Which statement best describes an artesian well in terms of contamination risk?

Which statement best describes an artesian well in terms of contamination risk?

• A. It is naturally pressurized and less prone to surface contamination
• B. It is usually shallow and highly prone to contamination
• C. It is constructed with multiple liners to prevent contamination
• D. It is fed by rainwater

Answer: (A)

In an artesian well, the water comes from a confined aquifer that is under natural pressure because it is trapped between impermeable rock layers. That pressure pushes the water upward in the well, often to the surface without pumping. Because the aquifer is capped by an impermeable layer, surface water has limited access to the groundwater, so the well is generally less exposed to surface contaminants. If the well is properly cased and sealed, this natural protection is maintained. So the statement that best describes the contamination risk is that an artesian well is naturally pressurized and less prone to surface contamination. It’s not typically shallow and not defined by multiple liners, and while rainfall recharges the aquifer, the water is groundwater from a confined source rather than rain feeding the well directly.

In an artesian well, the water comes from a confined aquifer that is under natural pressure because it is trapped between impermeable rock layers. That pressure pushes the water upward in the well, often to the surface without pumping. Because the aquifer is capped by an impermeable layer, surface water has limited access to the groundwater, so the well is generally less exposed to surface contaminants. If the well is properly cased and sealed, this natural protection is maintained.

So the statement that best describes the contamination risk is that an artesian well is naturally pressurized and less prone to surface contamination. It’s not typically shallow and not defined by multiple liners, and while rainfall recharges the aquifer, the water is groundwater from a confined source rather than rain feeding the well directly.