Lesson: Splish, Splash, I was Takin' a Bath!Contributed by: Integrated Teaching and Learning Program, College of Engineering, University of Colorado at Boulder
Educational Standards :
Learning Objectives (Return to Contents)
After this lesson, students should be able to:
Introduction/Motivation (Return to Contents)
Did you know that 97% of the water on Earth is salt water? The other 3% is fresh water, but of this amount, 2% is actually frozen in ice caps. So, that means that only 1% of the Earth's water is available for drinking and growing food.
On average, Americans use approximately 80 gallons of water per person per day. The U.S. population keeps growing year to year, and so does the use of water. The majority of water used by Americans goes through a waste water treatment facility that was designed by an engineer and eventually returns to the water supply. This means — for the bulk of American residents — that the water you used this morning to brush your teeth travels through the water system, gets cleaned up at a treatment facility and returns to the community water supply and, subsequently, your own sink!
Water is essential to all life on Earth. The human body is made up of 60%-70% water. Although much of the water in the body is recirculated, a human must have fresh water daily (obtained from eating and drinking) because some of our body's water is removed each day (through the natural processes of urination, breathing, perspiration, etc.).
Where does a body get its supply of water? Ask the students to list some liquids that a person drinks that contain water. Record their suggestions on the board. Next, ask the students to list some foods that a person eats that contain water. Record their suggestions on the board.
Water must be clean for humans and animals. Water pollution can cause poisoning and/or diseases in both animals and humans because they may either drink the contaminated water or eat the plants that grew from the contaminated water. What are some sources of water pollution? Ask the students to list some possible sources of water pollution. Record their suggestions on the board.
Globally, water pollution is a big problem. The United Nations reports that at least 1.7 billion people do not have an adequate supply of drinking water. At least 30,000 people die everyday in the poorest parts of the world because of either a lack of water or unsafe drinking water (about 10 million each year).
Engineers explore and design ways to keep water clean. They study water supplies (where water comes from) and methods for cleaning water. Water engineers' goal, of course, is to develop a process that keeps the water in our faucets — and everywhere else water is used — clean and healthy for the people who use it. Can you think of some additional reasons why clean water is important?
Lesson Background & Concepts for Teachers (Return to Contents)
Interesting Water Facts
Causes of Water Pollution
Point source pollution is the leading cause of water pollution. Point source pollution is pollution that comes from a definite source, such as: direct industrial discharge and dumping, accidents, deep-well injection, leaky landfills, leaking underground storage tanks, abandoned hazardous waste sites, septic tanks, etc. Point source pollution can usually be measured and there is strict government regulations on its discharge (i.e., permits must be obtained from the local government for permission to discharge such pollutants into the environment). Following are some examples of how point source pollution exists today.
Nonpoint source pollution follows point source pollution in terms of its cause for polluting our waters, but is still a major contributing factor. Nonpoint source pollution is described as water that runs over the ground and picks up — and then carries away — natural and human-made pollutants. This water is then deposited into our lakes, streams, coastal waters and even underground sources of drinking water, resulting in harmful effects on drinking water supplies, recreation and wildlife. Sources for nonpoint source pollution include: agricultural runoff, urban runoff, mining, logging, grazing, etc.
Effects of Water Pollution
Water pollution can cause diseases and poisoning in animals because they may drink the contaminated water or eat the plants that grow from the contaminated water. In essence, the pollution may very well prevent their survival and reproduction.
Phosphates and nitrates, in lakes, coastal waters, rivers, wetlands, etc. throw off the natural balance so that there is too much food for plants and too little oxygen for animals. Such pollutants can cause algae to grow too quickly, which uses up all the nutrients in the water. The algae then die and decompose which uses up all the oxygen in the water. Subsequently, without oxygen the fish die. In large doses, nitrates may cause cancer in humans, which may result in death.
Oil spills may kill aquatic animals, and ultimately, the oil covers ocean floors and beaches. Such large amounts of oil do not allow organisms to reproduce effectively or at all, and prevents normal animal activities (such as, oil-slicked feathers preventing birds from flying and staying warm).
Another effect of water pollution is in our bodies of water that are used for recreation or commercial fishing. Severe pollution restricts commercial fishing because there is little aquatic life left to fish for or because what aquatic life remains is contaminated. And, recreational activities that involve water may not be enjoyed if pollution is present.
There is an excellent history and time-line about water by The National Academy of Engineers at: http://www.greatachievements.org/
Vocabulary/Definitions (Return to Contents)
Associated Activities (Return to Contents)
Lesson Closure (Return to Contents)
Go to http://sandiego.surfrider.org/ to get tips on how little changes in everyday life can help prevent pollution. Emphasize that ordinary people can do ordinary things to prevent water pollution. Ask the students to describe one thing they could do to help clean up water pollution.
Read the following poem "Recycled," by Verne N. Rockcastle. Then, discuss with the students how the water they drank this morning may return to their children's glass many years from now using the water cycle. Why might engineers need to know about this process?
The glass of water you're about to drink
Deserves a second thought, I think.
For Avogadro, oceans and those you follow
Are all involved in every swallow.
The molecules of water in a single glass
In number, at least five times, outclass
The glasses of water in stream and sea,
Or wherever else that water can be.
The water in you is between and betwixt,
And having traversed is thoroughly mixed,
So someone quenching a future thirst
Could easily drink what you drank first!
The water you are about to taste
No doubt represents a bit of waste
From prehistoric beast and bird—
A notion you may find absurd.
The fountain spraying in the park
Could well spout bits of Joan of Arc,
Or Adam, Eve, and all their kin;
You'd be surprised where your drink has been!
Just think! The water you cannot retain
Will some day hence return as rain,
Or be held as the purest dew.
Though long ago it passed through you!
Source: Wisconsin Department of Natural Resources, http://dnr.wi.gov/org/caer/ce/eek/earth/groundwater/poem.htm
Attachments (Return to Contents)
Assessment (Return to Contents)
Brainstorming: Have students generate a number of possible ideas about a lesson or activity. Encourage wild ideas and discourage criticism of any ideas.
Discussion Question: Ask students to suggest reasons why clean water is important. Write suggestions on the board. (Possible answers: water is a necessity of life, it provides many entertainment/recreation options, many people earn their living by commercial fishing, etc.)
Lesson Summary Assessment
Problem Solving: Present the class with a problem and ask the students to calculate how much water they think the average person consumes in a lifetime. (Note: The water can be directly from drinking water or from other foods and liquids.) They can suggest the number in terms of 8-ounce glasses, gallons, swimming pools, etc.
Quiz: Have students take the Water Pollution Quiz. Review answers during the next class period.
Lesson Extension Activities (Return to Contents)
References (Return to Contents)
Carson, Rachel. Silent Spring, New York, NY: Houghton Mifflin Company, 1962.
Glencoe Science: An Introduction to the Life, Earth and Physical Sciences, Student Edition, Blacklick, Ohio: Glencoe/McGraw-Hill, 2002.
Hopkins, Jean, Johnson, Susan and McLaughlin, Charles William. "How Many Cans of Soda Pop?" Ecology Earth's Natural Resources Activity Book, New Jersey: Prentice Hall, Inc., 1993 (ISBN 0-13-987090-3).
Kerrod, Robin and Evans, Ted. The Environment (Let's Investigate Science), New York: Benchmark Books, 1993.
Lucas, Eileen. Water: A Resource in Crisis, Chicago: Childrens Press, Inc., 1991.
Sakamoto Steidl, Kim. Environmental Portraits – People Making a Difference for the Environment, Boulder, CO: Good Apple, Inc., 1993.
Stille, Darlene R. The New True Book – Water Pollution, Chicago: Childrens Press, Inc., 1990.
The National Academy of Engineer's ranking of the 20 best engineering achievements of the 20th century: http://www.greatachievements.org/
US Environmental Protection Agency: http://www.epa.gov/owow/nps/qa.html
US Geological Survey: http://ga.water.usgs.gov/edu/waterquality.html
Wisconsin Department of Natural Resources:http://dnr.wi.gov/org/caer/ce/eek/earth/recycle/index.htm
ContributorsAmy Kolenbrander, Jessica Todd, Malinda Schaefer Zarske, Janet Yowell
Copyright© 2005 by Regents of the University of Colorado
The contents of this digital library curriculum were developed under a grant from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education and National Science Foundation GK-12 grant no. 0226322. However, these contents do not necessarily represent the policies of the Department of Education or National Science Foundation, and you should not assume endorsement by the federal government.
Supporting Program (Return to Contents)Integrated Teaching and Learning Program, College of Engineering, University of Colorado at Boulder
Last Modified: March 7, 2014