Science and Engineering Day: Environmental Science

Become an environmental scientist and learn more about filtering water!

Activity best for children age 2 and up

We use water every day in so many ways. Brushing our teeth, washing our hands, cooking, giving our pets water to drink and watering plants so that they grow. A lot of the time the water that is out in nature is not clean or safe for us to use.  That is why the water that comes into our homes and schools has been cleaned and is safe to use for all of the ways that we need it. This interesting experiment demonstrates the steps that water filtration plants use to get water cleaned up. Let’s become environmental scientists and take on the challenge of cleaning up some dirty water!

Materials you’ll need:

Clear Container with water that has had some soil mixed into it

Cream of Tartar

Coffee filter

Clear empty berry container that has holes on the bottom

Large tray or container



Fill up a clear container with some water. Mix in some soil. This will act as your “dirty water”.  After the dirty water has been sitting in the container for a few minutes add a few tablespoons of the Cream of Tartar. Really mix that up with the water. Let that sit for about 1 hour. Observe what is happening.  What is happening is that the alum in the Cream of Tartar is pulling the large particles of dirt down to the bottom of the jar. When the alum and the dirt stick together that is called coagulation. All that dirt and alum sinks down and is called sedimentation.

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This next step  is called filtration and that will help to remove small particles of dirt. Place some gravel or small rocks in an empty berry basket that has holes on the bottom of it so that the water can come out. Slow pour the top water from your clear container that was treated with the cream of tartar. Have a tray underneath the berry container to collect the water.

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Now take out the gravel/rocks from the berry basket and put in a coffee filter. Pour the water that is in the tray into the coffee filter and have another tray underneath it to collect the water. The coffee filter will collect the tiniest particles of dirt.

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Your water looks clean but water in water filtration plants gets an extra cleaning to disinfect the water from germs we can’t see. We won’t do that at home but now we have a better understanding of how water from nature gets clean for us to use.

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Grown Ups-Are you looking for more ways to extend your child’s learning? Check out these extension activities to build upon today’s STREAM activity!

Reading Connections: 

The Magic School Bus at the Waterworks by Joanna Cole