A Global Water Crisis
IS 285 Meyer Levin, Brooklyn
Summer Research Program for Science Teachers
Subject: Earth Science
Grade Levels: 8-10
Unit: Humans in their Environment: Needs and Tradeoffs
Duration: 3 periods (40 minutes each)
Aim: What are the causes and effects of contaminated drinking water sources and what technological solutions are being used to address this global environmental crisis?
Identify 3 human induced activities that can lead to the contamination of drinking water.
Discuss 2 methods used to treat contaminated drinking water so that it becomes suitable for human consumption.
Evaluate the drinking water crisis in a developing country and make recommendations for improving its water and sanitation conditions.
Vocabulary: flocculants, filtration, purification, pathogens, contamination
· Student worksheet - A Global Water Crisis
· Student worksheet - Mock Muck: A Water Treatment Simulation
· Magazine article PUR and Simple by Stephen Fraser (Current Science Magazine Vol.94, Issue 12 (February 27, 2009)
· Materials for each cooperative learning group:
- 3 cup sample of mock wastewater (cooking oil, tuna fish water, chocolate milk, coffee grounds, soy sauce, tomato sauce, etc.)
- 1 coffee filter
- ¾ cup of sand
- 1 charcoal brick
- 2 empty containers
- glass graduated cylinder
Engage (Day 1)
Distribute the Student Worksheet: A Global Water Crisis. Assess the prior knowledge of the students by instructing them to brainstorm chemicals and other items that can be poured down the drain or dumped into freshwater sources such as lakes, rivers, streams, and groundwater. This should be followed by a brief class discussion to generate additional ideas that can be added to the web.
Explore (Day 1)
Ask the students to read the article PUR and Simple by Stephen Fraser. This article addresses the issue of cleansing contaminated water around the world so that it becomes safe for human consumption. After reading the article, students will test their understanding of the article by answering the reading comprehension questions given on the worksheet. A class discussion should follow to review the answers and to address student concerns about worldwide contamination of drinking water sources.
Explain (Day 1)
Instruct the students to assemble in their cooperative learning groups to plan the design of a filtration/purification device that can be used to treat a mock contaminated water sample and generate the cleanest water possible. Advice the students that they can only use the materials provide and should focus their designs on three major techniques: oil-water separation, sand filtration, and charcoal absorption/filtration. Students should refer to the guided questions given on the handout to assist then in the design process.
Extend (homework assignment)
The students should be encouraged to conduct further research to learn more about the filtration/purifications process. Any knowledge gained as a result of this research should be used to guide the design of their purification/filtration devise.
Engage (Day 2)
Present a short multimedia slide presentation that shows images of people worldwide obtaining and consuming contaminated drinking water. Be sure to also include images that show the effect of consuming these polluted waters e.g. Charts/graphs that show worldwide death tolls and diseases associated with drinking polluted water
Explore (Days 2 and 3)
1. Distribute copies of the Student Worksheet: Mock Muck- A Water Treatment Simulation.
Remind the students that they will use only the materials given to create a filtration/purification system that will treat the foul, contaminated water and produce “clean” water. To promote collaboration among the students and foster creative design ideas, inform the students that they will be competing against the other groups to produce the greatest amount of treated water as well as the cleanest sample of treated water. The students should be given the remainder of the period to write out a detailed procedure and to construct their water filter/purifier so that it is readily available for experimentation the next day.
2. The following day the students should be given time to conduct their experiment and complete the data table to show their results. After time is called, each group should place their treated water sample in the glass grated cylinder and display them side by side so that they can be compared in terms of volume and clarity. This data should be recorded on the data table shown on the student worksheet. The winning group should then be determined based on these results.
3. As a follow up, the students should be led on a gallery walk to observe and analyze the various filtration devices designed by their classmates. This will allow discussion as they evaluate the designs to determine which setups are more efficient and which ones are least efficient.
Explain (Day 3)
Ask the students to reflect on their expectations and experiences purifying the water and to discuss what they have learned about the global drinking water crisis. The students should be given time to record their reflections in paragraph form before a class discussion is held.
Extend (homework assignment)
Ask the students to select one of the following countries (Bangladesh, Ethiopia, Honduras, India, or Kenya) and visit the website http://water.org to learn more about the water crisis facing this country. Use the information gathered to create an informational brochure to teach others about the water crisis facing this country. The students should follow the guidelines written on the handout.
***This lesson has been modified from a lesson posted by the Water Partners International at www.water.org
New York State Science Standards:
Intermediate Level Science Core Curriculum (8th Grade Science)
Physical Setting/Earth Science Core Curriculum (Regents Earth Science)
Standard 1: Analysis, Inquiry, and Design-Students will use mathematical analysis, scientific inquiry, and engineering design, as appropriate, to pose questions, seek answers, and develop solutions.
Standard 2: Information Systems – Students will access, generate, process, and transfer information, using appropriate technologies
Standard 4: The Living Environment (6.1c, 7.1e, 7.2d)
Standard 4: The Physical Setting/Earth Science (1.2g)
Standard 6: Interconnectedness-Common Themes (Models) – Models are simplified representations of objects, structures, or systems used in analysis, explanation, interpretation, or design
Standard 6: Interconnectedness-Common Themes (Optimization) – In order to arrive at the best solution that meets criteria within constraints, it is often necessary to make tradeoffs