Artesian Wells
Maybe you've heard advertisements by water companies wanting to sell you "artesian-well drinking water." Is this water different from other bottled water taken from springs you may ask?
The water may not be different, but it comes to the earth's surface a bit differently. Groundwater in aquifers between layers of poorly permeable rock, such as clay or shale, may be confined under pressure. If such a confined aquifer is tapped by a well, water will rise above the top of the aquifer and may even flow from the well onto the land surface. Water confined in this way is said to be under artesian pressure, and the aquifer is called an artesian aquifer. The word artesian comes from the town of Artois in France, the old Roman city of Artesium, where the best known flowing artesian wells were drilled in the Middle Ages. The level to which water will rise in tightly cased wells in artesian aquifers is called the potentiometric surface.
The word artesian, properly used, refers to situations where the water is confined under pressure below layers of relatively impermeable rock. The picture shows an artesian well with the potentiometric surface being just above the land surface, but, as the picture above shows, artesian pressure can be very strong!
The water may not be different, but it comes to the earth's surface a bit differently. Groundwater in aquifers between layers of poorly permeable rock, such as clay or shale, may be confined under pressure. If such a confined aquifer is tapped by a well, water will rise above the top of the aquifer and may even flow from the well onto the land surface. Water confined in this way is said to be under artesian pressure, and the aquifer is called an artesian aquifer. The word artesian comes from the town of Artois in France, the old Roman city of Artesium, where the best known flowing artesian wells were drilled in the Middle Ages. The level to which water will rise in tightly cased wells in artesian aquifers is called the potentiometric surface.
The word artesian, properly used, refers to situations where the water is confined under pressure below layers of relatively impermeable rock. The picture shows an artesian well with the potentiometric surface being just above the land surface, but, as the picture above shows, artesian pressure can be very strong!
Artesian Wells
