You should have at least two weeks of water for each member of your family. At minimum, a person needs two quarts of water a day to maintain normal functioning. (Most people can usually live at least three days without water.) Of course, more water would be needed for personal hygiene and washing clothes.
[Those living in desert areas will probably need to make moving to another location part of their plan.]
Collecting water
1. [If you own a home:] Set up a rain barrel (or new plastic garbage can) that catches water from a gutter downspout. You can buy a “rain barrel downspout diverter,” and set up a system in advance. If you have no other option you could saw the metal downspout with a hacksaw and bend it so it goes into a plastic trash can.
Another option is to hang a clean plastic tarp between two clotheslines in such a way that one end dips into a bucket or clean plastic garbage can.
[If you have an apartment or group-living situation:] Talk to the property owner about being prepared to set up an emergency water collection system. Talk to other tenants, in order to get a large enough group to push for action. Be willing to pay for a portion of the emergency set-up. If the property owner is unwilling, a group can still buy the most essential materials needed to set up water collection.]
2. Also remember that a hot water heater has 30 to 50 gallons of water in it. Any small amounts of rust in the water can be filtered out with a clean piece of cloth.
3. Ahead of time, you can buy bottled water, but if you want to save money get empty 2-liter soda bottles, you can rinse them out well, refill them with tap water and then sanitized with bleach as described below. Leave some room for expansion, because the bottles might freeze when the heat goes off. (The water can usually be thawed in a window facing the sun, with a black backdrop or sitting on metal so that the black material or metal absorbs the heat.)
4. [Not a good alternative.] Water from pools and waterbeds often have toxic chemicals in them, and shouldn’t be used for drinking water unless filtered through activated charcoal. (See below.)
5. All things being equal, water that is flowing is likely cleaner than water that is stagnant. However, after a grid crisis, streams and rivers may possibly be contaminated by bacteria from even a small amount of untreated human feces, so boiling water from these sources or sterilizing with bleach are your only guaranteed options.
6. Solar still. If there’s no other way to get fresh water, small amounts of pure water can be produced by making a solar still. You will only need a sheet of clean plastic, a shovel, some rocks or 2x4s, some nonpoisonous vegetation and a clean pot or bowl to catch the water.
The principle of the solar still is that you will be using the sun’s heat to draw water out of vegetation and the ground, and condense it on the bottom of the plastic which is cooler. Here’s what is under the plastic:
Once you have dug a hole, and placed the vegetation in with the bowl in the center, you place the plastic (preferably clear) over top. The stone in the middle is to make the lowest point of the plastic be directly above the bowl. That way water that had condensed runs to the lowest point and then drips into the bowl.
If you were near the ocean, you could even put containers of sea water anywhere around the collecting bowl. If there is a lot of dew on ground cover and grass in the morning, you can collect it by wiping with a towel and put the towel in with the vegetation. In any case, put in freshly picked vegetation each day.
You must seal the perimeter of the hole, so that the humid aid does not escape. That’s the purpose of most of the stones or 2x4s. A solar still will only make about one cup to one pint of water a day. But it will be drinkable as long as the plastic and bowl are clean, and as long as the hole doesn’t contain funky stuff.
7. If you live in a climate that does not get much rainfall, and if you have the space, store about 50 gallons of water in a clean plastic trash can or plastic drum in your basement or garage. Change it out about every three months. It should be re-treated with bleach before drinking.
Sterilizing water
Any water you drink needs to be sterilized. Water for washing up should be odor-free and clear, and uncontaminated as far as you know, but does not need to be sterilized. (But do not get it in mouth, nose, eyes or open wounds.
1. You can sterilize a gallon of water with 8-16 drops of unscented household chlorine bleach (visually about 1/4 of a teaspoon) — double that amount for cloudy water. Stir or shake and let stand for 30 minutes. One teaspoon of bleach will disinfect five gallons. Immediately after treating, the water should have a slight smell of chlorine. If it doesn’t, repeat the process. The chlorine smell may be mildly unpleasant but that proves that it’s drinkable.
Bleach becomes weaker as it ages, and the concentration of different bleach brands varies seasonally. Buy at least three gallons of unscented bleach.
If there is any chance that the water was collected within 200 feet of buried human or animal feces (solid waste) then use the boiling method below. (Or use bleach after filtering through activated carbon below.) For the same reason, hands should be washed or sanitized after using the toilet, and before treating water with chlorine. This extra caution is needed because certain bacteria and viruses that cause severe diarrhea, vomiting and cramps are found in human and animal feces.
2. Pool shock that is 65% calcium hypochlorite and has no fungicides or algaecides is actually more stable than bleach. (Or you can search on “68% calcium hypochlorite” online.) Make a stock solution with one teaspoon (5.5 grams) in 1 gallon water. It lasts one month before losing potency. Don’t drink this, but use it in the following ways: Use three tablespoons of stock solution added to one gallon water, and let sit ½ hour before drinking. (Or add one quart stock solution to one gallon of water to sanitize dishes.)
3, If you don’t have bleach, boiling water is an alternative. After filtering water through cloth or a coffee filter, you can boil it (rolling boil) for at least one minute (or three minutes at altitudes higher than 2000 feet) to kill bacteria and viruses.
4. If you have clear 2-liter plastic diet soda bottles with caps, you can use them and sunlight if the outside temperature is not low. The UV light in sunlight sterilizes the water. (They must be clear bottles that didn’t have sugar, such as juice or regular soda. Residual sugar will feed bacteria.) Strain water through a clean cloth to remove all particulates. Halfway fill a 2-liter bottle, cap and then shake to oxygenate the water. Then fill the container all the way. Put in strong sunlight, preferably on its side, preferably on metal surface (a roof?), or a dark surface, so that more heat is transferred to the water in the bottle. Leave in direct sunlight for one day, or partly sunny conditions for two days. The UV light from the sun and the heat transferred are what sterilizes the water. CAUTION: Some microbes in UV treated water are not dead; they will have their means of reproduction turned “off” by the UV light. If the water is exposed to visible light without UV before consumption, the microbes can have their reproduction turned on again, and then multiply, causing illness if ingested. Therefore drink UV-treated water soon, or keep in the dark until you drink it.
5. An activated carbon filter is good for filtering out toxic chemicals but may not be sufficient for bacteria. It will also filter the chlorine out of bleach-treated water, so it should be used prior to bleach treatment. To make one you would need a two-liter bottle, coffee filter, activated carbon (available online or at pet stores where they sell equipment for fish tanks), fine sand, pea gravel. An alternative to the fine sand and pea gravel might be a layer of cloth or cotton to remove large particulates and debris, and doubling the layer of activated carbon.
Cut a 2-liter plastic bottle about 8 inches above where it begins to funnel toward the opening. Turn it upside-down. Put in the coffee filter, then at least 2-3 inches of activated carbon. Then two inches of the fine sand. Then a layer of pea gravel. Figure out a way to keep it from tipping over. (You could put it a clean bucket, along with some other 2-liter bottles to keep it from tipping over.) Put the homemade filter in a clean container that will catch the filtered water. Then pour water in the top and allow time for it to be filtered.
Use the filter until the water coming out is no longer clear. At that time, the activated carbon and the coffee filter need to be replaced.