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Re: Filter your water or not?

Posted: Tue Mar 24, 2009 10:42 pm
by gary c.
Mike McGuire wrote:Where abouts on the Kern did you see them? Are you sure it wasn't an otter or muskrat?

Mike
It was a beaver for sure. I had spooked him from the bank right next to me and he swam out into the current and he couldn't make any progress upstream because of the strong flow. Just as I was getting my camera on him he submerged and was then able to gain some distance before surfacing. Thats why he is so far away in the picture. We had backpacked into the special regs section above the Johnsondale bridge. He was just shy of the end of the river trail.

There are actually quite a few along the upper Kern. I see one about once a year and read regular reports of others seeing them on the Kern FF forum. One place that I know did have a resident beaver was right behind McNalleys along the river. I've seen it a couple times and have friends that have also seen him there.
Gary C.

Re: Filter your water or not?

Posted: Wed Mar 25, 2009 7:17 pm
by rlown
For those that have seen beavers in areas you are backpacking, do you filter or treat because they are in the area, and their alleged link to Giardia or "beaver fever?"

Re: Filter your water or not?

Posted: Wed Mar 25, 2009 7:58 pm
by Mike McGuire
maverick wrote:There is way to much traffic along the Kern River even if there were no beavers
to even consider it a safe water source.
I don't think so. Last summer, middle of August, walking from the headwaters down to Golden Trout Creek over a four day period, saw a total of 6 people.

Mike

Re: Filter your water or not?

Posted: Thu Mar 26, 2009 12:16 pm
by maverick
Hi Mike

Just because there was not a lot a people using using this corridor at the same
time that you were does not mean it is not a high usage route.
Because of the High Sierra Trail, Kern Hot Springs, and the entrance into SEKI
from Soda Springs makes this a high usage area by man and beast.
I have seen numerous backpacking groups(scouts), and pack animals coming thru
the area at same time.
In the 3 main backpacked months this area gets plenty of use, you were just lucky.
By the way do live near the Priory, I work there.

Re: Filter your water or not?

Posted: Thu Mar 26, 2009 1:52 pm
by Mike McGuire
maverick wrote:Hi Mike

Just because there was not a lot a people using using this corridor at the same
time that you were does not mean it is not a high usage route.
Still don't think so--high usage compared to what? There just weren't the hard used campsites, the microtrash that shouldn't be left but is, the copious quantities of horseshit, all signs of high usage that just weren't there. That area is one of the most remote in the Sierra. For most people it's at least two days from any trailhead.

Mike

Re: Filter your water or not?

Posted: Thu Mar 26, 2009 3:45 pm
by maverick
Granted it does not get the same usage as the JMT, but it still has the HST which
gets its fair share of backpackers hiking to Whitney from Crescent or to Kern Hot Springs.
We are talking about cutting the risk of getting Giardia here, right?
I have seen dung near the river, and have seen people wash off in the river.
I'll use a tributary stream or creek, which has no human or pack animal traffic above it
or around it, than use the Kern as a source of untreated water.

Re: Filter your water or not?

Posted: Thu Mar 26, 2009 7:32 pm
by oldranger
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

Re: Filter your water or not?

Posted: Thu Mar 26, 2009 7:56 pm
by rlown
i know that filters take giardia out of the water pumped. Does anyone know about filters effectiveness on e. Coli?

Russ

Re: Filter your water or not?

Posted: Thu Mar 26, 2009 9:42 pm
by trav867
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.

Re: Filter your water or not?

Posted: Fri Mar 27, 2009 8:44 pm
by gdurkee
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.