Each group needs:

• Recycled/reusable materials (collected by students over the previous week). Material may include: empty plastic jars, plastic bottles, PVC piping, sponges, tubing, sand, gravel, plastic wrappers, etc.
• 1 clean container (able to hold at least 500 mL)
• 1 clean cup (able to hold at least 200 mL)
• 2 - 3M™ E. Coli/Coliform Petrifilm™ tests or other simple bacteria test (3M™ Petrifilm™ test strips can be ordered directly from the manufacturer by calling 1-800-328-1671 (item call #6404); $150 for 100 tests)
• 2 - 1 mL sterile syringes (no needle), for use with coliform tests
• 1 sheet of paper, to sketch design ideas
• Let's Clean Some Water! Data Worksheet  

To share with the entire class:

• Secchi Tube Turbidity Meter (groups may make their own following the How to Make a Secchi Disk Turbidity Tube Manual, attached). Materials include:

1. one long (~3 ft) piece of clear tubing with a cap for the end (e.g., a fluorescent tube light cover from a hardware store which comes with end caps)
2. plastic container lid (e.g., from a yogurt or sour cream container)
3. scissors
4. flexible water-tight glue (e.g., Gorilla glue)
5. black permanent marker
6. meter stick (for measuring)

• variety of tapes and glues
• cutting tools, such as scissors and utility knives
• dirty water collected from a nearby creek, river, pond, lake or other surface water source; enough for approximately 0.5 L per group
• a large, wide-mouth container with a lid for transporting/storing source water (to hold enough for approximately 0.5 L per group); may want to use a smaller clean container (such as a cut-open gallon jug) to scoop water.
• 3M™ Petrifilm™ Interpretation Guide
• How to Use a Secchi Disk Turbidity Tube Guide.
• bucket and bleach (to disinfect used test strips prior to disposal).
• latex or rubber gloves (for teacher use only; to use when bleaching test strips).