Water Sources and Indicators

3-5. Almost any environment has water present to some degree. Table 3-1, on page 3-2, lists possible sources of water in various environments. It also provides information on how to procure the water as well as how to make it potable.

Procuring Water

3-6. Procure water using a variety of different methods depending upon the source. The first step to procuring water is obtaining a container that can temporarily hold water to enable purification and that can be sealed for long-term storage. If issued containers are unavailable or damaged, isolated persons can improvise them from non-nonporous materials. Water containers can be constructed out of plastic bags, condoms (placed inside a sock to protect the bladder), bamboo segments, life preserver units, birch bark and pitch containers; as well as gourds, tarps, sheets of plastic and waterproof evasion charts.

Table 3-1. Means to make potable water

Table 3-1. Means to make potable water (continued)

3-8. Water containers in a cold weather environment should be stores upside down to enable its use when frozen. Since water freezes from top to bottom, any unfrozen water would be on the bottom where it is accessible. If the container is stored improperly ice will block the opening making the water inaccessible.

3-9. Isolated persons always take into consideration the safety of different sources and procure water from the safest source. Some sources such as plants and certain types of precipitation do not require purification and make a great choice for personnel who do not have the ability to purify water. Other sources can provide large quantities of water on demand, but require purification. Avoid water that has a foul odor or smell, and water potentially contaminated with toxins, faster moving water contains more oxygen and typically fewer harmful microorganisms than stagnant water and is usually a better option to procure water. The first step to procuring water is obtaining a container that can temporarily hold water to enable purification or that can sealed for long-term storage.

Rain, Snow, and Ice

3-10. Fresh rainwater collected into containers does not require purification. However, rain that runs down leaves and other vegetation on its way to the container can contaminate the water and should be purified. If the isolated person allows rain to wash contaminants off overhead leaves for at least 15 min, it is safe to drink immediately.

3-11. Collect rainwater by putting out improvised nonporous items to catch the rains as it falls from the sky. Isolated persons can also construct an elaborate device that will catch a large volume of rain while they perform other tasks. An example would be the bamboo rain catcher (see figure 3-1 on page 3-4). Construct this apparatus by making a set of framework off the ground out of bamboo. Split the bamboo in half and layered in a shingle-type formation in a flat surface formation. Place one end higher than the other with a collection channel placed at the bottom that channels the water to a collection container.

3-12. Use fresh, clean snow as a water source. Place containers filled with snow near a fire or between clothing layers to allow body heat to melt it. Adding water to snow will help it melt faster. Avoid directly eating snow as it lowers the body’s core temperature and requires the body to use more energy reserves than if the snow is heated externally.

3-13. Isolated persons can construct a water machine that will produce water from snow while they are completing other tasks. Place snow on any porous material (such as cotton or parachute nylon), gathering up the edges, and suspending the “bag” of snow from any support structure near a fire. Radiant heat will melt the snow, and water will drip to the lowest part of the bag. Place a water container under the snow machine to collect the water. The isolated person only needs to fill the machine with snow as required and empty the container of water when full. Snow and ice are no purer than the water from which they come (see figure 3-2).

3-14. Sea ice provides a good source of water. Isolated persons use old sea ice that is crystalline and deep bluish or black in color and has rounded edges when shattered. This type of old sea ice has the least amount of salt content and is drinkable. Avoid gray-colored or opaque sea ice due to its high salt content. New sea ice has sharp edges when shattered. Do not consume until it is desalted. Ice provides a more concentrated source of water than snow and requires less heat to do so. Melt snow or ice with minimal effort by placing it on a dark piece of material in sunlight.

Dew

3-15. Collect dew by tying fine grasses, a sponge, or cloth around the lower legs and ankles and walking through tall grass to soak up the dew water. Collect up to one quart of water or more by wringing it out into a container.

Water from Plants

3-16. If no open water source is found, there are plants in many areas around the globe that will produce drinking water. Caution is taken to prevent obtaining water from a poisonous source. Positive plant identification is the safest and easiest method for determining whether water inside the plant is potable. Water procured from the inside of a plant, when sealed off from outside contaminants does not need to be purified, but the means are available to do so it is recommended as a precaution.

Green Bamboo

3-17. Green bamboo stores water inside its individual segments. Shake the plant to listen for water sloshing inside the plant. If it contains water, the bamboo is broken open to obtain it. The top of the green bamboo can be cut and the end bent and tied over toward the ground with a water container under the cut top to let the water drain out for collection (see figure 3-3).

Water Vines

3-18. Many different types of vines contain drinkable water. Vines can be 50 feet to several hundred feet in length and 1 to 6 inches in diameter. They grow from the ground at the base of a tree and climb toward the canopy to obtain sunlight. Water vines are usually soft and easily cut. Small vines may be twisted or bent easily and are usually heavy because of the water content. The water from these vines should be tested to ensure it is safe unless positive identification of safe plant is made. Use these steps to test the water from these vines:

• Step 1. Notch the vine and watch for sap running from the cut. If milky sap is observed, the vine should be discarded. If not, move to step 2.
• Step 2. Cut out a section of the vine and hold it vertically observe the liquid as it flows out. If the liquid is cloudy or milky-colored, the vine is discarded. If not, move to step 3.
• Step 3. Let some of the liquid flow into the palm of the hand and observe it. If the liquid changes color it is discarded. If not, it is tasted. Any liquid that has a woody or sweet taste is safe for drinking. Vines that produce a liquid with a sour or bitter taste are avoided.

3-19. Once the water is determined safe for drinking, it can be procured in larger quantities. The first cut is made high on the vine above the ground. The second cut is made low near the ground. This method maximizes the amount of water procured per vine and allows the water to freely flow through the plant. When drinking water from the vine, isolated persons should avoid placing their lips on the bark as it may contain skin irritants.

3-20. Obtain water from the rattan palm and spiny bamboo in the same manner as from vines. (See figure 3-4). The slender stem or runner of the rattan palm is an excellent water source. The joints are overlapping in appearance, as if one section is fitted inside the next.

Banana Plants

3-21. Water can be obtained from banana plants by cutting a banana plant down into a long section which can be easily handled. Take the section apart by slitting from one end to the other and pulling off the layers one at a time. A strip 3 inches wide, the length of the section, and just deep enough to expose the cells should be removed from the convex side. Fold this section toward the convex side to force the water from the cells of the plant. The layer must be squeezed gently to avoid forcing out any tannin (an astringent which has the same effect as alum) into the water.

3-22. Another technique for obtaining water from the banana plant is by making a banana-well. The tree is cut down leaving a 12 inch (30 centimeter) stump. A bowl is hollowed out of the plant stump, fairly close to the ground, by cutting out and removing the inner section. (see figure 3-5). Water will be drawn into the bowl by the plant’s roots, the first of which contains a concentration of tannin that is bitter and should not be consumed. Bitter water is discarded until it is palatable, about 3 fillings. A leaf from the banana or other plant should be placed over the bowl while it is not being used in order to prevent contamination. The roots provide refill the bowl for approximately 4 days. This same method can be used to procure water from plantain trees and sugarcane.

Water Trees

3-23. Water trees in the tropics can be a valuable source of water. It is important to properly identify the tree as the sap of some trees can be very dangerous. Water trees can be identified by their blotched bark which is fairly thin and smooth. The leaves are large, leathery, fuzzy, and evergreen, and may grow as large as 8 or 9 inches. The trunks may have short outgrowths with fig-like fruit on them or long tendrils with round fruit comprised of corn kernel-shaped nuggets.

3-24. The tree can be tapped in the same manner as a rubber tree, with either a diagonal slash or a “V.” When the bark is cut into, it will exude a white sap, which, if ingested, causes temporary irritation of the urinary tract. This sap dries up quite rapidly and can easily be removed. The cut should be continued into the tree with a spigot (bamboo, knife, or such) at the bottom of the tap (“V”) to direct the water into a container. The water flows from the leaves back into the roots after sundown, so water can be procured from this source only after sundown or on overcast (cloudy) days.

Coconut Water

3-25. Mature coconuts contain an oil that can cause diarrhea when consumed in excess. There is little concern if used in moderation or with a meal, but the symptoms may be present if consumed on an empty stomach. Green, unripe coconuts about the size of a grapefruit are the best for use because the fluid can be taken in large quantities without negative side effects. There are more fluids and less oil in unripe coconuts, so there is less possibility of diarrhea. Figure 3-6, on page 3-8 depicts how isolated persons may locate, obtain, and open a coconut for nutrients. The husk is first removed to expose the nut. The nut is then cracked or notched open to access the liquid inside.

Vegetation Bag Still

3-26. Water can also be collected through the use of a vegetation bag still (see figure 3-7 on page 3-9). This method requires a plastic bag filled one-half to three-fourths full with non-poisonous vegetation. A rock is then placed in the bag. Before closing the bag, it is filled with air by turning the opening into the wind. It is then closed air-tight, around the tubing if used, and placed in the hot sun, optimally located on a sun-facing slope. The sunlight heats the vegetation and distills the water vapor out of the vegetation to collect onto the surface of the bag and down to a collection point that has been modified by creating a low spot with a rock. Surgical tubing or a reed is used like a straw to drink directly from the bag. All condensed water is collected before the sun goes down. When dusk arrives, the water draws back into the vegetation. The vegetation bag is changed after extracting most of the water to ensure maximum output.

Transpiration Bag Still

3-27. A water transpiration bag still is very similar to the vegetation bag still, only easier (see figure 3-8, page 3-10). The isolated person ties a plastic bag around the leafy branch of a tree or plant. The process requires an airtight seal and that the branch be weighted to make a collection point for the water. All water is collected before sundown so the plant does not intake the water into its system. The same limb can be used for 3 or 5 days without causing long-term harm to the limb. It heals itself within hours of removing the bag.

Below-Ground Solar Still

3-28. To make a belowground solar still, isolated persons will need a digging tool, a container, a clear plastic sheet, and a rock (see figure 3-9 on page 3-11). A tube can be used as a straw to drink the water without disturbing the still. When the still is opened, the moist, warm air that has been accumulated is released and the distillation process is slowed.

3-29. A site is selected where the isolated person believes the soil contains moisture (such as a dry streambed or a low spot where rainwater has collected) to pull water from the soil. The soil at this site should be easy to dig and sunlight must hit the site most of the day. Plants can also be cut and placed along the wall of the still as the water source. Additionally, the belowground still can be used to separate drinkable water from saltwater or polluted water.

3-30. Use the following steps to construct a belowground solar still:

• Step 1. Dig a bowl-shaped hole about 3 feet (1 meter) across and 24 inches (60 centimeters) deep.
• Step 2. Dig a sump in the center of the hole. The sump’s depth and perimeter will depend on the size of the container that to be placed in it. The bottom of the sump should allow the container to stand upright.
• Step 3. Anchor the tubing to the container’s bottom by forming a loose overhand knot in the tubing.
• Step 4. Place the container upright in the sump.
• Step 5. Extend the unanchored end of the tubing up, over, and beyond the lip of the hole. Place the plastic sheet over the hole, covering its edges with soil to hold it in place.
• Step 6. Place a rock in the center of the plastic sheet.
• Step 7. Lower the plastic sheet into the hole until it is about 16 inches below ground level. It now forms an inverted cone with the rock at its apex. Ensure that the cone’s apex is directly over the container. Also, ensure that the plastic cone does not touch the sides of the hole because the earth will absorb the condensed water.
• Step 8. Put more soil on the edges of the plastic to hold it securely in place and to prevent the loss of moisture.
• Step 9. Plug the tube when not in use to keep the moisture from evaporating and to keep insects out.

3-31. If saltwater or polluted water is used as the moisture source, dig a small trough outside the hole about 10 inches deep and 3 inches wide. Pour the water in the trough. Be sure not to spill any polluted water around the rim of the hole where the plastic sheet touches the soil. The trough holds the water and the soil filters it as the still draws it. The water then condenses on the plastic and drains into the container. The process works extremely well for polluted and saltwater. Three or more of these devices should be constructed to produce enough water for one person’s needs.

3-32. Isolated persons should attempt to control energy output when building these devices to control body water loss that would defeat the purpose of the device. Use caution as this process is time and energy intensive and may not be worth the return of water quantity.

Beach Wells and Salt Water

3-33. Saltwater must be desalinated before drinking. This can be done by using a desalination pump or solar still. When on a saltwater beach isolated persons primarily search for freshwater. Freshwater can be procured through the use of a beach well, a hole behind the first group of sand dunes dug deep enough to hit the water table (see figure 3-10 on page 3-12). Wood is placed around the sides of the hole to stabilize it and control cave-ins from the sand. This water should be fresh and salt free. Alternately, isolated persons can dig a hole on the shoreline and let it fill with saltwater. Superheated rocks are then placed into the water resulting in steam, which is collected with a rag and transferred to a holding container, salt free and ready to drink.

Seepage Wells and Sub-Surface Water

3-34. A seepage well is a hole dug into the ground that will tap into the water polled or moving below the ground surface. If located, this water will pool in a seepage well and can be collected. (See figure 3-11). This technique can be used in most environments. Outside bends of a dry riverbed, the foot of cliffs or rocks, low areas protected from the sun, or damp subsurface sand would be ideal locations for a seepage well.

Preparing Water

3-35. Isolated persons should remain hydrated with good potable drinking water, making sure to purify any water that may be contaminated. Water that is high in sediment or debris content can be filtered to increase palatability and consumption. Rainwater and water collected from plants is usually safe for drinking; however, water from open sources such as lakes, streams, ponds, and swamps-especially any water near human settlements or in the tropics-will need to be purified. Springs are typically the safest open source to drink from, if the seepage is located, but should be purified whenever the means are available as a precaution. When possible, all water should be purified by boiling, chemical disinfectants, or commercial filters that purify water through the filtration of extremely fine particulates.

Drinking Water Hazards

3-36. Isolated persons drinking non-potable water may become ill from ingesting harmful organisms that can cause diarrhea and lead to death. Two prevalent pathogens found in most water sources throughout the world are—

• Giardia. Giardia causes giardiasis. This is an illness caused by Giardia lamblia, a single-celled, microscopic parasite that lives in the intestines of people and animals. The parasite is passed in the bowel movement of an infected person or animal. It is characterized by an extreme case of runny diarrhea accompanied by severe cramps, weight loss, and dehydration. The symptoms usually appear one to two weeks after the infection with the parasite. In a healthy person, the symptoms can last from four to six weeks. If giardiasis is suspected, isolated persons should increase their intake potable water to remain hydrated.
• Cryptosporidium. This also a small parasite, which causes cryptosporidiosis. It is much like giardiasis, only more severe and prolonged, and there is no known cure but time. Diarrhea may be mild and can last from 3 days to several weeks.

Note. The only effective means of neutralizing cryptosporidium is by boiling or by using a commercial micro filter or reverse-osmosis filtration system. Chemical disinfectants such as iodine tablets or bleach have not shown to be 100 percent effective in eliminating cryptosporidium.

3-37. Examples of other illnesses and organisms include:

• Dysentery. Personnel may experience severe, prolonged diarrhea with bloody stools, fever, and weakness.
• Cholera and typhoid. Personnel may be susceptible to these diseases regardless of inoculations. Cholera can cause profuse, watery diarrhea, vomiting, and leg cramps. Typhoid symptoms include fever, headache, and loss of appetite, constipation, and bleeding in the bowel.
• Hepatitis A. Symptoms include diarrhea, abdominal pain, jaundice, and dark urine. This infection can spread through close person-to-person contact or of ingestion contaminated water or food.
• Flukes. Stagnant, polluted water-especially in tropical areas-often contains blood flukes. If swallowed, flukes bore into the bloodstream, live as parasites, and cause disease.
• Leeches. If leech is swallowed, it can hook onto the throat passage or inside the nose and create a wound before moving to another area. Each wound can become infected.

Filtration

3-38. If the water is muddy, stagnant, and foul-smelling, it can be cleaned by placing it in a container and letting it stand for several hours so the sediment settles to the bottom. The water can be aerated by pouring it between two containers. This will improve the taste. If time and materials are available, a water filter can be improvised by using material or a large container and building layers of material in the container. The filter system is made from natural materials like sand, crushed rock or gravel, and charcoal. (see figure 3-12 on page 3-14). The filter will remove large and small particles from the water, aerate it for taste, and allow the isolated person to filter larger amounts of water for consumption.

3-39. A sediment hole or seepage basin can be built by digging a hole alongside a water source allowing the ground to filter the water through the soil. The water will flow through the surrounding soil and pool in the hole, ready for purification. Charcoal from a fire can also be used to improve water. When added to water, and allowed to set for 45 minutes, it helps remove odor and absorbs agricultural and industrial chemicals. After water has been filtered to improve palatability, it still requires purification prior to consumption.

Purification

3-40. Isolated persons should remain hydrated with good potable drinking water, making sure to purify any water that may be contaminated. Rainwater and water collected from plants is usually safe for drinking; however, water from lakes, streams, ponds, swamps, and springs-especially any water near human settlements or in the tropics-will need to be purified. When possible, all procured water should be purified by boiling, sun light, or chemical disinfectants to include water filters that filter out extremely fine particulates and at the same time treat the water with chemicals known as purification filters.

Boiling Method

3-41. Boiling is the safest method for purifying water. Bringing water to a rolling boil for one minute at sea level will kill all waterborne pathogens. If above 8,000 feet, the boiling time should be extended to 3 minutes. These boiling times are different than the time required for sterilizing water for medical use.

Chemical Purification

3-42. Chemicals can be used to purify water when necessary. When using chemicals, isolated persons must remember to let the water set for the prescribed amount of time and then open the cap and let the purified water rinse any unpurified water from the threads of the container before touching it to their mouth.

Types of Chemical Purification

3-43. The following are types of chemical purification:

• Purification tablets. When using water purification tablets always follow the manufacturer’s instructions for the recommended use of the product. Always verify that the tablets are within their specified stale date to ensure proper dosage. The tasks should be completed before the mission.
• Tincture of iodine. Use 5 drops of 2 percent tincture of iodine per full quart of water. If the water is cloudy or cold use 10 drops to ensure proper purification. After the iodine is mixed in, allow the water to stand for 30 minutes before drinking. If the water is cold and cloudy, wait 60 minutes.
• Providine iodine. Use 2 drops of 10 percent military-grade povidone iodine per full quart of water. Titrated providine iodine is the civilian equivalent at only 2 percent strength, and so requires 10 drops per quart. Let the water stand for 30 minutes. If the water is cold and clear, wait 60 minutes. If it is very cold or cloudy, add 4 drops and wait 60 minutes.

WARNING
If the isolated person is allergic to shellfish, they may also be allergic to iodine. An alternative is the use of bleach or boiling.

• Chlorine bleach. Place 2 drops of chlorine bleach (5.25 percent sodium hypochlorite) for 1 quart of water and let it rest for 30 minutes. If cold and cloudy, wait 60 minutes. Remember that not all bleach is the same around the world; check the available level of sodium hypochlorite.

3-44. There are several options for purifying water available on the open market and not covered in this publication. If other options are used, read and follow manufacture’s recommended instructions. When adding drink mix to the water to improve taste, always ensure that the water has completed the purification process before adding the mixture to the water.

Commercial Filters

3-45. All commercial filters do not achieve the same level of filtration. Filters that remove the smallest harmful microorganisms found in the area of operations should be selected. Mechanical water filters are simple to use and require no holding time. Filters do not add any poor taste and, in most cases, improve the taste of water. A water filter’s effectiveness is not dependent on water temperature. Disadvantages to water filters and similar filters are that they add bulk and weight to equipment, and most filters do not remove viruses. Filters are expensive compared to chemical treatments. As a filter becomes dirty it takes more pressure to push the water through, and small cracks and channeling in the filter can let small microorganisms through the filter. Eventually filters will need cleaning or some sort of field maintenance.

3-46. Smallest-pore Nano filters require higher pressure, as in reverse-osmosis filters. Freezing water within the filter element will compromise or destroy some filters. These types of filters provide little holding of contaminates and will clog rapidly; however, they can be easily stripped and cleaned by brushing and washing them without destroying the filter.

3-47. Maze or depth filters depend on a long, irregular labyrinth to trap organisms. Contaminates adhere to the walls of the filters or are trapped in the numerous dead-end tunnels. Granular media such as sand or charcoal, diatomaceous earth, or ceramic filters function as maze filters. A depth filter has a larger holding capacity for particles and lasts longer before clogging. These types of filters may be difficult to clean because particles can be trapped deep within them. Flow can be partially restored to a clogged filter by back flushing or surface cleaning, which removes the larger particles trapped near the surface.

Next Page : Chapter 4 – Food