A
pit toilet or compost toilet is a method of collection of
humanHumans are bipedal primates belonging to the species Homo sapiens in Hominidae, the great ape family. They are the only surviving member of the genus Homo. Humans have a highly developed brain, capable of abstract reasoning, language, introspection, and problem solving...
waste, used for
compostCompost is a combination of food material and other organic material that is being decomposed through aerobic decomposition into a rich black soil. The process of composting is simple and practiced by individuals in their homes, farmers on their land, and industrially by cities.Compost soil is...
ing,
controlled decompositionDecomposition is the process by which tissues of a dead organism break down into simpler forms of matter. The process is essential for new growth and development of living organisms because it recycles the finite matter that occupies physical space in the biome. Bodies of living organisms begin to...
, or waste disposal used most often in areas with no
sewerA sanitary sewer is a type of underground carriage system, , for transporting sewage from houses or industry to treatment or disposal...
system. Pit toilets are used in
ruralRural areas are large and isolated areas of a country, often with low population density.About 91 percent of the rural population now earn salaried incomes, often in urban areas...
and
wildernessWilderness or wildland is a natural environment on Earth that has not been significantly modified by human activity. It may also be defined as: "The most intact, undisturbed wild natural areas left on our planet—those last truly wild places that humans do not control and have not developed with...
areas as well as in much of the developing world. Many variations exist, but at its simplest, the principle is that waste is controlled and
decomposedDecomposition is the process by which tissues of a dead organism break down into simpler forms of matter. The process is essential for new growth and development of living organisms because it recycles the finite matter that occupies physical space in the biome. Bodies of living organisms begin to...
into harmless by-products.
In some former Soviet Union regions, particularly in Asia, pit toilets were called
Stalin's footprints , after the characteristic platform — mass-produced in Soviet times — with a hole and recognisable pits for feet on each side.
Types
The slit-trench
latrineA latrine is a structure for defecation and urination. Latrines allow for safer and more hygienic disposal of human waste than open defecation. They are used in rural areas and low-income urban communities, with significant use in the developing world...
is the simplest type of pit toilet, consisting of a relatively shallow (3-6 feet/1-2 metres in depth) trench narrow enough to stand with one leg on either side. This type is used either by squatting, with the users' legs straddling the pit, or by various arrangements for sitting or leaning against a support structure. Such support may vary from the simplest forms such as a log, plank, branch or similar arrangement placed at right angles to the long axis of the pit.
A
catholeA cathole is a pit for human feces. Catholes are frequently used for the purpose of disposing of bowel movements by hikers and others engaging in outdoor recreation....
is a one-time use pit toilet often utilized by
camperCamper can be one of several things:* A trailer or vehicle accessory used for camping, see recreational vehicle, travel trailer or camper shell.* A Campervan - a self-powered van converted for camping.* a person who engages in camping....
s, hikers and other outdoor recreationalists. In New Zealand a rudimentary toilet consisting of a small
outhouseAn outhouse is a type of toilet in a small structure separate from the main building which does not have a flush and is not attached to a sewer.- Terminology :...
over a pit is called a "long drop."
Advanced designs
While an "advanced pit toilet" might sound like an
oxymoronAn oxymoron is a figure of speech that combines two normally contradictory terms...
, in its more complex forms, or higher capacity forms - commonly associated with outhouses though sometimes used underneath a house, or as a central collection area for several outhouses or other
waste collectionWaste collection is the component of waste management which results in the passage of a waste material from the source of production to either the point of treatment or final disposal...
arrangements - the pit will be larger, and covered with a supporting structure. This structure may be simply a metal plate, or board floor - with a hole over which the user positions themselves during use. A provision for seating is often placed above a pit toilet, this may be a simple hole, or several holes, in a board surface at sitting height. In bitter cold Arctic climates,
honey bucketA honey bucket is a bucket that is used in place of a flush toilet in communities that lack a water-borne sewage system.The honey bucket sits under a wooden frame affixed with a toilet seat lid. The honey bucket gets its name from the actual five–gallon buckets which were once used as...
s are used inside the home and carried to such covered pits outside.
A more "inviting" structure may also be built. Many of the more elaborate
outhouseAn outhouse is a type of toilet in a small structure separate from the main building which does not have a flush and is not attached to a sewer.- Terminology :...
s provide not only a roof for shelter, but also one or more private rooms in which the users may find a comfortable seat with a hole in it, and perhaps access to water for washing.
Ventilated improved pit latrine (VIP)
The ventilated improved pit latrine, or VIP, is a pit toilet with a black pipe (vent pipe) fitted to the pit, and a screen (flyscreen) at the top outlet of the pipe. VIP latrines are an improvement to overcome the disadvantages of simple pit latrines,i.e. fly and mosquito nuisance and unpleasant odors. The smell is carried upwards by the chimney effect and flies are prevented from leaving the pit and spreading disease.
Odor and Insect Control Mechanism
The principal mechanism of ventilation in VIP latrines is the action of wind blowing across the top of the vent pipe. The wind creates a strong circulation of air through the superstructure, down through the squat hole,across the pit and up and out of the vent pipe. Unpleasant faecal odors from the pit contents are thus sucked up and exhausted out of vent pipe, leaving the superstructure odor-free. In some cases solar-powered fans are added giving a constant outwards flow from the vent pipe.
Flies, searching for an egg-laying site are attracted by faecal odors coming from the vent pipe, but they are prevented from entering by the flyscreen at the outlet of the vent pipe. Some flies may enter into the pit via the squat hole and lay their eggs there. When new adult flies emerge they instinctively fly towards light. However, if the latrine is dark inside the only light they can see is at the top of the vent pipe. Since the vent pipe is provided with a fly screen at the top, flies will not be able to escape and eventually they will die and fall back into the pit.
To ensure that there is a flow of air through the latrine there must be adequate ventilation of the superstructure. This is usually achieved by leaving openings above and below the door, or by constructing a spiral wall without a door.
Long-term pit toilets
The waste pit, in some cases, will be large enough that the reduction in mass of the contained waste products by the ongoing process of decomposition allows the pit to be more or less permanent. In other cases, when the pit becomes too full, it will need to be periodically backfilled, and the associated structure is moved or rebuilt over the new waste pit, dug in a new location. Pits may be dug or filled by hand, using shovels, but commonly
excavation equipmentAn excavator is a heavy equipment consisting of an articulated arm , bucket and cab mounted on a pivot atop an undercarriage with tracks or wheels...
is employed for such tasks.
Permanent pits
Some pit toilets, which are used by a great number of people -- such as a public restroom in rural areas, or in a woodland park or busy lay-by, rest stop or other similarly busy location -- are built with a
concreteConcrete is a construction material composed of cement as well as other cementitious materials such as fly ash and slag cement, aggregate , water, and chemical admixtures...
lining for permanence. In this type, the pit is periodically emptied, usually by a pump mounted on a large truck which also carries a tank for storage. The waste is transported by road to a
sewage treatmentSewage treatment, or domestic wastewater treatment, is the process of removing contaminants from wastewater and household sewage, both runoff and domestic. It includes physical, chemical, and biological processes to remove physical, chemical and biological contaminants...
facility, or to be composted elsewhere. There are numerous
Licensed waste hauling companies providing such service in areas where it is needed.
Dry pits
This concrete-lined waste pit is one type of
dry pit design. A dry pit does not penetrate the
water tableThe water table is the level at which the groundwater pressure is equal to atmospheric pressure. It may be conveniently visualized as the 'surface' of the groundwater in a given vicinity. It usually coincides approximately with the 'phreatic surface', but can be many feet above it...
, while a wet pit does. In locations near streams or where undue seepage may occur, such as on a slope, the dry pit design may be preferred, even in "low traffic" use.
Hygienic use
Covering the deposit prevents smells and discourages some fly species which might see it as a place to feed or reproduce. Earth, sand or sawdust (six inches) can be added to simple types pit toilet after each use. Ashes and lime (one inch) are also effective.
Hazards/gas collection
Due to the possible danger caused by containing potentially explosive
methaneMethane is a chemical compound with the chemical formula . It is the simplest alkane, and the principal component of natural gas. Methane's bond angles are 109.5 degrees. Burning methane in the presence of oxygen produces carbon dioxide and water. The relative abundance of methane and its clean...
or other gases created by the decomposition of human waste, as well as to provide a more pleasant-smelling outhouse, a ventilation pipe or other arrangement is used to allow the gas to escape. In some cases, the methane may be collected for later use as fuel. see: Methane recovery (gasification)