1.Contamination of drinking water is a common way for pathogens to enter the body.
2. Gather information from your local water supply authority or the Internet to find out the ways in which water can be treated and the range of pathogens that are targeted.
NSW drinking water supplies NSW Environment Protection Authority
http://www.epa.nsw.gov.au/soe/soe2000/cw/
3. Process your information by recording a description of each water treatment method and by looking for trends and patterns in why they are used.
4. Information to get you started
Examples of water treatments are filtration, chlorination and ozone filtration. In NSW water is filtered, chlorine is added to kill bacteria and samples are tested for the presence of coliform bacteria, giardia and cryptosporidium.
5. Use questions as an effective processing technique to focus your attention when looking for trends in information sources. Some examples in this case might be “Which microbes are controlled by the treatment?”, “Which microbes are not controlled by the treatment?” and “What combination of treatments can be used to make a water supply safe for drinking?”
6. Use the evidence you have gathered to propose logical explanations of how each form of water treatment protects people from the target pathogens.
