|
Overview:
Students will review the water cycle and investigate how a region's water supply can become contaminated. They will look at a list of the Environmental Protection Agency's maximum contaminant levels for drinking water, and sketch the water cycle of a fictitious town that is affected by several pollutants. Students will conclude by writing paragraphs explaining what a group of concerned citizens in this hypothetical town might do to improve the quality of its water supply.
Connections to the Curriculum:
Geography, earth science
Connections to the National Geography Standards:
Standard 7: "The physical processes that shape the patterns of Earth's surface"
Standard 14: "How human actions modify the physical environment"
Time:
Two to three hours
Materials Required:
- Computer with Internet access
- Drawing materials
Objectives:
Students will
- describe the water cycle;
- answer questions about the EPA's list of water contaminants;
- sketch fictitious towns, showing the water cycle, contaminants and their sources, and the health effects of these contaminants; and
- write paragraphs recommending where a citizen's group should focus its energies to improve their town's water quality.
Geographic Skills:
Acquiring Geographic Information
Organizing Geographic Information
Answering Geographic Questions
Analyzing Geographic Information
S u g g e s t e d P r o c e d u r e
Opening:
Development:
Have students go to this Environmental Protection Agency Web page about drinking water standards. Discuss the definitions of the six types of contaminants listed on this page: microorganisms, disinfectants (used to treat drinking water), disinfection byproducts, inorganic chemicals, organic chemicals, and radionuclides (radioactive materials).
Ask students to look at the list of contaminants under each classification and answer these questions as they look at the lists:
- If enteric viruses are found in drinking water, what are their likely source and what health effects might they have? How do you think these viruses could get into the water supply?
- What chemicals are used to disinfect the water supply? What positive and negative effects can these chemicals have?
- Is inorganic chemical pollution primarily the result of natural or human-made factors? Name two inorganic chemicals and their potential impacts on human health.
- What role can agriculture play in water contamination? What are the primary causes of agricultural contamination?
- What level of dioxin does the EPA currently allow in drinking water (MCL)? What is the goal for dioxin levels in drinking water (MCLG)?
Have students sketch hypothetical towns that lie near bodies of water such as rivers, lakes, or the ocean. Their diagrams should show the following things:
- the water cycle;
- the names of at least four pollutants next to the places they come from (for example, a town might have a pulp mill that leaks chromium into a river, which subsequently contaminates the ocean—students would draw the pulp mill and write "chromium" next to it);
- the potential human impacts of these contaminants (students can list these impacts next to the names of the pollutants or at the bottom of their drawings)
Students should be creative with their drawings, but they must include at least four pollution sources and show the full water cycle.
Closing:
Have students look at each other's drawings and describe them to each other.
Suggested Student Assessment:
Extending the Lesson:
- Have students read about the Cherry Creek Citizen Volunteer Monitoring Program. Ask them to write a paragraph briefly describing the project and explaining its projected impact.
- Have your class join an ongoing water monitoring project such as the Global Water Sampling Project. They will measure nitrates, phosphates, coliform bacteria, and other qualities of local water sources.
- Have students research the Clean Water Act of 1972. Ask them to find out what the Act's main points are and to find a few examples of how it has been implemented since the 1970s. Then have them research recent news articles to learn about recent debates and discussions related to the Act.
Related Links:
| 
Check out:
