Does placing contaminated water into clear plastic bottles and exposing the water to the sun (not inside a solar cooker) actually make it safe to drink? There is a technology called SODIS being promoted around the world for this purpose. There is some doubt about whether this really makes the water safe to drink. A good science project would be to test this by using toilet water and measuring using the Colilert System.
If you do the research, they will post your results.
