Name: Chris W.
What are the most basic freshwater properties that I should cover with a 10 -13
year old class of eager scientists? (with heaps of hands-on 'wet' activities.
Beginning with the WATER QUALITY ACT of 1965, individual states were required by federal law
to classify surface waters (streams) on the basis of their maximum beneficial use. These uses
can range from water suitable for recreational use such as swimming; water suitable for use
for fish, shellfish and wildlife; water suitable for public water supply; and water suitable
for agricultural and industrial use. The actual water quality criteria for the different use
classifications usually include limits on dissolved oxygen, coliforms, solids or turbidity,
pH, and toxic wastes. These criteria vary according to the freshwater (stream) classification.
For example, a minimum dissolved oxygen of 5 mg/l is typical for shellfish maintenance. On the
other hand, streams protected for the spawning of freshwater trout may have a minimum dissolved
oxygen limit of 8 mg/l. I hope that this is some help.
You might start with the information on the Illinois RiverWatch page of the
Illinois Department of Natural Resources:
This US EPA page has many links to water activities:
This one, also US EPA is a kids page on water:
The concept that bodies of water freeze from the top down, and that water is less dense in
its solid form, is incredibly important for life on Earth. Other things you would want to
cover: pH (acid ran), temperature, nitrogen-based compounds (nitrates, especially),
phosphates, hardness, perhaps some tests typically run by people with a freshwater
aquarium. Maybe some reactions, solutions (water is the "universal solvent"), etc.
If they can understand it, talking about the polarity of water would be good, too. If
you can get a copy, Project Wet has some great activities. It is hard to get it unless
you take a Project Wet class. You can probably find some other ideas on-line or in a
library. Good luck and have fun!
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Update: June 2012