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Sulfates in water while backpacking - what to do?

We will be backpacking in South America and were warned that in one camp there are sulfates in water which can cause diarrhea. Although we will have our water purifier with us I do not think the purifier can remove the sulfates.

Do you have any suggestions on safe and healthy way to prevent any undesirable side effects. Carrying bottled water along is not an option unfortunately.

thank you.

you might try a marine water maker if your worried about it, they'll take salt and everything else out of the water and the make small hand operated ones for emergency liferafts, otherwise you could pack two days water that day.

The units that J Hagar mentions use reverse osmosis. They aren't really backpackable, though they fit just fine in a liferaft.

One thing that helps a bit is to let the water sit in a fairly large pot overnight (though depending on where you are in SA, that might not be desirable). Or, boiling the water will drive some of the dissolved sulfur compounds off.

Then again, "sulfur water" is supposed to have "healthy properties", according to various old wives tales (thorough cleansing of the innards, maybe?).

There are ways to reduce the the sulfur in well water. Basically, aeration and heating help. Filtering can remove some of the bacteria that produce the H2S. Sodium hypochlorite and hypochlorous acid (plain old household bleach) will react with the sulfates to turn the sulfur into a solid. I have not tried any of this with sulfur water that has a strong odor, though the aeration and boiling are effective in my experience with water that has a slight sulfur smell.

Did those who warn you have any solution to said sulfates? Where in SA will you be backpacking? If it's one camp only, I would hydrate thoroughly prior, pack the water in and know/plan where my next source of sulfate free water would be coming from after that one camp.

Thank you for the quick replies. We will be i Peru, staying in a base camp for 3-4 days. That's where the questionable water is.

Here's a warning from sb. who stayed there:

"Glacial melt water often contains a good bit of rock flour, which will clog filters. I would expect this to be a problem in at least some places in the CB, especially Ishinca base camp. Boiling and or pills are the best bet. If you use the pills, treat the water the evening before you need it and don't add the neutralizer or any flavoring until the next morning.
One other concern that you can't do much about is sulfates in the water. The rocks along the stream at Ishinca base camp are stained rusty brown from iron in the water. The iron comes from pyrite (iron sulfide) in the granite in that area, which also contributes sulfates to the water. Sulfates are laxatives"

seven pound for a Survivor 35.

From spending some time in SA in the military, we used activated charcoal along with a water filter or treatment tablets and it worked find to take out sulfates, along with every other baddies that can be found in "wild" water.

You can get activated charcoal from most pet stores that carry aquarium supplies. You want the granulated and not powder. Activated charcoal will last for 1 month of often filtering use.

This is the method we used. We would take a small metal can, coffee can, vegetable can etc, #10 cans work great for large amounts. I personally used a small metal coffee can. Can needs the top removed and the bottom intact. Take a knife etc and poke about 20 or 30 small holes in the bottom of the can. Then take metal sieve mesh (from a hardware store)and put it in the bottom, you want a tight fit. Then pour in about 4 inches of activated charcoal and place another piece of mesh on top. If you wedge the mesh in right it will stay in place with no problem. Then get a bandanna, tshirt, cheesecloth etc and place over the top of the can, letting in drape slightly into it and secure around the outside of the can with a rubber band or twine etc. Place can over a water container of some sort and pour water into the can to get the charcoal wet and let it sit for 10 minutes or so then continue pouring water through the can until you fill up your container. At this point you water is safe to drink unless your water source contains viruses, which is common in many SA sources, especially in the jungle. If you suspect viruses then you either need to boil your water or use a water filter or treatment that can remove or kill viruses.

I used the plastic cap that comes with small coffee cans to seal the top while in my pack. There is enough room in the can to put a few bottles of water treatment and makes a nice little compact package that weighs about 1 lbs or less (never weighed it but its not too heavy as charcoal is pretty light).

This is a good poor mans water filter that lasts for a good solid month or more of constant use. Just replace the cloth piece or clean it when it gets clogged/dirty from silt and debris.

CB - Corderilla Blanca I assume. Good trip, you’ll love the people and place. If you are on a self guided trip, consider hiring a local “guide” to keep watch over your camp so it will still be there when you get back. Additionally they will provide beasts of burden to transport your stuff to base camp, and cook for you (Peruvian food is yummy!) all for a reasonalbe cost. Besides, ethics dictate you give back to these folks. You’ll understand when you get there.

Yea, the glacial silt will foul filters; take a two part chemical sterilizer/oxidizer. It will kill the microbes as well as partially offset the sulfate issue. The sulfates are not from aquatica, but from spring sources, as your source, sb, indicates. It was not a problem for me, but then I have stainless steel gut, and have little problem with drinking the local water (as long as it isn’t used as a sewer). I think the folks that had problems on our trip were caused by water consumed in Lima or Huaraz. We too went up via the Ishinca Valley, but I do not recal our water having a significant odor, taste or color, though the stream side rocks were stained brownish. Perhaps your camp is up a different canyon with a different water source?

If you intend to scale any the peaks, do not underestimate the aerobic demands of this trip. You will want to be in the best shape you have ever been, and then some. The snow is often deep and soft, even pretty high up. While not as cold as Alaska’s high-ups, the snow made the effort more difficult.

Very interesting topic to me as a representative for Katadyn water filters. This subject has never come up before.

I will agree that no standard portable water filter system will get sulfates SO4, out of backcountry water. The information I have looked at indicates that sulfates are very, very difficult to remove from water.

Activated charcoal does not remove sulfates.

The Katadyn marine desalinators are designed for ocean water.

I found this link useful in covering the problem of sulfate removal. It covers sulfates and removal in some detail. From the MN. Dept of Health:

I do need to mention that Hydrogen Sulphide H2S, in water is removed by the ion-exchange resin in some of the kitchen faucet filters. Sulfates are not.

On a brighter note: I had a great time in Peru in 2007. We did a 5 day backcountry trek in the Cuzco area. Interestingly, we filtered some of the dirtiest water I have ever seen------- at 13,000 Ft. It was out of an irrigation ditch, ½ mile below a dwelling/barnyard. There was no choice for better water within a couple miles and 2,000 vertical feet. Pumping 12 liters of that ditch-water stew resulted in clogging the prefilter 4 times, and the main filter once. The prefilter and filter cleaned right up though. No problems on the rest of the trip.

My picks for your trip filter: Katadyn Hiker Pro or MSR Miniworks, per four people, and take a spare cartridge. Katadyn Micropur tablets for backup.

If you are treating water below human fecal contamination: microfilter first, then add Micropur tablets to kill possible virus.

I just don’t have a portable solution for that sulfate water area. Packing in water, or mild diarrhea: seem to be the choices.

There is one approach that I have tested that does seem to work for the H2S and sulphate problem, along with a lot of other nasties. Pur, a division of P&G these days, based in Switzerland, makes a kit originally intended for third world countries. I mentioned it in my Trailspace article on water. One problem with the kit is that it is made to treat 10 liters at a time and is not really amenable to smaller quantities. The basic process is to put the untreated water in container number 1 (the kit has 2 10-liter foldable plastic jugs), add the pre-measured powder, and stir with the supplied paddle, then let it sit while the resulting flocculant settles out. The flocculant traps the larger critters (protozoa, most bacteria, particulates) and many chemical species (mostly heavy metals and a number of agricultural runoff chemicals). You then decant the water through a cloth filter (supplied in the kit) and let it sit for a specified time while the remaining chemical from the powder (chlorine dioxide, I think), kills the smaller bacteria and viruses.

I tested it before and during my trip to Africa a few years back. Really murky water comes out quite clear and taste-free (and I didn't get sick from the water, either). Apparently you can order it from (much as I hesitate to recommend BigBox WalMart), and from Campmor. At $20 for the kit and $15 for a package of 6 chemical packets, this should be a reasonably effective approach.

The 10 liter minimum size treatment should not be a problem at base camp.

The Katadyn Hiker and Hiker Pro that riverridgeray mentioned were originally Pur filters. Katadyn bought Pur's backpacking filter line a few years back and put the Katadyn name on them, though I believe their kitchen faucet filters are part of P&G. When I personally use a filter, it is a Hiker Pro.

August 8, 2020
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