Water is a necessity for life. Under normal circumstances a person cannot go three days without water. Hot weather and strenuous activity could lessen the time. An active person needs to drink two quarts/liters of water each day.
Water terminology can be confusing. Terms such as purified, disinfected, and filtered are not the same. Disinfected means that pathogens (germs, etc.) have been removed or killed but chemical contaminants may still be present. Purified water is usually super filtered to remove pathogens and contaminates. Filtered water depends on the degree by which it is filtered, so it can vary greatly.
For emergency storage the CDC recommends one gallon of water per person per day for a three-day minimum and if possible, a two-week supply. Purchased bottled water in 1-gallon containers is a good option for home storage. Most products have a one year best-by-date but will last longer. The FDA says that if purchased bottled water is stored properly (usually defined as a cool and dark place) it will store indefinitely but they recommend not over two years. Also recommended is that self-stored water in your own clean containers should be replaced every six months.
Boiling is an option to disinfect water. Boiling water for one minute at normal elevations will kill most pathogens. It should be boiled for three minutes for elevations of 6,500 feet or higher. If you have very questionable water, use a rolling boil for ten minutes just to be sure. Keep in mind, boiling water will not remove chemical pollutants.
If you are going into a primitive situation, you should carry some container in which you can boil water. We suggest a 32-ounce single-walled metal water bottle and a single-walled metal camp cup or camp pot. These containers should be stainless steel or titanium. They can often be purchased as a set where the water bottle nests inside the cup. Avoid ones that are painted or made from aluminum.
Caution, you should never boil water in a double-walled metal water bottle or metal double walled/insulated cup because they can explode on you. When using a metal water bottle to boil water, put it at the edge of the fire or suspend it above the fire to prevent warping.
Certain chemicals will disinfect water by eliminating pathogens from water. Chlorine bleach is the most common method, and it is available for purchase anywhere in the world.
Chlorine bleach has the active ingredient of sodium hypochlorite and can be used to disinfect water. If water is cloudy or muddy, first filter it with a t-shirt, coffee filter, etc. The bleach should be regular un-scented bleach; do not use scented or no-splash bleach. Bleach comes in different strengths, 6 percent, and 8.25 percent (concentrated).
Here are the formulas for disinfecting water for drinking:
Disinfect 1 liter/quart of water by adding 2 drops of either 6% or 8.25% bleach. Disinfecting 1 gallon add 8 drops of 6% bleach or 6 drops of 8.25% bleach. The formula for 4 gallons is 1/3 teaspoon for 6% bleach or 1/4 teaspoon for 8.25% bleach. The formulas can be doubled for cloudy or extremely cold water.
You should stir the treated water and let it stand at least thirty minutes before drinking or pouring to another container. Taste can be improved by letting it sit for a longer time or by pouring it back and forth between two clean containers.
You can also use 2% tincture of iodine (common first aid iodine). If you are disinfecting 1 liter/quart, add 5 drops of iodine. You can double the drops if the water is not clear. It should be stirred and let stand for thirty minutes before drinking or pouring to another container.
Water purification tablets can be purchased at pharmacies, sporting good departments, outdoor stores, or online. You should follow the instructions on the package.
Water Filter Products
There are many great water filter products available. Technology for water filtration has come a long way. You can purchase big household devices from companies like Berkey or smaller personal use filters.
Some that we are more familiar with, are the big Berkey household filters, and the personal size products made by LifeStraw, Grayl Geopress, Sawyer Mini, and Berkey Sport bottle. We have used most of these, but prefer the Grayl or Sawyer products for personal size use and the Berkey (large capacity) for home use.
When it comes to water filters, you do not need be a water specialist, but you need to know a little technical information to help protect yourself. There are water filters and there are water filters!
You need one that filters out harmful pathogens. The one that protects you from harmful pathogens should have 0.1-micron filter membranes that filters out most pathogens to the point of 99.99999%. Note: There are many water filters available that filter out lead and chlorine but not pathogens, be sure it filters out 99.99999% of pathogens such as E.coli, Giardia, Vibrio cholera, and Salmonella.
You need to keep hydrated but stay safe—don’t drink the contaminated water if possible. Going beyond three days without water in average conditions can be very dangerous, you can die from dehydration. Drinking questionable water may make you sick but can usually be treated.
The thin line between dehydration and drinking questionable water would be a difficult decision to make. A person would need to consider all their options and hopefully, never be faced with that dilemma. That being said, most survival experts say in an EXTREME situation where you do not have a means of disinfecting or purifying water, drink the water before dying of dehydration. This would be an extreme measure between life and death, not because we are just a little thirsty.
We are not health experts, water experts, survival experts, or microbiologists. Do your own research and ask a professional for advice. Follow the directions of the filter manufacturers, recommendations of product manufacturers such as Clorox, and emergency/health agencies such as the CDC, FDA, and FEMA.