Materials required 

For the discussion:

  1. Handout – Water Filter Design Notes

To make the water filters:

  1. 2 liter plastic soda bottle
  2. Gravel
  3. Sand
  4. Sponges
  5. Paper coffee filters
  6. Paper clips
  7. Straws
  8. Cotton balls
  9. Rubber bands
  10. Tape (electrical or duct)
  11. Panty hose
  12. Clay or putty
  13. Cotton batting
  14. Cheesecloth, mesh, or some other fabric with large porous holes
  15. Scissors

To make the dirty water:

  1. A large clear bucket filled with water
  2. Food coloring or soy sauce (to represent chemicals)
  3. Raisins or dried beans (to represent animal/human waste)
  4. Potting soil (to represent the earth)
  5. Baking soda (to represent road salt)
  6. Cooking oil (to represent motor oil)
  7. Torn pieces of paper & Styrofoam (to represent litter)

Time required 

1 hour, 30 minutes