[pct-l] Sierra Water

[Vic Hanson]

Thanks for the link, Eric. I think I had read it before but had forgotten where. On the subject of water purification, the standard line used to be that you had to boil water for 5 (or 10)minutes. I have read that all you really need to do is bring it to a boil and that kills all of the baddies. I live at 8800 ft. and often hike and camp up to 15,000 to 16,000 feet so obviously the water here boils at lower than 212 deg. F. 
 
According to About.com:
 
"While at sea level the boiling point of water is 212° Fahrenheit, for ever 500-foot increase in elevation, the boiling point drops one degree. Thus, at a city 5000 feet above sea level, water boils at 202°F."

So water boils here at 194.5 deg. F and at 15,000' it boils at 182 deg. Because of all the animals everywhere here (there were cattle feeding on the algae in a lake at 15,000' where I was last week) I normally use Aquamira for all water unless it is from a spring. But I don't usually treat water that I use for soup, tea or oatmeal, I just boil it. I have been wondering if I need to boil it for a period of time but usually I don't, just a good rolling boil. 
 
I have been experimenting with solar cookers and found this in Solar Cookers International's material. (www.solarcookers.org)
 
Disease-causing organisms in water are killed by exposure to heat in a process called pasteurization. Water that has been heated to 65ºC (149ºF) for a short period of time is free from microbes including Escherichia coli, Rotaviruses, Giardia and the Hepatitis A virus. At around 71ºC (160ºF), milk and food are pasteurized. Boiling is not required. 





Microbe

Killed rapidly at


Worms, Protozoa cysts (Giardia, Cryptosporidium, Entamoeba)

55°C (131°F)


Bacteria (V. cholerae, E. coli, Shigella, Salmonella typhi), Rotavirus

60°C (140°F)


Hepatitis A virus

65°C (149°F)
 
I don't know where they got this information but they work in 3rd world countries and promote using solar cookers to purify water. They also don't specify how long "rapidly" is.
 
FWIW  (For What Its Worth)
 
Sugar Daddy
 
PS  If anyone is interested in seeing the solar cookers I've made, email me.
>

This is not the original source, I don't think, but it's a newspaper
article about the guy who wrote it and it contains the statement about the top
few inches of lake water being among the safest sources.

http://travel.latimes.com/articles/la-os-giardia26jul26?single_page=y&print=y

Eric


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End of Pct-l Digest, Vol 9, Issue 54
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