Safe water in sufficient amounts is essential to field troops. Water not properly treated can give you diseases, such as typhoid fever, dysentery, cholera, and common diarrhea. In certain areas of the world, water may also transmit infectious hepatitis and amebic dysentery. The latter diseases are caused by organisms that are highly resistant to the water disinfection methods normally used.

The quantity of water required for troops varies with the season of the year, the geographical area, and the tactical situation. Dehydration may be the problem in both extremely hot and cold climates. In extremely hot climates, large quantities of drinking water are required to replace body fluid losses. In extremely cold climates, body fluid losses are not as great as in hot climates; however, water is needed in the reconstitution of dehydrated foods. Additional water is also required for maintenance of personal hygiene in both hot and cold climates. A guide for planning to meet the water requirements in a temperate zone is 5 gallons per man per day for drinking and cooking and at least 15 gallons per man per day when showering facilities are to be made available.

You may not be able to obtain water from water points set up by the Utilitiesman. If this should occur, you must obtain and treat your own water. The possible sources of water are surface water (lakes, rivers, streams, and ponds), groundwater (wells and springs), rain collected from roofs or other catchment surfaces, melted blue ice or snow, and distilled water. The cleanest source of water available should be selected. Water taken from any of these sources must be properly treated before being used, because all sources are presumed to be contaminated.

To treat water for drinking, you can use either a plastic or aluminum canteen with the water purification compounds available in tablet form (iodine) or in ampule form (calcium hypochlorite).

Before using iodine tablets, check them for physical change, as they lose their disinfecting ability with age.

If the tablets are stuck together, crumbled, or have a color other than steel gray, do not use them. When treating water in your canteen with iodine tablets, fill the canteen with the cleanest, clearest water available. Add one iodine tablet to a 1-quart canteen of clear water; add two tablets when the water is cloudy. Double these amounts for a 2-quart canteen. Place the cap on the canteen loosely; wait 5 minutes; then shake the canteen well, allowing leakage to rinse the threads around the neck of the canteen. Tighten the cap and wait an additional 20 minutes before using the water for any purpose.

To purify water in a 1-quart canteen with calcium hypochlorite ampules, fill the canteen with the cleanest, clearest water available, leaving an air space of an inch or more below the neck of the canteen. Take your canteen cup and fill it half full of water. Add the calcium hypochlorite from one ampule, and stir the water with a clean stick until the powder has dissolved. Fill the cap of a plastic canteen half full of the solution from the canteen cup and add it to the water in the canteen, then place the cap on the canteen and shake it thoroughly. NOTE: If you have a l-quart aluminum canteen, add at least 3 capfuls of the solution to the canteen, as its cap is much smaller than the one on the plastic canteen.

Loosen the cap slightly and invert the canteen, letting the treated water leak onto the threads around the neck of the canteen. Tighten the cap on the canteen and wait at least 30 minutes before using the water for any purpose.

You could save the remaining solution to use later if additional treated water may be needed, or you can discard it.

When you do not have disinfecting compounds, boiling the water is another method for killing disease-producing organisms; however, it has several disadvantages: (1) fuel is needed, (2) it takes along time to bring the water to a boil, and then allowing it to cool, and (3) there is no guaranteed protection against recontamination. Water must beheld at a rolling boil for at least 15 to 20 seconds to make it safe for drinking. Hand-washing devices that are easy to operate are usually provided at appropriate places in the bivouac area: outside the latrine enclosures, near the mess area, and at other locations as needed. A soakage pit is provided under each device to prevent water from collecting. The water containers for these devices are usually checked by a Utilitiesman to ensure the containers and the surrounding area are kept clean.

Figure 10-57.-Immersion heaters for mess kit washing setup.

In the field you must care for your own mess kit. Proper washing is important; otherwise, food particles remain and become breeding places for disease germs. The galley maintenance personnel usually set up four corrugated cans or other similar containers, placed in a row, for washing your mess kit. The first can is used to scrape the food particles from your mess kit into. The second contains hot water with soap or detergent, and the third and fourth cans contain clear water which is kept boiling throughout the washing period (fig. 10-57). Along-handled brush is furnished so you can wash your mess kit.

To clean your mess kit properly, follow the steps given below:

1. Scrape the food particles from your mess kit into the scrap can.

2. Wash your mess kit in the first container of hot soapy water, using the long-handled brush.

3. Rinse your mess kit in the second can of boiling water by dipping it up and down several times.

4. Disinfect your mess kit by immersing it in the third container of boiling water for several seconds.

5. Shake your mess kit to remove excess water and allow it to dry in the air; then close it to keep out dust and vermin.

If your mess kit becomes soiled or contaminated between meals, it should be washed again before use. When desirable to preheat utensils before a meal, a corrugated can with clear boiling water is placed near the start of the serving line. It is important that such water be maintained at a rolling boil throughout the meal service period.