1. How successful was your filtration apparatus in changing the physical appearance of your water sample, removing waste particulates, as well as waste chemical compounds?

2. How is the water beneath the surface of the earth purified naturally? How is your filtering apparatus similar to the filtration process water undergoes in nature?

3. What would be most effective in purifying polluted water, an aquifer composed of fine sand, coarse sand or gravel?

4. List three possible sources of water pollution in your area.

5. List three things that you or your community could do to improve water quality.