Waste Disposal in the Field



 Directing waste disposal in the field is a very important task. It is one that has bearing on your many other duties, including the control of arthropods and rats in the unit area. Solid and liquid wastes produced under field conditions can amount to as much as a whopping one hundred pounds per soldier per day. You can well imagine how quickly one hundred pounds of waste per soldier per day, when not properly disposed of, can accumulate and become the breeding grounds for all types of pests. The unit commander is responsible for proper waste disposal in his unit area. However, he will be looking to you, the soldier medic, to supervise the construction and operation of the necessary waste facilities.

Waste Disposal in the Field


Three categories of waste disposal in the field

(1)        Human waste Ė feces and urine

(2)        Liquid waste Ė liquid kitchen and bath waste

(3)        Rubbish Ė combustible and non-combustible solids


NOTE:            Any of these, when not properly disposed of can become a breeding ground for disease-carrying insects and animals


Human waste disposal

Human waste disposal facilities are a must
 (1)       Two categories of human waste disposal facilities

(a)        Latrines

(b)        Urinals

(2)        Type of facility is dependent on length of time the unit will remain in one place

(3)        The longer the stay, the more sophisticated the facility

(4)        Other considerations

(a)        Tactical situation

(b)        Weather

(c)        Ground conditions

(d)        Local environmental laws


WARNING:     Army units MUST follow all local, state, federal, and international environmental standards during operations. The waste disposal devices described in this lesson MUST be reviewed and authorized by Preventive Medicine personnel prior to their use. This information is presented so units can develop their own waste disposal capabilities in EMERGENCY situations.


(1)        Unit is responsible for its construction, maintenance, and closure

(2)        Decision on the type of latrine to be used is based upon: unit situation and ground conditions

(3)               Types of Latrines

(a)        Cat-hole latrine

(i)         Used when the unit is on the move

(ii)        A hole approximately one foot deep and one foot in diameter

(iii)       After use, a cat-hole it must be completely filled in and the dirt packed down

(b)        Straddle trench latrine

(i)         Unit is remaining in one place for up to three days

(ii)        Trench is dug one foot wide, two and one half feet deep and at least four feet long

(iii)       Multiple trenches should be dug at least two feet apart

(c)        Deep pit latrines

(i)         Unit is going on an extended stay, longer than three days

(ii)        Uses a two-seat or four-seat box

(iii)       The two-seat box is four feet long, two and one half feet wide at the base, and eighteen inches high

(iv)       The four-seat box is two feet long

(v)        To minimize flies entering the latrine, pack the dirt tightly around the base of the box

(vi)       Lids that are fly-proof and self-closing should cover the seat holes

(vii)      A metal urine deflector strip is placed inside the front of the box to prevent urine from soaking into the wood

(viii)      The pit for the latrine is dug two feet wide and either three and one half or seven and one half feet long

(ix)       The depth of the pit should equal one foot for each week the latrine will be used, plus one foot for the dirt cover when the latrine is closed

(d)        Burnout latrines

(i)         Suited to jungle areas with high water tables, but can also be used when the ground is hard or rocky and digging is difficult or impossible

(ii)        Do not use it in areas in which the air pollution regulations prohibit open fires

(iii)       Be aware that in combat areas, burnout latrines make great targets as the smoke and fire are easily seen

(vi)       When using this type of latrine, urine facilities should also be constructed as it takes extra fuel to burn the liquid

(v)        A burnout latrine is in use one day and being burned out the next, so take this into consideration when planning the number required for your unit

(e)        Pail latrines

(i)         Use the pail latrine instead of a deep pit latrine when the environmental conditions make it impossible to dig, in heavily populated areas, or when the tactical situation prohibits burning

(ii)        The same seat boxes constructed for a deep pit latrine can be modified for use as a pail latrine by placing hinged doors on the rear of the box, adding a floor and placing a pail under each seat.

(iii)       If the pail latrine is located in a building, the box should be placed to form part of an outer wall

(iv)       The box should be placed on a floor of impervious material, such as concrete, that slopes toward the rear

(v)        The slope allows wash water to drain rapidly

(vi)       If possible, line the pails with plastic to reduce the risk of accidental spillage

(vii)      Dispose of the contents by burial, burning, or other sanitary measures

(f)         Chemical toilets

(i)         Usually obtained where environmental laws prohibit the construction of latrines

(ii)        Are seen quite frequently these days during training exercises

(iii)       Chemical latrines are self-contained, having a holding tank with chemical additives to aid in waste decomposition and to control odor

(iv)       Must be cleaned daily, but the contents are emptied based on usage

(4)        Planning considerations

(a)        Location

(i)         Located at least 100 yards downhill from the unitís field food service facility

(ii)        100 feet away from any unit ground water source

(iii)       At least 30 yards from the edge of the unit area

(b)        Privacy

(i)         Place a canvas, brush screen or tent around each latrine

(ii)        Should have a drainage ditch dug around its edges to prevent rainwater from flowing into the latrine


NOTE:   In cold climates, you may consider heating the enclosure.


(c)        Hand-washing devices

(i)         Hands contaminated with fecal matter are the most common means of disease transmission

(ii)        Hand-washing devices are absolutely necessary

(iii)       Simple hand-washing device should be installed outside of each latrine

(iv)       Device should be easy to operate and must be kept constantly supplied with soap and water

(d)        Cleanliness

(i)         Keep the latrines clean

(ii)        Latrines should be policed daily to ensure they are being properly maintained

(iii)       Clean and sanitize every day to reduce germs and odor

(e)        Quantity

(i)         Construct enough latrines to handle the unit population

(ii)        Enough latrines to accommodate four percent of the unitís male soldiers and six percent of the unitís female soldiers at any one time

(f)         Closure

(i)         When a latrine pit is filled to within one foot of the top, or when it is to be abandoned, remove the latrine box and spray the contents of the pit, the side walls and the ground within two feet with an approved insecticide

(ii)        Fill the pit to ground level, packing the dirt after every three inches of dirt added

(iii)       Then mound the latrine with twelve inches of soil to prevent flies from entering or exiting the pit

(iv)       Place a sign on the pit that states the type of latrine, the date it was closed, and the unit designation


NOTE:      Unit designations should only be included on the closure sign in non-operational areas.


Field Urinals

(1)        Proper disposal of urine is as important as the disposal of any other type of waste

(2)        Urine disposal devices are always used in conjunction with a urine soakage pit

(3)        General guidelines for the urine soakage pit

(a)        Inform soldiers that they should not urinate on the surface of the pit; it defeats the sanitary purpose

(b)        Food service personnel should not use the pit for liquid waste disposal as grease and oils from kitchen waste will clog the pit

(c)        Closed or abandoned pits should be sprayed with a residual insecticide and covered with a two-foot mound of compacted dirt


NOTE:      If the latrine is located some distance from the sleeping area, a large can or pail may be placed at a convenient spot to be used as a urinal during the night. In the morning, empty the can into the urine disposal facility and wash it with soap and water before re-using it.


(4)        Urine soakage pit construction

(a)        Four by four foot hole, dug four feet deep then filled with rocks, flattened cans, broken bottles or other similar non-porous rubble

(b)        Ventilation shafts

(c)        Can be inserted in the pit extending from within six inches of the bottom to about seven inches above the surface

(d)        Be sure to top the ventilation shafts with screens to prevent flies from entering the pit

(5)        Pipe urinals

(a)        Pipe urinals are simply pipes

(b)        At least one inch in diameter

(c)        Placed at an angle at each corner of the soakage pit

(d)        Additional pipes can be placed on the sides, halfway between the corners to accommodate up to eight soldiers at a time

(e)        Enough pipes should be available to accommodate five percent of the male soldiers in your unit at any given time

(f)         The pipes should extend at least eight inches into the pit and about twenty-eight inches above the surface

(g)        Place a funnel made of tarpaper or sheet metal at the top of each pipe and cover it with a screen

(6)        Urine troughs

(a)        Used when the unit is going to be in one area for a long period of time

(b)        When more permanent facilities are desired

(c)        Need to accommodate five percent of the solders at any given time

(d)        Build two feet of trough per soldier

(e)        The trough may be U or V shaped and built of sheet metal or wood

(f)         Wooden troughs should be lined with heavy tarpaper

(g)        The legs on one end of the trough should be slightly shorter

(h)        A pipe is then connected to this end to carry the urine to the urine soakage pit


Liquid waste disposal


NOTE:            In the field, liquid waste refers to: Wash, bath, and liquid kitchen waste.


Liquid waste from food service operations contains particles of food, grease, and


(1)        Liquid waste from food service operations requires treatment before it can be disposed of

(2)        Liquid kitchen waste accumulates at the rate of one to five gallons per soldier per day

(3)        There are three basic devices used to dispose of liquid waste in the field

(a)        Soakage pit

(b)        Soakage trench

(c)        Evaporation bed

(4)        All three devices have one element in common - the grease trap

(5)        All liquids from food service operations must have the food, grease, and soap removed to avoid clogging the disposal device


Two main types of grease traps

(1)        Baffle grease trap

(a)        The most effective way to remove grease from kitchen waste

(b)        Construction of Baffle Grease Trap

(i)         Constructed from a barrel or a watertight box

(ii)        Inside the barrel or box is a wooden baffle that divides it into two chambers

(iii)       The baffle should run from the top of the barrel or box to within one inch of the bottom of it

(iv)       Above the entrance chamber, insert a strainer into the lid

(v)        The strainer can be made from a small-perforated box filled with straw, hay or burlap

(vi)       On the side of the exit chamber, closest to the pit, insert one end of a pipe about three to six inches below the top of the barrel or box

(vii)      This is the outlet, which will allow the liquid waste to pass into the pit or trench

(viii)      Once the grease trap is in place, the other end of the pipe should be inserted into the center of the pit or trench at least one foot deep

(ix)       When the baffle grease trap is properly positioned and the pipe is inserted into the pit, it is ready for use

(2)        Barrel filter grease trap

(a)        Construction of Barrel Filter Grease Trap

(i)         Constructed using a thirty to fifty gallon barrel or drum

(ii)        Remove the top of the drum and bore several holes into the bottom

(iii)       Put eight inches of gravel or small stones in the bottom of the barrel

(iv)       Cover these with twelve to eighteen inches of wood ashes or sand

(v)        Fasten a piece of burlap over the top of the barrel to serve as a course strainer

(b)        The barrel filter grease trap must be positioned in one of two ways for it to be effective

(i)         Place trap directly over the soakage pit or

(ii)        Place the barrel on a platform with a trough that leads to the pit

(c)        Requires some maintenance to operate efficiently

(i)         Every two days empty and wash the trap

(ii)        Refill it with fresh ashes or sand

(iii)       Wash or replace the burlap strainer daily

(iv)       Burn or bury the ash or sand to prevent infestations from pest or insects


Soakage pits

(a)        Four square feet and four feet deep

(b)        Bottom of the pit should be covered with non-porous rubble, such as rocks, broken bottles or cans

(c)        One soakage pit is adequate for smaller units located in an area for a brief period

(d)        Units with 200 or more soldiers it is recommended that you have two soakage pits

(e)        To close a soakage pit

(i)         Mound pit over with one foot of compacted soil

(ii)        The compacted soil will keep insects and vermin from entering and exiting the pit

(iii)       Post a sign on the mound that states the type of pit and the date it was closed


Soakage trenches

(a)        If digging is difficult due to rocky terrain or the water table is high

(b)        The soakage trench can be used to dispose of liquid waste

(c)        Construction

(i)         Dig a pit two feet square and one foot deep

(ii)        One-foot wide trenches are then dug, radiating outward from the pit in each direction

(iii)       These trenches vary in depth from one foot at the pit to one and a half feet at the outer edges

(iv)       Line the bottom with the same non-porous material as the soakage pit




Evaporation beds

(a)        Used in hot, dry climates where the soil is heavy clay

(b)        Heavy clay prevents the use of soakage pits and trenches since it is basically non-absorbent

(c)        Built in eight foot by ten-foot rectangles

(d)        Three square feet per soldier per day for kitchen waste and two square feet per soldier per day for wash and bath waste

(e)        Seldom used, but important to be familiar with their construction

(f)         Construction

(i)         Scrape the topsoil from the area and mound it around to form the outside edges of the bed

(ii)        Using a spade, turn the dirt over within the bed to a depth of between 10 and fifteen inches

(iii)       Using a rake, mound the loosened dirt into a series of horizontal or vertical ridges that are approximately six inches high

(vi)       Ridges will help to distribute the water evenly within the bed

Garbage and Rubbish Disposal



(1)        Food waste that occurs during food preparation, cooking and serving

(2)        Classified as either dry or wet



(1)        Non-food waste that usually comes from kitchens

(2)        Classified as either combustible or non-combustible


Garbage and rubbish are disposed of in one of two ways: burial or incineration

(1)        Tactical situation will dictate which method is most appropriate

(2)        Burial method

(a)        Two techniques used to bury garbage and rubbish:  Pit or trench

(b)        Tactical situation will assist you in selecting the most appropriate technique

(c)        Length of the mission is usually the primary factor in deciding whether to use a pit or a trench


NOTE:         When using either method, be sure to compact the rubbish before disposing of it. Doing so will help to prevent infestation by insects and rodents.


Burial pits

(1)        Preferred for overnight halts

(2)        Four feet by four feet and four feet deep

(3)        Suitable for one day for one hundred soldiers

(4)        Operational considerations

(i)         After depositing rubbish and garbage in the pit, cover it to keep pests away

(ii)        At the end of the day, or when the pit is filled to within one foot of the groundís surface, fill it in with earth

(iii)       Once it is filled in, mound it over with and additional one foot of compacted earth

(iv)       Mark the pit


NOTE:         Compacting the earth is very important. Doing so prevents flies and rodents from entering or exiting the pit.


(5)        Placement of the pit

(i)         Proximity to the foodservice area and the water supply are important

(ii)        Minimum of thirty feet and a maximum of thirty yards from the food service area

(iii)       At least one hundred yards downstream from any source of water that is in use, for either cooking or drinking


Continuous trenches

(1)        For stays of two days or more a continuous trench two feet wide and four feet deep should be used

(2)        Overall length of the trench will vary depending upon the length of time the trench will be in use

(3)        Operational considerations

(i)         To operate the trench, remove dirt to extend the length of the trench

(ii)        Use the dirt you remove to cover the garbage that has been added during the day

(4)        Placement of the trench

(i)         Same considerations for pit placement should be made when locating the continuous trench

(ii)        Locate the trench a minimum of thirty feet and a maximum of thirty yards from the food service area

(iii)       located at least one hundred yards downstream from any source of water that is in use, for either cooking or drinking


Incineration method

(1)        Your tactical situation must be taken into account in order to choose the incinerator that is best fitted to the needs of your unit

(2)        Located at least 50 yards downwind from camp (the further, the better)

(3)        Several types of incinerators


NOTE:         Although a significant amount of time is spent discussing incineration and the various types of incinerators, students should be aware that burial is almost always the best method for disposing of garbage and rubbish. Therefore, burial should be used whenever possible.


Rodent Control


Rodent Characteristics

(1)        Rodents are a large group of mammals that include a wide variety of animals such as squirrels, chipmunks, prairie dogs, rats, and mice

(2)        Two characteristics set rodents apart from other mammals

(3)        Two sets of chisel-like incisor teeth

(4)        The absence of canine teeth

(5)        These are the species we will discuss:

(a)        Norway rat

(b)        Roof rat

(c)        House mouse


Diseases carried by rodents

(1)        Rats and mice transmit to humans both through:

(a)        Direct contact

(b)        Contact with their feces and urine

(2)        Leptospirosis

(a)        Humans are infected when their broken skin or mucous membranes come in direct contact with the urine or tissue of an infected animal, contaminated water or moist infected soil

(b)        Humans can also contract the disease if they eat food that has been Ďmarkedí with the animalís urine or feces

(3)        Salmonellosis

(a)        Spread through urine or feces

(b)        Infections most commonly occur when humans eat food that is contaminated or food that is prepared on a contaminated surface

(4)        Hanta virus

(a)        Transmitted through dried rodent urine and feces

(b)        Infection occurs when the dried fecal and urine particles are inhaled

(5)        Rat bite fever:  Caused by the bite of the rat


Rodent management

(1)        Rodents can be a problem in any area where soldiers live

(a)        Where there is food, water, and shelter there is the possibility of rodent infestation

(b)        The earlier a rodent problem is detected, the easier it is to control or eliminate

(2)        Rodent survey

(a)        Must be ongoing to be effective

(b)        Looks for signs of rodents such as live rodents, dead rodents, droppings and smudge marks, rodent tracks and trails, gnaw marks, burrows, and rodent sounds and odors

(3)        Eliminating food sources

(4)        Eliminate access to garbage by using tight-fitting lids and disposing of garbage regularly in approved sites

(5)        Store all food in a tightly covered, metal, rodent-proof container

(6)        Clean up any food spills that may occur

(7)        Eliminating water sources

(a)        Like the food sources, anytime you can reduce the rodentsí access to a water supply you will greatly reduce the likelihood that they will stay in the area.

(b)        Drain run-off puddles

(c)        Remove any items that may hold water, such as old tires and cans

(d)        Keep stored water in bottles or five-gallon cans that close tightly

(e)        Store cases of bottled water off the ground on pallets

(f)         In areas with indoor plumbing, check to ensure that there are no leaky pipes. Repair any leaks found as soon as possible.

(8)        Eliminating shelter

(a)        Rodents rely on concealment when traveling, feeding, and resting.

(b)        Keep the unit area free of unnecessary debris, building material, and trash

(c)        Minimize the amount of vegetation around buildings

(d)        Keep living areas free from clutter


Safety measures to protect yourself from the parasites that may still be living on the dead rodent

(1)        Do not assume that because the rodent is dead that all the parasites have left its body

(2)        Spread insect repellent on your hands, sleeves, and the front of your uniform (This will help to protect you from any remaining parasites)

(3)        Use long-handled tongs or a shovel to pick up the dead animal

(4)        Place the carcass in a plastic bag or in a metal container with a tight-fitting lid

(4)               Burn or bury the remains IAW your unitís tactical situation and local environmental restrictions




Proper waste disposal in the field is essential in the prevention of the spread of disease. Solid and liquid wastes produced under field conditions can be as much as one hundred pounds per soldier per day. The unit commander is responsible for proper waste disposal in his unit area. However, he will be looking to you, the field sanitation team member, to supervise the construction and operation of the necessary waste facilities. Directing waste disposal in the field is a very important task. It is one that has direct bearing on your many other duties, including the control of arthropods and rats in the unit area. You can well imagine how quickly one hundred pounds of waste per person per day, when not properly disposed of, can accumulate and become the breeding ground for all types of pests.