water purification

[jlwilliams]

  I'm starting my research into water purification.  My goal is to find/make a system that would purify enough water for a family and some animals in the event that today's current water sources become unavailable.

  Have any of you got anything set up?  Anthing you have learned that may help?

  I will post what I find as I get a little further.  What I know now would fill a thimble, so I will hold off 'till I have something more to tell you.

[Graybeard]

Can't say that I know enough to fill a thimble really. But I'd first look at what a well would cost then go from there.

[243dave]

Go to the "Survivor Skills Discussion" section and look for the topic Bleach for water purification. More than bleach is talked about, might be what your look'n for.    Dave

[Winter Hawk]

A cup of Clorox in our cistern (10,000 gallon) per week took care of the bad bugs when we lived in SE Alaska.  Now I use a Big Berkey filter from British Berkefeld.  It worked for my grandfather in Indonesia back in the 1920s and it works fine now.

-WH-

[dpe.ahoy]

I have seen the British Berkefeld Water filter advertised for years in a magazine I get, called "The Backwoodsman".  The website for the company selling them is, www.arctic-1.com.  Been thinking about doing some reading on this as river water is pretty easy to find even in Montana.  By the way, that magazine is a pretty good one for people who are on this site as well, lots of good articals that tie in to what is being discussed here.  DP

[teamnelson]

Just posted a link on survival skills forum to plans for a home made slow sand carbon filter - will process hundreds of gallons of water with stuff you can dig or make. I'm pairing it with a rain barrel - 1" of rain on my roof equals 700 gallons.

[Ole Man Dan]

Put 2 drops of Chlorox per qt. of clean looking water and let set 30 minutes.  4 Drops for cloudy water...
Military & Boy Scouts have used this for years...
I have filtered water thru cloth to get out the particles.  Or... you can boil it for about 5 minutes, but it taste bad.  Add a touch of salt or pour it back & forth one container to another.  Puts the oxygen back in the H20.
Boiling is not cost efficient, but works if you are going to be at one loc. for prolonged period.
Most Important tip:  Never use water that does not have plants growing near it. 

[teamnelson]

Lots of folks, myself included, learned how to use bleach/clorox for camping and the EPA/FEMA are still posting instructions on it for early response to a short term crisis with expected return to services after a few weeks.

But for those that are thinking about needing to have clean water for a long time, bleach is not the answer. As has been proven over and over amongst the other 5.7 billion people on the planet not living in the US, most of whom do not have access to adequate clean drinking water, long term use of water that has been treated with chlorine has medical side effects, particularly on the kidneys, and can compound other infections & diseases which are typically associated with a societal break down. I ran an NGO in Africa that worked specifically in this arena, and worldwide data agrees. There is a direct relationship between long term use of chlorinated drinking water and various forms of cancer, GI problems, and even infant mortality. Short term emergency use is fine - not long term.

If you are moving towards a self-sustainable lifestyle then bio-sand and other similar technologies are the only way to go for long term use without any harmful side effects. Especially if you anticipate needing to use it in your later years when the organs are already going to start operating at reduced capacity.

[SDS-GEN]

Most city water has bleach as one of the purifying agents in it, I've drank it all my life with no health problems.

[teamnelson]

It's used in pre-treatment only to keep the system clean, and that's also prior to sedimentation and filtration, lots of cities use slow sand or some other form of sediment filtration. You've not been drinking water with the equivalent of 8-16 drops per gallon of water as recommended by the EPA for emergency short term use.

Seriously, I'm not selling anything; just trying to save your organs gents. Your call. Ever seen someone die of kidney failure but not in a hospital and with no pain meds?

[Cornbelt]

What about iodine?

[teamnelson]

Iodine is for short term also, and neither that or chlorine kill everything off. They also don't last long in storage; it'll break down and be worthless to you. If you're going to be stationary for awhile and you're looking for a sustainable solution, boiling works well as long as you have fuel for the fire, which you may want for other things, and you're limited by the size of the pot, can't use it cold right away, etc. The reason why slow-sand is so popular in humanitarian development is that it works with little maintenance using stuff you dig out of the ground. A 5 gal bucket with the right layers of sediment will filter hundreds of gallons for months untouched, then it's just stirring or replacing sand. A sludge forms in the sand that eats the harmful organisms in the water, and the sand filters minerals as well.

If you're collecting rain water, connect a sand bucket to the outflow, and you'll have better than bottled water for free.

[Ole Man Dan]

I'm going to try and set up a sand bucket system for our 'Hunting Club'. 'TeamNelson' makes sense.  I've never had to rely on Chlorox for more than a week at a time, but why take a chance on future problems.

[jlwilliams]

  Sounds good to me too.

  This is exactly the sort of thing that I want to try out now, when there is plenty of water available.  That way I will have tried it and have some idea what I'm doing should I need to do it because there isn't so much around.

[Dweezil]

TeamNelson: could you post your slow sand filter link here?  It sounds intriguing.  The nearest to that I've seen is a bucket filter using activated charcoal sandwiched between layers of sand. I'm looking at something for filtering rainwater off my roof.

[teamnelson]

I've looked at several plans and the one I like is in this video. If you can overlook the soundtrack and the foreign subtitles:
http://www.youtube.com/watch?v=8YeNvglOd-I&feature=related

5 gal bucket, 3 layers of sand.
- Coarse bottom layer: 1/4-1/2" gravel. 10-15% of bucket.
- Medium middle layer: 1/8-1/4" gravel. 70% of bucket.
- Fine top layer (where the bio interaction occurs): 0-1/8" sand. 10-15% of bucket.

Here's a picture of a 4 layer version:http://www.hydraid.org/wp-content/uploads/2008/09/hydraid_cutaway-lg.jpg For the reverse engineers out there, its all laid out in a picture.

You need a gap at the top between the top layer of sand and the lid. And the whole thing needs to stay wet or the bio layer (Schmutzdeke) won't work. It also takes about 10-14 days for the bio layer to become active, so once you build it out, you should wait 2 weeks. Keep it wet the whole time.

The one in the video has a diffuser which basically keeps the input from carving a channel through the top layer. Definitely a critical piece. My thought was to put this in series with an elevated rainbarrel that has a spigot on the barrel. I'll have a screen on the top of the rainbarrel for large stuff (leaves, etc). If I want filtered water, I'll connect a 5/8" hose and run that to a screen on the filter. That drops onto the diffuser - I'm going to test using double lids.

Instead of a runoff pipe like in the video, I'm going to use a spigot (cut a hole in the bottom, wrap pipe tape around a plastic garden spigot and thread it in. And just have the filter elevated high enough to clear a 2 liter bottle for the filtered water. But ideally I would think if you were handy enough, you could build the barrel and the filter in a closed system with pvc pipe which as long as you had water in the barrel, you'd have water in the filter to keep it alive. You'd need access for occasional maintenance, like if the volume slows down. Then you just stir the top layer, and keep going. I also want to keep my filter accessible for other water sources, so if its not raining, but I can grab a bucket and haul some over I can still use it.

If I wasn't in a townhouse, I'd probably have two barrels, a filter and a wet backup filter in storage. That'd give you access to 110 gals of filtered water on demand in a dry season. If you want to put a couple of drops of bleach in the rainbarrel, go for it, but that's just to keep the green stuff off the sides.

This video also reminded me to make some gravel strainers out of screen so when I need it I can dig my own appropriately sized medium for the filter.

Samaritan's Purse claims they have some that have been working for over 10 years with minimal maintenance.

[WD45]

So how well does this sand filter work ? Will it filter safe drinking water from water contaminated with raw sewege ?  I have a 5000 gal cistern to tap but your 110 gal system isn't gong to last that long in a katrina type situation where it could be a long time before essential services are restored. There was plenty of water around but all was contaminated. I like the sand filter idea over the charcoal as you would not need to search for a special filter medium in a long term situation. Heavy flooding can also cause problems with well water contamination and depending on what the actual source of the well is something that happens miles from where you live can affect your water source.

[teamnelson]

My 110 gal system is a rainwater collection system, not a storage system, so that means as fresh rainwater comes in, I'm processing it for drinking, or pouring stuff into it I collect elsewhere. 110 is just the current capacity, not long term storage. It is used to process raw sewage all around the world - the live bio layer feeds on it. You could pee right into if you wanted to. My guess is the more heavily contaminated biologically your input water, the more frequently you would need to stir the live layer, or even replace it. It would more than handle your 5000 gal tank; the flow rate is dependent on how large you build your filter. The 5 gal bucket has been known to process 100 liters an hours or more, which is more than adequate for my household of 4.

What it won't do is handle chemical/radiological. Which is another reason I like it in tandem with a rainwater system. Cut the system off if you experience fall out, pray for rain fall to wash your roof and gutters out, then reconnect it for fresh rainwater. Or if you have access to a protected system, you can easily pour that source into the filter.

[WD45]

Sounds good to me. You also kind of answered another question I was thinking on flow rate. A couple sacks of sand is cheap and easily stored for future use.