Both natural processes and pollution can cause foam (white soapy looking stuff) on a creek.
It is usually caused by a combination of several different pathways. A simple definition of foam is
"A gas (usually oxygen) mixed in a liquid containing some type of impurity." The foam is produced when
air bubbles created by water flowing over rocks and over objects, combine or mix with the impurity.
Sometimes foams are natural. White colors can tell you when the element aluminum is present, or when
sulfur producing bacteria are present. The foam may also be the result of human activities in or around the creek.
Tools and things you will need
- Eyedropper
- Gloves
- Jars with lids
- Litmus paper
- Microscope (if possible)
- Rubber boots
- Shovel or stick
What to do?
- How can you tell if an impurity is present in the environment?
- See if your creek has white foam.
- Collect the white flocculates (flakes that occur in the water, on rocks or on the bottom sediments) in a baby food jar with an eyedropper.
- Smell the mud under the white flocculate. What do you smell? A sulfur smell can indicate the presence of sulfur reducing bacteria.
What did you see?
- Look at the flocculates under a microscope.
- Observe the changes over time.
- What else did you see?
What do you conclude?
- What types of substances are in your creek?
- How can you find out what is in your creek?
- What are your conclusions? "Write down what you think."