You are hiking in an unfamiliar area and are running low on water. You find a meandering stream of water.
You put some sand and charcoal in a sock and allow the river water to seep through the sock — to remove the impurities.
Is it safe to drink now?
No. It must be boiled — or chemically treated.
How long should it boil before you know the water is safe to drink?
Suspect water must be boiled or chemically treated.
The rule of thumb is:
Boil water for 1 minute plus 1 minute for each 1000 feet over sea level.
Thus, if you are 2000 ft. above sea level, you must boil the water for a total of 3 minutes: 1 minute for sea level and 1 minute for each 1000 ft. above sea level!
This is the absolute minimum.
If you have the fuel, boil longer.
This blog is a companion to my website: GreatGhilliesAndGraphics.com
More than 1050 Rear Window Graphics in 28 Categories!