Filter your water or not? | High Sierra Topix  

Filter your water or not?

If you've been searching for the best source of information and stimulating discussion related to Spring/Summer/Fall backpacking, hiking and camping in the Sierra Nevada...look no further!
User avatar

Re: Filter your water or not?

Postby oldranger » Thu Mar 26, 2009 7:32 pm

I think maverick has it right about the Kern. Besides best as I can tell from reading the map the JMT and PCT cross several tribs that feed into the Kern. Also despite our preference for moving water as I recall it giardia are slightly heavier than water so risk of picking it up is greater where it is churned up in a stream compared to a lake. George can confirm or deny that point but I am certain that he will not claim ignorance! Also as I recall in the eighties 2 backcountry rangers got giardiisis (or however you spell it). I never used a filter until I stopped being a ranger. Now I figure for 7 to 11 oz I can avoid the risk, which I admit is infinitesimal with any single cup of water but the more you drink the more the odds are to catch up with you. The other thing I seem to recall is that a percentage of the population are asymtomatic carriers and basically immune to the little critter. George, help me here!

Mike
Mike

Who can't do everything he used to and what he can do takes a hell of a lot longer!



User avatar
oldranger
Topix Junkie
 
Posts: 2164
Joined: Fri Jan 19, 2007 9:18 pm
Location: Bend, Oregon
Experience: N/A

User avatar

Re: Filter your water or not?

Postby rlown » Thu Mar 26, 2009 7:56 pm

i know that filters take giardia out of the water pumped. Does anyone know about filters effectiveness on e. Coli?

Russ
User avatar
rlown
Topix Junkie
 
Posts: 5325
Joined: Thu Oct 25, 2007 5:00 pm
Location: Petaluma and Wilton, CA
Experience: Level 4 Explorer

User avatar

Re: Filter your water or not?

Postby trav867 » Thu Mar 26, 2009 9:42 pm

You'd have to check the specific filter, but I believe that most filters are like 99.99% effective against all bacteria (e. coli incuded). In order to kill viruses however, you need a chemical like bleach or iodine. Boiling kills pretty much everything.
User avatar
trav867
Topix Regular
 
Posts: 166
Joined: Mon Nov 12, 2007 6:12 pm
Experience: N/A

User avatar

Re: Filter your water or not?

Postby gdurkee » Fri Mar 27, 2009 8:44 pm

OK. The Kern in Sequoia Park gets a lot of traffic -- both hikers and stock. The trail crew camps there for weeks with about 10 head. In addition, there's a fair amount of private stock traffic through there. It also gets a pretty good amount of hiker traffic from the Hot Springs up. That's one area I'd be kind of cautious about just drinking the water out of the main river. Odds are, it's OK, but the risk is somewhat higher than other water sources. Also, there are definitely beaver there. Not completely sure of the history, but I think they were introduced in the 30s. There's no eveidence that they're any greater source of giardia in that part of the Sierra than any other mammal, but they do live in the water so any cysts they do carry would go directly in.

There's an unpublished paper that finds that something like 7% of horses in Yosemite carry giardia. The same research team also measure the amount of, ummmm, feces they left per mile of travel and, from that, derived the number of giardia cysts they shed. Although only 7%, it's a huge amount of giardia potentially reaching the rivers and streams. It's a little suspicious it hasn't been published. But, I have the raw data and it's public domain because it was done in a National Park. As soon as Nature Notes comes back up (down for a remodel), I'm hoping to publish that as an article.

Mike's correct on asymptomatic carriers. I've read several percentages, but something like 20% of the population carry giardia but have no symptoms. I'm less sure of "safest" place to drink. Dr. Bob Derlet thinks the top 3" or so of a lake is best because of the UV light hitting that. In the great scheme of things, giardiasis is pretty rare in either Yosemite or Sequoia Kings. Definite cases, but only a few per season. Mostly, it's cows and not washing your hands after taking a crap (or, I suppose, cow tipping).

E. Coli itself is not the problem, usually, but is an indicator of other pathogens that could be there as a result of feces in the water.

g.
User avatar
gdurkee
Founding Member
 
Posts: 658
Joined: Tue Nov 08, 2005 8:20 pm
Experience: N/A

User avatar

Re: Filter your water or not?

Postby maverick » Sat Mar 28, 2009 10:51 am

GD thanks for the horse info, even more reason to be wary of routes where stock
travels!
User avatar
maverick
Forums Moderator
Forums Moderator
 
Posts: 8027
Joined: Thu Apr 06, 2006 5:54 pm
Experience: Level 4 Explorer

User avatar

Re: Filter your water or not?

Postby rlown » Mon Jul 06, 2009 1:37 pm

Thought i'd post this cross ref to Hetchy's PCT adventure. I've been following his postholer log, and he appears to be making great time against plan, despite his bout with Giardia. http://postholer.com/journal/viewJournal.php?sid=c72539ad72102b694ba6d1187ca2d0dd&event_id=414

I think he's carrying a filter and clorox, but he'll have to tell us more when he finishes/reports.
User avatar
rlown
Topix Junkie
 
Posts: 5325
Joined: Thu Oct 25, 2007 5:00 pm
Location: Petaluma and Wilton, CA
Experience: Level 4 Explorer

User avatar

Never

Postby gregw822 » Tue Jul 07, 2009 10:32 am

I've been a high Sierra backpacker for many years. I've never filtered my my water. I don't even carry a filter. I've never met anyone who picked up giardia in the Sierra. In fact, I've never known anyone who knows anyone else who has suffered from drinking the water in the Sierra. Rangers will tell you to filter the water, but I think that's just Forest Service policy to eliminate liability. :drinkers:
User avatar
gregw822
Topix Acquainted
 
Posts: 54
Joined: Wed May 06, 2009 3:46 pm
Location: Eugene, OR
Experience: N/A

User avatar

Re: Filter your water or not?

Postby ERIC » Tue Jul 07, 2009 10:58 am

maverick wrote:Here is a link to a previous discussion on the subject:
viewtopic.php?f=1&t=1968&p=12599&hilit=giardia#12599

Here is another link with a lot of info:
http://www.yosemite.org/naturenotes/Giardia.htm

And another:
http://www.highsierrahikers.org/Derlet- ... n-2006.pdf


Other previous discussions:

viewtopic.php?f=9&t=113

viewtopic.php?f=15&t=3092

http://sierrapacktrip.proboards.com/ind ... thread=483
New members, please consider giving us an intro!
Follow us on Twitter @HighSierraTopix. Use hashtags #SIERRAPHILE #GotSierra? #GotMountains?
Follow us on Facebook: https://www.facebook.com/HighSierraTopix
User avatar
ERIC
Your Humble Host & Forums Administrator
Your Humble Host & Forums Administrator
 
Posts: 2909
Joined: Fri Oct 28, 2005 9:13 am
Location: between the 916 and 661
Experience: Level 4 Explorer

User avatar

Re: Filter your water or not?

Postby rlown » Tue Jul 07, 2009 3:59 pm

ok.. i was just crossposting Hetchy's experience. nothing more. If you don't filter, i'm not judging. Personally, i filter all my drinking water. For cooking uses, it's boiled. thanks for the backpost references though, Eric.
User avatar
rlown
Topix Junkie
 
Posts: 5325
Joined: Thu Oct 25, 2007 5:00 pm
Location: Petaluma and Wilton, CA
Experience: Level 4 Explorer

User avatar

Re: Filter your water or not?

Postby ERIC » Tue Jul 07, 2009 4:23 pm

rlown wrote:ok.. i was just crossposting Hetchy's experience. nothing more.


Ya..I know.

rlown wrote:thanks for the backpost references though, Eric.


You're welcome.
New members, please consider giving us an intro!
Follow us on Twitter @HighSierraTopix. Use hashtags #SIERRAPHILE #GotSierra? #GotMountains?
Follow us on Facebook: https://www.facebook.com/HighSierraTopix
User avatar
ERIC
Your Humble Host & Forums Administrator
Your Humble Host & Forums Administrator
 
Posts: 2909
Joined: Fri Oct 28, 2005 9:13 am
Location: between the 916 and 661
Experience: Level 4 Explorer

User avatar

Re: Filter your water or not?

Postby rrivera » Thu Jul 09, 2009 10:17 pm

how timely I just had someone ask me about this today...it depends for me...I've been lucky no unfortunate situations to date probably thx to Purell more than anything but if I am going to be in a heavily trafficed area like some areas in Yosemite or Emigrant I pump...otherwise I don't worry about it.
User avatar
rrivera
Topix Acquainted
 
Posts: 62
Joined: Sat Aug 19, 2006 9:54 am
Experience: N/A

User avatar

Re: Filter your water or not?

Postby AlmostThere » Sat Nov 21, 2009 8:32 am

I've talked to a lot of folks (also posted on a lot of forums) and always filter.

The sort of trouble you get from not washing hands is very distinguishable from crypto or giardia. People who get sick are lazy hand washers, most of the time. The authenticated diagnosed cases of giardia I've heard about were treated (sometimes for weeks, not happy people) and the one case of crypto I've heard of was worse than giardia.... You "I've been drinkin' it straight for 40 years" folks can brag forever, but you know, Murphy's Law dogs me everywhere. I'm the hiker who loses gear, trips, drops stuff, etc. If there's road work I'll get stuck in it, if the ranger's pulling people over, he gets me. Not gotten lost yet (knock wood) and not gotten anything but transient tummy upsets.... But pushing my luck anywhere without a filter? Not on your sweet mother-lovin' life. Especially not in Yosemite where people are doing nasty @#%# in the rivers and streams. Not going to be a "I've been drinking it without filtering for 50 years UNTIL I GOT SICK" type of person.
User avatar
AlmostThere
Topix Fanatic
 
Posts: 1758
Joined: Wed Jun 24, 2009 4:38 pm
Experience: N/A

PreviousNext

Return to Backpacking / Hiking / Camping



Who is online

Users browsing this forum: Google Adsense [Bot], MSNbot Media [Bot], Yahoo [Bot] and 1 guest