Science Seekers: Safe Water Unit
Students began their mission on the computer. Their mission was to locate the source of a pollution spill. ....But first they had to learn about groundwater, the saturated zone, aquifers, recharge zones, permeable and porous rock and much more. They watched video for briefings by hydrogeologists on the computer and read in their booklets. After each of the three computer sessions they did a lab in the classroom.
Here the students are building a GroundwaterModel using gravel, sand and top soil. In the center they place a "well" which reaches down into the saturated zone.
Ryan adds 75 mL of water to our model as Brandon holds his finger over the "well". It took the water quite a long time to seep down to fill the spaces between the gravel. The book suggested a ten minute wait, but our water took over an hour!
Karl uses a straw to remove water from our "well".
In the Pollution Plume test, five drops of green food color were added to the ground water model. Students used the pipettes to simulate rain. Water was drawn from the well. Students measured the amount of time it took the "pollution" to reach the well.
Katlyn is adding gravel for the Porosity Test. The bottom of the tube is sealed with plastic wrap. Her group is checking to see which will hold more water: sand or gravel. (The gravel held more water)
Measuring 2 mL of water with a pipette is not easy. Students practiced being as exact as possible.
In the Permeability Test, Chase and Anja are checking to see which will hold more water: sand or gravel. The bottom of the tube is covered with a layer of nylon. They will see which will allow the water to move through more quickly. (The gravel won!)
The group used the pipettes to add 2 mL of water at a time to the gravel. They use the clock to check the length of the it takes the water to move through the sand and gravel. (It moved considerably faster through the gravel.)
Use these Internet links to gather additional information.
Continuing the Pollution Plume test, Katie simulated "rain" and then drew water from the "well". About half the class took a turn before the water in the well once again ran clear. Everyone was surprised at the amount of time.
