hypochlorite should be used to disinfect the water in
the tank trailer. The procedure for preparing and adding
the solution to the tank trailer is as follows:
1. Fill the tank trailer half full of water.
2. Prepare a small amount of HTH concentrate by
dissolving the required amount of HTH in a canteen cup
or other container. In this case, place the 10 ounces of
HTH in a l- or 2-gallon bucket of water.
3. Stir the mixture thoroughly. All of the granules
will not dissolve. Allow undissolved granules to settle
to the bottom of the bucket.
4. Add only the clear concentrate liquid to the tank
trailer. By pouring the supematant into the tank trailer
slowly, you can see that the settled granules will remain
in the bucket.
5. Fill the remainder of the tank with the water to
6. The water now must be agitated to distribute the
HTH. In this example, you could simply attach the tank
trailer to a vehicle and go for a short drive.
7. The final step is to take a FAC reading 30
minutes after adding the HTH. The reading must be at
or above the required ppm. In this example, the FAC
must read 100 ppm or higher. If the ppm is not high
enough, add more HTH until the desired ppm is
Remember that during superchlorination
the FAC may not fall below 50 ppm wihin 4
hours or the whole procedure must be repeated.
After the 4-hour contact time and the tank trailer
ppm has stayed above 50 ppm, the trailer is now
disinfected. Rinse the tank thoroughly with potable
water and then refill it for usage. An occasion may
occur when you must use the water that you
superchlorinated. If the chlorine ppm is too high, you
may use sodium thiosulfate or sodium bisulfate to
dechlorinate the water.
Table 2-3 shows water sources and the required
For further information, see chapter 9 of the
Manual for Preventive Medicine, NAVMEDP-50109.
Table 2-3.Chlorine Residual Chart
Public water supply
5.0 ppm FAC after 30-
system of questionable
minute contact time and
maintain at a minimum of
2.0 ppm FAC throughout
the distribution system
5.0 ppm FAC at the
standpipe or fill hose
Water tankers, trailers,
Maintain between 5.0 ppm
bladders, and cans
and 2.0 ppm FAC when
filling from an approved
water point. Maintain 5.0
ppm FAC when used as a
source of distribution
Maintain 5.0 ppm at the
source and 2.0 ppm FAC at
Lyster bags and
Maintain 2.0 ppm FAC
when filling from an
approved water source.
Chlorinate to 5.0 ppm FAC
initially and maintain at 2.0
ppm FAC when filling from
an unapproved or raw water
Diatomite Water Purification
The 3000-D Water Purification System is portable
and completely self-contained, as shown in figure 2-25.
The unit purifies turbid and bacteria-polluted water.
Particular attention was paid to design and packaging to
increase efficiency, mobility, and cost effectiveness. It
also provides a trouble-free method of producing
potable water at the rate of 3,000 gallons per hour.
The system is constructed in separate modules,
interconnected, and mounted in a common chassis. The
chassis is not required for operation, but it greatly eases
the transportability of the system. The system contains
all of the functional apparatus and supplies necessary to
process approximately 20,000 gallons of potable
water. The user must have a water source and a