquifers formed?

Aquifers are created when water seeps through earth and permeable rock until reaching a layer of impermeable rock. A confined aquifer forms when water collects, by pressure or gravity, between two layers of impermeable rock. Fissures in solid rock also allow water to pool.

Where does water in a confined aquifer come from?

Climate Change and Groundwater Confined aquifers with upper impermeable layers where recharge only occurs from precipitation where the water-bearing formations outcrop at land surface. 2. Unconfined (phreatic) aquifers in wet regions where rainfall is high and evapotranspiration is low.

How does water get into an aquifer?

An aquifer is a body of porous rock or sediment saturated with groundwater. Groundwater enters an aquifer as precipitation seeps through the soil. It can move through the aquifer and resurface through springs and wells.

Do you get more water out of a confined or unconfined aquifer?

Thus from a hydraulic standpoint, unconfined aquifers are generally preferable to confined aquifers for water supply, because for the same rate of water extraction there is less drawdown over a smaller area with an unconfined aquifer than with a confined aquifer.

How does a confined aquifer work?

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 rise above the top of the aquifer.

Are confined or unconfined aquifers better?

What is the difference between a fractured aquifer and a confined aquifer?

In a fractured aquifer, the water flow is along the fractures. However, a groundwater replenishment system is necessary for the maintenance of adequate water reserves. A confined aquifer or deep rock aquifer enables storage of large water quantities deep underground. This storage will decrease the requirement for expensive reservoirs.

Why study ground-water flow through fractured rock aquifers?

Understanding ground-water flow through fractured-rock aquifers is an area of ground-water research that will have increasing importance to our Nation over the coming years. Many areas of the United States rely on fractured-rock aquifers for water supply.

What is an unconfined aquifer?

A water-table, or unconfined, aquifer is an aquifer whose upper water surface (water table) is at atmospheric pressure, and thus is able to rise and fall.

What happens when you pump water from an aquifer?

Pumping can affect the level of the water table Groundwater occurs in the saturated soil and rock below the water table. If the aquifer is shallow enough and permeable enough to allow water to move through it at a rapid-enough rate, then people can drill wells into it and withdraw water.