Although Canada has a large amount of fresh water, there is a myth about the quality of the water. You should never drink water from Canadian fresh-water lakes and streams - even in the high mountains!
Giardia lambia and crypto sporidium are water-born parasites that cause intestinal disease. Tiny cysts are produced in the intestinal tract. They pass into the environment via the feces of infected animals or humans and transferred to humans by fingers or contaminated food.
Water must be treated to kill the cysts before it is safe to drink. One method is to boil water at least one minute; 10 minutes is better. Certain filters that can filter 1 micrometre particles will remove the cysts. Chlorine and ultraviolet light will kill most bacteria and mold but will NOT kill these organisms.
For more information, contact your provincial environment ministry or call 1-800-567-9707.