Earth/Space Science
Worksheet
GRADE LEVEL:
Fifth
Topic:
Hydrosphere
Grade Level Standard:
5-4 Determining the importance of the hydrosphere, its
functioning, and how it affects Michigan.
Grade Level Benchmark:
3. Explain how water exists below the earth’s surface
and how it is replenished. (V.2.MS.3)
Learning Activity(s)/Facts/Information
Resources
Central Question:
Where is water found on earth and what are its
characteristics?
1.
Investigating groundwater: The Fruitvale Story 
AIMS, “Water Precious Water.
2.
Groundwater Movement 
Time magazine
3.
The Porosity Puzzle & Permeability Picture 
A River Runs Wild. Cherry
 Activity is attached
Process Skills: Observing, Describing, Communicating, Predicting, Comparing, Interpreting
New Vocabulary:
ground water (water table, spring, porous, saturates, filtration)
sources (snow melt, rainfall)
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GROUNDWATER
Investigating Groundwater: The Fruitvale Story
OVERVIEW:
Students observe differences in the movement of water through individual earth
materials, such as gravel, sand, and clay, and also in combinations of these
materials. They then discuss how these observations can be used to predict
behavior and movement of groundwater and compare general characteristics of
aquifers and aquitards.
TIME:
Takes 1 ½ - 2 class periods
Purpose
The students will:
1. Develop skills in accurately describing experimental results.
2. Understand factors affecting groundwater movement through various earth
materials.
3. Develop an operational understanding of porosity, permeability, aquifer, and
aquitard.
MATERIALS:
For the students:

Student sheet 1.1 Solids and Liquids

Student sheet 1.2 Groundwater Movement
For the teacher:

Clay, approximately 30-35 cm³

Gravel, approximately 30-35 cm³

Sand, approximately 30-35 cm³

Stopwatch or watch with sweep second hand

Food coloring (optional)

Four 25 cm x 3.75 cm plastic tubes

Water

Blackline master of student sheet 1.1 Solids and Liquids, and 1.2 Groundwater
Movement
GETTING READY:
Make sure the clay, gravel, and sand are dry and ready for use. Label the tubes AD. Fill one tube with clay, making sure to tamp it down firmly so that there are no air
pockets. Repeat for the gravel and sand. Tube D will be used during the activity.
Duplicate copies of student worksheets 1.1 and 1.2.
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THE ACTIVITY
1.
Introduction
Tell the students they will soon begin to investigate the possible contamination of an
underground water supply. The underground water supplies a town with its drinking water.
Before beginning this exploration, they will find it useful to learn more about how water
moves through different earth materials.
Distribute student sheet 1.1. Ask whether anyone knows how water gets underground
to become groundwater. (Some precipitation does not immediately evaporate or get carried
off in streams; instead it travels down below the surface of the earth to become
groundwater.) Explain that groundwater will be explored in this activity.
Challenge the class to think of examples of liquids moving through solids they have
seen in the last week as they respond to question 1 on the student sheet. List some
examples on the overhead. Some possible responses include syrup through pancakes,
muddy water through clothes, milk through cereal, rain through sand, and soy sauce
through rice. Then ask the class to answer question 2. When they finish, discuss what
factors determine whether a liquid might move quickly or slowly through a particular solid.
Write some of their responses on the overhead.
Tell the students they will observe liquid flow through earth materials and then discuss
their observations.
2. Comparing tubes
Display the three filled tubes in front of the class. Make sure that everyone can see the
earth materials in the tubes. Identify the contents of each tube, and ask students to record
the materials in the data table in student sheet 1.1.
Select two tubes and hold them up for the students to see. Ask them to decide which
tube will permit water to pass through more quickly. Discuss any difference in opinion and
encourage students to describe the reasons for their choices. Continue this procedure with
other pairs of tubes until all combinations have been used. Use students choices and
reasons to introduce the concepts of permeability and porosity. Porosity refers to the
amount of open space in a material, while permeability refers to how well the pores are
connected.
As a result of the comparisons of the pairs of tubes, ask students to rank the
three materials in the data table on student sheet 1.1 according to their prediction of the
speed at which water will move through them. Use a scale of 1 to 3, where 1 is the fastest.
3. Predicting transmission times
Tell the group that you are going to pour equal amounts of water into each tube and
time how long it takes the water to reach the bottom. You may wish to use several drops of
food coloring in the water to make the water movement more visible at a distance. The food
coloring rinses with water, so the earth materials can be reused.
Ask students to predict the length of time it will take for the water to reach the bottom
of the tube. Instruct them to record their predictions in their data table. Then pour a
measured amount (30-35 ml is sufficient) of water quickly into the top of one of the tubes. It
is suggested that the materials be tested in order of decreasing permeability. Note the
actual elapsed time for the water to move to the bottom. Ask the students whether they
noticed if the speed of the water changes as it moves through each of the earth materials.
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Ask if anyone's predicted time was close to the actual time. Have students who were
closest describe how they made their predictions.
Inform the class that watching water move through one earth material gives them
evidence that can be used to predict how quickly water will move through the rest of the
earth materials. They may wish to modify their earlier predictions for the other materials in
their data tables. Emphasize that evidence of the behavior of water with one earth material
makes it possible to predict accurately the transmission times for the other earth materials.
Emphasize the difference between random guessing and predicting.
After students finish making changes in their data tables, add water to the other tubes.
Record the transmission times on the overhead, instructing students to record these times
on their student sheets. Some earth materials, such as clay, transmit water very slowly if at
all. It is suggested that you record the starting time for the clay sample and display it for the
rest of the period. Depending on the composition of your clay sample, it may take several
days for the water to reach the bottom. With some clay samples, water may never reach
the bottom. Mark the tube to show the initial position of the water; later examinations will
reveal how far the water has moved in a given amount of time.
Allow time for students to record transmission times and fill in the actual results on the
data table.
4. Sources of error
Ask whether observing the side of the tube provides a true picture of how the liquid actually
moves through the earth materials. Do we know what is happening in the part of the tube
that cannot be seen? Only one part of the flow pattern is visible from the edge. The walls of
the container serve as a smooth surface along which liquid can flow easily. Students may
have noticed that water speeds up when it touches the edge of the tube.
Ask the students whether they would expect the same results if they were to do the
experiment again. What might change the results? Students may name a number of
factors, including how fast the water is poured into the tube, the temperature of the water
and earth materials, whether or not the solid material is compacted or settled, whether
water runs down the side of the tube or makes its way through the center, and the
orientation of the pieces of earth material.
Ask students to give reasons for the difference in transmission times. Students may
say that one earth material is more porous or more permeable than the other. This might
be because it had more "holes," or because the “holes" were arranged to allow easier
movement. They may also report that differences in the way the water is added to the tube
might affect transmission times.
5. Groundwater movement
Distribute student sheet 1.2. You may wish to spend a little time discussing the composition
of the surface layers of the earth, as shown un the diagram on the student sheet. These
layers are often mined or excavated; various earth materials have a variety of uses. Ask the
students to name some of these materials and list them on the chalkboard. Responses are
likely to include sand or sandstone; clay; limestone (chalk is a particular form of limestone);
igneous rock such as granite or basalt; soil near the surface; and others. You may want to
display some examples of earth materials found near the school. Add a drop or two of
water to the surface for the students to examine. Water behaves differently on granite, for
example, than it does on sandstone.
Sand or gravel, in general, transmit water readily. Earth materials with lots of cracks
and open spaces, such as limestone caves, allow for easy liquid flow. Earth materials that
81
contain groundwater and permit its flow are called aquifers. Ask the students to find
aquifers on their diagram and to label them.
Clay and unfractured igneous rock transmit water very slowly if at all. Earth materials
composed of particles of different sizes retard the transmission of water because their
porosity is lower. Earth materials that prevent easy flow of liquid are called aquitards. Ask
students to find the aquitard on their diagram and label it.
Challenge students to come up with a way to make a model of an aquifer and aquitard
in the remaining tube or similar container, using the materials from the previous
experiments. Use tube D to construct a model based on their suggestions. Ask the
students to record their predicted transmission times and test the aquifer or aquitard as you
previously tested the individual earth materials. Have the students offer their reasons for
differences in transmission times if any. You may wish to leave the model in the room for
several days and observe it periodically if the water does penetrate the aquitard. It is
suggested that you cover the top of the tube to reduce water loss by evaporation.
You may wish to construct and test additional models with the entire class or to offer
this option to interested students. Groundwater often contains high concentrations of
dissolved solids. Might this affect the way it moves through earth materials? Ask interested
students to investigate.
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6. Conclusion
Ask students to use the clues on the groundwater diagram to describe ways that
groundwater and surface water (oceans, lakes, streams) are related. Groundwater can
become surface water by bubbling to the surface in the form of springs or artesian wells, or
surface water can penetrate surface soil layers into an aquifer, becoming groundwater .
Ask the student to now consider ways that groundwater might become contaminated.
Students responses may include flows from contaminated rivers, lakes, and estuaries; from
accidental leaks and spills; from precipitation; from agricultural sources such as spraying
and irrigation; and from wells of various types.
Review how the activities and diagrams model the movement of the groundwater
through different layers and materials in the earth. Groundwater that had been
contaminated moves in exactly the same way. Remind students that they will apply their
knowledge of groundwater movement to investigating the Fruitvale problem later in the
module.
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Name __________________________________
Date:______________________
STUDENT SHEET 1.2
Groundwater Movement
Surface water trickles down through the earth at a rate of several inches to several feet
per day. This water may reach rock, sand, or gravel formation where it collects as if in a
saturated sponge at various depths below the surface. This is groundwater. The
diagram below shows the movement of groundwater and some of its sources.
1. What is an aquifer? __________________________________________________
__________________________________________________________________
Label the aquifer on the diagram.
2. What is an aquitard? _________________________________________________
__________________________________________________________________
Label the aquitard on the diagram.
84
THE POROSITY PUZZLE AND
PERMEABILITY PICTURE
SOURCE:
Michigan DNR
Adapted from Groundwater, Michigan's Hidden Resource
BACKGROUND:
All soil contains pores. Porosity, the ratio of open pore space to the total volume of a soil
sample, is one of the factors that determines how much water a particular soil can hold
and how fast water can move through that soil.
The sizes of the particles in the soil determine the size and number of pores in soil.
The size of soil particles also affects the ease of plowing the soil, what crops can be
grown, the efficiency of certain fertilizers, and the ability of soil to store water.
The pebbles and sand demonstrate that the pore space is larger in coarse soils. In
actual coarse soils, these spaces may be partially filled with smaller particles, producing a
less porous soil. When small particles fill the large pore spaces, there is less "empty
space" remaining for water to fill. However, soil containing a mixture of large and small
particles retains its water more efficiently than coarse soils, because the small particles
provide more surface area for the water to adhere to. Coarse soils dry out much faster
than do fine soils. You may have noticed, for example, how quickly beach sand dries after
a rainfall.
Soil scientists classify soils according to their particle size. Clay particles are the
smallest (less than 0.004 mm in diameter), followed by silt (up to 0.06 mm in diameter),
then sand (up to 2.0 mm). Particles larger than sand are classified as gravel, and range in
size from very fine pebbles to large boulders.
PREPARATION:
You can buy sand for this activity at most home and garden supply stores. Any reasonably
clean, fine sand may be used. The type of sand sold in large bags for use in children's
sand boxes works very well
Dry the sand by spreading it on a cookie sheet and placing it in an oven set at 180°C
(350°F) for 15-30 minutes. Stir it several times while it is heating. Sand dried in this
manner may be stored in plastic bags for several weeks.
In this activity you should make frequent references to the "empty space" between soil
particles. Remind your students that this empty space contains air. The water poured into
the empty space is not filling a vacuum—it is displacing the air that surrounds the particles
of sand or the marbles.
This activity will help participants visualize the concepts of porosity and permeability and
how they impact the movement of groundwater.
MATERIALS: for each group of three people
1. 1 cup each of sand, gravel, and clay (fine grain–clumping).
2. A one cup measuring device, some duct tape, and a coffee stir stick.
3. Dish pan labeled "aquifer."
4. Three 16 oz, or larger, clear pop bottles.
85
5. A piece of paper, a watch with a second hand, and a pen or pencil.
6. *For teacher - an electric drill with 1/8" bit.
DIRECTIONS:
1. Drill one 1/8 inch diameter hole in the bottom of the clear plastic pop bottles. Put a
single piece of duct tape on the bottom of the pop bottle so that it covers all of the
holes.
2. Explain that porosity is the percentage of air space in a particular material and that
permeability is the measurement of a material's ability to allow water to pass through
it. Divide everyone into groups of three, give each group 3 containers and have every
group measure out 1 cup of each material (sand, clay, gravel) and put them into their
three plastic containers. (Note: to save time, have the containers already filled with a
cup of the different materials.)
3. Give each group a copy of the porosity and permeability graphs found on the next
page, and before they pour water into the cups, have them guess how much water
each of the different materials will hold by placing an "X" at the appropriate portion
above the name of each material.
4. Beginning with exactly one cup of water in the group's measuring device, slowly pour
the water over the first material until the level of the water is at the top of the material.
If necessary, use a stir stick to poke holes in the clay to help the water get to the
bottom of the container.
5. Determine the volume of water that was poured into the material by subtracting the
amount of water remaining in the measuring device from the 1 cup of water that you
started with. Mark this amount on the graph with the "0" above the appropriate
material. Read to the left to get the porosity in percent. Repeat steps 4 and 5 for the
other two materials. Discuss the results with the group. How close were their
guesses? Any surprises?
6. Next, tell the groups that they are going to look at the "Permeability Picture". Using the
permeability graph have the groups guess at the permeability rates for each of the
materials by marking on the graph how much time they think it will take for 1 cup of
water to move through the material.
7. Beginning with exactly 1 cup of water, pour the entire cup on top of one of the
materials. Now, holding the cup over the aquifer (dish pan) carefully tear the tape off
the bottom of the cup and time how long it takes for the cup of water to move through
the material. Stop timing when the water goes below the top of the material. Mark the
actual times on the graph next to your guesses.
8. Discuss the results. How were the guesses? Which material allowed the cup of water
to move through it in the shortest amount of time (most permeable)? Least
permeable? Explain that clay has the highest porosity because it has many tiny pores,
but it is the least permeable because the pore spaces are not connected very well, so
water has a difficult time moving through it.
86
POROSITY GRAPH
100% - 1 cup
75% - 3/4 cup
66% - 2/3 cup
50% - ½ cup
33% - 1/3 cup
25% - 1/4 cup
SAND
CLAY
GRAVEL
PERMEABILITY GRAPH
Over 3 minutes
3 minutes
2 ½ minutes
2 minutes
1 ½ minutes
30 seconds
SAND
CLAY
GRAVEL
Source:
Adapted from “Groundwater, Michigan’s Hidden Resource, Workbook,” Michigan Department of Natural Resources.
Student Activity Procedure
87
Name ______________________________
Date:__________
Period: _________
POROSITY and PERMEABILITY
PROCEDURE:
Porosity
1. Beginning with exactly one cup of water in the group’s measuring device, slowly pour the
water over the first material until the level of the water is at the top of the material. If
necessary, use a stir stick to poke holes in the clay to help the water get to the bottom of
the container.
2. Determine the volume of water that was poured into the material by subtracting the amount
of water remaining in the measuring device from the 1 cup of water that you started with.
3. Mark this amount on the graph with an “O” above the appropriate materials.
4. Read to the left to get the porosity in percent.
5. Repeat steps 4 and 5 for the other two materials.
POROSITY GRAPH
100% - 1 cup
75% - 3/4 cup
66% - 2/3 cup
50% - ½ cup
33% - 1/3 cup
25% - 1/4 cup
SAND
CLAY
GRAVEL
Permeability
1. Beginning with exactly 1 cup of water, pour the entire cup on top of one of the materials.
2. Now, holding the cup over the aquifer (dish pan) carefully tear the tape off the bottom of the
cup and time how long it takes for the cup of water to move through the material.
3. Stop timing when the water goes below the top of the material.
4. Mark the actual times on the graph next to your guesses.
PERMEABILITY GRAPH
Over 3 minutes
3 minutes
2 ½ minutes
2 minutes
1 ½ minutes
30 seconds
SAND
CLAY
GRAVEL
88
STUDENT REFLECTION:
% of H2O in sand
% of H2O in gravel
% of H2O in clay
__________
__________
__________
Compare the amount of water needed to fill the pores between the gravel with the amount
of water needed to fill the pores between the sand. On the basis of your observations, circle
the statement that best describes the amount of pore space found between the grains of sand
and gravel:
a.) There is more pore space between the grains of sand than between the gravel.
b.) There is more pore space between the gravel than between the grains of sand.
c.) The pore space was about the same for both the gravel and the sand.
time needed to drain pool from sand
time needed to drain pool from gravel
time needed to drain pool from clay
__________
__________
__________
Compare the time needed to drain the water from the clay, sand, and gravel. On the basis
of your observations, explain why it took less time for the gravel to drain than either the
sand or clay.
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
On the basis of your observations, which material drained the slowest _______________.
Why do you think this is so?
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
89
Assessment
Grade 5
HYDROSPHERE
Classroom Assessment Example SCI.V.2.MS.3
Working in small groups, students will design and create three-dimensional models that show
movement of groundwater. Students will provide written explanations of their designs and
models as they relate to the real world. These models should be based on the diagrams developed
by the students and may include household materials such as foam rubber, cereal, etc. or natural
Earth materials.
(Give students rubric before activity.)
Scoring of classroom Assessment Example SCI.V.2.MS.3
Criteria
Apprentice
Basic
Meets
Exceeds
Construction of
groundwater
model
Attempts to build
a working model.
Produces a
working model
that shows water
movement
without labeling.
Produces a
working model
that correctly
labels and
demonstrates the
movement of
water.
Produces a
working model
that replicates two
or more pathways
that water takes.
The model
demonstrates and
correctly labels
those pathways.
Completeness of
explanation
Provides an
incomplete
explanation of the
model and does
not demonstrate
how it works or
show how the
model connects to
the real-world
context.
Provides a
complete
explanation of the
model and does
not demonstrate
how it works or
show how the
model connects to
the real-world
context.
Provides a
complete
explanation of the
model and
demonstrates how
it works,
connecting the
model to the realworld context.
Provides a
complete
explanation of the
model and
demonstrates how
it works,
connecting the
model to the realworld context.
90
Earth/Space Science
Worksheet
GRADE LEVEL:
Fifth
Topic:
Hydrosphere
Grade Level Standard:
5-4 Determining the importance of the hydrosphere, its
functioning, and how it effects Michigan. (5-4)
Grade Level Benchmark:
4. Describe the origins of pollution in the hydrosphere.
(V.2.MS.4)
Learning Activity(s)/Facts/Information
Resources
Central Question:
How do human activities interact with the
hydrosphere?
1.
“Freddie the Fish” 
2.
Informational Reading, “Toxins on Tap” 
3.
Field Trip: Waste Water Treatment Plant.
4.
“Piggish People, Pollute. . .“ 
AIMS, “Water, Precious
Water”
Time Magazine
A River Runs Wild. Cherry
 Activity is attached
Process Skills: Observing, Describing, Communicating, Predicting, Comparing, Interpreting
New Vocabulary:
sources of pollution (sewage, household dumping, industrial
wastes, agriculture run-off)
91
FREDDIE THE FISH
MICHIGAN ESSENTIAL GOALS AND OBJECTIVES:
C I:
Generate reasonable questions about the world, based on observation.
R3:
Develop an awareness of and sensitivity to the natural world.
EH4:
Describe uses of water.
LEC5: Describe the positive and negative effects of humans on the environment.
EGG: Demonstrate means to recycle manufactured materials and a disposition
towards recycling.
THINK QUESTION:
How can people pollute an ecosystem?
ACTIVITY:
Telling a story about Freddie the Fish and his polluted ecosystem.
SCIENCE PROCESSES:
observing, communicating
NEW VOCABULARY:
reduce, reuse, recycle, ecosystem, habitat
OBJECTIVES:
Students will I) listen to a story about polluting an ecosystem and 2) discuss ways to
decrease pollution by reducing, reusing, and recycling the materials we throw away.
MATERIALS:
 sand
 soil
 vinegar
 dish soap
 worksheet, “Freddie the Fish Story”
 worksheet, “Reduce, Reuse and Recycle!”
Teacher Provided:
 plastic milk jug
 scissors
 clear container (bowl. plastic tub)
 paper clip
 permanent marker
 motor oil or dark food coloring
 plastic sandwich bag
 leaves and twigs
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TIME:
20 minutes
PROCEDURE:
Prior Teacher Preparation:
1. Before the lesson, make Freddie, by cutting out a small fish (3" x 3") from the milk
carton.
2. Poke a small hole in the top of the fish.
3. Open the paper clip and thread one end through the hole. Use the paper clip to
move Freddie in the water .
4. Color Freddie with a permanent marker.
5. Find a clear container and fill it 3/4 full with water .
6. Collect pollution items listed above: leaves & twigs, motor oil or food coloring,
plastic sandwich bag, sand, soil, vinegar, and dish soap.
Anticipatory Set:
1. Ask: Where can fish live (what type of ecosystems)? Brainstorm their ideas.
Discuss how some fish live in salt water and some in fresh water .
2. Explain that they will be hearing a story about Freddie the Fish. Freddie must have
fresh water to survive.
3. Read the story (or make up your own if you are more creative that I am!) about
Freddie.
4. As you read the story, show what happens to Freddie's ecosystem as he travels
down the river.
Input:
1. Discuss how the students feel about the pollution in Freddie's river.
2. Ask: Did all the pollution have to end up in the river? What are some ways we
could help keep Freddie's water clean?
3. Ask: What is recycling? What things can be recycled? What can people do to
reduce the amount of trash they make? Are there some things that can be reused
instead of thrown out? Discuss their ideas.
4. Read and discuss the worksheet. Reduce, Reuse and Recycle.
DISCUSSION:
1. What materials polluted Freddie's river ecosystem?
2. What are other ways people pollute ecosystems? (air pollution, water pollution, soil
pollution, litter, etc.)
3. What could be done with the trash instead of throwing it into the water?
4. How does trash harm bodies of water?
5. How does trash harm other ecosystems (lakes, forests, oceans, ponds, farms,
etc.)?
6. Why is it important to reduce, reuse, and recycle our garbage?
93
CLOSURE:
Have the students brainstorm a list of ways they can reduce the amount of garbage
that entered Freddie's ecosystem. Discuss ways of recycling, reusing, and reducing
the garbage. Ask: What items can be recycled? What items can be reused? What can
we do to reduce the amount of trash we make? Make a chart of their ideas.
NOTES FOR REVISION:
94
FREDDIE THE FISH STORY
Once upon a time, there was a fish named Freddie. Freddie
liked to swim in his clean river (show Freddie swimming
around the river). One day Freddie decided to go on a trip.
He wanted to see what was down river. So, he packed a small
lunch and began swimming (show Freddie swimming). As
Freddie swam, he passed a school play-ground. The children
were just finishing their lunches. A few children threw their
candy bar wrappers on the ground. The wind blew the
wrappers into the river (throw the candy bar wrappers into
the water). Freddie was surprised! “What is this?" he said. Freddie was used to fresh water.
He didn't expect to find trash on his journey.
As Freddie swam downstream, the wind blew dead leaves and twigs into the river (drop
leaves and twigs into the water). This made it difficult to swim, but he kept going.
Next, Freddie swam by a park. Children were swinging, running, and having a great
afternoon. Some families were eating peanut butter and jelly sandwiches. They were not
very careful with their trash. They left plastic sandwich bags on the ground. One of those
bags landed in the river (throw a sandwich bag into the water). Freddie swam past it.
Up ahead, Freddie saw a big machine plowing a field. He was fascinated by the machine.
But the machine moved a lot of sand and soil. Some of this land ran-off into the stream
during a rain storm (pour sand and soil into the water). Freddie couldn’t see very well, but
he kept swimming.
Next, Freddie swam by a gas station. He watched the mechanics change oil in a big pickup
truck. Some of the oil spilled and washed into the river (pour oil or dark food coloring
into the water). All of a sudden, the water became dark. Freddie couldn't see very well! He
decided to move on down river.
Finally, Freddie passed a chemical company. He watched as chemicals poured into the
river (pour vinegar and dish soap into the water). All this pollution made Freddie very
sad. He didn't like this river anymore! When he opened his mouth, he swallowed some
chemicals. "Yuck!" he said as he quickly swam away.
Now, Freddie wasn't feeling too well. But he kept
swimming, and swimming, and swimming. Freddie
wasn't moving as fast anymore (show Freddie
slowing down).
Freddie couldn't swim anymore. It was too polluted.
Freddie wanted his fresh water back. But it was too
late—Freddie died! (drop the paper clip and
fish—Freddie will float on top of the water).
95
The water Americans drink may
look clear and clean, but it often
contains noxious chemicals and
malicious microbes
By MICHAEL D. LEMONICK
ON'T DRINK THE WATER, goes the old
admonition to tourists visiting
underdeveloped countries. But most
Americans don't look with
suspicion at their own kitchen faucet
Maybe they should. Overall, the U.S. still
has one of the cleanest water supplies in the world,
but that doesn't mean it's safe in all places at all
times. This year's head-lines have destroyed any
illusions about the purity of water coming from
spigots in town and country.
In April enough of a microorganism got
through treatment plants in Milwaukee, Wisconsin
to turn the city's drinking water into a bilious
brew, sickening nearly half the population and
killing one person—and a few weeks ago, the
same bug turned up again during a routine test. In
July residents in the Chelsea section of New York
City had to boil their water to kill potentiality
dangerous bacteria. Just three weeks ago, health
officials tacked warnings on 71 houses in
Gastonia, North Carolina, advising people that an
industrial chemical had been detected in their
wells at levels many times higher than what the
U.S. Environmental Protection Agency allows.
Hardly a week goes by, in fact, without reports
about contaminated water some- where in the
nation, and the incidents that make news are only a
tiny part of the problem. According to a new study
by the Natural Resources Defense Council, there
were some 250,000 violations of the federal Safe
Drinking Water Act in 1991 and 1992 alone,
affecting more than 120 million people. Americans
are ingesting such noxious pollutants as bacteria,
viruses, lead, gasoline, radioactive gases and
carcinogenic industrial compounds. “Like so many
other problems that we have swept under the rug
during the past decade and more." says David
Ozonoff of Boston University’s School of Public
Health, "the national task of assuring that our
drinking water is safe to drink can no longer be
D
96
postponed."
Fortunately, it doesn’t have to be. The Senate has
Percentage of the population served
begun hearings that will ultimately lead to the reby water systems cited in 1992 for
authorization, and possible strengthening, of the 1974 Safe
violating he Safe Drinking Water Act
Drinking Water Act. But the debate will be long and
Arizona
26%
difficult. Environmental groups such as the N.R.D.C. want
New Jersey
22
stricter enforcement of the existing rules, along with new
Idaho
21
or tougher standards on contaminants like radioactive
New Hampshire
20
radon gas and arsenic. Lined up on the other side are state
Vermont
18
and local governments and water utilities, which insist
Oklahoma
17
they don't have enough money to comply with the law as it
Washington
15
Louisiana
14
is, let alone additional rules. The regulations should be
Illinois
13
relaxed, they say, not strengthened.
South Carolina
12
It's true that the N.R.D.C. report is far from perfect.
Many of the violations it cites involve nothing more than
late filing of field reports, and its complaint that only 1
percent of violations result in “final formal enforcement actions" is misleading. Says James Cleland of
the Michigan public service department: “In our state, we address 99% of the violations, but we don't
address them all with formal enforcement. Sometimes all it takes is a telephone call."
Yet it isn't just the environmentalists who see a problem. A survey by the federal Centers for
Disease Control shows that in 1989 and 1990, 4,288 people in 16 states got sick, and four died, from
bacteria and viruses in their water. And last spring the nonpartisan General Accounting Office found,
among other things, that many water systems do not test for all the pollutants the EPA considers
dangerous, and don't evaluate distribution systems, operators, or inspectors. Based on these and other
studies, the N.R.D.C. has identified several especially worrisome hazards:
PATHOGENS: These include bacteria, viruses, and protozoa such as the cryptosporidium that struck
Milwaukee. These sicken 900,000 people a year, says the N.R.D.C. report and kill perhaps 900, usually
those with weak immune systems (the very young and very old, AIDS sufferers, and organ-transplant
patients).
TRIHALOMETHANES: Ironically, these compounds are by-products of the chlorine used to kill
water-borne pathogens. The N.R.D.C. estimates that these chemicals may cause more than 10,000
bladder and rectal cancers a year.
ARSENIC: The dangers of lowlevel exposure are still being
debated, but some 350,000 people
may be taking in more than the
EPA allows.
LEAD: The risks have been known
for years, but plenty of lead still
gets into drinking water, since
testing for the heavy metal is not
universal. About 560,000 children
have unacceptably high levels of
lead in their blood, which could
lead to neurological problems. The
Laid low by a nasty microorganism last spring, Milwaukee promptly spent
EPA also calculates that 680,000
$1 million to upgrade treatment plants like this one, which filters water
cases of high blood pressure in
through sand.
adult men could be prevented by
reducing lead in drinking water.
The 10 Worst States
97
RADIOACTIVE CONTAMINATION: There are no rules about how much is safe, but the N.R.D.C.
cites EPA figures showing that about 50 million Americans drink radon tainted water. The tasteless,
odorless gas, which seeps into water naturally from underground rocks in many areas, is a proven cause
of both lung and rectal cancer.
All the reports and studies agree that the problem is not so much with large water systems like
Milwaukee's and New York City’s, which have the resources and expertise to prevent contamination or at
worst deal with it when it occurs. Even when the government has to pressure a system to force
compliance with water standards as with the $900.000 fine levied under the Safe Water Act against Butte
Water Company in Montana for bacteria contamination—enforcement usually focuses on systems that
serve thousands of people.
The real danger lies with the 83% of systems that have fewer than 3,000 customers each but serve a
total of 20 million Americans. These systems can't charge enough to pay for the necessary tests, and the
law allows them an exemption from the rules if they can demonstrate economic hardship. That puts
customers at risk.
What can be done? Predictably, the two sides in the debate mostly talk past each other, with
environmentalists stressing the dangers and water providers focusing on costs and the inflexibility of the
laws. For example, the EPA requires testing for dioxin, a possible human carcinogen, but, argues Wayne
Kern of the North Dakota Department of Health, “the industries that are common sources of dioxin just
do not exist in North Dakota."
And while admitting that some pollutants are indeed present and dangerous, officials protest that
there are limits to what they can do. Radon may cause 200 fatal lung and rectal cancers a year. Yet the
Association of California Water Agencies estimates that to eliminate it completely from water in that
state alone would cost $3.7 billion. Is that a reasonable investment for preventing perhaps a score of
deaths? Is $711 million per case of cancer too much to pay for the elimination of pentachlorophenol, a
fungicide used in the lumber industry, or $80 billion per case too much to get rid of alachlor, an
agricultural chemical?
Water agencies want the revised Safe Water Act to make the EPA take such calculations into
account when imposing rules, and to forbid the U.S. government to issue standards without supplying the
money it takes to meet them —a position the National Governors' Association has seconded. A 1991
study showed that the cost of meeting environmental mandates will eat up more than 23% of the budget
of Columbus, Ohio, by the year 2000—and that assumes no new regulations between now and then. In
many cities, the costs of environmental laws will soon exceed those of police and fire protection.
Something clearly has to give, and several ideas have already surfaced. One is that Congress could
finally start offering financial assistance to the small water companies that need it most. Another is to
encourage small systems to merge and share costs, an approach that has made headway in South Dakota.
The role of the EPA will be crucial. Administrator Carol Browner says she is willing to reconsider the
water law's simplistic “one size fits all" approach; she is looking at a strategy that would allow local
governments to deal with local problems in their own way without sacrificing national safety standards.
Browner also supports a novel proposal in which cities and towns buy up land in watershed areas and
regulate its use so that less pollution gets into reservoirs—something New York City is already doing
under a court order.
The one thing everyone agrees on in this debate is that rainwater and groundwater are inherently
clean: the trouble usually comes when chemicals, sewage and the like seep into water sources. “Are we
going to allow pollutants to get in and then attempt to remove them with engineering,” asks Robert R.
Kennedy Jr., a lawyer with the N.R.D.C., "or is the most sensible way to stop the kind of development
that is causing pollution?" The clean-it-up strategy might work for a while, but in the end, prevention
makes much more sense. —Reported by Greg Aunapu/Miami, Marc Hequet/St. Paul and Dick Thompson/
Washington
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How to Protect Yourself
S YOUR WATER SAFE? The company or
municipal authority that supplies it is required by
federal law to give you an analysis and disclose
any violation of health standards. But even if you can
trust the company, the report won’t tell you what
happens to the water in the dank recesses of your own
plumbing system. The only way to know precisely
what’s coming out of your tap is to have your water
tested. The EPA’s Safe Drinking Water Hotline (800426-4791) offers names of testing laboratories in
individual states. The hot line can also answer
technical and health questions such as “How much
cryptosporidium is too much?”
Special mail-order labs can help as well. They
send you empty bottles and instructions; you ship
back samples and receive a detailed analysis. Two
particularly reliable labs are Suburban Water Testing
Laboratories (800-433-6595) and National Testing
Laboratories (800-458-3330). Prices range from $25
for a simple test for lead to $178 for the works,
including screening for bacteria, nitrate, lead and
PCB levels.
What if the lab raises the red flag? Let’s take
lead as an example, since it’s one of the most
common problems. Too much lead (more than 15
parts per billion) tends to show up in older, turn-ofthe-century houses with lead pipes and in homes
where lead solder has been used to join and repair
plumbing. Lead solder was banned in 1986, but it is
till around in older pipes.
The longer water sits in the system, the more
lead it absorbs, So let the water run for at least two
minutes, until it is cold to the touch, before using it.
That way you’re using water from the main lines
under the street, which do no contain lead.
(Apartment dwellers can’t do this if their building’s
plumbing system is huge.) Don’t cook with water
coming from the hot water tap; it draws more lead
from pipes than cold water does.
If you’re dissatisfied with your municipal
water supply, you can always buy bottled water. But
it is not always free of contaminants either (even
Perrier had that little problem with the chemical
benzene). Look for a seal of approval from NSF
International, an Ann Arbor, Michigan, company that
certifies bottled water as safe. Unfortunately, NSF
does not analyze all brands.
Another option is to buy one of the many
filters or other water-purifying devices on the market.
Be sure to choose one that specifically removed the
toxins turning up in your water. Carbon filters, for
example, are good at purging organic compounds,
I
such as pesticides and solvents, but they will not
remove minerals or most heavy metals. And one of
the more elaborate devices, a distiller, is excellent at
taking away heavy metals but is not effective against
chloroform and benzene.
Before investing in a treatment device, which
ranges from $30 for a simple filter to $850 for a
reverse-osmosis system, check that it is certified
effective by NSF. Above all, remember that home
devices need plenty of maintenance. If they are not
cleaned or their filters are not replaced regularly, they
put back into your water the very pollutants they
removed and they wind up a health hazard
themselves.
By Janice M. Horowitz
99
PIGGISH PEOPLE POLLUTE . . .
WATER CLEAN-UP MACHINES
(1-2 days)
MICHIGAN ESSENTIAL GOALS AND OBJECTIVES:
EH4:
Describe uses of water.
LEC5: Describe positive and negative effects of humans on the environment.
R3:
Develop an awareness of and sensitively to the natural world.
THINK QUESTION:
How can fresh water become polluted?
BACKGROUND:
When the dye is first put into the water, it is visible. This is because the molecules
of red color are compacted (close together). As water is added, the color
molecules continue to spread evenly. As they spread, the color becomes less and
less visible.
This is the same thing that happens to many pollutants that enter our waterways.
The substances may be visible where they are dumped, but soon spread out so
that they are no longer noticeable. This process is called diffusion. Even though
the pollutant cannot be seen, it does not mean that it is gone. These pollutants can
affect our drinking water and plant/animal life. Often, the pollutants have negative
affects on the environment many miles from the original dumping site.
There are two hydrogen atoms and one oxygen atom in every water molecule.
Water molecules are held together so that they draw substances in to fill the
spaces. Therefore, water can dissolve many things. Unfortunately, this property
makes water an easy target for pollution. There is no absolutely pure water
existing in nature. All water contains natural pollutants.
The definition of water pollution is contamination of water. Water pollution is
broken down into four categories.
Sediment: It is the largest water pollutant that exists. It is a mineral or organic
solid material that has washed or blown from the land into lakes, rivers, or
streams. Sources include: construction, row-cropping, livestock operations,
logging, flooding, and urban runoff.
Nutrients: A certain amount of nutrients are necessary to maintain healthy water.
However, an excessive amount can be damaging. Sources include: sewage and
septic runoff, livestock waste, fertilizer runoff, detergents, and industrial wastes.
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Bacteria: Bacteria play an important role in the decomposition of organic materials
in water. Too much bacteria will compete with other water organisms for oxygen.
If the oxygen supply is used up, plants, fish, and insects will be killed off. Sources
include: runoff, industrial wastes, paper mills, and poorly managed landfills.
Toxins: Safe chemicals can become toxic if improperly disposed of. The negative
effects of toxins can be delayed for many years before resulting in sickness,
disease, or death. Sources include: industry, agriculture, and household cleaners.
ACTIVITY:
Discovering how pollutants travel undetected in our environment and designing an
imaginary water clean-up machine.
SCIENCE PROCESSES:
experimenting, observing, predicting, recognizing, relationships
NEW VOCABULARY:
garbage, habitat, destruction, land management, resource management
OBJECTIVES:
Students will 1) discuss why clean water is necessary for survival, 2) observe a
demonstration to see how polluted water can be invisible, and 3) design a water
clean-up machine that can be used to protect our water supply.
MATERIALS:
 measuring cup
 red food coloring
Teacher Provided:
 large, clear container
 bowl
 salad oil
TIME:
30-45 minutes each day
PROCEDURE:
Anticipatory Set:
1. Ask: Why do we need clean water?
2. Have you seen polluted water? What kinds of pollution did you see? How
would pollution affect animals? plants?
3. How do water supplies become polluted?
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Input:
1. Gather the students so that they can see the clear container. Note: It takes a
lot of water to dilute the food coloring.
2. Ask: Can you always see pollution? Can you always tell if water is polluted?
3. Explain that the experiment that the class will conduct today will show how
pollution can get into our drinking sources without our knowledge.
4. Pour ½ cup water into a gallon jug.
5. Add and stir in one drop of red food coloring.
6. Add one cup of water at a time to the container until the red color disappears.
7. Explain that pollution is not always visible and animal life in the stream is
affected by pollutants many miles from the source.
8. Can we get rid of all pollution? Why or why not?
CLOSURE:
Have the students design a water clean-up machine. Fill a bowl with water. Add
pollutants, such as salad oil and/or garbage to the water. Explain that students
need to design a machine (that can be built from common household items) that
will clean up the water. For example, students might create a machine using a
paper towel or cotton ball to absorb the oil. Students should first draw a diagram of
their machine on paper. They should describe how their machine works, label the
parts, and give it a title. Next, have them bring the materials from home to build
their machine in class. Have them try to use their machine to clean up the water.
Use the grading rubric to assess the activity.
EXTENSION:
Look for newspaper articles concerning pollution. Assign as homework: cut out
articles from newspapers or magazines that discuss water pollution. Bring the
articles to class to be shared. Then glue the articles into the student journals.
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GRADING RUBRIC: WATER CLEAN-UP MACHINE
TASK:
Design a water clean-up machine.
REQUIREMENTS FOR THE TASK:
1. Detailed drawing of your machine with a title and parts labeled.
2. Description of how your machine should work.
3. List of materials needed to build your machine.
4. Build your machine from materials found around your house.
5. Test your machine to see if it works (you earn points for trying, even if the
machine does not clean-up the water)
AUDIENCE:
Your teacher and classmates
PURPOSE:
The purpose of the story is to use your creativity to show how everyday materials
can be used to clean-up pollution.
GRADING:
Neatness of Drawing
Drawing labeled and titled
Description of your machine and how it works
List of materials needed to build your machine
Neatness of description and correct spelling
Model of your machine
Test your machine
Total Points Possible
5 points
5 points
50 points
5 points
5 points
20 points
10 points
100 points
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Assessment
Grade 5
HYDROSPHERE
Classroom Assessment Example SCI.V.2.MS.4
Students will write lab reports about the investigations they performed in the Instructional
Example that include analysis of the data and the rationale behind their decision to consider
water consumable or not. The data should be represented in data tables and graphs that include
the results of chemical tests, sketches of microscopic observations, and collection of
geographical data.
(Give students rubric before activity.)
Scoring of classroom Assessment Example SCI.V.2.MS.4
Criteria
Apprentice
Basic
Meets
Exceeds
Completeness of
chemical test
data
Presents a chart
that shows results
of one test.
Presents a chart
that shows results
of two test types.
Presents a chart
that shows results
of three test types.
Presents a chart
that shows results
of all testing
types.
Accuracy of
microscopic
sketches
Attempts a sketch
of microorganism(s).
Completes a
sketch of microorganism(s).
Completes a
sketch of microorganism(s)
showing detail.
Completes
sketches of microorganism(s) that
are detailed and
concise.
Completeness of
geographical
data
Attempts to
present
geographical data.
Displays one or
two areas of
geographical data.
Displays all
geographical data.
Displays
geographical data
that is accurate
and complete.
Accuracy of
conclusion
Attempts a
conclusion.
Provides an
acceptable
conclusion.
Provides a
detailed
conclusion.
Provides a
detailed and
accurate
conclusion.
Completeness of
lab report
Presents limited
information that
is relevant to
water
consumption.
Presents
information that
demonstrates an
effort to organize
the information.
Presents an
accurate,
interesting, and
well-organized
report.
Presents an
interesting and
accurate report
that is clearly
focused with
explanation of
results.
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