Name: 
 

Groundwater Study Guide



Modified True/False
Indicate whether the sentence or statement is true or false.  If false, change the identified word or phrase to make the sentence or statement true.
 

1. 

Aquifers are barriers to groundwater flow. _________________________

 

2. 

Limestone consists mostly of calcium carbonate, which dissolves readily in water. _________________________

 

3. 

When a zone of saturation overlies an aquiclude and separates it from the water table below, it forms a(n) perched water table. _________________________

 

4. 

The most easily polluted groundwater reservoirs are water table confined aquifers. _________________________

 

5. 

Only a small portion of precipitation becomes groundwater and is returned directly to the oceans through streams and rivers. _________________________

 

6. 

The depth of the water table in stream valleys is close to Earth’s surface. _________________________

 

7. 

The flow velocity of groundwater depends on the height of the water table. _________________________

 

8. 

Groundwater is slightly acidic and evaporates limestone. _________________________

 

9. 

The combination of water (H2O) and carbon dioxide (CO2) produces hydrogen (H). _________________________

 

10. 

Common sources of groundwater pollution include sewage and harmful chemicals. _________________________

 

Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
 

11. 

Much of the water that falls on the ground as precipitation ____.
a.
enters the ground through the process of infiltration
b.
evaporates back into the atmosphere
c.
becomes runoff and finds its way back to the ocean
d.
forms small pools
 

12. 

In the diagram below, the area labeled A is called the ____.

groundwater_files/i0140000.jpg
a.
zone of infiltration
c.
zone of saturation
b.
recharge zone
d.
zone of permeability
 

13. 

What is responsible for the production of most ions in groundwater?
a.
precipitation of calcium carbonate
b.
groundwater surges
c.
dissolution of carbonic acid and calcium carbonate
d.
geyserite reacting with carbonic acid
 

14. 

What two materials are necessary for the formation of most caves?
a.
water and carbon dioxide
c.
soft water and travertine
b.
carbonic acid and groundwater
d.
acidic groundwater and limestone
 

Completion
Complete each sentence or statement.
 

15. 

Through the process of ____________________, most precipitation that falls on land becomes groundwater.
 

 

16. 

The percentage of pore space, or ____________________, of sand is about 30 percent.
 

 

17. 

The ______________________________ is an area below Earth’s surface that is completely saturated with water.
 

 

18. 

The upper boundary of the zone of saturation is the ____________________.
 

 

19. 

Materials, such as sand, with large, connected pores have a high ____________________.
 

 

20. 

Most groundwater flow takes place through ____________________, which are permeable layers of material.
 

 

21. 

Many ____________________ are three-dimensional underground passages, shafts, and chambers that stretch for many kilometers.
 

 

22. 

Calcium carbonate deposits that hang from the ceiling of a cave are called ____________________.
 

 

23. 

Dripstone formations are composed of ____________________, which is a type of limestone.
 

 

24. 

The localized natural discharges of groundwater are called ____________________.
 

 

Matching
 
 
Match each item with the correct statement below.
a.
subsidence
d.
recharge zone
b.
geyser
e.
spring
c.
drawdown
 

25. 

Where groundwater discharges a volume of water at the Earth’s surface
 

26. 

The land surface above an aquifer sinks because of excessive groundwater withdrawal
 

27. 

Explosive hot springs that erupt at regular intervals
 

28. 

The process that adds water from precipitation to the zone of saturation
 

29. 

The difference between the original water-table level and the water level in a pumped well
 
 
Match each item with the correct statement below.
a.
sandstone and limestone
d.
aquifer
b.
silt, clay, and shale
e.
polar ice caps and glaciers
c.
the ocean
 

30. 

Permeable layers through which groundwater flows
 

31. 

Permeable subsurface material
 

32. 

Contains 80 percent of all freshwater
 

33. 

Impermeable subsurface materials
 

34. 

The ultimate source of all water
 
 
Match each item with the correct statement below.
a.
hot spring
c.
karst topography
b.
artesian well
d.
groundwater
 

35. 

Limestone regions with sinkholes and sinking streams
 

36. 

Heated water discharged from the ground
 

37. 

Water under pressure in a confined aquifer
 

38. 

Major source of freshwater for human use
 

Short Answer
 

39. 

Trace a drop of water as it evaporates from the ocean, falls over land, and then finds its way back to the ocean.
 

40. 

Look at features A and B in the picture below. What are they? How are they formed?

groundwater_files/i0480000.jpg
 

41. 

Are water table unconfined aquifers or confined aquifers more easily polluted? Explain your answer.
 

42. 

What are the most common sources of groundwater pollution, and how do they enter the aquifers?
 

43. 

Give examples of how the depth of the water table varies with the terrain.
 

44. 

What two things can happen to a raindrop after it falls on land?
 

45. 

What type of subsurface material is able to store groundwater?
 

46. 

How are caves formed?
 

47. 

How do hard water and soft water differ?
 

48. 

How can groundwater resources be protected from pollution plumes?
 
 
Use the diagram illustrating mineral size and porosity to help you answer the following questions.

Sample A
Sample B
groundwater_files/i0570000.jpg
groundwater_files/i0570001.jpg

groundwater_files/i0570002.jpg
 

49. 

Describe the porosity and mineral size of Sample A and Sample B.
 

50. 

Describe groundwater flow through the two samples. Explain your answer.
 

51. 

Which of the two samples has the greater permeability? Why?
 

Problem
 
 
You would like to build a house in a wooded area close to your school. Since city water is not available, you will need to drill a well. The well-drilling company you hired did test drillings to find a clean, accessible, and maintainable aquifer. After completing its work, the company gave you a map of four available drill sites, numbers 1, 2, 3, and 4. Use the map illustration to make your analysis. Then answer the questions that follow.

groundwater_files/i0620000.jpg

Flow Rate in Meters Per Year
Material
Shale
Clay
Limestone
Sandstone
Rubble
Flow Rate
0.5
0.0
100
50
200
 

52. 

Compare and contrast wells 1, 2, and 3. Analyze the potential of each well for a clean, accessible, and maintainable water supply.
 

53. 

What is the potential for a clean, accessible, and maintainable water supply from well 4? Could there be a problem with the water?
 

54. 

Use the flow rate table to determine when the sewage from the broken septic tank will contaminate the water in well 3.
 

55. 

Use the flow rate table to determine when the industrial waste will contaminate the water in well 2. Is it possible that the waste could be made harmless before it reaches the well?
 

56. 

Which site has the best potential for your well? Explain your decision.
 



 
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