Sinkholes can occur when water, sometimes a bit acidic in nature, dissolves underground rock, often limestone or dolomite. You might be confusing land subsidence with sinkholes, and this statement is truer for sinkholes (not for the 'granite' part). (2) Land subsidence occurs in areas underlain by highly fractured granite, which is readily dissolved by moving groundwater, especially when the water is slightly acidic. In a confined aquifer if you drill a well, the pressure will push water up the well casing sometimes all the way to the land surface-no pump is needed!

Unconfined aquifers do not have this internal pressure (called artesian pressure), so if you drill a well into it, the water will only rise in the well casing up to the top of the aquifer (the water table) you will need a pump to get the water to the surface. As water flows into this aquifer it gets 'squeezed' between the rock layers, thus causing pressure to build up in the aquifer. The only thing that makes it false is referring to 'confined aquifer,' instead of an 'unconfined aquifer.' A confined aquifer is an aquifer with layers of generally impermeable rock above and below the aquifer (aquifers tend to run in horizontal layers below ground). Maybe it is not fair to start off with a trick question, but the correct answer is false. (1) The water table is the altitude (below ground) where the water level in a well will rise to when the well taps a confined aquifer. Below are your responses to our groundwater true/false quiz, and some explanations to help make you more groundwater knowledgeable. Water exists in significant amounts below just about Earth's entire surface. If you are standing on the ground, it is a safe bet that you are also standing on water (more like, 'over' water).

How does your home drinking water taste?.

How much water does it take to grow a hamburger?.

How much water does a dripping faucet waste?.

How serious are these environmental problems?.

JUST LIKE THAT by Sandra Wells