For introductory teacher presentation:

• Gravity-Fed Water Systems Presentation (a PowerPoint® file)
• computer and LCD projector to show a PowerPoint presentation
• drill with ½" bit to start holes in tubs
• utility or Exacto® knife to further widen holes (as an alternative, ask the hardware store where you buy the tubs to drill the holes for you; ensure you have the pipe adapters to illustrate and clearly explain the layout of the holes)

Each group needs:

• access to water or, if necessary, a 5-gallon bucket filled with water
• safety glasses/goggles, one per student
• Gravity-Fed System Design Worksheet, one per student
• turbidity chart (to measure cloudiness), on the last slide of the presentation
• 2 calculators, for two students to check calculations
• 2 6-ft long 0.25" or 0.5" clear polymer tubing (or 1 of each; available at hardware stores)
• 1 3-ft long 0.5" clear polymer tubing to represent the tap (available at hardware stores)
• 5 0.25-in and 5 0.5-in threaded hose barbs (thread on one end and barbed on the other), with o-ring that goes over the threaded section, along with a metal or plastic nut that threads on to the threaded section (available at hardware stores)
• 3 clear 5-gallon tubs, holes drilled for the following; for more information, see the Procedures section and Figure 1 (tubs available at hardware/discount stores): pipe adaptors for exit of spring catchment basin or dam (tub 1), entrance and exit for sedimentation tank (tub 2), entrance only for "community" tank (tub 3)
• 2 cups of dirt (sediment)
• 2 stopwatches to measure flow rate
• (5) 2' x 2' cardboard boxes, or larger cardboard boxes (to place tanks on)
• 1 clear plastic cup (end user) (note: this is the cup of water that students fill with tub 3 water to insinuate drinking)

To share with the entire class:

• 12 6-ft long 0.25" clear polymer tubing (available at hardware stores)
• 12 6-ft long 0.5" clear polymer tubing (available at hardware stores)
• 3 hoses connected to classroom taps to fill tub 1 (dam/catchment)
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