Turbidity of Rain Water

(How dirty is the water?)

During the month of March we collected rain water samples to test the turbidity. On March 21, 2002 we met with Robert Bourke from Oceanit and made Turbidity meters, created a standard turbidity substance and tested our water samples. We sorted our samples by time and date then ranked the bottles from cleanest to dirtiest (see chart).

How to make a Turbidity Meter:

1. Get a 3 feet long plexiglass tube and mark lines up the tube every 10 centimeters

2. Place a cork in the bottom to keep the water from falling out.

3. Fill with rain water

4. Drop a 1 inch long metal nut with a happy face sticker on it into the tube. It will drop to the bottom.

5. Using a magnet on the outside of the tube, raise the nut with the happy face on it until you can see the face clearly looking down from the top of the tube.

6. Record the measurement


How to make a Standard Turbidity Substance:

1. Measure 1/2 teaspoon of white Pilsbury Flour

2. Mix with 2 liters of clean fresh water

3. Dilute by half (mix 1 liter of mixture with 1 liter of clean fresh water

4. Dilute by half again (mix 1 liter of new mixture with 1 liter of clean fresh water)

5. Repeat "Dilute by half" 3 more times

6. Pour mixture into your Turbidity meter and test.

7. Use this subtance if rain water meatures "0" in your meter