Friday, January 11, 2013

Lessons Learned - Water Treatment

When I started thinking seriously about long distance hiking, one area that concerned me was how best to keep myself hydrated - Collecting, filtering, treating and carrying it, how much to carry, and other questions I didn't know to ask. I had an MSR Sweetwater Microfilter, Nalgene bottles, a Camelback bladder system, a folding bucket - It all added up to a lot of weight ...

I delved into the resources of the intertubes to see what people were packing, and spent way too much time on Backpackinglight and WhiteBlaze. I found the Ultralighter, gram-weenies lurking therein to be invaluable resources.

To a person, they advocated leaving the filter behind, and using Aquamira drops as a 3 oz solution to the issue of treatment ... (More after the jump ...)

That they didn't have to rely on a mechanical system prone to breaking down, clogging, freezing and cracking was a bonus. Detractors complained of taste, concerns over ingesting chemicals, bespoiling wonderful tasting mountain spring water, having to mix the two parts, then wait for them to activate, then having to wait for the water to be treated.

All good points. Still, 3 ozs vs 11 ...

What are these chemicals I'd be ingesting daily? Per Aquamira, the active ingredient is Chlorine dioxide, which has been used by municipal water treatment plants to kill waterborne pathogens since the late 1940s. It's iodine and chlorine free, and works by releasing "nascent oxygen" which is a strong oxidant and a powerful germicidal agent. Ok, I can live with that.

As to questions of efficacy, you can read this report. I'm satisfied.

Then there's that process with all the wait times. Aquamira's process goes like this:


  • Add 7 drops each of parts A & B in the provided mixing cap,
  • Let mixture react for 5 minutes to ensure full activation,
  • Fill your container with 1L of water and add contents of mixing cap,
  • Shake or stir and let stand 15 or more minutes. If water is very cold or turbid, let stand for 30 minutes.
Ugh.

That's about the time I read the Ultralight Backpacker's bible, Mike Clelland's "Ultralight Backpackin' Tips," (which every one of you reading this blog ought to buy cause it's that good.) Tip #106 suggested pre-mixing the parts into a third bottle to be used for the day. One then just needs to fill their bottle from a source, add the appropriate number of drops, shake it up, clear the threads of untreated water, and hike on.

So I found a bottle of eye drops, dumped out the eye drop solution, and cleaned the bottle real well. Being somewhat anal-retentive, I was concerned as to whether the drops would have the same volume of liquid as those from the Aquamira bottles. I placed 14 drops of both parts into the new pre-mix bottle, and squeezed out 27. This is close to ideal considering I probably left a drop in the bottle.

I found the flavor to be present, but unobjectionable. There is no chlorine or iodine taste, just a faint citrus flavor. Not a deal killer.

As for what to use to carry water, the aforementioned gram weenies were also fairly unanimous in support of recycling plastic drink bottles at a fraction of the cost and weight of Nalgenes, stainless bottles, surplus Army canteens and camelback-type bladders (Tip #102). My ULA Circuit provides for hanging such bottles from its shoulder straps, so I procured two wide-mouthed, 600ml gatoraide bottles for the trek. When one sprung a leak, a bit of duct tape held it till I could procure a new one - Available in any gas station or convenience store!

When water is plentiful, I rotate between the two 600ml bottles, filling and treating one, and drinking out of the other. That generally takes care of the 15-30 min wait time.

If 14 drops of Aquamira treats 1 liter, 8.4 drops treats 600ml. I assume that the full strength dictated by Aquamira is for any water source up to puddles in cow pastures. So I varied the number of drops I put in a bottle depending on my analysis of the water source, and my comfort with assuming risk. I.E I assume spring water at the source needs less treatment than the aforementioned cow puddle. Clelland's book goes into this concept in some detail. In 644 miles I never got sick.

Because I'm old and feeble-minded, I use a brown hair scrunchy I found on the trail that fits in a groove in the 600ml bottle, and tells me it's dirty.

For additional capacity, I picked up two 1L Platypus Bottles. They're generally empty in my pack until I intend to camp away from a water source, or when water sources are far and few in between. Then I can load up. At 2.2 lbs/liter, I try to avoid it, but sometimes it can't be helped. I don't generally treat that water, cause I don't want to waste drops on water I use for cooking.

Total weight of Aquamira system, 600ml Gatorade bottles and Platypus Bottles is 9.5 ozs.

So, my daily routine goes something like this. I wake up to find I have two full 600ml bottles I treated the night before, and at least a liter of untreated water in a Platypus. I make coffee and a hot breakfast using the untreated water since it's going to boil.

I dump out whatever premix is left over from the day before, curse the waste, and mix enough to get me through the day. Usually enough for 3-4L. I err on the side of too little because I can always mix more and I hate to throw unused mix away. I put the premix bottle in my pants pocket. I brush my teeth and camel up out of one of the treated bottles, refill and treat it. I put Emergen-C in one 600ml bottle, Carnation Essentials in the other, pack up and hit the trail.

As I hike, when I come to a water source, I kill whatever's left in the first bottle, fill it from the source, add the appropriate number of drops from my premix bottle, put the cap on, shake it good, turn it upside down and slowly unscrew the cap till water leaks thru to clear the threads of untreated water. Then I start drinking out of the other one. I do this till I'm ready to camp, then fill my two platypus bottles. Cook and make hot drinks with untreated water, and then fill and treat my two 600ml.


I get no small amount of pleasure from scooping water out of a source, adding a few drops to it, and walking on while others are fumbling with filters. I don't say anything tho ...

Having said all that, The new Sawyer squeeze filter is advertised as weighing less than my Aquamira setup, and looks to be considerably easier to manage than previous versions with all the tubes that have to be segregated to prevent cross-contamination. Might have to look into those ...