Smell of (Cold) Water

1. First, you have to collect different samples of water from different watercourses.
2. Half-fill plastic bottles to using water samples from streams and close them well.
3. Shake the closed bottle for approximately 1/2 minute. Then open a bottle and smell at once.
4. Determine the intensity of smell with Ball’s odour intensity scale. Try to also determine the type of smell.

0 without odour undetectable
1 very weak odor is detected only by professional
2 weak odor is detected if we are warned
3 perceptible odor is easily detected
4 distinct, prominent odor draws attention
5 very strong odor drives away