Figure 6-6. Deep pit latrine for 50 men.
a. Construction. The pit is dug two feet wide and 7-1/2 feet long. This will give
the latrine box three inches of support on all sides. The depth of the pit will depend on
the estimated length of time the latrine is to be used. As a rough guide, a depth of one
foot is allowed for each week of estimated use plus one foot of depth for the dirt cover
when closed. Generally, it is not desirable to dig the pit more than six feet deep
because of danger that the walls may cave in. Rock or high ground water levels often
limit the depth of the pit. In some types of soil, a support of planking or other material
for the sides may be necessary to prevent wall cave-ins. Earth should be packed tightly
around the bottom edges of the box so as to seal any openings through which flies
might gain entrance.
b. Sanitation. In order to prevent fly breeding (deposit and hatching of eggs) in
the pit and to reduce odors, it is necessary to keep the latrine box clean, the seat lids
closed, and the cracks sealed; also, a good fly control program must be maintained in
the area. The use of lime in the pit or the burning out of the pit contents is not effective
for fly or odor control and should not be used. The box and the seats of the latrine
should be scrubbed daily with soap and water. When a unit leaves the area or when
deep pit latrines are filled to within one foot of the ground surface, the latrines should be
closed in the manner described in paragraph 6-9e.