Make your own catchment
Burying rubbish may remove it from sight, but pollution can still leak from it into the catchment by flowing through the ground. To see how burying rubbish can pollute the water, you'll need:
- a 2-litre PET bottle
- a knife
- a coffee filter bag
- sand
- paint
- a paper towel
- water.
Cut the 2-litre PET bottle in half. Pour about ¼ litre of water into the bottom half of the bottle to represent a clean reservoir. Turn the top half of the bottle upside down and place it in the bottom half, with the coffee filter bag sitting inside.
Next, put about two handfuls of sand in the filter. Squirt some paint on the paper towel -- this will be your rubbish. Put the rubbish on the sand, then bury it using more sand.
Finally, make it 'rain' by pouring water over the sand. Watch what happens to the water in the bottom of the bottle. You probably wouldn't want to drink water that looks like that!
Can you think of ways to clean the water to make it drinkable? How could you avoid pollution seeping through the ground or flowing along streams into a reservoir in the first place? Which is easiest?
