It certainly takes more trip pre-planning but I tend to go with > empty water containers now (other than enroute requirements plus > reserve) and a water purifier. Specifically a PUR Explorer, with the > screw on carbon element, and the carbon stop-top. The convenience of > virus/bacteria/cyst free water with reasonable taste via a filter > extends useful load for such things that can't be manufactured on the > spot, such as fuel (well at least in the absence of a cold-fusion > solution). I use the Pur and I would like to second the virus warning. On our 94 Grand Canyon trips half the party became sick from the Norwalk virus. When we got off the river we found out there was an epidemic of it on the river. The Park Service recomended chemical treatment as well as filtering for the water due to the Norwalk virus. On subsequent trips we used a high capcity gravity filter ( for 16 people you need a lot of water) and treated the filtered water with iodine. We called the Center for Disease Control for their recommendations. Since we use excellent filters for giardia and amoeba, we only needed to kill viruses. The CDC said that it takes about 1/10 the amount of iodine to kill viruses. We were conservative and took 1/4 of the usual iodine amount (to kill giardia) to complete the purification of our water. If you use one of the Pur, Sweet Water or other filters with iodine resin or virus protection it is not an issue. When members of our party contracted the Norwalk virus they were violently sick and completely incapable of rowing or paddling. Fortunately we had enough back up rowers because much of it happened in the inner Gorge of the Canyon , which is where the biggest rapids are. There was another outbreak of Norwalk virus in the Grand Canyon this past summer. http://www.sltrib.com/2002/jun/06182002/utah/746372.htm Note the recomendation for disinfection. Other reports said the virus was chlorine resistant. http://www.sltrib.com/2002/oct/10312002/utah/12207.htm We are much more careful since that first Grand Canyon trip. Pay attention to your water sources and don't rely on filtering alone you need disinfection as well (which you can get from some filters). Believe it! Amazing how these threads morph! -- MZ *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
> If you use one of the Pur, Sweet Water or other > filters with iodine resin or virus protection it is not an issue. And so I've always thought. The EPA seems to be making a ruckus in recent years though. The total history has been difficult for me to piece together though as the info generally seems to come watered down, second hand through dealers, and the EPA databases are vague and non-specific. I recall many years ago when choosing a filter, being swayed to the PUR as it was the only one whose display included a hefty binder of included test results backing up the purifier claims. You can still find remnants of that info on site blurbs such as: http://www.ogo.com/outdoorsman/pur1.htm More often the dealer info typically contains references to "EPA REGISTERED AND MEETS (some say exceeds) THE EPA MICROBIOLOGICAL PURIFIER TEST STANDARD. But things started to change. The first I heard of issues a couple years ago when I was buying replacement filters. The dealers were misreporting some issue with the Stop-top accessory. They said there was a recall on just the stop-tops. Some issue with the carbon they said which could allow bacteria to grow. They further suggested that I could keep using my stop-top, but that I should just replace the carbon from a third party source. Puzzling, but carbon is so cheap and it was due for replaceing anyway, I didn't give it further thought. Seemingly a press with both similar and different facts vaguely along these lines is reported near the bottom of this link for the date of June 16 2000: http://131.104.232.9/fsnet/2000/6-2000/fs-06-17-00-01.txt Later I noticed fewer dealers stocking the PUR filters, reduced prices, reduced availability of replacement filters, etc. And the PUR website stopped mentioning the outdoor filters. I later discovered Katadyn had scooped up the PUR line. And Sweetwater had also had pulled their purifier equivalent from their line, and a browse to the purifier section under the PUR banner gives only: http://www.katadyn.com/outdoor/pur/our_products/Purifiers.asp And their FAQ gives a note to the change of hands, and more info on the issue: http://www.katadyn.com/outdoor/pur/faq/default.asp#available Further, dealers, in addition to "out-of-stock" notices started adding blurbs such as, "IMPORTANT NOTICE: All PUR portable units EXCEPT THE HIKER are experiencing a delay due to reevaluation of the carbon StopTop. The StopTop, sold with all the purifiers below, was revealed to interfere with the main purifier's ability to fully eliminate viruses in outdoor (untreated) water. Normally it acts as a water bottle adapter and reduces the water's iodine content from treated water for improved taste. This issue does not affect the ability to remove cysts or bacteria. If you already own a PUR, you can still use it. It is advised to remove the StopTop and follow use directions for "How to Handle Difficult or Extreme Water Conditions" located in the use and care manual." You also see a bit of mis-information in Q&A's like this: http://web.outsideonline.com/gear/gearguy/200106/20010629.html Obviously the EPA *used* to believe they worked just fine. We have reams of test data. And the filters have been registered with the EPA as level 1 purifiers for years. So what happened? There and notices from the EPA in 2000 about new water quality rules, the EPA taking a world wide leadership role... etc, etc. I won't contrive to connect dots, but it would seem there's some redifining going on, perhaps in response to bad press over water issues in the news that have been horrifying people on both sides of the media reports. Essentially it seems to boil down (sorry for the pun) to the following. The theory was always that water was filtered down to 0.3 microns for the purposes of cysts, and most bacteria. By happy happen-stance most viruses are glommed onto larger molecular groups such that you end up shedding most of those with the filtration as well. For everything smaller, there's the iodine resin layer to kill what remains. Then it's on to the carbon stage to remove pestisides, chemicals, "flavors", etc. Iodine is quite useful as an anti-viral stage in quite small levels, but it also affects taste. Moreover while it's fine to consume over short periods, the added benefit of the carbon layer was to remove a good portion of the iodine at the end of the filteration cycle because the other issue is that continuous increased iodine levels over multiple months (if one was using the filter on a long excursion) is not great for such organs as the thyriod etc. Hence the other benefit of limiting iodine level in the final stage. The temporary recomendations were to: "In the meantime, consumers who already own PUR camping purifiers can still use them. In order to ensure full anti-virus efficacy, we advise you to remove the StopTop and follow use instructions for "How To Handle Difficult or Extreme Water Conditions" located in your Use and Care Manual. Briefly, the process involves the following four steps: 1. Disconnect the StopTop carbon filter and pump water into a temporary container at a rate of less than 10 strokes per minute. 2. Remove the inlet hose from the water source and pump the purifier until air comes out of the output hose. 3. Place the inlet hose into the temporary container and pump water into your water bottle or canteen at a rate of less than 10 strokes/minute. 4. Let the water stand for 20-minutes before consumption." Doesn't sound like any "irregular" batches of carbon, rather it sounds as though you're simply iodine loading the water and letting it stand to accomplish the AV work (and living with all the stuff in the water that the carbon would have removed). Seems they also forgot about the carbon accessory the screws onto the bottom of the device between the filter and the hoses (which I have installed for a double carbon scrub). There's been no mention of that, and removing it as well. I guess I would have thought it much less hassle to collect your water, treat it with liquid iodine for the required time, then filter it with the PUR (carbon layers in place). But it's a little tough to know when you're left without details. And after all that you're left wondering if these hoops all because the EPA is after that last 0.001%. Or what the deal is. All I know, is I've been sick from unfiltered water, and never again since using my PUR (well, that is unless I look back at the unfiltered source of the water I just consumed, but that's just a mental thing ;-) When all else fails, there's still one name in the purifier market happily gloating: http://www.generalecology.com/EPA%20Microbiological%20Std.html And the hope for the mythical new purifier replacement filter from Katadyn for current PUR filters. But it's been a year and a half since they took over... *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
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