Introductory Geology
team
________________________
names _____________________________________
_____________________________________
_____________________________________
_____________________________________
LAB 11: GROUNDWATER PROCESSES AND WATER RESOURCES
The objectives of this lab are to:
 Understand the relationship between sedimentary rock types and groundwater processes.
 Construct and understand water-table topography. Determine the rate and direction of groundwater
movement.
 Evaluate the hazards and risks associated with groundwater contamination.
PART I: THE TRAGEDY AT LOVE
CANAL, NY
Watch the video clip summary of the terrifying tragedy of Love Canal from your prelab History: Love Canal: the Start of a Movement: http://www.bu.edu/lovecanal/canal/index.html
1. How did the contamination get into the soil and groundwater at Love Canal?
2. What types of chemicals were in the soils?
3. What happened to the people who lived in or went to school at Love Canal?
4. What was the response of the government when they learned of the contamination and its
effects on the residents of Love Canal?
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5. What is the relationship between Love Canal and Superfund?
6. What is the relationship between the residents of Black Creek Village and those of Love
Canal
7. Is the situation at Love Canal unique? What can be done to prevent this from happening
EVER again?
PART II: POROSITY AND PERMEABILITY
Reread sections 12.1 and 12.2, pages 280-283, in your lab manual. You will be conducting the
experiments in Exercise 12.1 on pages 282-283.
Observation
Container A
Container B
Container C
Container D
Grain Size
Sorting
Grain Shape
Porosity
Permeability
1. Before the experiments, in the table above, describe each material using qualitative
observations (i.e. large or small grains; well or poorly sorted; rounded or angular; low-medhigh porosity). Then, predict which material will have the greatest permeability. Which will
be the least permeable? Why did you make these predictions?
2. How did the results compare to your predictions? Was there anything surprising in the
results?
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PART III: SEDIMENTARY ROCKS AND AQUIFERS
Rocks: 13, 16, 19, 20, and 23
What types of earth materials are most likely to be contaminated by groundwater? Which ones
are more likely to hold water and which materials are more likely to cause water to be repelled?
The following section explores the different types of sediments and rocks that are affected by
groundwater processes.
An aquifer is an underground layer of water bearing rock, which transmits water to wells and
springs. Sediments and sedimentary rocks play a critical role in the groundwater story. For
sedimentary rocks to be good aquifers they must have high porosity and permeability.
 Porosity is a measure of the void spaces in a material.
 Permeability is the measure of the ability of a material to transmit fluids.
Many sedimentary rocks consist of grains such as sand, silt or clay.
 Aquifers: When sediment is deposited and lithified there may be spaces or pores
between the grains. For example, sandstone is a sedimentary rock that often makes an
excellent aquifer. Limestone: While limestones do not have high porosity initially, they
dissolve in slightly acidic groundwater so they also can make good aquifers.
 Aquitards: Some sediment, such as clay, does not have much pore space when lithified
to form shale. Shale is often an aquitard.
3. What is the significance in relation to groundwater systems of each of the rocks above? In
other words, how would an aquifer be affected if the bedrock consisted of #13 (sandstone)?
Specimen
Number
Rock/Sediment Name
Significance to groundwater systems
N/A
Sand
Example: Uncemented sand is typically porous and permeable therefore
it would make a good aquifer.
N/A
Clay
N/A
Gravel
13
19
20
23
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PART IV: GROUNDWATER MODELING
To enhance your understanding of groundwater, you will observe the movement of water
through different types of sediments in a groundwater model.

First, you will need to make sure the models are saturated with water.

Check with your instructor or TA to make sure the model is ready.

Second, you will place dye in one of the wells and watch how the dye moves through the
model.

The porosity and permeability of the different sediments will affect the direction and rate
of groundwater movement.
a.
b.
c.
d.
e.
f.
Fill the plastic water bottles, insert stopper assembly, and invert it at the ends of the
groundwater model tank.
Allow the water to run through the groundwater model.
Add dye to one of the monitoring wells. DO NOT PLACE DYE INTO THE SMALL
POND!! BE SURE TO ONLY PLACE DYE INTO ONE OF THE WELLS!
Observe the direction and rate of groundwater movement as the dye flows through the
aquifer sediments. You can time the rate of groundwater movement either using
stopwatches, your watch, or your cell phone.
What direction does the groundwater flow - toward the lake or toward the river?
________________
Why?
g.
Use the box as the edge of the model and
make a sketch of the sediment layers in the
groundwater model. Label the types of
sediment and location of the river and wells.
h.
Using the syringe, withdraw water from one of
the wells, simulating pumping. Observe what
happens to the groundwater motion. Draw
arrows on your sketch to illustrate.
i.
What happened to the direction of the groundwater flow when you began pumping from
the well?
________________________________________________________________________
j.
What happened to the direction of the groundwater flow when you STOPPED pumping?
Why did this happen?
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k.
Suppose a company that manufactures solvents dumped nasty chemicals into the ground
in the middle of the night. What would happen to the farmer’s well water next door?
________________________________________________________________________
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PART IV: GROUNDWATER CONTAMINATION
Section A: Rate of Contaminant Transport
In 1985, Voldemort Industries paint manufacturing company dumped chemical wastes
(containing chromium, lead, and zinc compounds) from their paint pigment operations in a
landfill near River Hogwarts (Figure 1). In response to concerns expressed by nearby residents,
Voldemort Industries conducted an investigation of the landfill in 2010 in which they installed the
groundwater monitoring wells T-1, T-2, T-3, and T-4. The 2010 water sample results from these
wells are listed below.
Well Number
T-1
T-2
T-3
T-4
Well at Hagrid’s Residence
Depth to water table (m)
11
14
17
18
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Contaminants Present
None
None
Pb, Cr, Zn
None
None
 Using the depth to water table for each well, draw the water table with a dashed line on
Figure 1. Measure the depth to water from the top of the well - not from the ground surface
 Show the direction of groundwater flow with arrows on Figure 1.
 In 2010, the water sample from T-2 was not contaminated. When T-2 was sampled in 2011
it showed significant levels of lead, chromium, and zinc. Sketch the approximate boundaries
of the contaminant plume (area of contaminated groundwater) on Figure 1.
8.
How many years, since the chemical waste was dumped in the landfill, has it taken for
the contaminant plume to reach well T-2? Show your work!
(HINT: when did contamination BEGIN?)
______ years
9.
Approximately how fast is this plume moving (in m/year)? Measure the horizontal
distance from the middle of the landfill and well. Show your work!
_______ m/yr
10.
In what year will the contamination reach the well at Hagrid’s residence? Show your
work!
11.
___________
Why were no contaminants found in well T-4?
______________________________________________________________________
12.
Is the Dumbledore Formation likely to act as an
13.
Will the plume contaminate the well water at Hogwarts?
14.
Why or why not?
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AQUIFER or
AQUITARD?
YES
NO
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Figure 1: Voldemort Industries Landfill Cross-section
WEST
EAST
100
50
0
Horizontal Scale
200
meters
Landfill
Meters
T-4
Sandstone
T-2
T-3
10
20
30
Shale
T-1
0
Vertical Scale
40
Sand and Gravel
Hagrid’s Residence
Hogwarts
River Hogwarts
Humphreys Shale
DumbledoreHumphreys
Formation
Dumbledore Formation
Shale
Hermione
HermioneFormation
Formation
Weasley Formation
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Section B: Exercise 12.7 – Someone is Polluting My Water!
In this scenario, homeowners noticed a strange smell in whenever they took showers, washed
dishes, or ran the tap for drinking water. Many complained of the water smelling and tasting
suspiciously of gasoline! Your Environmental Assessment company has been hired to
determine if there has been a gas leak from one of the nearby gas stations and if so, which one
is causing the contamination of the homeowners’ drinking water.
The background information in Section 12.4, 12.5, pages 288-290 and questions for this
scenario are found in Exercise 12.7 on pages 294-295 in your lab manual. Be sure to READ
the exercise background before answering the questions!
You and your teammates will need to determine what you need to know in order to find a
solution for these homeowners.

What information do you need to solve this case?
a. Does either gas station have a leakage problem? Explain
______________________________________________________________________
______________________________________________________________________
b. Which homes or neighborhoods will be affected next? Indicate on the map below
(Figure 12.13) where the gasoline contamination will go.
c. Gasoline concentrations of 50 ppm and higher are considered dangerous. Circle those
locations on Figure 12.13 below and.
d. Are there other locations on this map that are likely to be in danger of contamination in
the future?_______________
e. If so, indicate those locations on your map (Figure 12.13, page 295).
f.
How do you know?
______________________________________________________________________
7
30
10
20
Contour Interval: 10
60
50
70
80
10
90
20
30
40
10
20
Figure 12.13
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