U.6 Shallow Trench Latrine

A Shallow Trench Latrine is a simple improvement of a defecation field (U.5). It consists of one or several shallowly dug trenches into which people defecate.

Faeces are covered after each use with the dug-out soil, thereby improving overall hygiene and convenience compared to that of defecation fields. A Shallow Trench Latrine is only recommended for the immediate emergency response.

Design Considerations

Shallow trenches should be around 20–30 cm wide and 15 cm deep, and shovels may be provided to allow each user to cover their excreta with soil. If several trenches are foreseen they should be divided into strips of around 1.5 m width with associated access paths. Trenches furthest from the entrance should be used first. When a section of trench has its bottom layer fully covered with excreta it is filled in. Only short lengths of a trench should be opened for use at any one time to encourage the full utilisation of the trench in a short time. It may be appropriate to have a number of trenches open at the same time. Shallow Trench Latrines are very land use intensive. The area needed is approximately 0.25 m2/person/day. For 10,000 people nearly two hectares per week are needed. The area chosen should be at a safe distance from food and water sources, but close enough to population centres to assure the safety and dignity of users. Shallow Trench Latrines should include screening for privacy and should be gender segregated. Where possible, screening should be higher than a standing person (> 2 m) to promote privacy. Furthermore, there should be an attendant at all times, ensuring security and order. The important design difference between a Deep Trench Latrine  S.1 and a Shallow Trench Latrine is that the shallow version is not as deep, and therefore no lining is required.

Consists of urine and faeces that are not mixed with any flushwater. Excreta is relatively small in volume, but concentrated in both nutrients and pathogens. Depending on the characteristics of the faeces and the urine content, it can have a soft or runny consistency.Refers to (semi-solid) excrement that is not mixed with urine or water. Depending on diet, each person produces approximately 50–150 L per year of faecal matter of which about 80 % is water and the remaining solid fraction is mostly composed of organic material. Of the total essential plant nutrients excreted by the human body, faeces contain around 39 % of the phosphorus (P), 26 % of the potassium (K) and 12 % of the nitrogen (N). Faeces also contain the vast majority of the pathogens excreted by the body, as well as energy and carbon rich, fibrous material.The liquid produced by the body to rid itself of nitrogen in the form of urea and other waste products. In this context, the urine product refers to pure urine that is not mixed with faeces or water. Depending on diet, human urine collected from one person during one year (approx. 300 to 550 L) contains 2 to 4 kg of nitrogen. The urine of healthy individuals is sterile when it leaves the body but is often immediately contaminated by coming into contact with faeces.Any substance that is used for growth. Nitrogen (N), phosphorus (P) and potassium (K) are the main nutrients contained in agricultural fertilisers. N and P are also primarily responsible for the eutrophication of water bodies.
An organism or other agent that causes disease.The organic molecule (NH2)2CO that is excreted in urine and that contains the nutrient nitrogen. Over time, urea breaks down into carbon dioxide and ammonium, which is readily used by organisms in soil. It can also be used for on-site faecal sludge treatment. See. S.18

Materials

Simple digging tools are needed for Shallow Trench Latrines, such as shovels and picks. In order to assure privacy screening should be provided. This can be done with plastic canvas or materials such as bamboo, fabrics and others. Shovels for users can be provided to allow each user to cover their excreta with soil.

Consists of urine and faeces that are not mixed with any flushwater. Excreta is relatively small in volume, but concentrated in both nutrients and pathogens. Depending on the characteristics of the faeces and the urine content, it can have a soft or runny consistency.Refers to (semi-solid) excrement that is not mixed with urine or water. Depending on diet, each person produces approximately 50–150 L per year of faecal matter of which about 80 % is water and the remaining solid fraction is mostly composed of organic material. Of the total essential plant nutrients excreted by the human body, faeces contain around 39 % of the phosphorus (P), 26 % of the potassium (K) and 12 % of the nitrogen (N). Faeces also contain the vast majority of the pathogens excreted by the body, as well as energy and carbon rich, fibrous material.The liquid produced by the body to rid itself of nitrogen in the form of urea and other waste products. In this context, the urine product refers to pure urine that is not mixed with faeces or water. Depending on diet, human urine collected from one person during one year (approx. 300 to 550 L) contains 2 to 4 kg of nitrogen. The urine of healthy individuals is sterile when it leaves the body but is often immediately contaminated by coming into contact with faeces.Any substance that is used for growth. Nitrogen (N), phosphorus (P) and potassium (K) are the main nutrients contained in agricultural fertilisers. N and P are also primarily responsible for the eutrophication of water bodies.
An organism or other agent that causes disease.The organic molecule (NH2)2CO that is excreted in urine and that contains the nutrient nitrogen. Over time, urea breaks down into carbon dioxide and ammonium, which is readily used by organisms in soil. It can also be used for on-site faecal sludge treatment. See. S.18

Applicability

A Shallow Trench Latrine is only recommended as temporary solution for the acute emergency response and is not a suitable long-term sanitation solution. It is not considered an improved sanitation technology and should be stopped as soon as other improved emergency sanitation solutions are in place.

Sanitation technologies are defined as the specific infrastructure, methods, or services designed to collect, contain, transform and treat products, or to transport products to another functional group. Each of the technologies included in this compendium is described on a 2-page technology information sheet in the technology compilation section. Only those sanitation technologies that have been sufficiently proven and tested are included, with a few notable exceptions of emerging technologies, which are clearly marked as such. The compendium is primarily concerned with systems and technologies directly related to managing human excreta. It does not specifically address greywater and only partially addresses stormwater management, although it does signal when a specific technology can be used to co-treat stormwater or greywater with excreta. Greywater and stormwater technologies are thus not described in detail, but are still shown as products in the system templates.The means of safely collecting and hygienically disposing of excreta and liquid
wastes for the protection of public health and the preservation of the quality of public water bodies and, more generally, of the environment.

Operation and Maintenance

After each defecation, faeces should be covered with soil. After one trench section is full, the soil with excreta should be treated with on-site disinfection such as lime treatment or should be taken away to a treatment facility. When closing one defecation trench section, privacy screens and simple slabs (if applicable) need to be moved to the next trench section. In order to ensure security, proper use and the opening and closing of defecation trenches there should be an attendant at all times.

Consists of urine and faeces that are not mixed with any flushwater. Excreta is relatively small in volume, but concentrated in both nutrients and pathogens. Depending on the characteristics of the faeces and the urine content, it can have a soft or runny consistency.Refers to (semi-solid) excrement that is not mixed with urine or water. Depending on diet, each person produces approximately 50–150 L per year of faecal matter of which about 80 % is water and the remaining solid fraction is mostly composed of organic material. Of the total essential plant nutrients excreted by the human body, faeces contain around 39 % of the phosphorus (P), 26 % of the potassium (K) and 12 % of the nitrogen (N). Faeces also contain the vast majority of the pathogens excreted by the body, as well as energy and carbon rich, fibrous material.The liquid produced by the body to rid itself of nitrogen in the form of urea and other waste products. In this context, the urine product refers to pure urine that is not mixed with faeces or water. Depending on diet, human urine collected from one person during one year (approx. 300 to 550 L) contains 2 to 4 kg of nitrogen. The urine of healthy individuals is sterile when it leaves the body but is often immediately contaminated by coming into contact with faeces.The elimination of (pathogenic) microorganisms by inactivation (using chemical agents, radiation or heat) or by physical separation processes (e.g., membranes). See POST
The common name for calcium oxide (quicklime, CaO) or calcium hydroxide (slaked or hydrated lime, Ca(OH)2). It is a white, caustic and alkaline powder produced by heating limestone. Slaked lime is less caustic than quicklime and is widely used in water/wastewater treatment and construction (for mortars and plasters). It can also be used for on-site treatment of faecal sludge. See S.17Any cellular or non-cellular microbiological entity capable of replication or of transferring genetic material (e.g. bacteria, viruses, protozoa, algae or fungi).
Any substance that is used for growth. Nitrogen (N), phosphorus (P) and potassium (K) are the main nutrients contained in agricultural fertilisers. N and P are also primarily responsible for the eutrophication of water bodies.
An organism or other agent that causes disease.A diverse group of unicellular eukaryotic organisms, including amoeba, ciliates, and flagellates. Some can be pathogenic and cause mild to severe illnesses.
The organic molecule (NH2)2CO that is excreted in urine and that contains the nutrient nitrogen. Over time, urea breaks down into carbon dioxide and ammonium, which is readily used by organisms in soil. It can also be used for on-site faecal sludge treatment. See. S.18An infectious agent consisting of a nucleic acid (DNA or RNA) and a protein coat. Viruses can only replicate in the cells of a living host. Some pathogenic viruses are known to be waterborne (e.g., the rotavirus that can cause diarrheal disease).
Used water from any combination of domestic, industrial, commercial or agricultural activities, surface runoff/stormwater, and any sewer inflow/infiltration.

Health and Safety

Although a Shallow Trench Latrine minimises indiscriminate open defecation and faeces are covered with soil the technology is not an improved sanitation option. It should only be implemented to bridge the gap in the acute response phase. Shallow Trench Latrine technology requires continuous user orientation and needs to be managed well in order to keep the public health risk low. In addition, the facility needs to be gender segregated, illuminated at night and sufficiently staffed to ensure a minimum level of security. Shallow Trench Latrines have to be equipped with Handwashing Facilities U.7 . Solid waste containers  X.8 at the entrance/exit can further promote public health and can be an important measure for menstrual hygiene management.

Refers to (semi-solid) excrement that is not mixed with urine or water. Depending on diet, each person produces approximately 50–150 L per year of faecal matter of which about 80 % is water and the remaining solid fraction is mostly composed of organic material. Of the total essential plant nutrients excreted by the human body, faeces contain around 39 % of the phosphorus (P), 26 % of the potassium (K) and 12 % of the nitrogen (N). Faeces also contain the vast majority of the pathogens excreted by the body, as well as energy and carbon rich, fibrous material.The liquid produced by the body to rid itself of nitrogen in the form of urea and other waste products. In this context, the urine product refers to pure urine that is not mixed with faeces or water. Depending on diet, human urine collected from one person during one year (approx. 300 to 550 L) contains 2 to 4 kg of nitrogen. The urine of healthy individuals is sterile when it leaves the body but is often immediately contaminated by coming into contact with faeces.Sanitation facilities that ensure hygienic separation of human excreta from human contact.
Any substance that is used for growth. Nitrogen (N), phosphorus (P) and potassium (K) are the main nutrients contained in agricultural fertilisers. N and P are also primarily responsible for the eutrophication of water bodies.
Practice of defecating outside in the open environment.
An organism or other agent that causes disease.The means of safely collecting and hygienically disposing of excreta and liquid
wastes for the protection of public health and the preservation of the quality of public water bodies and, more generally, of the environment.

The organic molecule (NH2)2CO that is excreted in urine and that contains the nutrient nitrogen. Over time, urea breaks down into carbon dioxide and ammonium, which is readily used by organisms in soil. It can also be used for on-site faecal sludge treatment. See. S.18

Costs

The technology itself does not require substantial financial investment. The materials needed usually can be obtained locally. For the operation, a full-time staff member is required to ensure correct use of the trenches. Staff can be volunteers; no engineering knowledge is needed. Major costs associated with Shallow Trench Latrines could arise from renting or acquiring the land. If the contaminated soil is treated off-site there will be transport costs and costs for sanitising the land after use.

Social Considerations

Shallow Trench Latrines should be located where they are less likely to be public health hazards, where costs for acquiring land are relatively low, and where they are accessible enough for people to use them. Gender segregation of facilities is critical. Having separate entrances and exits, not entirely exposed to the public, can help improve privacy. Full time attendants can promote privacy, security and correct use of the facility. Attendants can also train parents on how children should use the facility. In addition, intensive awareness raising and hygiene promotion measures are needed to ensure that the Shallow Trench Latrines are used and random open defecation is avoided.

Practice of defecating outside in the open environment.

Fact Sheet Overview

Input Products

Excreta
Faeces

Output Products

Excreta

Emergency Phase

Acute Response + +

Challenging Ground Conditions

Semi-Suitable

Application Level / Scale

Neighbourhood + +
City +

Water-based and Dry Technologies

Dry

Management Level

Public + +

Technical Complexity

Space Required

Objectives & Key Features

• Minimising immediate public health risk
• Prevention of random open defecation
• Fast implementation

Strength & Weakness

  • Can be built and repaired with locally available materials
  • Low (but variable) capital costs depending on land availability
  • Can be built immediately
  • Flies and odours are noticeable
  • Limited privacy
  • Short lifespan
  • Big land area required and costs to rehabilitate the land may be significant
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