Water Pollution

Student Work




Title: Water Pollution
(Note: This is a 3-day mini-unit designed for Mrs. Carral’s 2nd Grade Bilingual class at Grant Elementary School, Trenton, NJ.)

This mini-unit is designed to teach students about the concepts of pollution and conservation.  To accomplish this, a variety of techniques will be used, such as demos, lectures, and group work.  Throughout this mini-unit, the students will be asked to identify different types of pollutants and think about ways they can help conserve water.

There are many ways in which people pollute our water supply.  Some habits we have, we are very aware of; others are not so obvious.  This mini-unit will show students the ways we pollute our water supply.  Some of these ways are not so familiar to children.  We need to cause them to look for alternatives.  Our water supply is limited and precious, and we need children to be a part of water conservation efforts.  Everyone who helps becomes an asset to society.

Subject Area(s):
Language Arts / Literacy
Social Studies

3.1G – Comprehension Skills and Response to Text
3.3A – Discussion
3.4B – Listening Comprehension
5.8B – Atmosphere and Water
5.10A – Natural Interactions and Impact
5.10B – Human Interactions and Impact
6.7D – Human Systems
6.7E – Environment and Society

Day One (Tuesday):

The purpose of today’s lesson is to introduce the topic of water pollution through the use of story and a demo.  This lesson will also provide the foundation for future activities dealing with water pollution.


bulletthe students will identify the different types of pollutants present in our water supply
bulletthe students will identify the ways man pollutes our water supply
bulletthe students will determine the harmful effects of our careless habits
bulletthe students will state the effects water pollution has on plant and animal life
bulletthe students will be able to define the term pollution


bullet2 plastic two- or three-liter clear soda bottles ¾ full of water
bullet2 sponges cut in the shape of a fish
bullet2 pieces of thin string
bullet2 washers
bulletsmall amounts of soil, pancake syrup, salt, paper dots, brown sugar, soapy water, red and green food color
bulleta copy of the “Freddy the Fish” story

Approximately 60 minutes

We will ask the students to define water pollution.  This will help us assess their prior knowledge on this topic as well as lead into a discussion on what water pollution is.

Note to the teacher: The EPA defines water pollution as “any human-caused contamination of water that reduces its usefulness to humans and other organisms in nature.  Pollutants such as herbicides, pesticides, fertilizers, and hazardous chemicals can make their way into our water supply.  When our water supply is contaminated, it is a threat to human, animal, and plant health unless it goes through a costly purification procedure” (“Water Pollution Prevention and Conservation” 1).

Although this is an accurate and complete definition of water pollution, it may be too advanced for a second grade level.  It may be helpful to use the definition above, altering some of the terms.  For example, the teacher can say, “Pollution is items, such as poisons, chemicals, and litter, that harm our air, water, animals, plants, people, and the Earth.”


bulletFirst, we will go through the “hook” activity, which will involve discussing what water pollution is.
bulletNext, we will begin the “Freddy the Fish” activity.  After attaching the string and washer to the sponge fish, the teacher will put Freddy the Fish inside the empty soda bottle.
bulletThen, the teacher will fill the soda bottle ¾ full of water.
bulletThe teacher will begin to tell the story of Freddy the Fish.  As the story progresses, the teacher will add the “pollution” at each step of the way and ask how Freddy is doing.  It may be helpful to ring a bell or have a visual cue for the students so they know when it is time to move on to the next part of the story.

bulletThe story of Freddy the Fish:
bulletImagine a clean river as it runs through a protected wilderness area.  In this river lives Freddy the Fish.  How is Freddy?  Freddy has lived in this stretch of the river all his life.  But now he is going on an adventure and travels downstream.
bulletFreddy swims into farm country.  He passes a freshly cut riverbank.  It begins to rain and some soil runs into the river.  (Dump soil into Freddy’s jar.)  How is Freddy?
bulletFreddy nears a housing development.  Some fertilizer from the lawns washed into the river awhile back.  (Place brown sugar in Freddy’s jar).  The fertilizer made the plants in the river grow very fast and thick.  Eventually the river could not give them all the nutrients they needed, and so they died and are starting to rot.  Because they are rotting they are using up some of Freddy’s oxygen.  How is Freddy?
bulletFreddy swims beside a large parking lot.  Some cars parked on it are leaking oil.  The rain is washing the oil into the river below.  (Pour pancake syrup into Freddy’s jar.)  How is Freddy?
bulletDuring some cold weather, ice formed on a bridge.  County trucks spread salt on the road to prevent accidents.  The rain is now washing salty slush into the river.  (Put salt in Freddy’s jar.)  How is Freddy?
bulletFreddy swims past the city park.  Some picnickers did not throw their trash into the garbage can.  The wind is blowing it into the river.  (Sprinkle paper dots into Freddy’s jar.)  How is Freddy?
bulletSeveral factories are located downstream from the city.  Although there are laws or rules that limit the amount of pollution the factories are allowed to dump into the river, the factory owners are not following them.  (Pour warm soapy water into Freddy’s jar.)  How is Freddy?
bulletThe city’s wastewater treatment plant is also located along this stretch of the river.  Also a section of the plant has broken down.  (Squirt two drops of red food coloring into Freddy’s jar.)  How is Freddy?  (Giving an example of what wastewater is may be helpful as some students may not know that term.  The teacher can say that wastewater is water that goes down the toilet and/or the water that goes down the drain after you wash your hands.)
bulletFinally, Freddy swims past a hazardous waste dump located on the bank next to the river.  Rusty barrels of poisonous chemicals are leaking.  The rain is washing these poisons into the river.  (For each leaking barrel, squeeze one drop of green food coloring into Freddy’s jar.)  How is Freddy?
bulletAfter we finish the story of Freddy the Fish, we will ask the students to list the “bad things” that Freddy had to swim through.  We will also ask where these pollutants came from and how they affected Freddy.

Day Two (Wednesday):

The purpose of today’s lesson is to demonstrate how pollutants can get into our water supply.  In addition, we will help the students become aware of pollution prevention tips.


bulletthe students will experience and observe how pollutants get into and mix with our water supply
bulletthe students will identify ways to help keep water clean
bulletthe students will list ways to help prevent water from becoming polluted


bullet3 aluminum pans
bullet3 spray bottles filled with water
bullet3 sheets of white paper with a blue strip down the center and different colored spots made with washable markers
bulleta copy of the book The Magic School Bus at the Waterworks by Joanna Cole

Approximately 60 minutes

We will start by reviewing the definition of pollution and listing examples of pollutants.  We will then review their homework, which was to think of ideas to help Freddy keep his water clean.


bulletAfter going through the “hook” activity, we will continue our investigation on water pollution through an activity that involves a watershed.  The use of the watershed will demonstrate how easily pollutants can get into our water supply.
bulletWe will break the class into 3 groups of six for this part of the lesson.  First, we will give each group a piece of white paper that has a blue strip running down the center (which represents a river) and different colored spots scattered throughout the paper (which represents different types of businesses, farms, residential areas, etc. where waste is present).  We will ask the groups to crumble this sheet of paper.
bulletNext, we will ask them to smooth out the paper, leaving the creased areas higher, and place it into an aluminum pan.  Then, we will distribute spray bottles filled with water to the three groups.  We will instruct the groups to spray the top of the paper, which represents rain.  We will ask the students to observe what happens.  They should see the colored spots running into other colored spots and into the river.  Next, we will ask them what this shows.  Some possible responses include: this shows how pollutants get into our water; this shows the many places where pollution comes from, etc.
bulletNext, we will read to the students The Magic School Bus at the Waterworks by Joanna Cole.   This book discusses water pollution and the purification process of the water that we use in our homes.
bulletWe will also go over the ways that students can become involved to help clean up the water supply and the ways in which they can personally keep it clean.
bulletFor homework, we will ask the students to go home and observe how and where water is used in their homes.

Day Three (Thursday):

The purpose of this activity is to help students become aware that the amount of water that exists on Earth is not unlimited.  In addition, we will stress the importance of conservation of water and identify the various ways that exist to save water.


bulletthe students will recognize that there is a lot of water in the world, but that not very much of it can be used for our drinking water and other water supply needs
bulletthe students will understand how important it is that we take care of our ground water
bulletthe students will explain why water conservation is important
bulletthe students will develop water conservation tips of their own and pass that information on to family, friends, and neighbors


bullet18 globes or world maps
bullet97 pieces of uncooked ziti dyed (or painted) blue, 1 piece dyed (or painted) red, and 2 pieces dyed (or painted) green
bulletfood coloring
bulleta gallon of water
bullet18 Dixie cups
bullet18 little salt packets

Approximately 60 minutes

In this lesson, we will take a look at the globe with the students.  We will ask if they can find where they live on the globe and have them point out lakes, rivers, and oceans.  We will explain that these are called surface waters.

We will ask the students if they think there is more water or land on the globe.  We will also ask if they think there is water beneath the surface of the ground that we cannot see on the globe.  Next, we will ask the students if they know which kinds of water bodies are salt water and which are freshwater.  Oceans are salt water while fresh water is found in glaciers, ice caps, and snowy mountain ranges.  We will explain that fresh water supplies are stored either in the soil (aquifers) or bedrock fractures beneath the ground (ground water) or in lakes, rivers, and streams on the earth’s surface (surface water).

Next, we will ask if anyone has ever been to the ocean.  We will ask if they have ever tasted salt water.  Did you like it?  Did it taste better than the water you drink at home?

Although it looks like a lot of water, not all of it can be used.  Most fresh water is frozen in polar ice caps, icebergs, and glaciers.  In addition, salt water is too salty to use for most purposes, and the salt is very costly to remove.  To demonstrate the difficulty in removing salt from salt water, we will distribute a plastic Dixie cup filled half way with water and one salt packet to each student.  We will instruct the students to empty the salt packet into the water.  We will ask them if they can see the salt in the water and if the water looks any different now that the salt is in it.  Next, we will ask them to remove the salt they just poured in.  Whether or not the students are physically able to remove the salt is not the point of this activity.  Hopefully, they will see the difficulty that exists in the process of removing salt from salt water and how this difficulty makes the process costly.


bulletFirst, we will go through the “hook” activity, which will entail looking at the globe to identify the various sources of water that are available on Earth.
bulletNext, we will spread the colored ziti out on a table.  We will explain that there are 100 ziti pieces, which can be thought of as 100 drops of water.
bulletWe will explain that the 97 blue drops of water represent the salt water we find in oceans and seas.  The two green drops of water represent the water that is stored as ice in glaciers and at the poles.  The lonely red drop of water represents the fresh water that is available for plants, animals, and people.  We will ask the students if they think there is a lot of water available for use, reminding them that the one red drop of water represents the amount of fresh water on Earth.
bulletTo recap, we will ask the students the following questions:
bulletWhy isn’t all fresh water usable?  Possible answers: Some is not easy to get at; it may be frozen or trapped in unyielding soils or bedrock fractures.  Some water is too polluted to use.
bulletWhy do we need to take care of the surface water/ground water?  Possible answers: Water is very important for humans, plants/crops, and animals.  If we waste water or pollute it, we may find that there is less and less of it available for us to use.
bulletNext, we will review the students’ homework and ask them to verbally describe how and when they use water.  Making a list on the board with their responses may help them visualize just how much water we use everyday and the different ways in which we use it.
bulletWe will then explain that water is a resource that has many uses, including recreational, transportation, hydroelectric power, and agricultural, domestic, industrial, and commercial uses.  Water also supports all forms of life and affects our health, lifestyle, and economic well being.  As individuals, we use water for sanitation, drinking, and many other human needs, and we pay for the public water utilities that provide water.
bulletThe next part of the lesson involves the use of a poster that lists statistics about how much water a certain activity uses.  The poster should be set up so that there is a picture of the activity on a flap and underneath the flap is the amount of water in gallons that activity uses.  This can be turned into a game where a student comes up to the poster and guesses the amount of water he/she thinks that activity consumes.  He/she tells his/her guess to the class, and the class can agree or disagree.  If the class disagrees, they can say what they think the real amount is.  The student then lifts the flap to reveal the amount of water that activity utilizes.  (Before starting this part of the lesson, we will pass around a full gallon of water to let the students feel how heavy it is and to physically see just how much a gallon will hold.  This may help them visualize amounts of water when the students are trying to make their guesses.)  Examples of the amount of water used by an individual during everyday activities are shown below:
bulletTo flush a toilet 5 to 7 gallons
bulletTo run a dishwasher 15 to 25 gallons
bulletTo wash dishes by hand 20 gallons
bulletTo water a small lawn 35 gallons
bulletTo take a shower 25 to 50 gallons
bulletTo take a bath 50 gallons
bulletTo wash a small load of clothes in a washing machine 35 gallons
bulletTo brush teeth (running water continuously) 2 to 5 gallons
bulletThe average American uses 140 to 160 gallons of water per day.
bulletAlthough more than three quarters of the earth's surface is made up of water, only 2.8 percent of the Earth's water is available for human consumption.  The other 97.2 percent is in the oceans; however, this water is too salty to use for most purposes, and the salt is very costly to remove.  Most of the Earth's fresh water is frozen in polar ice caps, icebergs, and glaciers.  Although water flows from our faucets throughout the day, we often take the amount of fresh water available on Earth for granted.  As the world's population increases, water consumption increases.  Preventing water pollution and conserving water are important to assure a continuing abundance of water that is safe to use for ourselves and future generations.
bulletThen, we will ask the students what we should do to save and take good care of the water we use in our homes and businesses.  Using their responses, we will make a web using the overhead projector.  Possible ideas for the web include: turn off the faucet while brushing your teeth and washing your face; do not let the water run while washing the dishes by hand; only run the washing machine or dishwasher if you have a full load; tell an adult if you see a leaky faucet so that it can be fixed quickly; do not throw in the trash, pour down the drain, or dump on the ground paint, antifreeze, motor oil, and other household hazardous wastes because they can migrate to your water source; dispose of tissues, dead insects, and other waste in a trash can rather than a toilet; put all litter in trash cans so it does not get washed into the storm sewers; clean up waste products while walking your pets.
bulletWe will end this lesson (and mini-unit) by discussing how what we do now can affect future generations.  Therefore, it is important that we protect and save water for our future families, neighbors, and friends.

Assessment for All Three Days:
We will assess the children’s understanding of the topic and their interest level throughout the mini-unit.  Their answers to our questions, along with their facial expressions and behavior, will indicate to us whether the subject and presentation is capturing their interest.  In addition, the group work, the way in which the children answer our questions on pollution and conservation, and their explanations of how pollutants get into and mix with our water supply will tell us whether the students understand the concepts presented.  How well they complete the web of water conservation we do in class is another form of assessing their learning.  We can also see this with the list of water clean-up tips they make.



“All the Water in the World.”  14 November 2002, Environmental Protection Agency, 1-5.  Retrieved from: http://www.epa.gov/region01/students/pdfs/ww_intro.pdf

Cole, Joanna.  The Magic School Bus at the Waterworks.  New York: Scholastic and Co., 1986.

Grammar, Debbie.  “Freddy the Fish.”  14 November 2002, University of Texas El Paso TES Course, 1-3. 

“Water Pollution Prevention and Conservation.”  13 November 2002, Environmental Protection Agency, 1-8.  Retrieved from: http://www.epa.gov/reg5rcra/wptdiv/p2pages/water.pdf

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