Water Supply in the Field

1. Water Supply in the Field

2. Objectives • Importance of safe water in the field • Responsibilities • Definitions • Rules for water use • Types of sources and considerations • Types of water treatment and containers

3. Medical Importance • Safe water is essential • Prevents water borne diseases • Increases mission effectiveness

4. Responsibilities • Unit Commander: Overall responsible for providing safe water for drinking and hygiene. • Preventive medicine: • In charge of testing water • Ensures training for personnel on water discipline

5. Definitions • Palatable Water: Water that looks, smells, and taste good. • Potable water: Water that is safe for human consumption. • Water treatment: Water that is treated chemically to improve its quality. • Disinfection: Aprocess of killing infectious agents outside the human body by direct exposure to chemical or physical agents.

6. Definitions • Chlorination:A treatment process that combines the water with chlorine or chlorine compound. • Chlorine Dosage:The total amount of chlorine or chlorine compound added to a given amount of water. • Chlorine Demand: The amount of chlorine dosage used or consumed by substances in the water.

7. Definitions • Chlorine Residual:The amount of chlorine left in the water after the chlorine demand has taken effect. • Parts per Million (PPM):The parts of chlorine present in a given volume of water (concentration). • This value may also be expressed in Milligrams per Liter (Mg/L).

8. Rules for Water Use • Drink approved water only. • Prevent water waste. • Protect water sources with good sanitary practices.

9. Water Source Types and Considerations • Surface Water: Streams, rivers, ponds, and lakes. • Most commonly selected. • Ground water: Wells and springs • Costly to obtain • Difficult to determine its quantity • Rainwater, Ice, Snow, Seawater

10. Surface Water

11. Ground Water

12. Considerations • The military situation (Combat situation compared to training.) • The Quantity needed (Will the unit be here for 6 months or 2 weeks.) • The accessibility to the source. (Is the water easy to reach) • The general quality of the source. • The equipment available for use (Chlorine, purification unit)

13. Water Treatment • Methods: Coagulation/Sedimentation, Filtration, Disinfection, Chemical treatment (Chlorine or Calcium Hypochlorite), Boiling • Chlorination of water containers

14. Water Treatment Chart

15. Inspection of 18hl Water Trailer • Inspect: • Container • Manhole • Spigots • Drains

16. Chlorine Residual Monitoring Kit • Components: • 100 calcium hypochlorite ampoules • 150 diethyl-p-phenylenediamine (DPD) #1 tablets • One plastic color comparator

17. Procedure For Monitoring Residual • Wash your hands. • Flush the taps of the 400-gallon water trailer. • Triple-rinse the color comparator. • Fill the comparator with water. • Add a DPD #1 tablet. • Wait one minute.

18. Procedure For Monitoring Residual • Place your thumb over the opening and invert the comparator three times to ensure that the DPD #1 tablet is completely dissolved. • Compare the color of the water in the right window to the color in the left window. • Location where color break can be seen is where residual is measured

19. Monitoring the Chlorine Residual • Emergency field water requires a chlorine residual of 5 ppm or a chlorine residual established by medical or engineering. Color Break Approx. 2-3ppm

20. Re-chlorinating a Water Buffalo • Mix 1 MRE spoonful of Calcium hypochlorite from the 6-ounce bottle, or use 4 ampoules with one-half canteen cup of water. • Thoroughly mix the slurry and then add it to the water in the trailer. • Mix the solution with a clean stick or other clean device and flush the four taps. • Wait 10 minutes, flush the taps again, and check the chlorine residual.

21. Re-chlorinating a Water Buffalo • When chlorine residual reaches 1 ppm, wait 20 minutes and release water.

22. Re-chlorinating a 22L Water Can

23. Re-chlorinating a 22L Water Can • Add 1 ampoule of calcium hypochlorite to a ½ canteen cup of water and stir the slurry solution. • Add approximately ½ of the solution to one 5-gallon can. • Shake the container and wait 10 minutes. Loosen the cap and invert the can to let some treated water flow over the threads of the can. • Wait an additional 20 minutes, for a total contact time of 30 minutes.

24. Disinfecting a 1L Canteen With Iodine Tabs

25. Disinfecting a 1L Canteen With Iodine Tabs • Drop two iodine tablets into a canteen filled with water and wait 5 minutes for the tablets to dissolve. • Cover the canteen and shake it. • Loosen the canteen cap and invert the canteen to allow the treated water to flow across the threads of the canteen neck. • Wait a minimum of 30 minutes before consumption.

26. Disinfecting Canteen with Calcium Hypochlorite

27. Disinfecting Canteen with Calcium Hypochlorite • Dissolve the contents of 1 ampoule in ½ canteen cup of water to make a slurry. • Fill an NBC compatible canteen cap or ½ non-NBC cap with the slurry. Pour the cap contents into the canteen and wait 5 minutes. • Cover the canteen and shake it. • Loosen the cap and invert the canteen to allow treated water to flow across the threads of the canteen neck. • Wait a minimum of 30 minutes before consumption.

28. Boiling • Use in emergencies ONLY. • Boil water for 5-10 minutes.

29. Bottled Water Operations • Use when operations are short or source can not be obtained and resources available and waste disposal proper. • It is important to protect open bottles of water from secondary contamination.

30. Review Questions • What is the importance of clean/safe water? • What is the difference between disinfection and chlorination? • What is the difference between Ground and Surface water?

31. Review Questions • How many ppm of chlorine residual is required for emergency field water? • When re-chlorinating a water buffalo, how many ppm of chlorine residual must be reached prior to release? • When do you boil water for use?