cool stuff thanks for that always rolling boiled for 3 mins so will save me a lot of chopping wood time
One thing i have found with boiling water is to BLAST it with flames by which i mean get the flames lapping up the side the billy/tatonka or what ever you use. The reason i say this is many times i have tried to get it going nice and steady and you can be there for ever so get the gas mark upto 6 quicker and your brew will be there a lot quicker also
Props to that. My wilderness first aid instructor told me that the reason people are told "5 minutes" or whatever is because some people think that when the bubbles form on the bottom, the water has boiled! Gotta inform to the lowest common denominator, I suppose.
Technically you only need to get it to 75 degreesC for 10 seconds. You've then killed all the things that can be killed without resorting to pressure cooking. Some nasties can form spores that only die in excess of 120 degreesC. As most folks don't take a thermometer with them bringing your water to a good rolling boil is a good visual indicator. Boiling for three or four minutes is a waste of fuel and water.
And as the guy called John states at the bottom of the link, boiling water will only kill germs and bacteria, it will not neutralise chemicals and metals in the water but will in fact concentrate them as water is lost as vapour. Take your water initially from the cleanest source possible, even if it means a two mile walk. You may save yourself a chronic illness.
IMHO your only guide to chemical content is your location, upstream intensive farming or industry etc. Barring serious pollution, provided you're not drinking from the same slightly tainted source on a regular basis you'll be ok. It's the build up of these sorts of toxins in you system over time that can be the problem. Someone correct me if they know better, I'm no expert.