Question

Which of the following statements regarding confined aquifers are correct?
A. They are called as leaky aquifers
B. They do not receive significant amount of recharge from overlying surface
C. Water present is at a pressure greater than the atmospheric pressure
Choose the correct answer from the options given below:

• A. B and C only
• B. A and C only
• C. A and B only
• D. Only C

Hint:

- Unconfined Aquifer: Water is at atmospheric pressure.
- Confined Aquifer: Water is under hydrostatic pressure (greater than atmospheric pressure).
- Leaky Aquifer: Semi-confined, allowing vertical leakage.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
An aquifer is an underground layer of water-bearing permeable rock, gravel, sand, or silt.
Based on their hydraulic boundaries, aquifers are classified as unconfined, confined, or semi-confined (leaky).
Detailed Explanation:
Let us analyze each statement:
- Statement A:
Leaky aquifers are semi-confined aquifers bounded by low-permeability aquitards that allow some water to seep through.
Fully confined aquifers, by contrast, are bounded above and below by completely impermeable aquicludes.
Therefore, Statement A is incorrect.
- Statement B:
Because a confined aquifer is sealed by an upper impermeable layer, water cannot seep down into it directly from the overlying land surface.
Instead, it is recharged only where the aquifer layer crops out at the surface, which is often far away from the well.
Therefore, Statement B is correct.
- Statement C:
Confined aquifers are pressurized because they are sealed between impermeable layers and recharged from higher elevations.
This pressure, called artesian pressure, is greater than atmospheric pressure.
When a well taps into a confined aquifer, this pressure forces the water level to rise above the top of the aquifer.
Therefore, Statement C is correct.

Step 2: Final Answer:
The correct statements are B and C only.