Wednesday, June 28, 2023

Your questions answered on emergency water purification

 

Following my "Oops, my bad!" article yesterday, I had a number of exchanges with readers and friends.  They asked, in so many words, the following questions:

  1. Why duplicate the filtration function, by having both a Lifestraw Family 1.0 and a Survivor Filter Pro?  Both can filter similar volumes of water;  the only important difference is that the first does it by gravity, and the second by pumping.
  2. Why not have a big countertop water filter as well?  It can process much larger volumes of water, and is more convenient than the smaller systems I mentioned.
  3. Why bother with a potable water hose in your emergency kit, when in an emergency taps are unlikely to provide potable water?
  4. Why use pool shock as well as filtration?  Won't the latter take care of diseases, pollution, bugs and beasties anyway, without needing chemical assistance?
  5. How much fresh water should you store for immediate use in emergency?
In this article, I'll try to answer those questions.  If you haven't read yesterday's article, you might want to do so now before continuing.

The first and most important point is that clean, drinkable water is absolutely critical to our survival.  The time-honored "Rule of Threes" applies:

  • You can survive three minutes without breathable air (unconsciousness), or in icy water.
  • You can survive three hours in a harsh environment (extreme heat or cold).
  • You can survive three days without drinkable water.
  • You can survive three weeks without food.

Given that potable water is so essential (for drinking, cooking, and washing ourselves, our clothes and our cooking and eating utensils), we have to ensure we can get it when we need it.  If the electrical grid goes down, every water purification plant and sewage processing plant is going to go down within a day or two.  That means no more potable water out of our taps, so everyone is going to have to go get water from any available source.  Within days, those sources (rivers and streams, lakes and dams, etc.) are likely to be polluted by dirty bodies, sewage (human and animal), and any other pollution that comes along.  The only way we'll have guaranteed potable water is if we purify it ourselves . . . so we'd better have the means to do so, right up front.  Without it, we're at risk (very serious risk!) of catching diseases and/or disrupting our digestive systems, with consequences that we really don't want to deal with in the midst of everything else that will be going on.

(That's also a very good reason to have several containers that will be used only for "raw" unprocessed water.  You'll transfer it from them during the purifying and/or filtering process, so it ends up in clean containers that you know are free from diseases or pollution.  The "raw" water containers will be reserved solely for collecting unprocessed water, not for storing clean water.)


OK.  First question:  "Why duplicate the filtration function, by having both a Lifestraw Family 1.0 and a Survivor Filter Pro?  Both can filter similar volumes of water;  the only important difference is that the first does it by gravity, and the second by pumping."

The answer is simple, and an old saying in the prepping and self-reliance community:  "Two is one and one is none".  You can read more about it at the link.  If I have only one larger water filter, and something goes wrong, I suddenly have no large water filter.  I want to be able to get clean water no matter what - so I have a backup unit.  As for one being gravity-fed and the other being pump-operated, there's a reason for that.  I may not have anywhere to hang a gravity-fed unit, so in that case I can use the pump unit.  In another place, I may not have a stable level surface, out of the way of any local pollution or other problem, to pump water;  so I can hang a gravity-fed unit out of the way and use it there.  Having both gives me redundancy and options I wouldn't otherwise have.


Second question:  "Why not have a big countertop water filter as well?  It can process much larger volumes of water, and is more convenient than the smaller systems I mentioned."

You're quite right.  I do have a countertop water filter, and value the higher capacity it provides.  However, there are two issues with such a filter.  First, they are very expensive compared to smaller filters.  The well-known Royal Berkey line, while outstanding pieces of kit, will cost more per unit (often $300-$400 or even higher) than everything put together that I listed in my previous post.  If you can afford that, great - but not all of us can.  The Lifestraw or Survival Pro cost no more than a fifth of that, and offer adequate function for a family of 2-4 people, with careful management.  There are alternatives to the Royal Berkey, of course, but they also tend to be expensive.  I looked at what was available, and identified Lehman's Bucket Water Filter as a useful option, but it was still too high-priced for my liking:  so I made my own (instructions may be found here) by cutting holes in the bottom of a food-grade five-gallon bucket, inserting Berkey-style filters in the holes (in the process, finding that non-Royal-Berkey-brand filters offer equivalent performance at a much lower price, I might add), and positioning it on top of a second food-grade bucket of the same size.  Hey presto!  I now have Royal Berkey-equivalent performance at a total cost to me of under $100.

(The only reason I didn't mention it yesterday is that it doesn't live in the tote along with my smaller water filters - it's far too large for that - so it wasn't contaminated by whatever polluted them, and didn't need to be replaced.)

The second problem with large countertop water filters is their size.  They're great if you're staying put:  but if you have to "bug out" for any reason, they're too large to fit easily into a motor vehicle or tightly-packed trailer, and they're too unwieldy to be carried on foot for more than a short distance.  The smaller filters I named yesterday are much more packable and portable, while offering adequate performance.


Third question:  "Why bother with a potable water hose in your emergency kit, when in an emergency taps are unlikely to provide potable water?"

You may not always be out of reach of potable tap water.  If you're "bugging out" and trying to get to a safer place, you may find yourself in a community where safe drinking water is available.  Taps aren't always conveniently placed to stand a container under them and fill it.  If you have a potable water hose, you can lead it from the tap to an open space where you can fill your containers.  It can also be led from a tap to the water inlet on a travel trailer or RV if necessary.  It's just another tool in the toolbox.


Fourth question:  "Why use pool shock as well as filtration?  Won't the latter take care of diseases, pollution, bugs and beasties anyway, without needing chemical assistance?"

If the water you collect is badly polluted, or infected with organisms and diseases such as e. coligiardia, cholera, dysentery, etc. (all of which can be water-borne), it's really not a good idea to introduce those into your filter.  Sure, the filters may stop it getting through to the end product, but you've still contaminated the filter housing and perhaps the filters themselves with it.  Why not deal with such poisons and diseases before they get to your filter?

That's a lesson I learned the hard way in the Third World.  You want to keep your filter units and potable water containers free from contamination by any and all means available.  Once they're contaminated, you can no longer trust them and should replace them - but replacements may not be easily available.  Much better to protect them from the very beginning, to prevent that need.  To that end, we reserved specially marked or colored containers to collect water from potentially contaminated sources, and hit them with chlorine bleach, iodine or other purifying agents for anywhere from an hour to a day before decanting the water they contained into our filtering systems.  That killed off the germs, and also gave pollutants suspended in the water (e.g. mud, decaying vegetation, snails, etc.) a chance to sink to the bottom, so that cleaner water could be scooped out with jugs and transferred to filters without taking them along.  As soon as the chemically treated water had been transferred, we would wash out the containers and refill them from the next water source, then do it all over again.  (Five-gallon buckets are very useful for that application.  They nest inside each other when not in use, and offer enough space to scoop treated water out of them.  We used to color-code them:  red for untreated water, white for filter units - see above - and blue or green for purified and filtered water.)

I suppose it's a practical application of the "belt and braces" approach.  In my case, having learned the hard way on far too many occasions in the Third World, I prefer "belt and braces and a piece of string".  It may be overkill, but it works!

As a side note, the US Environmental Protection Agency - for all that we dislike its bureaucratic excesses - endorses using the chemical in pool shock as a water purification method.  From its PDF article on the subject:


Granular calcium hypochlorite. The first step is to make a chlorine solution that you will use to disinfect your water. For your safety, do it in a ventilated area and wear eye protection. Add one heaping teaspoon (approximately ¼ ounce) of high-test granular calcium hypochlorite (HTH) to two gallons of water and stir until the particles have dissolved. The mixture will produce a chlorine solution of approximately 500 milligrams per liter. To disinfect water, add one part of the chlorine solution to each 100 parts of water you are treating. This is about the same as adding 1 pint (16 ounces) of the chlorine solution to 12.5 gallons of water. If the chlorine taste is too strong, pour the water from one clean container to another and let it stand for a few hours before use. CAUTION: HTH is a very powerful oxidant. Follow the instructions on the label for safe handling and storage of this chemical.


The document also lists other methods of water purification.  It's only two pages long.  I recommend printing it and storing a copy with your emergency gear, along with the article I recommended yesterday.


Fifth question:  "How much fresh water should you store for immediate use in emergency?"

The generally accepted minimum is one gallon per person per day, but that's an absolute minimum - for cooking, cleaning, washing and drinking, it's not really enough.  I prefer to double that figure, and store two gallons per person per day, and even that's not a lot in a hot climate like Texas, where I live.  You'll have to make your own call on that.

The first few days after an emergency happens may be tumultuous.  We really don't know what to expect - only that our normal routine will be disrupted.  There may be active competition to get what water is available, and that might turn violent.  I'd rather avoid that, if possible.  I therefore suggest storing at least one weeks' water for your family, and if possible two weeks or more.  For a four-person family, at two gallons per person per day, that means storing a minimum of 56 gallons, or for two weeks, 112 gallons.  That's not a small amount, and takes up a fair amount of space.

Some of it should be in the form of one-pint drinking bottles.  They're easy to hand out in a hurry, and can be refilled if necessary.  Most of it, though, will need to be in larger containers - and water containers can be very expensive (and many are not well reviewed by customers, due to leaks and other problems, so shop carefully).  The cheapest will be food-grade five-gallon buckets with lids, usually available from hardware and home improvement stores for under $5 apiece if bought in 10-packs.  (Be very careful about used buckets obtained from food vendors.  Many have held pickles, olives, or other substances that leave a nasty odor and flavor behind.  It'll make fresh water taste and smell very unpleasant.  Better to buy clean, unused buckets, IMHO.)

By far the most convenient solution I've found are the four-gallon jugs offered by Sams Club, to fit most water dispensers.  At present they cost $5.98, which gives you both the water and its container.  That's a bargain in anyone's language.  Add a water jug stand, a dispenser valve and a resealable cap for re-use, and you're good to go.


Well, there you have it:  your questions answered.  If you have more, leave them as a comment to this article, and I'll try to cover them in future.  Thanks!

Peter


9 comments:

Anonymous said...

Thank you for the additional information on the importance of water. Except for air, probably the 2nd most important 'Need To Have' on the list.

Maniac said...

I have purification tabs and a pair of Lifestraws for my Dad and I.

Anonymous said...

The only suggestion i would make to this is to filter through a tight weave pillow case or similar favric when pouring your shocked water into your filter unit.

I used to work at a power plant and we used shock and biocide to treat the cooling pond water as it came into holding tanks for 24hrs. Then we had a 10 micron bag filter then the catridge filters.

The bag filter was because one of the chemicals we added broke down the bodies of the tiny snails in the freshwater. The bodies would be like a gel slime and destroyed filters very quickly. The fabric bag filter was a cheap way to vastly extend the life of the very expensive filters. Our filters were a $1000 each and the bag filters were under $6 and more than doubled filter life. Our bags were polypropelene (milk jug material) so they absorbed trace hydrocarbons as well.

Exile1981

James said...

Coffee filter can be a useful prefilter for removing particulate matter in waster.
Prooneusa.com has a more affordable counter top water filter and their filters are ceramic and can be used as replacement filters for the Berkey line. These filters are better than the Berkey's and don't require priming, and they are cheaper also.
Check the concentration of your pool shock, the percentage of active ingredient varies between brands. Also some pool shock has other chemicals in it for algae removal and may not be suitable for water purification.

Anonymous said...

Strong chemicals: pool shock, gasoline, acids, acetone, and many others should be stored separate from other items.
Unless stored in glass (and even then, depending on the lid and seal), you have to assume the chemicals will off gas.
When I had a pool, anything metal near pool shock would rust fast, and badly, even when factory sealed in hard containers.

Anonymous said...

I have had good luck with this company, with the specific tank linked:

https://www.surewatertanks.com/products/260-gallon-tank

We have not had any leaks going on 10 years now. At the time I looked, it was the lowest cost per gallon stored. When I bought it was direct from the dealer. The tank arrived but one of the spigots was missing a part; one call and it was in our mailbox a few days later.
Not sure about how the quality and service is now, given the age of our tank.
We purchased as we have lived in areas where you can go several months without rain. Even though we live in what I consider rainforest conditions now, just can’t shake the anxiety of forgoing bulk stored water.
Also, I have used both the life straw and the Sawyer while hiking the AT, pulling water from creeks and streams. No problems.

Anonymous said...

If you are staying put and need filtration for more than 4-5 people, look into slow sand filtration. A barrel, some plumbing parts and sand. Keep a supply of pool shock and the rest of that kit for use during the two week startup of your sand filter, then you are good to go.

Anonymous said...

Question #3 reply - A convenient water routing hose can be made from household washing machine hoses, which already have a screw on receptor for outside hose bibbs. These hoses come in lengths of about 5 feet, so cutting one in half effectively nets you two units per hose. That length can then route the water to the container's mouth, rather than water gushing forth from wall unit all over the place. A 4 way sillcock key for secured water faucets too would be a good idea as well.

Linda Fox said...

Thank you. Although I'd done the Girl Scout thing, back in the day, I had little direct knowledge of the pros and cons of various filtration systems/methods.
This gives me some basis on which to make choices.