What is the difference between a well and an artesian well?

What is the difference between a well and an artesian well?

Conventional wells are created by drilling or digging into an existing aquifer. A drilled well can reach hundreds of feet into the ground until it reaches the water table, much deeper than a dug well or artesian well. An artesian well is formed by the pressure present within the aquifer.

Why are unconfined aquifers more likely to be contaminated than confined aquifers Why are confined aquifers more likely to be depleted than unconfined aquifers?

water from unconfined aquifers is much more likely to be contaminated with chemicals released by human activities, since it has a direct connection with surface. areas where soil has been baked hard by drought cannot soak up water from heavy rainfall- instead it runs off into storm swears or nearby streams.

Which type of aquifer is most likely to be contaminated?

Aquifers that have a layer of clay above them are ‘confined’: the impermeable clay layer blocks surface contaminants from reaching the wa- ter table. Unconfined sand and gravel aquifers are more vulnerable to contamination.

What is the difference between water table and potentiometric surface?

An unconfined aquifer is also referred to as a water table aquifer. The potentiometric surface is the level to which water will rise in tightly cased wells. A water table map shows the spatial distribution of water levels in wells in an unconfined aquifer, and is a type of potentiometric surface map.

What is an unconfined aquifer sometimes called?

There are two end members in the spectrum of types of aquifers; confined and unconfined (with semi-confined being in between). Unconfined aquifers are sometimes also called water table or phreatic aquifers, because their upper boundary is the water table or phreatic surface.

What makes a good aquifer?

Gravel makes a good aquifer because it is extremely permeable and porous. The large pieces of sediment create significant pore spaces that water can travel through. Often, gravel must be surrounded by a less permeable soil type, such as rich clay or impenetrable rock.

What is a non-confined aquifer?

Unconfined aquifers are those into which water seeps from the ground surface directly above the aquifer . Confined aquifers are those in which an impermeable dirt/rock layer exists that prevents water from seeping into the aquifer from the ground surface located directly above.

Can unconfined aquifers produce artesian wells?

-only unconfined aquifers can be drilled for wells to extract water -only confined aquifers can produce artesian wells -only unconfined aquifers are overlain by a layer of impermeable rock -only unconfined aquifers have a water table above them