Re: Why Rockwell is Wrong about Giardia
Posted: Fri Feb 22, 2013 7:37 am
Dave 54, if you could find the reference to that study I would be interested in looking it up. Another logical factor in the seasonality of concentrations is the exposure to more people/ livestock and animals after the snow melts combined with less flushing.
I freely admit that I don't get on to this site very often so let me introduce myself. My name should be obvious (Chris) and my background is in geology, ground water hydrology, and groundwater geochemistry. Basically I spent 9 years working contaminated sites with some ground water resource work thrown in off and on. I have been rambling in the Sierra Nevada for 45 years and was taught by my dad how to pick water for drinking. Around 1985 I started treating water when I went up with newbies. What I do now depends upon what I am doing and where I am going. Never been sick...so I guess I am one of those who are immune???
I've spent a little time looking at Coulter's postings at other forums and sites. He's been at this for at least 2 years now and it does seem like he is mostly interested in understanding the problem. The information on this topic has not been summarized well (to my knowledge at least) and there seems to be a distinct lack of data on the topic. I will try to go through what I can again as its been awhile and see if anything new can said; It will take a while, I mean there are 4 threads just on this site alone and a LOT of second and third hand info. I'll at least PM Coulter as I do have some problems with some of his conclusions as written. About Rockwell? well I need to re read the thing but he was somewhat clueless about the surface layer of the lake being safe. In a totally stagnant lake the UV light may be enough to kill what's there, but wind (common in the Sierra) causes upwelling and turnover is common in most if not all lakes as soon as the ice melts.
Bottom line though, each person needs to assess risk for themselves in all things in the backcountry, not just in the Sierra which is one of the "safest" ranges out there. I know what I need to do when I am out there for water and that is what matters. If I'm worried about somebody else, I treat. Simple.
I freely admit that I don't get on to this site very often so let me introduce myself. My name should be obvious (Chris) and my background is in geology, ground water hydrology, and groundwater geochemistry. Basically I spent 9 years working contaminated sites with some ground water resource work thrown in off and on. I have been rambling in the Sierra Nevada for 45 years and was taught by my dad how to pick water for drinking. Around 1985 I started treating water when I went up with newbies. What I do now depends upon what I am doing and where I am going. Never been sick...so I guess I am one of those who are immune???
I've spent a little time looking at Coulter's postings at other forums and sites. He's been at this for at least 2 years now and it does seem like he is mostly interested in understanding the problem. The information on this topic has not been summarized well (to my knowledge at least) and there seems to be a distinct lack of data on the topic. I will try to go through what I can again as its been awhile and see if anything new can said; It will take a while, I mean there are 4 threads just on this site alone and a LOT of second and third hand info. I'll at least PM Coulter as I do have some problems with some of his conclusions as written. About Rockwell? well I need to re read the thing but he was somewhat clueless about the surface layer of the lake being safe. In a totally stagnant lake the UV light may be enough to kill what's there, but wind (common in the Sierra) causes upwelling and turnover is common in most if not all lakes as soon as the ice melts.
Bottom line though, each person needs to assess risk for themselves in all things in the backcountry, not just in the Sierra which is one of the "safest" ranges out there. I know what I need to do when I am out there for water and that is what matters. If I'm worried about somebody else, I treat. Simple.