Clean Water vs. Dirty Water
Evelyn Carter, D'Lisa Pinkham, Jackie Taylor
Nez Perce Indian Reservation, Lapwai, Idaho

Grade level
Kindergarten

Time required
90 minutes, plus a fieldtrip

Materials
Small transparent containers
Water
Dirt
Thermometers
Nez Perce Reservation map
Water temperature investigation data sheet
Drawing materials – paper, markers, etc.
Small red and blue fish icons for graphing
Chart paper for graph

Goals
By completing this lesson, students will

1. learn about the importance of clean water to the survival of organisms,
2. learn about water polluting materials and activities,
3. develop skills in inquiry investigation and
4. learn about how the Nez Perce Tribe manages their waters and fish.

Science standards addressed
National Science Standards

• Abilities necessary to do scientific inquiry
• Organisms and environments
• Science as a human endeavor
• Types of resources

American Indian Science Standards

• Various forms of scientific and technological work currently engaged in by American Indian men and woman and in what ways their fields require the process of problem identification, design and solution
• Observations and understandings of nature and ecological relationships traditionally formed an essential base of knowledge among American Indian cultures

Teacher tips
As a pre-lesson activity, facilitate a class discussion on the different forms of water on Earth and where it comes from. Hang posters of waterways, fish, etc.

Students may require practice in reading a thermometer. Using digital thermometers can be helpful. In order to understand the temperature measurements, students should understand two digit number values, and the meaning of the word temperature. The teacher should practice the experiment in advance, to be able to anticipate how to scale the graph.

Ask a tribal fisheries biologist to accompany your students on a fieldtrip to study macroinvertebrates. Consult with them about equipment availability, such as nets, pans and magnifying glasses to use in catching and examining macroinvertebrates.

Background information
One of the waterways located on the Nez Perce Reservation is the Clearwater River. It was named appropriately and is a beautiful and scenic river that is home to the salmon. Many other bodies of water are located nearby, all of which run into the Columbia River that flows into the Pacific Ocean.

Clean water is vital to survival on Earth. Many of the organisms that live in the rivers and streams of the Nez Perce Reservation, such as the culturally significant salmon, can only live in clean, cold water. There are many types of pollution that threaten rivers and streams in the northwestern United States, including soil erosion, pesticide, herbicide and fertilizer runoff, as well as industrial pollutants. When rivers become turbid due to soil erosion, for example, the dirt particles in the water reflect sunlight and cause the water temperature to increase. This causes a decrease in the amount of oxygen dissolved in the water. Decreased oxygen levels make the water unsuitable habitat for salmon, which require high levels of oxygen. This is the basis of the water temperature investigation in this lesson.

Like temperature and clarity, the presence or absence of specific organisms in waterways is an indicator of water quality. For example, certain macroinvertebrates, such as bloodworms, are only found in warm, oxygen poor water. Ask the tribal fisheries biologist to discuss this with students as they catch and examine macroinvertebrates in local waterways.

Procedure
Engagement

1. Show a glass of clean water and a glass of dirty water. Ask students which water they would prefer to drink. Which water would they prefer to swim in?
2. Ask students what bodies of water exist on the reservation. Point to the reservation rivers, streams and lakes on the map. Tell students that the Nez Perce Tribe manages the water on the reservation. Ask students to predict what types of things create water pollution. Make a class chart.

Exploration

1. Give student pairs two small transparent containers, each with about one inch of water in it. Have them add a teaspoon of dirt to one of the containers and stir.
2. Tell them that they will be measuring the temperature of the water in each container after it sits in sunshine. Give them thermometers and have them place them in the containers. Let the water containers sit in sunshine for twenty minutes. Ask students to predict which container will have warmer water. Have them draw, color and label the containers on their data sheets while they wait. Ask students to read the temperature for each container’s water after twenty minutes, and to write their results on the data sheet.

Explanation

1. Ask students to report the results of their experiment. Make a class graph of their results, using blue fish for cold water and red fish for warm water points on the graph.
2. Ask students to predict whether salmon would prefer to swim in warm dirty water or cooler clean water. Explain to students that salmon prefer cold, clear water that contains high levels of oxygen. Dirty water is warm and has low oxygen, so it is not good habitat for salmon.

Elaboration
Go on a field trip with a tribal fisheries biologist to a local river or stream to catch and study macroinvertebrates. Ask the biologist to talk with students about fish and macroinvertebrates in relation to water quality, and about reservation water management work done by the Nez Perce Tribe.

Evaluation

1. Have students create an environmental crest that shows two things they will do to keep water clean.
2. Assess students’ process skill proficiency by observing them while they perform the investigation and by reviewing their data sheets.

Follow up activities
Explore how astronauts clean their water in space. Write a letter to John Herrington, the first Native American astronaut to go into space, and ask him about water use on the Space Shuttle.

Vocabulary