Which of the following describes a confined aquifer?

A confined aquifer is defined by its position between layers of impermeable materials, which prevents water from easily moving in or out of the aquifer. This characteristic distinguishes confined aquifers from unconfined aquifers, which have direct contact with the surface and are not restricted by impermeable layers. The presence of these impermeable layers above and below the aquifer creates pressure within the water it holds, often leading to artesian conditions where water can rise above the level of the aquifer when tapped by a well.

The other options do not accurately describe a confined aquifer. For instance, being freely accessible from the surface pertains to unconfined aquifers, as they do not have barriers preventing direct access. A confined aquifer is not partially saturated; rather, it is fully saturated with water due to the pressure from the impermeable layers. Lastly, a confined aquifer does not typically lie near the atmosphere; rather, it is generally deeper underground, shielded by the impermeable materials that contain it. This understanding is crucial for groundwater management and exploration practices in residential development.