In a perched water table, where is free water located?

In a perched water table, where is free water located?

• A. In a sandstone layer above a clay deposit
• B. In the bedrock
• C. In a saturated split between two dunes
• D. In a surface aquifer only

Answer: (A)

A perched water table forms when an impermeable layer, like clay, lies beneath a permeable layer, such that water cannot move downward and instead pools in the upper layer. In this case, the sandstone layer above the clay deposit provides the permeable space where groundwater can accumulate. The free water is located in that sandstone, within its pore spaces, creating a localized saturated zone (a perched aquifer) above the impermeable clay. The bedrock would not typically host the perched water as the primary source of groundwater, a saturated split between dunes isn’t a defined perched aquifer, and a surface aquifer only would ignore the separate perched zone.

A perched water table forms when an impermeable layer, like clay, lies beneath a permeable layer, such that water cannot move downward and instead pools in the upper layer. In this case, the sandstone layer above the clay deposit provides the permeable space where groundwater can accumulate. The free water is located in that sandstone, within its pore spaces, creating a localized saturated zone (a perched aquifer) above the impermeable clay. The bedrock would not typically host the perched water as the primary source of groundwater, a saturated split between dunes isn’t a defined perched aquifer, and a surface aquifer only would ignore the separate perched zone.