2. An artesian (p. 573) system. The water in an unconfined aquifer will rise to the level of the water table.

4. The pollution of groundwater is more difficult to detect. The redemption of groundwater pollution is very time consuming and extremely expensive.

6. If the water supply is robbed of free oxygen the life forms, fish for example, that depend on oxygen will parish. This could affect the food chain as other animals depend the aquatic life. The source of this type of pollution is sewage and agricultural waste.

7. A well will produce water as long as it taps the aquifer. The water table will drop if the amount of recharge does not equal the amount of discharge.

11. A sinkhole is a large cavity opening upward. It can form as a cave with a collapsed roof or the dissolution of carbonate rock by acidic rain of groundwater.

12. In order to be considered a safe site for garbage burial, it must be located where it cannot be affected chemically by water, physically by earth movements, or accidentally by people.

16. Ice has the greatest competence (p. 584). Moving glaciers carve through the earth picking up large rocks which then move with the glacier. Wind has the lowest competence, since it is less dense than water or ice, it cannot support the weight of objects moved by the other two.

17. The residence time (p. 593) for ground water ranges from a few hundred years up to a few thousand years. The much longer residence time of groundwater means it takes a lot longer to naturally filter out any contaminants.

18. The water table rises as the damn raises the water level of the river or lake it damns. The increased water level in the river or lake saturates the surrounding land.

20. Water slows down as it enter the reservoir and deposits sediments. As time progresses, the amount of sediment continues to increase. If not removed this buildup will make the damn useless.

22. A glaciated mountain valley begins its formation in a previously formed stream valley. The glacier carves out the existing features and further accentuates them. a glaciated mountain valley is characterized by a U-shaped valley. Non- glaciated mountain valleys are characterized by a narrow V-shaped valley (p. 591).