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Re: water filters

PostPosted: Tue Jul 02, 2013 5:45 pm
by hightinerary
I'll comment just to increase the sample size, and to remind people that the original post is about the Sierra Nevada. I don't filter in the Sierra Nevada, but I stick to sources generally above about 10,000 feet and where I am confident it is unadulterated snowmelt.

Re: water filters

PostPosted: Tue Jul 02, 2013 9:14 pm
by tomd
Has anyone used these cheap filter bags ?
The idea is that giardia and other cysts are 4-6 microns and these filter membranes are .5 microns. They don't do anything for bacteria, but that is usually not a concern for the Sierras unless you are in a livestock area or are starting with nasty water. A lot of folks, including a UC Davis professor who has tested water all over the Sierras for the last 20 years, drink Sierra water completely untreated and just make sure they are smart about where they get it from (e.g. run off from high, untrafficked basins). I had a "dirty" cutoff plastic water bottle I used for scooping and poured thru the filter into my platypus or nalgene. I got water from lakes and streams..
http://www.dudadiesel.com/choose_item.php?id=PTFEP3S

Re: water filters

PostPosted: Tue Jul 02, 2013 9:58 pm
by ExcitableBoy
When I did my research into Giardia spp and Cryptosporidum parvum I was also investigating possible surrogates as collecting and analyzing the protozoans from surface waters is expensive and time consuming so I analyzed fecal coliform bacteria to see if there was a correlation between bacteria and protozoa concentrations. There was not, however, if protozoa were present then fecal coliform bacteria was typically extremely high, in the hundreds of thousands CFU/100 ml. I have since come to believe that one is more likely to contract a bacteria illness than a protozoan.

Re: water filters

PostPosted: Sun Jul 07, 2013 8:38 pm
by Sierra Ledge Rat
I have been filtering my water for 30+ years and have never been sick from any water

Re: water filters

PostPosted: Mon Jul 08, 2013 2:58 pm
by simonov
peninsula wrote:Here we go again, the big debate about water safety in the wilderness.


Ackshully, this thread was resurrected by a spambot, with the post above yours.

Re: water filters

PostPosted: Mon Jul 15, 2013 8:10 am
by cybordolphin
I live at the very base of the Eastern Sierra. I will always filter my water after a hike last week.... whereby upon closer look into a pool..... I saw a knot the size of a baseball.... looking like thin grass in a ball. Well..... after further investigation.... this was a ball of tape worms. They came to life and I was sickened by the sight. Tiny thin threadlike worms in 2 foot strings that started swimming like sea snakes. Further I found leaches that swam to the surface trying to attack my shade created by my hand. The leaches had sharp teeth and swam across the surface face up. Granted this was slow moving water.... I am certain the eggs make their way up and down stream from spots like this. I now believe our water supply has become contaminated by all the livestock that is allowed up into our Sierras. I am happy to return to take photos for anyone interested. It was a nightmare to behold. I will NEVER chance drinking from our streams here without filtration.

That being said.... I have read that the SteriPENs does NOT work against tapeworm? Is that true?

Anyone want to recommend the MSR over the Katadyn or vice versa with the latest 2013 models that are out?

This quote is right on from what I have found. "Now, after 10 years of fieldwork and 4,500 miles of backpacking, Derlet knows for sure. What he has learned, after analyzing hundreds of samples dipped from backcountry lakes and streams, is that parts of the high Sierra are not nearly as pristine as they look. Nowhere is the water dirtier, he discovered, than on U.S. Forest Service land, including wilderness areas, where beef cattle and commercial pack stock — horses and mules — graze during the summer. There, bacterial contamination was easily high enough to sicken hikers with Giardia, E. coli and other diseases."

Oh and in case you all did not know.... the cattle are allowed to graze ALL over the Sierra's. And now I would join a fight to ban that..... without hesitation.

Thanks

Re: water filters

PostPosted: Mon Jul 15, 2013 11:06 am
by mrchad9
How about you go to Tuolumne Meadows and take a picture of some cattle grazing there.

You know... since they are ALL over the Sierra.

Re: water filters

PostPosted: Sun Jul 28, 2013 12:50 am
by JackYoung
A recent 5 yr UCD study concluded that there was little if any water problems in the Sierra and that almost all reported incidents where caused by fecal > oral transmission. In other word, your better off with a good finger nail brush than a water filter.

Re: water filters

PostPosted: Sun Jul 28, 2013 11:50 am
by Roger
I am curious, how many of our American trekking/climbing colleagues drink bottled water on a regular basis at home and out and about?

Re: water filters

PostPosted: Mon Jul 29, 2013 5:48 pm
by SpazzyMcgee
JackYoung wrote:A recent 5 yr UCD study concluded that there was little if any water problems in the Sierra and that almost all reported incidents where caused by fecal > oral transmission. In other word, your better off with a good finger nail brush than a water filter.


Link?

Re: water filters

PostPosted: Thu Aug 08, 2013 4:17 pm
by AceSierra
All I know is I was quite glad to have my filter after climbing University Peak this past weekend. Had zero water by the time we reached the unnamed lake below the peak on the north face route. The lake was filled with these weird looking small red bugs, and there was no way to refill without filtering (unless I wanted to find out what these things may do in my guts). Perhaps they were harmless, but it made me feel much better not taking the water raw. Probably the first time I was glad to be able to filter my drinking water, aside from the pond at Trail Camp.

Re: water filters

PostPosted: Thu Aug 08, 2013 4:25 pm
by anita
I drank unfiltered water from that tarn above bench lake and I'm still alive... for now!