A Few Thoughts on Water Storage, by N.P.


I’d like to discuss a few ideas about water storage and describe what I’ve decided to do in our situation.

My background, since most of this is my opinion, is that I work as the chemist (meaning I manage the water treatment systems) in a large power plant, hold the highest drinking water license possible in the state where I live, and am a degreed microbiologist. I’ve dealt with various water treatment systems for awhile. I don’t claim to know everything, but I do think that I’ve learned some things, and I hope to pass along a few ideas and opinions that hopefully will be of some value.

The Need for Water

Most of us aren’t fortunate to live on isolated farms/mountain retreats where we have our own supply of clean water. As you are well aware we are very dependent on utilities and workers in those utilities to supply us with our drinking water. In a TEOTWAWKI situation, I guarantee those workers won’t leave their families at home while marauding gangs are wandering the streets just so they can try and treat water for you to drink. Besides, those treatment plants, tanks, booster stations, and pumps all need electrical power, which I don’t expect to be around either. I’d argue that before anything else, a prepper should have a good water storage system in place. It is highly likely that you will need clean water before almost anything else, including food, weapons (most likely), fuel, emergency medical response, and so forth.

Need for Water Storage

While things may settle down after a while, my expectation is that the first few weeks when calamity strikes will be the most critical/volatile period. There’ll likely be a short period of relative calm, followed by chaos, fueled in part by desperation. Eventually, I expect that will be followed by groups of survivors banding together. I think it is vital to have water that will last until you make it through the first and most extremely violent/volatile periods of time. The safest way would be to have a sufficient volume of water stored where you will be (for many of us, likely) barricaded in our homes. Further, in prepping for other situations, such as localized problems that might include a terrorist attack, storm, power outage, or blizzard, a water supply is a good thing to have.

Different Water Storage Containers Used for Water Storage

I’ll just cut to the chase and say I think you need to get a large tank to store water in. I’ve seen a large variety of water storage solutions, and honestly I just don’t like most of them. A lot of the reasons I don’t like them are because of cost and inconvenience, frankly. I’ve detailed various storage methods I have seen below.

As a side note, I’d like to put a plug in for bathtub water storage solutions, like the “waterBob”, the “reservoir”, AquaPodKit, and others that allow you to use a bathtub to cleanly store and use water. The trick with these though is filling them while the water supply is still around and good to use. If you can fill these in time, I think they are a great idea, but I don’t think they are a substitute for a good tank.

Boxed Bags of Water

I recently helped someone move who had a few boxes of “emergency water” in boxed mylar bags. Quite a few of these boxes had leaked or were broken while moving, despite being treated carefully. They are an expensive way to store water. They frankly just didn’t seem very robust. I can’t vouch for the water quality, but I question how the water was sterilized without damaging the bag when they were filled.

Canned Water

This is not a bad idea, but I wonder just how much metal would eventually be dissolved in the water after years of storage. There would be some. They are also a very expensive method to store water, and they use up quite a bit of space.

Two-liter Soda Bottles and Other Bottles

How on earth do you actually store a large quantity of these? They don’t stack well, and they use an inordinate amount of space. (I certainly don’t have unlimited storage space.) They have another problem– keeping the water sanitary. I think that any water stored in a container that it is not sterilized (irradiated or canned) needs to be periodically dumped and refilled. I’ll discuss that more below, as well as a few opinions about the difficulty of really rinsing out a plastic container.

Stackable Three or Five Gallon Blocks

I think these are much better than the used 2-liter bottles. They at least solve some of the storage space difficulties of small bottles. However, draining and refilling a huge number of containers takes time we don’t have, especially when the same can be easily done in a few minutes with a single tank. Further, the more complicated the internal structure of a vessel, the more difficult it is to clean. They are also a relatively expensive way to store water.

Fifty-five Gallon Drums

These are better than some of the other smaller options listed, and they are more cost effective. However, they still take up a large amount of floor space, and I think that a 55-gallon drum is difficult to use. Draining the last bit out of a drum is never easy. You are also dependent on a pump to pull the water out, unless you have them stored horizontally, which makes me rather nervous. Personally, I haven’t found many drum pumps that were dependable for long-term use; it seems like I’m always ordering a new one every couple of years at the plant for only occasional use. There is also a tendency to buy used drums for water storage. I’ll discuss why I don’t suggest that either.

Totes or IBC Tote (275 gallon, metal-caged, plastic tanks)

A tote really isn’t a bad method for storing water, if your space allows; they are essentially a decent-sized water tank. You can fill them pretty easily; they have caps and drain valves. However, the valves on the drain are designed to be open/close valves, and although you can try to throttle them, actually getting a small amount of flow can be very difficult. These valves work great when you are wanting to dump the contents of the tote into a larger bulk tank, but they would not work well when you need only a few cups of water. You could probably rig up a bit of plumbing to help slow the flow of water, but every drain I’ve seen on these uses camlock fittings, which you probably aren’t going to find at your local hardware store. Further, most of these totes are sold used, which is my real problem with them.

Water Storage Tanks

I’d argue that this is the best way to store water. You can get a tank in nearly any size that you want, which allows you to get one that will fit your storage area very well. A tank doesn’t have the empty space around it that a bunch of bottles or cans do. You can also get a relatively tall tank, which will allow you to store much more water in the same floor space than other solutions. By buying a new tank, there are no questions about the history of the tank or what was really stored inside it. You don’t have to wonder if the guy selling them even really knew what they contained before. Another reason I like them is that you can set them up where they can be filled and drained conveniently. This allows you to refresh the water inside easily and frequently.

However, every water tank I’ve seen sold by prepping companies are extremely over-priced and can be oddly shaped. Oddly shaped interiors are hard, if not impossible, to clean well. I’d suggest that you buy the largest tank that you can fit in the space you have from a tank supply company. They aren’t going to mark them up, because they are selling them as emergency supplies. I’ll describe my setup below (after discussing a couple of other items).

Tank color:

There are a few options when it comes to tank colors. One of the more popular prepping supply companies sells blue tanks. I’ve also seen quite a few tank supply companies selling black tanks as ideal for water storage because of less light transmission. I’m personally a fan of white/opaque tanks for the simple reason that it allows you to easily see how much water you actually have, as well as to see if you have significant slime growth. While the absence of light will slow microbio growth in your tank, it will not stop it. I’ve seen a black poly tank that was kept in a dark shed and that hadn’t been flushed often enough; the interior of the tank was coated in a nasty slime that was very difficult to remove. Some slime is harmless, but other slime isn’t. A blue tank is also not some magic color that will stop microbio growth because the sky is blue. I’d rather be able to see how much water I have left easily (and if the tank is sliming up) rather than not. That said, the less light and heat your tank experiences the better.

Chemical Disinfectants vs Flushing

Most people think that the water that they get out of their faucet is bacteria free. It isn’t. It is treated to be pathogen free, but it is not sterile. Most bacteria in the environment aren’t disease causing, and honestly your body is designed to handle ingestion of quite a bit of bacteria. (Stomach acid/digestive juices really do kill most of them.) Whatever your “clean” water source is, it has bacteria, as well as dead bacteria and other microorganisms in it. As you fill your container(s), you’ll also add more bacteria from the air, your skin, et cetera no matter how careful or clean you are (unless you have some very specialized equipment). Even if you were to boil all the water you store (which would be VERY difficult), boiling alone doesn’t kill bacteria spores.

However, you can just kill the bacterial/fungi/algae with bleach/chemicals, right? There seems to be a general thought that you can just put some bleach in your water and then you’ll never see bacteria/algal growth in it, despite storing it for very long periods of time. There are also various articles that will give you specific amounts of bleach to add, such as “2 drops per gallon” and so forth. While perhaps, as a general guideline, these amounts have some value, they ignore the fact that the amount of bleach needed will vary from water source to water source. There is no set amount of chlorine (or whatever oxidizer you use) that will work best for every water system out there. The ideal chlorine dose is dependent on chlorine demand. Chlorine demand is the measure of the amount of chlorine that will react with stuff in your water before you can detect any unreacted chlorine; this differs in every situation; it depends on your container and how much organic material is dissolved in your water. This could be material from plants (say leaves floating on a stream), bacteria, dead bacteria, et cetera. Once your chlorine has reacted will all that stuff in the water the “chlorine demand” is met, and then any unreacted chlorine that remains in the water is “free chlorine”. The only way to know that you’ve added enough chlorine/bleach to the water to make it safe to drink is to check that you have detectable free chlorine. This means you’d need to test YOUR water. Another common misconception is that once you’ve met the water’s chlorine demand and have free chlorine present that you’ve killed everything in the water. While you may have killed most or all of the pathogens, there will still be some microorganisms that survive. Often these are inside small clumps of bacteria, or are bacteria in spore form. Eventually the free chlorine will dissipate, eventually leaving you with no unreacted chlorine. These microbes will then be free to grow. Although they may not be a health hazard, they could make your water smell and taste unpleasant.

So, why not just add a ton of bleach/chlorine and sterilize the water? That much chlorine would not only taste horrible, but it would also be toxic to you. Since we don’t really know when we’ll need our water supply I wouldn’t put in more than the maximum allowed by law in drinking water (4ppm free chlorine), which is an amount that tastes and smells horrible, but it would not sterilize the water. If you just dump in a ton, you may end up with a bunch of undrinkable, extremely-chlorinated water because you timed your treatment scheme right before you ended up needing the water.

Okay, so why not just open the bottles occasionally and give them a little spike of bleach/chlorine? Well, you could keep them from growing bacterial colonies by doing this, but every time you add some more bleach, you are adding more than pure chlorine. Eventually you could probably build sodium or calcium to rather high levels. Both sodium and calcium hypochlorite also tend to have a fair amount of hydroxide in them as well. You’ll also eventually raise the pH of the water a fair amount. This will probably taste nasty before you reach concentrations that are hazardous, although that is entirely dependent on the amount you add.

The other major reason why I really don’t like this idea is because of disinfection by-products. While chlorination of water has saved countless lives and is the primary reason why we don’t worry about diseases like cholera here, in the U.S., as I noted chlorine does react with organic material in water, which is present in all surface water and to some degree most groundwater systems. When it reacts with this stuff, it produces cancer-causing compounds– trihalomethanes and haloacetic acids. This isn’t some pseudo-science (like hating fluoride or vaccinations); this is a known fact, which is why the concentrations of these compounds are measured and regulated. By over-chlorinating your stored water, you will form more of these compounds. Letting the container sit open to the air will remove some of them, but personally I’d rather not form a bunch of carcinogens in my drinking water.

That all said, if you have your storage tank set up for easy filling/draining, you can just drain it and refill it periodically and avoid all of the additional home chemical treatment of that water. The treatment and disinfectant added by your municipal water system will keep the water clean for a while. The frequency that you need to drain and refill it depends on the storage conditions and source water quality; generally the warmer and brighter the storage area, the more frequently you will need to flush it. My tank is in a corner of my basement. I refill it every six weeks or so, which may be more often than needed, but I’d rather flush it more than needed rather than less.

NSF-certified Tank?

So there is an international organization– the NSF– that tests products and certifies that they don’t adversely affect the quality of drinking water. Generally, all public water systems are required by regulatory agencies to ensure that anything that touches or enters the drinking water is NSF certified. When something is NSF certified, it means that the manufacturer of that item paid a fair amount of money to have the item tested to prove it doesn’t put anything harmful into water. Even if you reasonably know that there wouldn’t be anything harmful, if it doesn’t have the stamp of approval a public water system can’t use it. Living in a (mostly) free market means that if you buy anything NSF-approved, you also ultimately pay for that testing.

The water tank I bought for our family’s water storage isn’t NSF-certified. That meant it was quite a bit less expensive (a whole lot) than one that was. It is a new poly tank. There is no reason to think that it couldn’t be “NSF” certified, if they paid the cash to get it that way. I just didn’t see a reason to pay the extra money for that. I don’t care to follow those regulatory requirements in my own home when I frankly think there is not any risk.

Why I Would Not Store Water in a Used Container

There are two reasons why I wouldn’t buy a used container for water storage. The first is possible chemical contamination of the water, and the second is bacterial growth. Many 55-gallon drums and many, if not most, totes are used in industrial settings. I order large quantities of various chemicals in both types of containers for work. Some of the chemicals are relatively benign, but others are absolutely, positively, extremely nasty. I’d drink water out of a filthy ditch (and I am a microbiologist) before I would drink water out of some of these containers, even if they had been rinsed multiple times. A few minutes of spraying (or even hours of soaking) isn’t necessarily going to remove all of the residue. Even if only trace amounts of toxins remain, I personally just hate the idea of possibly ingesting water with them in it,-and I especially hate the idea of giving that to my family.

The container you are going to buy is sold as only having held “food grade” whatever before. Do you really know that? All the totes I get I send to a tote recycler. I doubt they separate every tote by every product it has held, although they may put them in two piles (food grade and not). How well are they actually cleaned? Does that employee with the pressure washer really follow their procedures to a “T” every time?

So perhaps you actually do KNOW that the drum/tote wasn’t used for some industrial chemical; it only held food safe products (or even food itself). Be aware that there a some products designated food safe that are thought of as “safe” in minute quantities, but could be somewhat harmful when concentrated. Remember those employees at the microwave popcorn factories with “popcorn lung” from diacetyl fumes? I expect that chemical was a “food safe” item stored in food grade containers, as it was added to the popcorn as flavoring.

Are you sure you actually rinsed all of it out? The interior of a drum and tote can actually be really difficult to get to if you are trying to spray them down to get something sticky off. Some products or chemicals don’t readily dissolve in water, even if they are supposedly water soluble; so even if you fill the container, you may not have gotten all of it off. If you can’t see, feel, or smell anything, there could still be small amounts of product left, which is why industrial grade totes shouldn’t or ”can’t” be resold as food grade. That small amount of leftover residual food product could easily become food for microbial growth. The same argument goes for two-liter bottles. Even if you rinsed them well, there is still probably some residual soda in them. How would it have a smell if there wasn’t still some of the item that gave it that smell still present? That flavor/smell of cola (or whatever) that goes into the water after rinsing it multiple times means you didn’t get all of it out.

“You shouldn’t store water on concrete floors.”

Honestly I’ve been a bit baffled by this idea. What are these “chemicals” that are supposed to leach through the concrete and the plastic tank walls into your water? There is nothing in cement or concrete that I know of that would pass through the wall of a tank. I have my water tank at home sitting on a concrete floor, and I have many large bulk chemical tanks at work that are resting on concrete. To be frank, I think if you are building supports to keep water tanks off concrete, you are wasting your time and money. There is also some risk that the support may not be adequate/will weaken/give way under the weight of a tank, which is very significant. Do put your tank on a concrete floor. Keep in mind that a full tank of water can be extremely heavy. My home water storage tank (250 gallons) weighs over 2000 pounds, when full.

My Experience Buying/setting Up a Tank:

I bought a tank from this site http://www.boydsequipment.com/products/399-250-gallon-vertical-storage-tank.aspx. I only give the link to demonstrate exactly what I got– a 250-gallon tank, with a lid that allows air to enter as it drains, with a bulkhead fitting on the bottom so it can be drained easily (and completely). It has markings on the side that show volumes and allow you to easily measure the rate of usage or just know how much you have left. The bulkhead fittings are threaded, which made connecting a hose bib (a small enough valve to slow flow to a small stream/trickle) and associated fittings easy to find and install. I just bought them at my local Home Depot. The major reason why I chose this tank is that the size is the largest I could fit through my doors to get down into the space I have for it in my basement. As finances allow I’d like to add a second, although at a gallon a day usage, we’ve have a while before needing another water source.

It is tall and skinny, so I did put some banding up around it just to make sure it isn’t going to fall over.

I simply tapped into the water lines in my house and ran a line above the tank (to fill it easily). Also, I have a small hose connected to the valve on the bottom that runs to the sump in the corner of the basement. To drain it, I just open the valve and let it flow into the sump where it is pumped onto my lawn. The base of the tank probably doesn’t take up much more room than a 55-gallon drum. Well, okay, it is a bit wider, but it holds 250 gallons with only a 30’’ diameter. It was easy to buy, easy to get, easy to move around through my house (empty), easy to plumb in, and even with all the fittings my final cost was no more than $1/gallon. If your space allows for a larger tank, it could cost you much less than that. Quite importantly, it is also very easy to drain and refill.

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One Response to A Few Thoughts on Water Storage, by N.P.

  1. Anonymous says:

    Interesting and apparently quite educated comments. Thanks for spending the time to share them.

    I have a slightly different take (OK, it’s a lot different) on water storage and use. I have used stored water in off-grid locations every once in awhile for many years. After all is said and done, I find that 99% of the game simply requires storing the water. If one starts out with a food grade water storage container, and fills it with potable water from the tap of any reputable water company/supply, he can render it potable again with very little work. There are many methods to accomplish this. Is it 100 % guaranteed to be perfectly safe for consumption? Nope. Nothing in life comes with this kind of certainty.

    I have consumed water stored for years without being treated. There are no substantive risks for chem contamination under these circumstances, only pathogens. And treating for pathogens is really pretty easy if one has a modicum of knowledge in this regard. I have never had an issue in over 25 years. The problem with providing folks with all the myriad ways in which water MIGHT be problematic for consumption is simply that most of them will opt out of storing water whatsoever.

    In the real world, it’s about merely trying to put the odds in one’s favor as best as can reasonably be done.


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