Experiments give students insight into water contamination Caleb Bong, Year 6, Dimbulah P-10 State School
PETER Harrison, a geologist from the Northern Gulf Resource Management Group, came to Dimbulah P-10 State School to tell us about clay in the soil and salt in the water.
He told us about the hydrological cycle (water cycle) and how the water drops are held up by the wind after it evaporates but when they get too heavy they fall as rain.
He also told us how the rain soaks into the ground and plants use it to live.
We did an experiment to see if water will flow faster through gravel, sand, gravel and sand mix, or through soil.
We all predicted that the gravel would be the fastest, gravel and sand would be the second fastest, sand would be third and water would flow through the soil slowest.
But the sand-gravel mix and sand flowed through at the same speed. Peter explained that it was because the mix had the same amount of sand but it looks to be less because it fell in between the gravel pieces. So the water flowed at the same speed as the sand.
We did a second experiment to see how salt in the water impacts the clay in the soil.
When we used normal tap water the clay was like putty but when we used salt water, the clay became very runny.
He showed us what it looked like when these clays are dry. Saltwater clay was like powder when you touched it, but the healthy clay was hard.
Our third experiment involved comparing how water moves through dirt, mulch, and mulch with grass. We poured water through to see which water would come out the cleanest.
Of course, the dirt made the water the dirtiest. We explained that the dirt was dragged with the water because it had nothing to hold on to.
The mulch made the water the second dirtiest. We explained it the same way but not as much got dragged with the water. Finally, the grass with mulch made the water the least dirty because the mulch could get stuck on the grass and not get dragged through into the waterways.
We did a final experiment with water and food colouring where we simulated an irrigation system and showed what would happen if a bad chemical was spilt.
This experiment showed us how a chemical spill would spread and contaminate water a long way from the spill site.