Water Q&A: My mom drinks "artesian well water". What is it?

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Find out more about artesian groundwater and confined aquifers under pressure.

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My mom drinks "artesian well water". What is it?

Water Questions and Answers

Chemically and physically, artesian groundwater is not different than other groundwater, but it comes to the surface differently. Your mom is drinking water from a well that taps an aquifer that is "confined". This aquifer is water-bearing rock (the pores and cracks between rock particles are filled with water) that is surrounded by other rock or material that does not allow water to pass through. So, the water in this aquifer is squeezed by the other rocks, creating pressure in the water-bearing aquifer.

When an artesian aquifer is tapped by a well the pressure pushes the water up the well, sometimes all the way to the surface, creating a flowing well. Imagine it as a very wet sponge contained in a closed plastic bag. Put a straw through the bag into the sponge, hold the bag tightly around the straw, and SQUEEZE - that would be artesian water squirting you in the face.