5 Water quality

By Daniell DiFrancesca

Provided by Kenan Fellows Program.

Students will study water quality and the effect of common pollutants while practicing their critical-thinking skills in an inquiry-based experiment. Students should focus on their local water source, however, materials are provided for the Falls Lake water source in Raleigh, North Carolina. This lesson is written using the 5E learning model, which includes five phases: engage, explore, explain, elaborate, and evaluate.

Learning outcomes

• Students will evaluate the quality of various water samples.
• Students will evaluate the effect of common pollutants on the quality of water.
• Students will research the impact of human activities on the presence of pollutants in their own water source and the impact of the pollution.
• Students will increase their inquiry skills.

Teacher planning

Time required

Approximately 6 class periods (about 50 minutes each) are needed, however, some things can be assigned as homework to decrease the time spent in class.

Materials needed

For the Explore and Explain portions of the lesson:

• You will need to purchase test kits to find the pH, nitrites, phosphates, and chloride in the water. These can be purchased through scientific suppliers and aquarium stores.
• Create a procedure sheet for each lab station that has the directions for each test.
• bottled water, tap water, distilled water, and outdoor water
• distilled water mixed with fertilizer, pesticide, soap, and gasoline

For the Evaluate portion of the lesson:

• Materials to create posters and brochures

Student handouts

Technology resources

Overhead projector

Activities

Engage

Water pollution discussion

1. Use the following example to begin the discussion of water pollution:
   

   Kurt Vonnegut’s 1963 book Cat’s Cradle introduced a “new chemical” called ice-nine. Ice-nine is a different form of water that is solid at room temperature. Ice-nine trains regular water molecules to also be a solid at room temperature. When a single crystal is introduced into water, the water almost instantly becomes ice-nine as well. What would happen if ice-nine was introduced into our water?

2. Introduce this idea to the students and chose one of the following activities to help them engage in the topic:
   1. Write a paragraph describing what would happen if ice-nine was placed into our water (Falls Lake for instance).
   2. As a class, discuss what would happen to all of the water on the planet if ice-nine was introduced. What would happen to living things because of this?
   3. The discussion questions above can also be turned into small group discussions.
3. After students have discussed the effects of ice-nine, ask them to compare ice-nine to other pollutants that we add to water. What would happen if we destroyed our water systems like ice-nine would?

Explore

Water quality

(Time: 55 minutes)

1. Students will complete a water quality lab to first study the differences among tap, bottled, and outdoor water samples and then study the effects of soaps, fertilizers, and oil products on water quality.
2. Students will use the Water quality testing lab worksheet to complete the lab.
3. Make sure the directions for these tests are available for the students at their lab stations. You can type one combined direction sheet for the tests and place it at each lab station.

Explain

Water quality follow-up

1. Complete the lab questions. The questions focus on analyzing the data and relating the information to their own lives.

Elaborate

Water-monitoring plan

1. The students will create a water-monitoring plan for their local water source.
2. All materials are provided for Falls Lake in Raleigh, North Carolina. These should be adjusted for your local water source. Students will need an outlined map of their water source. A map of Falls Lake is provided with this lesson.
3. Students should first complete the Water source map activities worksheet and complete the required map for each part.
4. The students should then discuss the Before You Begin questions listed near the end of the worksheet with their groups and determine the focus of their water-monitoring plan.
5. The students will then complete the Water quality experimental design graphic organizer, which has been slightly adjusted for this particular activity.
6. Finally, the students will write a water-monitoring plan using their design.

Evaluate

Our water quality

Students should be allowed to choose and complete one of the following:

• Create a poster about how to protect their local water source.
• Create a brochure on how to protect their local water source.
• Present what they have learned about water quality in another creative way of their choice.

A sample rubric based on content, depth, accuracy, graphics, and neatness is provided below. Adjust as needed.

Assessment

• The students’ water-monitoring plan should demonstrate their ability to design an experiment using information gathered in the Water Quality Testing lab. Students should be able to move beyond simply testing the water and be able to organize the location, frequency, depth, and other factors that will affect their water source. Review graphic organizer and plan for consideration of these factors.
• The Evaluation section serves as an overall assessment of the student’s knowledge of water quality.

Modifications

• The experimental design graphic organizer can be edited for any motor-skill deficiencies by making it larger, or making it available to be typed on.
• If there is a water source, stream, or river near the school, visit and involve it in the lesson.
• All basic modifications can be used for these activities.

Supplemental information

This is a list of all the attachments used in this lesson.

Critical vocabulary

• water quality
• water pollution
• runoff

Comments

This lesson is part of the Critical Thinking in Science unit and relies on the inquiry skills and vocabulary practiced in the first two lessons (Introduction to Experimental Design and The Story of Pi). This lesson should be used while teaching Goal 3 of the science curriculum for grade 8 in the North Carolina Standard Course of Study, which focuses on water. Because students are using their local water source as a basis for the monitoring plan it helps them understand the importance of water health and safety. In addition, students are designing their own experiments to improve their ability to approach problems and questions scientifically. By developing their ability to reason through problems they are becoming critical thinkers.

• Next: Change over time

Contents: Critical thinking in science

• Next: Change over time
• Previous: Experimenting with pH

(Image source. More about the photograph)

Learn more

Related topics

• Search LEARN NC for more resources on hydrosphere, pollution, science, water, and water quality.

• Print this page

• Share: