(3) Boil water. Bring the water to a rolling (bubbling) boil for at least 15
seconds. (Local policy may increase the boiling time based upon local conditions.)
(4) Cool. Allow the water to cool sufficiently before using as drinking water.
Take measures to protect the water from becoming contaminated during the cooling
2-15. MAINTAINING CHLORINE RESIDUAL
Water treated by quartermaster purification methods contains sufficient chlorine
to destroy the organisms that cause intestinal diseases. However, it is difficult to
prevent subsequent recontamination of the water when transferring the water from one
container to another. Therefore, tests must be conducted periodically to check the
chlorine residual. If the chlorine residual is below the level prescribed for the command,
additional calcium hypochlorite must be added.
a. Schedule Checks. Water in a large container, such as a 400-gallon trailer,
should be checked when it arrives and every three or four hours thereafter.
b. Perform Residual Check. Test the chlorine residual level using the same
base procedures given in paragraph 2-9g.
c. Add Disinfectant, If Needed.
(1) If the test shows the water to have a chlorine residual equal to or greater
than one ppm, no additional disinfectant is added.
(2) If the test shows that the chlorine residual is less than one ppm,
additional disinfectant needs to be added to the water. For a 400-gallon trailer, add one
heaping tablespoon of bulk calcium hypochlorite to the water. (If bulk calcium
hypochlorite is not available, add 30 calcium hypochlorite ampules.) This should return
the water to a 5-ppm chlorine residual.
d. Continue Checks. Continue to recheck the chlorine residual of the water
according to schedule.