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</o:shapelayout></xml><![endif]--></head><body lang=EN-CA link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'>Dear Friends<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'>Keeping water in the total dark for 3 days kills quite a lot of things including Bilharzia. When I worked in Rural Water Supply in Swaziland we provided covered tanks with more than 3 days storage on most systems for this reason (in the lowveld). We also used dosing boreholes with chlorination occasionally (always when new) and precautionary chlorination using bypass jets on pumped systems to get a 2 ppm level at the last standpipe. No one boiled water to purify it in those days. <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'>In contrast, nearly everyone in peri-urban and rural Indonesia boils their drinking water. Completely different situation, for which stoves are required.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'>Regards<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'>Crispin<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><div><div><p class=MsoNormal style='background:white'><span style='font-family:"Tahoma","sans-serif";color:black'>Jeff-<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-family:"Tahoma","sans-serif";color:black'>Thanks for the post. Yes, it's true that pasteurization at 65C kills all pathogenic bacteria and viruses, as well as worms and cysts. I don't recommend "feeling it with your hand" however as even a 10 degree lower temperature will have a much lower effectiveness. As you note, a wax indicator developed by Dr. Robert Metcalf accurately and safely demonstrates when the water is pathogen free. We distribute them at no cost to families and instruct them on their use. Filtration through a clean cloth probably helps a little, as does letting the water settle, but is not necessary for pasteurization. Some methods that use solar UV disinfection do require clean water and clear PET water bottles for effectiveness. They also take longer, lack an end point and have inconsistent results and for that reason we don't recommend them.<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-family:"Tahoma","sans-serif";color:black'>The last step is keeping safe water safe, by storing it in clean containers with small openings so that people cannot recontaminate it by dipping in with dirty containers or hands.<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-family:"Tahoma","sans-serif";color:black'>I'm going to give a water testing and water pasteurization workshop here in Portland in the next months if anyone is interested in being trained.<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-family:"Tahoma","sans-serif";color:black'>Tom Carter<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-family:"Tahoma","sans-serif";color:black'><a href="http://us-mg4.mail.yahoo.com/neo/aguapuraparaelpueblo.org">Agua Pura Para El Pueblo</a><o:p></o:p></span></p></div></div></div></body></html>