Chap 3
2/6/05
STUDENT HANDOUT
WATER PROCUREMENT


TERMINAL LEARNING OBJECTIVE
In a survival situation, and given a survival kit, and water procurement materials, obtain potable water, in accordance with the references. (Chap 3 )
ENABLING LEARNING OBJECTIVES
(1) Without the aid of references, list in writing the types of incidental water, in accordance with the references. (Chap 3 a)

(2)
Without the aid of references, list in writing the hazardous fluids to avoid substituting for potable water, in accordance with the references. (Chap 3 b)

(3)
Without the aid of references, list in writing the methods for disinfecting water, in accordance with the references. (Chap 3 c)


(4) Without the aid of references and given a military bottle of water purification tablets, state in writing its self-life, in accordance with the references. (Chap 3 d)

(5)
Without the aid of references, and given the water temperature and chemical concentration, state in writing the contact time, in accordance with the references. (Chap 3 e)

(6)
Without the aid of references, construct a solar still , in accordance with the references. (Chap 3 f)

OUTLINE
1 . WATER INTAKE

a. Thirst is not a strong enough sensation to determine how much water you need.

b. The best plan is to drink, utilizing the OVER DRINK method. Drink plenty of water anytime it is available and particularly when eating.

c. Dehydration is a major threat. A loss of only 5 % of your body fluids causes thirst, irritability, nausea, and weakness; a 10% loss causes dizziness, headache, inability to walk, and a tingling sensation in limbs; a 15% loss causes dim vision, painful urination, swollen tongue, deafness, and a feeling of numbness in the skin; also a loss of more than 15% body fluids could result in death.


d. Your water requirements will be increased if:

(1) You have a fever.

(2) You are experiencing fear or anxiety. (3) You evaporate more body fluid than necessary. (i.e., not using the proper shelter to your advantage)

(4) You have improper clothing.


(5) You ration water.

(6) You overwork.

2. INCIDENTAL WATER. (Chap 3 a)

a. During movement, you may have to ration water until you reach a reliable water source. Incidental water may sometimes provide opportunities to acquire water. Although not a reliable or replenished source, it may serve to stretch your water supply or keep you going in an emergency. The following are sources for incidental water:

(1) Dew. In areas with moderate to heavy dew, dew can be collected by tying rags or tuffs of fine grass around your ankles. While walking through dewy grass before sunrise, the rags or grass will saturate and can be rung out into a container. The rags or grass can be replaced and the process is repeated.


(2) Rainfall. Rainwater collected directly in clean container or in plants that contain no harmful toxins is generally safe to drink without disinfecting. The survivor should always be prepared to collect rainfall at a moments notice. An inverted poncho works well to collect rainfall.



3. HAZARDOUS FLUIDS (Chap 3 b)

a. Survivors have occasionally attempted to augment their water supply with other fluids, such as alcoholic beverages, urine, blood, or seawater. While it is true that each of these fluids has a high water content, the impurities they contain may require the body to expend more fluid to purify them. Some hazardous fluids are:

(1) Sea water. Sea water in more than minimal quantities is actually toxic. The concentration of sodium and magnesium salts is so high that fluid must be drawn from the body to eliminate the salts and eventually the kidneys cease to function.


(2) Alcohol. Alcohol dehydrates the body and clouds judgment. Super-cooled liquid, if ingested, can cause immediate frostbite of the throat, and potential death.


(3) Blood. Blood, besides being salty, is a food. Drinking it will require the body to expend additional fluid to digest it.


(4) Urine. Drinking urine is not only foolish, but also dangerous. Urine is nothing more than the body’s waste. Drinking it only places this waste back into the body, which requires more fluid to process it again.

4. WATER QUALITY. Water contains minerals, toxins, and pathogens. Some of these, consumed in large enough quantities may be harmful to human health. Pathogens are our primary concern. Pathogens are divided into Virus, Cysts, Bacteria, and Parasites. Certain pathogens are more resistant to chemicals and small enough to move through microscopic holes in equipment (i.e., T-shirt, parachute). Certain pathogens also have the ability to survive in extremely cold water temperatures. Pathogens generally do not live in snow and ice. Water quality is divided into three levels of safety with disinfection as the most desired level, then purified, followed by potable.

a. Disinfection. Water disinfection removes or destroys harmful microorganisms. Giardia cysts are an ever-present danger in clear appearing mountain water throughout the world. By drinking non-potable water you may contract diseases or swallow organisms that could harm you. Examples of such diseases or organisms are: Dysentery, Cholera, Typhoid, Flukes, and Leeches.

b. Remember, impure water, no matter how overpowering the thirst, is one of the worst hazards in a survival situation. c. The first step in disinfecting is to select a treatment method. The two methods we will discuss are as follows: (Chap 3 c)

(1) Heat. The Manual of Naval Preventive Medicine (P-5010) states that you must bring the water to a rolling boil before it is considered safe for human consumption. This is the most preferred method.

(a) Bringing water to the boiling point will kill 99.9% of all Giardia cysts. The Giardia cyst dies at 60OC and Cryptosporidium dies at 65C. Water will boil at 14,000’ at 86OC and at 10,000’ at 90C. With this in mind you should note that altitude does not make a difference unless you are extremely high.

(2) Chemicals. There are numerous types of chemicals that can disinfect water. Below are a few of the most common. In a survival situation, you will use whatever you have available.

(a) Iodine Tablets.

(b) Chlorine Bleach.

(c) Iodine Solution.

(d) Betadine Solution. 

(e) Military water purification tablets. (Chap 3 d) These tablets are standard issue for all DOD agencies. These tablets have a shelf-life of four years from the date of manufacture, unless opened. Once the seal is broken, they have a shelf-life of one year, not to exceed the initial expiration date of four years.

49703
Month / Year / Batch Number

(3) Water Disinfection Techniques and Halogen Doses.

Iodination 
techniques

Added to
1 liter or
quart of water
Amount 
for
4 ppm
Amount 
for
8 ppm
Iodine tablets

Tetraglcine
hydroperiodide
EDWGT

Potable
AquaGlobaline
½ tablet
1 tablet
2% iodine 
solution
(tincture)
0.2 ml
5 gtts
0.4 ml
10 gtts
10% 
povidone
-iodine
solution*
0.35 ml
8 gtts
0.70 ml
16 gtts




Chlorination 
techniques
Amount 
for
5 ppm
Amount 
for
10 ppm
Household  
bleach 5%

Sodium
hypochlorie
0.1 Ml
2 gtts
0.2 ml
4 gtts
AquaClear 

Sodium
dichloro-
isocyanurate


1 tablet
AquaCure, 
AquaPure,
Chlor-floc
Chlorine plus
flocculating
agent


8 ppm
1 tablet

*Providone-iodine solutions release free iodine in levels adequate for disinfection, but scant data is available.

Measure with dropper (1 drop=0.05 ml) or tuberculin syringe

ppm - part per million 
gtts - drops
ml - milliliter
Concentration of Contact time in minutes at various water temperatures (Chap 3 e) halogen


5 C/
40 F
15 C/
60 F
30 C/
85 F
2 ppm

240

180

60

4 ppm

180

50

45

8 ppm

60

30

15


Note:
These contact times have been extended from the usual recommendations to account for recent data that prolonged contact time is needed in very cold water to kill Giardia cysts.

Note:
chemicals may not destroy Cryptosporidium. d. Purification. Water purification is the removal of organic and inorganic chemicals and particulate matter, including radioactive particles. While purification can eliminate offensive color, taste, and odor, it may not remove or kill microorganisms.

(1) Filtration. Filtration purifying is a process by which commercial manufacturers build water filters. The water filter is a three tier system. The first layer, or grass layer, removes the larger impurities. The second layer, or sand layer, removes the smaller impurities. The final layer, or charcoal layer (not the ash but charcoal from a fire), bonds and holds the toxins. All layers are placed on some type of straining device and the charcoal layer should be at least 5-6 inches thick. Layers should be changed frequently and straining material should be boiled. Remember, this is not a disinfecting method, cysts can possibly move through this system.

W A T E R

F
I L
T E R
 
 

(2) Commercial Water Filters. Commercial water filters are generally available in most retail stores and may be with you. Understanding what the filter can do is the first step in safeguarding against future illnesses.

(a) A filter that has a .3 micron opening or larger will not stop Cryptosporidium.


(b) A filter system that does not release a chemical (i.e., iodine) may not kill all pathogens.


(c) A filter that has been overused may be clogged. Usage may result in excessive pumping pressure that can move harmful pathogens through the opening. 

e. Potable. Potable indicates only that a water source, on average cover a period of time, contains a "minimal microbial hazard," so the statistical likelihood of illness is acceptable.

(1) Sedimentation. Sedimentation is the separation of suspended particles large enough to settle rapidly by gravity. The time required depends on the size of the particle. Generally, 1 hour is adequate if the water is allowed to sit without agitation. After sediment has formed on the bottom of the container, the clear water is decanted or filtered from the top. Microorganisms, especially cysts, eventually settle, but this takes longer and the organisms are easily disturbed during pouring or filtering. Sedimentation should not be considered a means of disinfection and should be used only as a last resort or in an extreme tactical situation.
5. SOLAR STILLS. (Chap 3 f)
a. Solar stills are designed to supplement water reserves. Contrary to belief, they will not provide enough water to meet the daily requirement for water. b. Above-Ground Solar Still. This device allows the survivor to make water from vegetation. To make the aboveground solar still, locate a sunny slope on which to place the still, a clear plastic bag, green leafy vegetation, and a small rock.

(1) Construction.

(a) Fill the bag with air by turning the opening into the breeze or by "scooping" air into the bag.
(b) Fill the bag half to three-quarters full of green leafy vegetation. Be sure to remove all hard sticks or sharp spines that might puncture the bag.

CAUTION
Do not use poisonous vegetation. It will provide poisonous liquid.


(c) Place a small rock or similar item in the bag.


(d) Close the bag and tie the mouth securely as close to the end of the bag as possible to keep the maximum amount of air space. If you have a small piece of tubing, small straw, or hollow reed, insert one end in the mouth of the bag before tying it securely. Tie off or plug the tubing sothat air will not escape. This tubing will allow you to drain out condensed water without untying the bag.


(e) Place the bag, mouth downhill, on a slope in full sunlight. Position the mouth of the bag slightly higher than the low point in the bag.

(f) Settle the bag in place so that the rock works itself into the low point in the bag.

(g) To get the condensed water from the still, loosen the tie and tip the bag so that the collected water will drain out. Retie the mouth and reposition the still to allow further condensation.


(h) Change vegetation in the bag after extracting most of the water from it.


(i) Using 1 gallon zip-loc bag instead of trash bags is a more efficient means of construction.

ABOVE GROUND SOLAR STILL

c. Below-Ground Solar Still. Materials consist of a digging stick, clear plastic sheet,container, rock, and a drinking tube.

(1) Construction.

(a) Select a site where you believe the soil will contain moisture (such as a dry streambed or a low spot where rainwater has collected). The soil should be easy to dig, and will be exposed to sunlight.

(b) Dig a bowl-shaped hole about 1 meter across and 24 inches deep. (c) Dig a sump in the center of the hole. The sump depth and perimeter will depend on the size of the container you have to place in it. The bottom of the sump should allow the container to stand upright.

BELOW GROUND SOLAR STILL

(d) Anchor the tubing to the container's bottom by forming a loose overhand knot in the tubing. Extend the unanchored end of the tubing up, over, and beyond the lip of the hole. 


(e) Place the plastic sheet over the hole, covering its edges with soil to hold in place. Place a rock in the center of the plastic sheet.
 

(f) Lower the plastic sheet into the hole until it is about 18 inches below ground level. Make sure the cone's apex is directly over the container. Ensure the plastic does not touch the sides of the hole because the earth will absorb the moisture.

(g) Put more soil on the edges of the plastic to hold it securely and prevent the loss of moisture.

(h) Plug the tube when not in use so that moisture will not evaporate. (i) Plants can be placed in the hole as a moisture source. If so, dig out additional soil from the sides.

(j) If polluted water is the only moisture source, dig a small trough outside the hole about 10 inches from the still's lip. Dig the trough about 10 inches deep and 3 inches wide. Pour the polluted water in the trough. Ensure you do not spill any polluted water around the rim of the hole where the plastic touches the soil. The trough holds the polluted water and the soil filters it as the still draws it. This process works well when the only water source is salt water.

(k) Three stills will be needed to meet the individual daily water intake needs.
REFERENCE:

1. FM 21-76, Survival, 1992.
2. Paul Auerbach, Wilderness Medicine, 3rd Edition 1995.