Clean Enough to Drink: Making Devices to Filter Dirty Water

Each group needs:

• computer with Internet access
• 2-liter clear plastic beverage bottle, cut in half by instructor
• 300 ml of "dirty water," made by the instructor by adding to water small bits of plant material, soil and paper; see the Procedure section for instructions
• measuring cup or graduated beaker, to measure dry materials (amounts to be determined by group)
• Water Filtration Planning Worksheet 1 (PDF)
• Water Filtration Planning Worksheet 2 (PDF) (may not be needed)
• Suggested Poster Design Layout (PDF)
• Water Filtration Project Rubric (PDF)
• lab book/journal/notebook (or paper), one per student, to keep track of research, design ideas, sketches, materials lists, notes, etc., throughout the activity
• pencil or pen, one per student
• poster board
• colored pencils

To share with the entire class:

• a copy of the book, The Magic School Bus at the Water Works by Joanna Cole
• half-gallon jug filled with water, to show the class during the introduction
• clear pitcher, in which to show the class the "dirty water" during the introduction
• assorted filtration materials, such as top soil, sand (fine and coarse), gravel, coffee filters, cheese cloth, rubber bands, cotton balls, napkins, paper towels; because groups select which filtration materials and amounts to use in their designs, the quantities needed will vary; suggested quantities to have on hand for the class to share: ~3 liters of top soil, 2 liters of sand (fine and coarse), 2 liters of gravel, 20 coffee filters, 20 4 x 4-inch (~10 x 10-cm) squares of cheese cloth, 20 rubber bands, 50 cotton balls, 20 napkins or paper towels
• scissors, to cut the plastic bottles
• paper towels, for clean-up
• sink with water and drain