photo taken from:Give Water a Hand: organization to get students involved in water issues: http://www.uwex.edu/erc/

Table of Contents: Objectives Background Lesson Plans Activities; 1. Sediments 2: acid rain experiments

Objectives: Students will be able to:

• Define pollution and give examples of several kinds of pollution.
• Develop a list of water pollutants which may exist in their immediate environment.
• Relates the ways in which human activities pollute water
• Explore ways it can be prevented
• Observe microscopic organisms in polluted water
• Design an experiment to filter polluted water.

Background:

• Citizens of the United States expect clean and safe drinking water, however, they pollute the environment. According to a published Sept. 1991 EPA report, although water supplies in the US are the cleanest and safest in the world, on occasion they may be contaminated resulting in thousands of illnesses. Depending upon where and when you get your water there could be protozoa, bacteria, chemicals, pesticides, viruses, as well as fecal matter.

  There are several classes of common water pollutants:

• Disease-causing agents (pathogens), which include bacteria, viruses, protozoa, and parasitic worms that enter water from sewage and untreated human and animal wastes. In least developed countries, they are the biggest cause of sickness and earth, killing an estimated average of 13,700 people each day. half of the them under the age of 5.
  
• Oxygen-demanding wastes, organic wastes that can be decomposed by aerobic (oxygen-requiring) bacteria. Large populations can degrade water quality by depleting water of dissolved oxygen, causing fish and other forms of oxygen-consuming aquatic life today.
  
• Water-soluble inorganic chemicals, which are acids, salts, and compounds of toxic metals such as mercury and lead. High levels of these chemicals can make water unfit to drink, harm fish and other aquatic life, depress crop yield and accelerate corrosion of equipment that uses water.
  
• Inorganic plant nutrients are water-soluble nitrates and phosphates that can cause excessive growth of algae and other aquatic plants, which then die and decay,m depleting water of dissolved oxygen and killing fish. Excessive oxygen-carrying capacity of blood and can kill unborn children and infants.
  
• Organic chemicals which include oil, gasoline, plastics, pesticides, cleaning solvents, detergents and many other chemicals. They threaten human health and harm fish and other aquatic life.
  
• Sediment or suspended matter- insoluble particles of soil and other solids that become suspended in water, mostly when soil is eroded from the land. Sediment clouds water and reduces photosynthesis. It disrupts aquatic life and carries pesticides, bacteria, and other harmful substance. Sediment that settles out destroys feeding and spawning grounds of fish, clogs and fills lakes, artificial reservoirs, stream channels and harbors.
  
• Genetic pollution occurs when aquatic systems are disrupted by the deliberate or accidental introduction of nominative species, such as mussels and phytoplankton. Each day several thousand species are transported in cargo and ballast water in ships to new marine systems, where they may out compete many marine species, reduce biodiversity, and cause economic losses.
  

Lesson Plan one: sediments

Engagement

1. Have you ever thought about the safety of your drinking water?
2. What else besides water molecules resides in a glass of water?
3. What are pollutants?
4. Who is responsible for polluting the drinking water?

   Exploration

   Students will design, illustrate and label a filtration system that will clean a dirty water sample ( sediments) .

   Materials:

• 2 Plastic or foam cup with a small hole cut in the bottom(pencil size hole)
• Dirty water sample
• Aquarium charcoal
• Coffee filters
• Sand
• Crushed sea shells
• Pea size gravel
• Soil
• Cotton balls or fabric

  Procedures:

Using any or all items, construct a filter such that, as the dirty water is poured over the top of the cup, it is filtered as it comes out of the bottom of the cup, into the second cup. Make your sample as clean as possible. Be sure to give step-by-step instructions for devising your filter. Once your filter is complete, draw and label the parts.

Explanation

1. Was your filter a success? Explain.
2. Were you able to remove all pollutants? Why or why not?
3. What modifications were made?
4. How did the filtration process take place?
5. What were some of the limitations of your system?
6. What kinds of tests could you perform on your filtered water to prove that it has been cleansed?

   Elaboration

   Develop a list of water pollution problems that might exist in your area. Select one to research by reading local newspapers using your public library and other local resources such as the local branch of EPA. Include ways to either prevent or ways to dispose of some pollutants.

   Evaluation

   Create a graphic organizer showing the causes and effects of water pollution.

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   Modified by E. Iglich 6/99

   For more information on the Howard Hughes supported Prince George's Middle School Science Teacher's Outreach Program contact: eiglich@wmdc.edu