EO 011.04 TP4

1. EO 011.04 TP4 Water Trailers

2. References A. Management of Water in the Field; B. CGSO Safety Bulletin 004 Water Trailer; and C. CFP 213

3. Introduction • maintain potable water for issue to the troops • CDN 2 Water Tank Trailer

5. Water Trailer CDN2 The water tank trailer has a capacity of1500 litres. and is equipped as follows: • a manhole cover is provided on the manhole collar welded to the tank • an external valve is located in the base of the tank

6. Water Trailer CDN2 • two (2) gate valves, located on the piping between the faucet boxes • piping is provided for unloading the water from the tank • a drain plug is located in the bottom of the tank at the rear

7. Confined Space An enclosed or partially enclosed space that: • Is not designed or intended for human occupancy • Has a restricted means of access and egress • May become hazardous to an employee entering

8. Confined Space “Entry in Confined Spaces” The above definition clearly includes the DND Water Trailer. This being the case no water trailers SHALL be entered unless the requirements of “Entry in Confined Spaces” as laid down in Chapter 7, of DND Safety Standards Vol 2 are met.

9. Inspection of Water Tank Trailers • Areas to inspect: cover, cover seal, valves, tank interior, drain plug • Points to check: proper fit effecting a tight seal, no leaks, interior is serviceable • Remedial action: repair, replace, clean

10. Cleaning a Water Tank Cleaning of the tank interior is performed whenever contamination is suspected or when directed by PMed Tech. Cleaning methods available and acceptable are as follows: • Steaming: This is the quickest and easiest method of combating the contamination in the tank. If steaming is not available or fails to accomplish its purpose the next method will have to be incorporated

11. Cleaning a Water Tank • Manual cleaning (scrubbing by hand) • after cleaning, drain out all the water and replace the plug back into the drain

12. Cleaning a Water Tank • NOTE: new trailers may have been delivered to units with residual contamination from the manufacturing process left on the bottom of the water tanks

13. Superchlorination Procedures This procedure is required when: • prior to the use of new drinking water containers (part of the trials program) • following routine cleaning and refinishing • dismantled or replaced for purposes of repair or alteration • before tanks that have been used for storage of contaminated water are put into use again for the storage of potable water • at any time that contamination of the tanks or system is suspected

14. Superchlorination Procedures • Tanks must be scrubbed clean and flushed out • Superchlorination shall be carried out at 50 PPM of the whole system • 1. 5 L (53 oz) of sodium hypochlorite solution (Javex 5%) is sufficient to achieve 50 ppm in a 1500 L (330 gal) water tank trailer

15. Superchlorination Procedures • Once tank is ¾ filled with 50 ppm solution, have operator drive the water trailer around for at least 30 minutes, preferably over uneven roadways • Drain tank, refill with fresh water • Drain fresh water and refill • Protect from re-contamination

16. Water Sampling • Once superchlorination is complete, water is ready to be sampled and sent to provincial laboratory for microbiological analysis • 0 total coliforms • 0 feacal coliforms • FAC and pH testing also conducted • Trailer should not be put into service until cleared by PMed

17. Laboratory Results 0 coliform per 100 mls of H2O…...…..No action 1 - 10 coliforms per 100 mls of H2O….resample 10 + coliforms per 100 mls of H2O…..sample fails If sample fails, superchlorination must be repeated.

18. Superchlorination Procedures Amount of 5% sodium hypochlorite required to make 50 PPM: • 20 L Jerry Can: 20 ml • 1 L Water Canteen: 1 ml Amount of 10% sodium hypochlorite required to make 50 ppm: • 1 L Water Canteen: .5 ml • 20 L Jerry Can: 10 ml

19. Chlorine Residual Maintenance Amount of 5% sodium hypochlorite required to maintain Chlorine residual of 0.2 - 0.5 PPM: • Water Trailer: 15 ml Amount of 10% sodium hypochlorite required to maintain Chlorine residual of 0.2 - 0.5 PPM: • Water Trailer: 7 ml

20. Calculations for Chlorination • 1 gallon of water weighs 10 pounds or 160 ounces; • 1 cubic foot of water weighs 62.5 pounds; • 224 gallons of water weighs 1 long ton (2240 pounds); • volume of 1 cubic foot of water is 6.25 gallons or 28.3 litres; chlorine required: gal of water X wt of 1 gal of H2O X dosage required (ppm) 10,000 X % available chlorine Calculation for standard 330 gal water tank trailer is as follows: 330 gal X 160 oz X 50 ppm 10,000 X 5%

21. Post-Chlorination • Treated water should not be consumed for at least 1 hour after contact • Water should also be tested for chlorine residual prior to use

22. Filling Water Tank Prior to introducing water from an approved source into the water tank via a filler pipe, the following precautions to guard against re-contamination must be observed: • a. inspect the water trailer as previously described • b. ensure filling hose is free from pollutants by using approved pre-chlorinated hose • c. flush hose by turning on water ensuring that the output end is not re-contaminated by leaving or dropping on ground

23. QUESTIONS