Tuesday, October 2, 2012

Emergency Preparedness: Water

Image from Wikimedia Commons
We are running an occasional series on improving your emergency preparedness, with special attention to preparedness for families.

We already talked about fire safety for families. Now, let's talk about one of the most neglected things in emergency preparedness ─ extra drinking water, or what the experts call "potable" water.

Do you have enough potable water on hand?  How do you store it?  How would you get more in an emergency if water access was cut off?  How can you avoid water-borne diseases that are so common after emergencies?

Storing Extra Potable Water

The number one emergency preparedness thing that people fail to do is to store enough water.

This is especially true for families. People often have some extra food and a little stored water on hand, but very few families have enough water stored up for emergencies.  You can go without food for a long period of time, but you can only go a few days without water before your health is affected.

Basically, the rule of thumb is to store a gallon of water per day per person.  You need to drink at least 2 quarts of water per day, plus you need extra water for sanitation and preparing food.  Thus, experts recommend storing about a gallon per day per person.

Even in just a 3-day kit (which is the bare-bones minimum for preparing for an emergency), this can really add up for a family! Especially if you have multiple children, extended family, or pets living with you.  Thus, most people have inadequate back-up stores of water.

So how do you build up a supply of water?  There are a number of options.

The most recommended method is to buy bottled water (the big bottles); professionally bottled water lasts the longest because it has been bottled under strict conditions. Or you can get boxes of regular-sized bottled waters when on sale. (I'm not a fan of these because of the waste, but having some can be useful in an emergency.)

Of course, you can always store your own instead.  Water doesn't rot, but it can start growing bacteria, so you do have to take some precautions.

Get durable food-grade plastic 5-gallon water containers (many stores have them), then wash them with soap and water, sterilize them with a bleach solution, rinse them, and fill them with water. If you use city tap water, no extra measures are needed.  If you have well water, you should pre-treat the water with some bleach or other treatments before storing it.  Some experts recommend rotating your stored water every 6-12 months.

If you have room and a lot of people to store water for, you can consider a water barrel specially designed for long-term potable water storage.

If space or money is an issue, wash out old pop bottles, sterilize and rinse them, then fill with water and tuck them into various corners around your house. Don't use fruit juice or milk jugs, as milk proteins and fruit sugars can't be adequately removed from them and will provide a strong medium for bacterial growth.

Store water in dark, cool places to slow the growth of bacteria.  If you don't have a dark place to store the water, put it in a box or under a dark cover to minimize light exposure. Don't store it directly on concrete floors; have something underneath preventing direct contact.

Sometimes water access is available right after an emergency but may go away in a few hours. After a disaster (of if you know a disaster is coming), try to fill up the bathtubs and sinks in the house for more stored water.  There are special containers (called a "Water Bob") that you can use to store water in bathtubs more cleanly and efficiently; these are an especially good idea for those in areas prone to hurricanes.

Don't forget that you can access the water in your hot water heater if you really need it. That's an extra 30 or so gallons that many people forget about.

If you have extra freezer space, consider freezing some containers of water (leave a few inches at the top for expansion with freezing).  This will help keep your freezer food cold longer in a power outage, and can be used for extra drinking water if there is an extended emergency.

Also have paper plates and cups on hand so you won't have to waste water on washing dishes.  You want to keep as much of your water for drinking as possible, especially when you don't know how long an emergency will last.

Outside, you can harvest rainwater into barrels for non-drinking use, or learn how to convert it into drinkable water.

Replenishing Water Supplies

Stored drinking water is very important, but you can only store so much, and it only lasts so long.  Preparing for emergencies also means knowing how to convert water from the environment (creeks, lakes, rivers, rainwater barrels, puddles, ditches, etc.) into safe drinkable water.

Trust me, you do not want to drink water straight from these sources, even if it looks clean. (Read about the bad things that can be caught from untreated water here.)  Remember, a death toll is often not just from the disaster itself, but also from the diseases people catch from untreated water afterwards.  Just because the water looks clean doesn't mean that it is!

The bottom line is that you need to learn how to take non-potable water and make it safe for drinking.  Always pre-treat water you intend to drink.

You do this by:
  • filtering the water to get rid of sediments, particulates, and other nasty bits
  • purifying the water to get rid of viruses, bacteria, and other micro-organisms.
The first thing you do is strain or filter the water.  You can use coffee filters, paper towels, clean cloth (like a bandanna), clean t-shirts, or a layer of sand to strain the water. A ceramic or carbon filter does an even better job at getting rid of sediments and other particulates.

It is very important to filter water as your first step, as purifying cloudy/dirty water is much more difficult (and less effective) than purifying clear water.

Once the water is filtered, you need to purify it.  There are several ways to do this.

Boiling water is one of the best ways to purify it.  FEMA recommends boiling clear water at least one full minute at a complete rolling boil. (Some sources recommend 3-10 minutes, especially if the water is cloudy.)  If you live at a higher altitude, you need to boil the water longer, at least 3 minutes, because the altitude makes water boil at a lower temperature and thus is not as efficient at killing organisms quickly.

Boiling is the best way to purify water, but it has some disadvantages.  Boiling will make the water taste flat; you can fix this by pouring it back and forth between two containers to aerate it, or you can add a pinch of salt to it.  In addition, it takes a fair amount of fuel to boil large amounts of water.  In an emergency, you may not always have enough fuel or the right equipment to boil water. Therefore, it's important to have other ways to purify water.

Bleach (sodium hypochlorite) with no additives or fragrances can also be used to purify water.  Recommendations differ, but the most common guideline is 8 or 16 drops of bleach per gallon of water.  However, remember that liquid bleach degrades in a fairly short period of time, and older bleach may not do the job effectively.  Also remember that you need twice as much bleach if you are purifying cloudy water.

Some preppers use the powdered chlorine of pool shock treatments instead.  This form is calcium hypochlorite. The advantage of the powdered form is that it doesn't degrade nearly as fast as liquid bleach, is more powerful, and doesn't take up as much storage room.  However, remember that this is dangerous stuff, highly corrosive and under the right conditions, explosive too. It must be stored and used with extreme care.  Research this thoroughly if you plan to use this method!

Many people like Steri-Pens. They use ultra-violet light to purify the water.  They are very non-toxic, quick, portable, and easy to use.  However, it's more expensive, and most models need AA lithium batteries, which are expensive and eventually need to be replaced. You can buy the crank model (although users report this version is hard to use), store lots of extra batteries, or buy the model that comes with a solar charger for batteries.  Still, for quick emergency use or for traveling, a Steri-pen is a great option.

Solar water disinfection (also called SODIS) is a water purification option that doesn't take many resources.  You simply fill a small transparent PET plastic bottle or plastic bag with clear, pre-filtered water and leave it in the sun for 6 hours.  The UV rays in the sunlight will kill any micro-organisms, given enough time. The advantage of this method is that it's extremely cheap and works well in resource-poor areas where cooking fuel is unavailable or very expensive. The disadvantage of this method is that it takes a lot of time and good strong sunlight, which may not always be available. It doesn't work well on cloudy water, so good pre-filtering is vital.

There are also water purification tablets or drops.  These use chemicals like iodine or chlorine dioxide (a different form of chlorine than household bleach or pool shock) to treat the water.  Sample brands include Katadyn MicroPur tablets, Aquamira tablets or water treatment drops, and Potable Aqua tablets.  The main advantage of these is that they are extremely small, portable, and have a relatively long shelf life.  Another important advantage is that they are "residually effective" ─ once the water is treated, it will stay safe even if exposed to new pathogens, unlike boiling, UV light, or solar disinfection. The disadvantage is that they take a long time to fully treat the water, chemically-treated water doesn't taste great, and iodine tablets are contraindicated for people with thyroid issues.

Obviously, there are many ways to purify water, and every method has its pros and cons. The best method for your situation depends on the exact conditions you are facing. (You can read more about filtering and purifying water in the links at the end of this post.)

Water Safety Considerations

However you decide to filter and purify your water, don't forget that a vital part of water safety is making sure the water stays purified.  Many people do a lot of work to make their water safe, only to then contaminate it afterwards with poor handling techniques and unsafe practices.

Make sure your carrying receptacle, your storage receptacle, and your hands are clean so you don't contaminate the water you have worked so hard to make safe.

Have a way to extract and serve the clean drinking water that will not spread germs.  Don't have people sip from a common ladle, and don't let people dip their individual cups into the clean water.  Think about ways to serve the water to individuals while still keeping it pure.

Don't forget to wash/sterilize the outside of your water receptacles.  This includes the threads of any water bottles and lids.  Re-sterilize your water receptacles frequently.

Also make sure that you use only clean, treated water for cooking meals, preparing drinks, and brushing teeth. It doesn't matter if your drinking water is safe if you brush your teeth with untreated water!  Think about all your water usage, not just what you drink.

These practices cannot guarantee you 100% safe water, of course, but they go a long way towards keeping your water as safe as possible.  People often want to take hygiene short-cuts, especially in emergencies, but being scrupulous in your practices can save you a lot of illness later.


In conclusion, have sufficient emergency water storage on hand to use if your water supply is contaminated or cut off during a disaster.  Store about one gallon per person per day, and keep it in a dark, cool place.

Second, be ready to filter and purify other sources of water to make them potable if your emergency is prolonged.  Know different methods for filtering and purifying water so that you can use the method most suitable to the challenges of your situation.  Have back-up methods ready, just in case.

Third, be consistent and vigilant about safe water practices in an emergency.  Doing so may help you avoid or minimize the disease aftermath that often follows major disasters.

A safe emergency water supply is the most pressing, yet most neglected area of emergency preparedness. Other preps can wait.  If you do nothing else, do this.


Water Storage and Purification Articles
Places to Buy Water Storage Supplies


AsSnugAsABug said...

I love this post - you have not only considered how much water to store, but the practical considerations of doing so.

A very important consideration for emergencies and water storage is what to do for babies under 12 months. Room temp bottled water (even commercially bottled water) cannot be used to mix up powdered formula since the powder isn't sterile so it needs hot water to kill the bacteria in the powder. Hot water is also needed to clean bottles.

As you noted fuel and equipment for boiling water is a significant consideration. Fuel use for formula can be reduced by using ready to drink tetra packs of formula which are sterile, although these are expensive and have a short shelf life of a few months.

The water required to wash a bottle and the fuel to heat it can be reuced by using a cup to feed (much easier to clean) and/or by using disposable bottles (or buying a while bunch of cheap bottles and using a fresh one each feed, then discarding.)

When working out how much water and fuel or tetra packs are needed, you need to account for lots of waste (since there may be no electricity and therefore refrigeration) so any formula left in a tetra pack needs to be discarded etc.

To my knowledge Queensland Health are the only organisation/ department which provided evidence based information about formula use and water storage etc.

References: http://www.internationalbreastfeedingjournal.com/content/6/1/16

Maitri said...

Another water storage idea is the plastic tubs that we all have around the house to store our loads of crap, toys, etc. They're fairly cheap - $5 to 10 each - and can hold a lot of water. Keep a couple of clean ones wrapped in plastic in the basement/garage. You can put them in the bathtub to hold more than the tub would, or put them outside to catch rainwater.