Groundwater That is Trapped Between Two Layers of Impermeable Rock

Question

Groundwater that is trapped between two layers of impermeable rock is called a/an:
A) confined well.
B) confined aquifer.
C) unconfined aquifer.
D) unconfined well.

Accepted Answer

Groundwater that is trapped between two layers of impermeable rock is called a confined aquifer. A confined well refers to a well drilled into a confined aquifer, but the question is specifically asking about the groundwater itself. Unconfined aquifers are those with permeable rock or soil above and below, and unconfined wells are those that reach down into unconfined aquifers.