Friday, February 20, 2009

Water Treatment on the PCT

As a rule, most American backpackers filter or otherwise purify all their water in the backcountry. The ones who are least likely to treat water are... ultralight thru-hikers. In Colorado we met plenty of short-distance backpackers (even those on the Colorado Trail) who seemed paranoid about getting ill from untreated water, even if it was flowing directly from a snowbank. "I don't know... Look at all the pink algae growing on the snow... I'd rather play it safe," someone actually told us. Then we'd meet some experienced thru-hiker who said he never treated any water on the CDT and had never gotten sick. Hm...

Read this article for a better understanding of the prevalence of much-feared Giardia in the Sierra Nevada. Basically, in two words, Giardia is uncommon, and you're more likely to get intestinal problems from poor hygiene or meals in restaurants in town. 

On the PCT, I will be using the same treatment strategy I used on the CDT, namely:

  • Drink from the best water sources possible: snowmelt trickles/streams, springs, and small streams coming out of ungrazed areas. Get water from larger streams when necessary.
  • Treat only water that is not flowing rapidly or water from areas that might have been grazed (i.e. has been exposed to cow dung). I will use Aquamira tablets and drops.
Following this strategy, I hope to treat no more than 5-10% of the water I drink on the PCT.


  1. Obviously, you have not gotten to experience the joy of water born illness. I drank from a stream above 10,000 ft north of Tennessee Pass on the Colorado Trail and became the sickest I have ever experienced.

  2. I don't know for sure, but I'd guess that was a cattle-grazing area. There's a lot more of that on the CDT than the PCT.

    That said, some people just seem more susceptible to bad water.