Section II. INDIVIDUAL AND SMALL UNIT WATER DISINFECTION
Whenever possible, troops in the field should consume only potable water
prepared by Quartermaster Corps units. However, this is not always possible under
tactical conditions. Isolated units may not be able to obtain water from engineer water
points. In this case they must obtain and treat their own water. Since the primary
reliance for protection against pathogens is placed upon disinfection, it is important that
all possible measures betaken to obtain a raw water that is as free from gross impurities
as possible. The more impurities present in the raw water, the more chlorine will be
required to satisfy the chlorine demand. There are now two chlorination kits. Methods
to more accurately determine chlorine residual are contained in paragraphs 2-10
a. Selection of a Water Source. Possible sources of water are discussed in
paragraph 1-8. The source that appears the cleanest should be selected.
b. Pretreatment. In order to reduce the chlorine demand as much as possible,
water from a surface source should be clarified to the maximum extent possible before
disinfecting. Sticks, leaves, and other debris may be removed by straining through a
clean cloth. Water from a muddy stream can be improved in quality by digging a
settling basin near the edge of the bank and below the water level. Water will then seep
slowly through the bank and remain still. After the dirt has settled, the clean water may
be removed and treated by one of the methods described in the following paragraphs.
Other containers, such as buckets and tubs, may also be used for settling turbid water
prior to disinfection.
ORIGINAL CHLORINATION KIT
The chlorination kit (see figure 2-2) is a standard expendable supply item
available for issue to all units through normal supply channels. It is used for chlorinating
unit water supplies and for testing water for the proper chlorine residual. This method is
only approximate. The kit is to be used until the stock is depleted.
a. Components. The chlorination kit consists of the following components:
(1) 100 glass ampules of calcium hypochlorite, each containing0.5 grams, for chlorination;
(2) three plastic tubes for measuring chlorine residule. Each tube has a translucent
yellow band around it. Each of the yellow bands is of a different shade; the lightest
indicates a chlorine residual of I ppm; the medium shade indicates 5 ppm; and the
darkest shade indicates 10 ppm. These figures are printed on the tubes.); and (3) three
vials of orthotolidine tablets. The vials are packed inside the plastic tubes.
Orthotolidine is a chemical that, upon contact with chlorine in solution, turns the solution
a yellow color. The higher the concentration of chlorine, the darker will be the shade of