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Field Facilities for Human Waste Disposal

Human waste disposal
becomes a problem for both the individual and the unit
in the field. Local, state, federal, and host-nation
regulations or laws may prohibit burning or burial of
waste. Chemical latrines are the preferred human waste
disposal devices for use during field exercises or
missions. When chemical latrines are not available,
individuals and units must use improvised devices as
discussed in paragraph c, below. During short halts when
troops are on a march, each soldier uses a brief relief
bag or a �cat-hole� latrine. The cat-hole latrine is dug
approximately 1-foot (30-centimeters) deep and is
completely covered and packed down after use. In
temporary bivouac areas (1 to 3 days), the straddle
trench latrine is used unless more permanent facilities
are provided for the unit. When setting up a temporary
camp, a deeppit latrine and urine soakage pits are
usually constructed. Alternate devices, which may be
used to dispose of human waste in the field, are the
burn-out, mound, bored-hole, or pail latrines (see FM
21-10). The burn-out latrine is the preferred method for
improvised devices. If possible, urinals should be
provided in these facilities to prevent soiling the
toilet seats. The numbers of latrines are based on one
commode or urinal per 25 male soldiers and one commode
per 17 female soldiers.

  1. Latrines are so constructed to
    prevent the contamination of food and water. They are
    located at least 100 yards (90 meters) downwind
    (prevailing wind) and down gradient from the unit food
    service facility and at least 100 feet (30 meters)
    from any unit ground water source. They should never
    be placed above gradient of the unit food service
    facility. For further protection, latrines are not dug
    to the ground water level or in places where pit
    contents may drain into the water source. Usually they
    are built at least 30 yards (30 meters) from the
    border of the unit area but within a reasonable
    distance for easy access. A drainage ditch is dug
    around the edges of the latrine enclosure to keep out
    rainwater and other surface water. A handwashing
    device is installed outside each latrine enclosure;
    these devices should be easy to operate and kept full
    of water. Each individual must wash his hands after he
    uses the latrine.
  2. When a latrine is filled to within 1 foot (30
    centimeters) of the ground surface or when it is to be
    abandoned, it is closed in the following manner. The
    pit is filled to the ground surface in 3-inch
    (8-centimeter) layers; each layer is compacted. This
    is to prevent fly pupae from hatching and gaining
    access to the open air. Dirt is then compacted over
    the pit to form a mound at least 1-foot
    (30-centimeters) high. A sign is posted with the date
    and the words �closed latrine,� if the tactical
    situation permits.

Chemical Latrines:

  1. Chemical latrines are used in the
    field when federal, state, or local laws prohibit the
    use of other field latrines. These toilets are
    self-contained in that they have a holding tank with
    chemical additives to aid in decomposition of the
    waste and for odor control. The number of such
    facilities required is established by the surgeon or
    other medical authority in the AO.
  2. The facility must be cleaned daily, and the
    contents pumped out for disposal in a conventional
    sanitary waste water system. The frequency of emptying
    is determined by the demand for use of the device

Improvised Devices:

When chemical latrines are
not available, the following improvised devices can be

  1. Burn-out Latrine. The burn-out latrine may
    be provided when the soil is hard, rocky, or frozen,
    making it difficult to dig a deep pit latrine. It is
    particularly suitable in areas with high water tables
    because digging a deep pit is impossible. The burn-out
    latrine is not used when regulations prohibit open
    fires or air pollution. Personnel should urinate in a
    urine disposal facility rather than the burn-out
    latrine, as more fuel is required to burn out the

    1. To construct a burn-out latrine, an oil drum is
      cut in half, and handles are welded to the sides of
      the half drum for easy carrying. A wooden seat with
      a flyproof, self-closing
      lid is placed on top of the drum.
    2. The latrine is burned out daily by adding
      sufficient fuel to incinerate the fecal matter. A
      mixture of 1 quart (1 liter) of gasoline to 4 quarts
      (4 liters) of diesel oil is effective, but must be
      used with caution. If possible, have two sets of
      drums, one set for use while the other set is being
      burned clean. If the contents are not rendered dry
      and odorless by one burning, they should be burned
      again. Any remaining ash should be buried.

      DANGER Highly volatile fuel
      such as JP4 (jet propulsion fuel, grade 4) should
      not be used because of its explosive nature.


  2. Straddle Trench Latrine. The trench is dug
    1-foot (30-centimeters) wide, 21/2-feet
    (75-centimeters) deep, and 4-feet (120-centimeters)
    long. Two feet (60 centimeters) of length are allowed
    per person. These trenches, which are constructed
    parallel to one another, are spaced at least 2-feet
    (60-centimeters) apart. Since there are no seats on
    this type of latrine, boards may be placed along both
    sides of the trench to provide sure footing. As the
    earth is removed, it is piled at one end of the
    trench, and a shovel or paddle is provided so that
    each soldier can promptly cover his excreta. Toilet
    paper is placed on suitable holders and protected from
    bad weather by a tin can or other covering. The
    straddle trench latrine is closed, using the same
    method described in a(2) above.
  3. Deep Pit Latrine. The deep pit is used with
    the standard latrine box which is issued to or built
    by the unit. The two-seat box is 4-feet
    (120-centimeters) long, 21/2-feet (75-centimeters)
    wide at the base, and 18-inches (45-centimeters) high.
    A four-seat box 8-feet (240-centimeters) long,
    21/2-feet (75-centimeters) wide at the base, and
    18-inches (45-centimeters) high may be built by the
    unit using scrap lumber or other material.

    1. The pit is dug 2-feet (60-centimeters) wide and
      either 31/2- or 71/2-feet (105- or 225-centimeters)
      long, depending upon the size of the latrine box.
      This allows 3 inches (8 centimeters) of earth on
      each side of the pit to support the latrine box. The
      depth of the pit depends on the estimated length of
      time the latrine will be used. As a guide, a depth
      of 1 foot (30 centimeters) is allowed for each week
      of estimated use, plus 1 foot (30 centimeters) of
      depth for dirt cover. Generally, it is not desirable
      to dig the pit more than 6-feet (2-meters) deep
      because of the danger of the walls caving in. Rocks
      or high ground water levels may also limit the depth
      of the pit. In some soils, supports of planking or
      other material may be necessary to prevent the walls
      from caving in.
    2. To prevent fly breeding and to reduce odors, the
      latrine box must be kept clean, the lids closed, and
      all cracks sealed. If a fly problem exists, they may
      be controlled by the application of a residual
      pesticide. Control effects should be based upon fly
      surveys and pesticides applied in accordance with
      label directions. Pit contents should not be sprayed
      routinely since flies can develop resistance to
      pesticides if used over and over. The latrine boxes
      and seats are scrubbed daily with soap and water.
      Using lime in the pit or burning out the pit
      contents is not effective for fly or odor control;
      therefore, these methods are not recommended. The
      deep pit latrine is closed as described in a(2)
  4. Mound Latrine.
    1. This latrine may be used when a high ground
      water level or a rock formation near the ground
      surface prevents digging a deep pit. A dirt mound
      makes it possible to build a deep pit and still not
      extend it into the ground water or rock.
    2. A mound of earth with a top at least 6-feet
      (2-meters) wide and 12-feet (4-meters) long is
      formed so that a four-seat latrine box may be placed
      on top of it. It is made high enough to meet the
      pit�s requirement for depth, allowing 1-foot
      (30-centimeters) from the base of the pit to the
      level of the ground water or rock level. The mound
      is formed in approximately 1 foot (30 centimeters)
      layers. The surface of each layer is compacted
      before adding the next layer. When the desired
      height is reached, the pit is then dug in the mound.
      Wood or other bracing may be needed to prevent the
      pit walls from caving in. An alternate method is to
      construct a latrine pit on top of the ground, using
      lumber, logs, corrugated sheet metal, or whatever
      other material is available; to pile dirt around it
      and up to the brim, thus creating the mound around
      the latrine pit. The exact size of the mound base
      depends upon the type of soil; it should be made
      large to avoid a steep slope. It may be necessary to
      provide steps up the slope. The mound latrine is
      closed as described in a(2) above.
  5. Pail Latrine. A pail latrine may be built
    when conditions (populated areas, rocky soil, and
    marshes) are such that a latrine of another type
    cannot be constructed. A four-seat latrine box may be
    converted for use as a pail latrine by placing a
    hinged door on the rear of the box, adding a floor,
    and placing a pail under each seat. If the box is
    located in a building, it should, if possible, be
    fitted into an opening made in the outer wall so that
    the rear door of the box can be opened from outside
    the building. The seats and rear door should be
    self-closing, and the entire box should be made
    flyproof. The floor of the box should be made of an
    impervious material (concrete, if possible) and should
    slope enough toward the rear to facilitate rapid water
    drainage used in cleaning the box. A urinal may also
    be installed in the latrine enclosure with a drainpipe
    leading to a pail outside. This pail should also be
    enclosed in a flyproof box. The waste in pails may be
    disposed of by burning or by hauling to a suitable
    area and burying. Emptying and hauling containers of
    waste must be closely supervised to prevent careless
    spillage. The use of plastic bag liners for pails
    reduces the risk of accidental spillage. The filled
    bags are tied at the top; they then are disposed of by
    burning or burial.
  6. Urine Disposal Facilities. Urine disposal
    facilities should be provided for the males in the
    command. Urine should be drained from the urinals into
    a soakage pit, into a standard deep pit latrine if the
    urinals are constructed in conjunction with the
    latrine, or into the chemical latrine. The urine may
    be drained into a pit latrine through a pipe, hose, or
    trough. If a soakage pit is used, it should be dug
    4-feet (1.2-meters) square and 4-feet (1.2-meters)
    deep and filled with rocks, flattened tin cans,
    bricks, broken bottles, or similar nonporous rubble.

    1. Urinal pipes. Urinal pipes should be at
      least 1 inch (2.5 centimeters) in diameter and
      approximately 39-inches (1-meter) long and placed at
      each corner of the soakage pit and, if needed, on
      the sides halfway between the corners. The pipes are
      inserted at least 8-inches (20-centimeters) below
      the surface of the pit with the remaining 28 inches
      (80 centimeters) slanted outward above the surface.
      A funnel of tar paper, sheet metal, or similar
      material is placed in the top of each pipe and
      covered with a screen.
    2. Urinal trough. A urinal trough, about
      10-feet (3.3-meters) long, is provided when material
      for its construction is more readily available than
      pipes. The trough is made of sheet metal or wood
      with either V- or U-shaped ends. If the trough is
      made of wood, it is lined with tar paper or metal.
      The legs supporting the trough are cut slightly
      shorter on one end where a pipe carries the urine
      into the soakage pit or latrine pit. A urinal trough
      about 12-inches (30-centimeters) long is attached to
      the inside wall of the chemical latrine. A pipe is
      connected to the trough to drain urine into the
      latrine holding tank.
    3. Urine soakage pit. For the urine soakage
      pit to function properly, soldiers must not urinate
      on the surface of the pit. The funnels or trough
      must be cleaned daily with soap and water and the
      funnels replaced as necessary. Oil and grease must
      never be poured into the pit, as they will clog it.
      When a urine soakage pit is to be abandoned or it
      becomes clogged, it is sprayed with a residual
      insecticide and mounded over with a 2-foot
      (60-centimeter) covering of compacted earth.
    4. Urinoil. In areas where the ground water
      level is more than 3-feet (1-meter) below the
      surface, the urinoil is an acceptable substitute for
      other types of urine disposal facilities. The
      urinoil is a 55-gallon drum designed to receive and
      trap urine and to dispose of it into a soakage pit.
      Urine voided through the screen onto the surface of
      the oil immediately sinks through the oil to the
      bottom of the drum. As urine is added, the level
      rises within the 3-inch diameter pipe and overflows
      into the 11/2-inch diameter pipe through the notches
      cut in the top of this pipe. The oil acts as an
      effective seal against odors and against fly
      entrance. The screen on top of the oil is lifted by
      supporting hooks and cleaned of debris as necessary.