31.07.2018

Schematic drawing of a tank for children

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A pit latrine or pit toilet is a type of toilet that collects human feces in a hole in the ground. They use either no water or one to three liters schematic drawing of a tank for children flush with pour-flush pit latrines.

A pit latrine generally consists of three major parts: a hole in the ground, a slab or floor with a small hole, and a shelter. The shelter is often known as an outhouse. A basic pit latrine can be improved in a number of ways. One includes adding a ventilation pipe from the pit to above the structure. This improves airflow and decreases the smell of the toilet. As of 2013 pit latrines are used by an estimated 1. This is mostly in developing countries.

About 892 million people, or 12 percent of the global population, practiced open defecation in 2016, mostly because they have no toilets. Pit latrines are sometimes also referred to as “dry toilets” but this is not recommended because a “dry toilet” is an overarching term used for several types of toilets and strictly speaking only refers to the user interface. A pit latrine without a slab is regarded as unimproved sanitation and does not count towards the target. The user positions themself over the small drop hole during use.

Light should be prevented from entering the pit to reduce access by flies. This requires the use of a lid to cover the hole in the floor when not in use. A shelter, shed, small building or “super-structure” houses the squatting pan or toilet seat and provides privacy and protection from the weather for the user. Subsequently, these liquids from the pit enter the groundwater where they may lead to groundwater pollution. This is a problem if a nearby water well is used to supply groundwater for drinking water purposes. The degree of pathogen removal strongly varies with soil type, aquifer type, distance and other environmental factors. As a very general guideline it is recommended that the bottom of the pit should be at least 2 m above groundwater level, and a minimum horizontal distance of 30 m between a pit and a water source is normally recommended to limit exposure to microbial contamination.

However, no general statement should be made regarding the minimum lateral separation distances required to prevent contamination of a well from a pit latrine. In addition to the issue of pathogens, there is also the issue of nitrate pollution in groundwater from pit latrines. Schematic of the pit of a pit latrine. The defecation hole in the slab is shown at the top, and the user squats or sits above this defecation hole. Pits can be lined with a support ring at the top of the pit as shown in this schematic. A “partially lined” pit latrine is one where the upper part of the hole in the ground is lined.