Here's some information concerning Boiling Water to make it safe for drinking.
Minutes and Temperatures (Below Elevation)
* 30 minutes at 160° F
* 3 minutes at 185° F
* Instant at 212° F
Boiled water will not remove chemical toxins that may be present.
Very dirty water should be filtered first with a cloth or other material to remove sediments, and/or let stand for awhile to allow sediments to settle – then pour off clearer water on top.
Keep in mind that boiling temperature decreases with altitude at roughly one degree per 500 feet. So on top of Mount Washington (6,288 feet), the boiling temperature will be almost exactly 200 degrees F. If you're traveling to high country outside of the Northeast, boiling temps can be as low as 195 degrees F (9,000 feet) or 190 degrees F (12,000 feet).