More than three-fourths of your body is composed of fluids. Fluids are continually lost due to heat, cold, stress, and exertion. The fluid your body loses must be replaced every day for you to live, especially in hot areas where you need a gallon a day while losing so much through sweating. Even in cold or freezing areas, you need a minimum of 2 quarts/liters of water a day to maintain efficiency. Cooking typically requires water as well so the ability to ensure CLEAN WATER is at the top of any survival task list. Remember – it takes time to prepare raw water for drinking or cooking. Plan early so it’s ready for use before you get thirsty.
Water may be obtained from various outdoor sources including the following:
Surface Water is considered the best source of water. Water can be procured from lakes, rivers, streams, and ponds. Moving water or large bodies of water are generally considered less contaminated due to the aeration which significantly decreases growth of bacteria, algae, and fungus. Adequate disinfectant is required.
When considering salt water, however, the water must be desalinated and disinfected before it is used. This requires the use of a Reverse Osmosis Water Purification Unit (ROWPU). Salt water cannot be easily purified for individual use.
Ground Water is water procured from wells and springs. Ground water is generally less susceptible to chemical and biological pollution than other sources and is considered a great source during an emergency. The quantity and quality
may be hard to determine without proper equipment. Adequate disinfectant is required. Ground water may or may not be used for individual use, depending on its accessibility.
Local Community municipal water system is a potential water source. Even though there may be a water treatment system in place, it must be considered a raw water source until it is confirmed potable.
The potential for accidental or intentional contamination of the water system by natural disaster, vandals or even terrorism should be considered.
Consider the pH scale when selecting a water source, and when testing potability.
The pH scale measures how acidic an object is. Objects that are not very acidic are called basic. The scale has values ranging from zero (the most acidic) to 14 (the most basic).
As you can see from the pH scale below, pure water (aka sweet water) has a pH value of 7.
Some remote desert locations have "bad water" that can kill you so be aware - if animals don't frequent a body of water, it's nasty!
Water Purification Basics:
Purify all water before drinking, either (1) by boiling; or (2) by using water purification tablets or (3) by using household bleach, HTH, or iodine.
Rainwater collected directly in clean containers or on plants is generally safe to drink without purifying.
Salt water cannot be purified for individual use.
Don’t drink urine or sea water -- the salt content is too high. Old bluish sea ice can be used, but new, gray ice may be salty.
Glacier ice is safe to melt and drink.
NOTE: For best results, first FILTER the water and then DISINFECT the water to remove bacteria, parasite, and virus threats, see below.
*Chemicals like hydrocarbons, insecticides, cyanuric acid in swimming pool water, and/or metals are not removed simply by boiling and disinfecting water. These require extra steps to remove.
For civilian water purification tablets, use chlorine dioxide type like Katadyn MicroPur MP1. It destroys viruses and bacteria in 15 min., Giardia in 30 min. and Cryptosporidium in 4 hrs (a microorganism that is the most common cause of
upset stomach/diarrhea in untreated water in the US).
Unlike iodine, chlorine dioxide does not discolor water, nor does it give water an unpleasant taste. It also doesn’t leave behind any by-products in treated water, unlike other purification agents like bleach or iodine.
These have a 5-year shelf life from date of mfg.
Potable Aqua brand or military type iodine tablets contain tetra glycine hydro periodide, which releases titratable iodine.
The procedures for disinfecting small quantities of water with these tablets are as follows:
- Fill the water bottle with the cleanest, clearest water available.
- Add two iodine tablets to each quart/liter of water.
- Tincture of iodine, 2 percent, may be used in place of the tablets. Five drops of the liquid are equivalent toone iodine tablet.
- Put the cap on the container. Shake to dissolve the tablets.
- Wait 5 min, loosen the cap slightly and tip the container over to allow leakage around the cap threads.
- Tighten the cap and wait an additional 30 min before drinking.
- For personal hydration systems (Camelbak etc) use four iodine tablets for 70- or 72-oz water reservoirs an dsix for 100- or 102-oz reservoirs and allow 30 min of contact time before drinking the water.
*Caution: Iodine is not effective against Cryptosporidium.
1. BOIL WATER if you are unsure of its cleanliness! Water boils at 212° F (100° C). 212° F as a boiling point is usually at sea-level. The boiling temperature will change with the altitude. The higher you are above sea-level, the lower the boiling point of water. Example: At 7,500 feet, water boils at about 198° F.
If water is cloudy, let it settle and filter it through a clean cloth, shirt, towel, or coffee filter BEFORE boiling. Then:
- Bring water to a rolling boil for at least one minute. At altitudes above 5,000 feet (1,000 meters), boil water for at least three minutes.
- Let water cool naturally and store it in clean containers with covers.
- To improve the flat taste of boiled water, add one pinch of salt to each quart or liter of water, or pour the water from one clean container to another several times.
*Note: Boiling for a full five (5) minutes kills all the rare bacteria and pathogens that are able to survive in boiling water temperatures (E.coli, Giardia) per the CDC.
*Note: Chemicals like hydrocarbons, insecticides, cyanuric acid in swimming pool water, and/or metals are not removed simply by boiling and disinfecting water. These require extra steps to remove.
2. DISINFECT water using Sodium Hypochlorite (common household bleach). Only use regular, unscented chlorine bleach products that are suitable for household disinfection and sanitization as indicated on the label.
The label may say that the active ingredient contains 6 or 8.25% of sodium hypochlorite. Do not use scented, color safe, or bleaches with added softeners or cleaners.
If water is cloudy, let it settle and filter it through a clean cloth, paper towel, or coffee filter before disinfection. Then:
- Locate a clean dropper from your medicine cabinet or emergency supply kit.
- Locate a fresh liquid chlorine bleach or liquid chlorine bleach that was stored at room temperatures for less than one year.
- Use the table below as a guide to decide the amount of bleach you should add to the water, for example, 8 drops of 6% bleach, or 6 drops of 8.25% bleach, to each gallon of water. Double the amount of bleach if the water is cloudy, colored, or very cold.
- Stir and let stand for 30 minutes. The water should have a slight chlorine odor. If it doesn’t, repeat the dosage and let stand for another 15 minutes before use.
- 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.
*Note: Common liquid household bleach may contain six percent (6%) or 8.25% sodium hypochlorite. Pay attention to what you are using, see chart below:
Volume of Water--------Amount of 6% Bleach to Add*---Amount of 8.25% Bleach to Add*
- 1 quart/liter--------2 drops/0.1 mL---------------------2 drops/0.1 mL
- 1 gallon------------8 drops/0.4 mL---------------------6 drops/0.3 mL
- 2 gallons-----------16 drops (1/4 tsp)------------------12 drops (1/8 teaspoon)
- 4 gallons-----------1/3 teaspoon-----------------------1/4 teaspoon
- 8 gallons-----------2/3 teaspoon-----------------------1/2 teaspoon
3. ALTERNATIVE DISINFECTION using HTH aka Granular Calcium Hypochlorite. HTH is a common pool or hot tub disinfectant usually found in a dry solid or powder form.
*CAUTION: HTH is a very powerful oxidant! Follow the instructions on the label for safe handling and storage of this chemical. For your safety, do this in a well-ventilated area and wear eye protection.
The first step is to make a chlorine solution that you will use to disinfect your water:
- Add one heaping teaspoon (approximately ¼ ounce) of high-test granular calcium hypochlorite (HTH) to two (2) 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.
4. ALTERNATIVE DISINFECTION using common household iodine (“tincture of iodine”).
You may have iodine in your medicine cabinet or first aid kit. Add five (5) drops of 2% tincture of iodine to each quart or liter of water that you are disinfecting. If the water is cloudy or colored, add ten (10) drops of iodine.
Stir and let the water stand for at least 30 minutes before use.
5. FILTRATION is a technique where water is passed through an absorbent, porous media to remove contamination (typically a ceramic or charcoal based filter).
Microfiltration facts: Filtration of particles is usually measured in microns. The symbol for micron is μm. A microfiltration filter has an average pore size of approximately 0.1 to 0.2 μm (pore size ranges vary by filter from 0.05 μm to 5 μm)
- Microfiltration has a very high effectiveness in removing protozoa (for example, Cryptosporidium, Giardia)
- Microfiltration has a moderate effectiveness in removing bacteria (forexample, Campylobacter, Salmonella, Shigella, E. coli)
- Microfiltration is not effective in removing viruses (for example, Enteric (fecal-oral), Hepatitis A, Norovirus, Rotavirus)
- Microfiltration is not effective in removing chemicals.
Pre- and post-filters are often incorporated along with the reverse osmosis membrane itself.
A reverse osmosis filter has a pore size of approximately 0.0001 μm.
- Reverse Osmosis Systems have a very high effectiveness in removing protozoa (for example, Cryptosporidium, Giardia);
- Reverse Osmosis Systems have a very high effectiveness in removing bacteria (for example, Campylobacter, Salmonella, Shigella, E. coli);
- Reverse Osmosis Systems have a very high effectiveness in removing viruses (for example, Enteric, Hepatitis A, Norovirus, Rotavirus);
- Reverse Osmosis Systems will remove common chemical contaminants (metal ions, aqueous salts), including sodium, chloride, copper, chromium, and lead.
- Reverse Osmosis may reduce arsenic, fluoride, radium, sulfate, calcium, magnesium, potassium, nitrate, and phosphorous.
- Distillation Systems have a very high effectiveness in removing protozoa (for example, Cryptosporidium, Giardia);
- Distillation Systems have a very high effectiveness in removing bacteria (for example, Campylobacter, Salmonella, Shigella, E. coli);
- Distillation Systems have a very high effectiveness in removing viruses (for example, Enteric, Hepatitis A, Norovirus, Rotavirus);
- Distillation Systems will remove common chemical contaminants, including arsenic, barium, cadmium, chromium, lead, nitrate, sodium, sulfate, and many organic chemicals.
- Ultraviolet Treatment Systems have a very high effectiveness in removing protozoa (for example, Cryptosporidium, Giardia);
- Ultraviolet Treatment Systems have a very high effectiveness in removing bacteria (for example, Campylobacter, Salmonella, Shigella, E. coli);
- Ultraviolet Treatment Systems have a high effectiveness in removing viruses (for example, Enteric, Hepatitis A, Norovirus, Rotavirus);
- Ultraviolet Treatment Systems are not effective in removing chemicals.