Water purification

**Rick** · 03-21-2008, 07:13 AM

Piece of cake - Forget the condensation route if you have access to that much water. Unless the water is contaminated with heavy metals or other serious pollution, purifying it is a snap.

First, let me say that you can't judge a book by it's cover. You need to treat all water the same regardless of what it looks like. Your principle concern is treating the water to avoid illness and crystal clear water can still contain "nasties" like Giardia and a host of other organisms including bacteria and viruses. So make certain all water is treated before you drink it. If the water is really nasty then you might want to strain it through your bandanna or other cloth to remove the "floaties" before treating it.

A few fairly quick and easy methods are boiling, filtering and chemical disinfecting.

Boiling -

Universally accepted as the safest way to purify water. The conventional wisdom has been to boil the water vigorously for 1 minute and allow it to cool. At altitudes greater than 6,562 feet (>2,000 m), boil water for 3 minutes or use chemical disinfection after water has been boiled for 1 minute. However, another member on here, Robert Rogers, from a very popular survival site, says just bringing the water to a boil will kill the nasties.

Filtering -

There are many commercial filters on the market. All do a reasonably good job and you can choose from a number of different sizes depending on how much weight and room you want to take up. However, even filtered water should be treated chemically to remove all bacteria and viruses that can pass through the filter. Some portable water filters designed to remove parasites have an "absolute” pore size of 0.1 to 1-micrometer and may also remove most diarrhea-causing bacteria. Viruses are smaller than 0.1 micron and will NOT be removed by filters with a pore size of 0.1 or larger. To kill viruses that may pass through these filters, iodine can be added to the filtered water before you drink it. Some of the larger companies, MSR for one, also include a chlorine based disinfectant to treat filtered water.

Chemical Treatment -

There are a number of ways to safely treat water by chemically disinfecting it. Chemical disinfection with iodine, for example, (e.g., Globaline, Potable-Aqua, or Coghlan’s, found in pharmacies and sporting goods stores) is another method for making water safer to drink. Cryptosporidium (a parasite that can cause diarrhea) and other coccidian parasites (e.g., Cyclospora, Toxoplasma) might not be killed by this method.

Make certain you know the recommended dosage for the amount of water you are treating. Make certain you know the recommended waiting time for the clarity and temperature of the water you are treating.

Trying to use a solar still is quite a bit of work with a small return and it takes a long time to manufacture the water. One of the methods above will produce a lot of water in a short amount of time with far less expended energy.

**Ridge Wolf** · 03-21-2008, 12:36 PM

Originally Posted by Prophet5150

Thanks again for all the replies and info!! The main reason that for my question is that when I am "out and around" I always keep tabs on my surroundings as far as what is available to me if I am stuck here, and have noticed that the places that I go usually have water near by, but it is usually from a source with a lot of wildlife around or a nasty seep pond. I feel much better now knowing that those sources can be turned into safe drinking water.

Don't forget that a dry creek bed might be dug down to the water level beneath too..

**bulrush** · 03-24-2008, 03:28 PM

Rick,
I assumed currently the US used high-tech semi-permeable membranes for purifying urine on US space vehicles. These membranse let h2o molecules through but nothing else. I knew a guy who sold these to industry. He showed me how you can take raw sewage, and the membrane only lets pure water through.

Neat stuff.

**Rick** · 03-24-2008, 04:25 PM

Yea. It's not rocket science. Well, yea, Come to think of it I guess it is.

That's the way I understand it. The contaminates are shipped back with the rest of the garbage and burn up in the atmosphere on reentry.

A way to do it on earth:

I've been to the Tampa MOSI several times. It's just a really cool place. They had a couple of tanks next to the parking lot, maybe eight foot in diameter that were loaded with water plants. They piped the gray water out of the building through those tanks and the plants absorbed the "crud" out of the water. That was another pretty cool way to make clean water. It wasn't drinkable at the end but it could be released into the wild without damaging the eco systems.

**BraggSurvivor** · 03-24-2008, 05:15 PM

Ive do that here Rick, all grey water from showers and sinks goes to watering plants & bushes. I try to water the grass with gray water just before a rain as sometimes it will smell a bit. Greenest grass around. (with the odd macaroni noodle kicking around)

All black goes to septic then onto a field.