S.7 Raised Latrine

Raised Latrines are alternatives to pit-based latrines in areas with rocky ground, high water tables or flood affected areas. Depending on site conditions they can either be built as autonomous facilities entirely above ground with a holding tank below the user interface or by raised partially above ground, reducing the risk of groundwater contamination.Describes the type of toilet, pedestal, pan, or urinal that the user comes into contact with; it is the way users access the sanitation system. In many cases, the choice of user interface will depend on the availability of water and user preferences. Additionally, handwashing facilities have been included here with a dedicated technology information sheet as a constant reminder that each sanitation user interface needs to be equipped with handwashing facilities for optimal hygiene outcomes.A sanitation system is a multi-step process in which sanitation products such as human excreta and wastewater are managed from the point of generation to the point of use or ultimate disposal. It is a context-specific series of technologies and services for the management of these sanitation products, i.e. for their collection, containment, transport, treatment, transformation, use or disposal. A sanitation system comprises functional groups of technologies that can be selected according to context. By selecting technologies from each applicable functional group, considering the incoming and outgoing products, and the suitability of the technologies in a particular context, a logical, modular sanitation system can be designed. A sanitation system also includes the management and operation and maintenance (O & M) required to ensure that the system functions safely and sustainably. Water that is located beneath the earth’s surface.
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.

User interface used for urination and defecation. Used water from any combination of domestic, industrial, commercial or agricultural activities, surface runoff/stormwater, and any sewer inflow/infiltration.

If Raised Latrines are built entirely above ground, the excreta must be collected in a sealed vault below the user interface. As no percolation occurs from the sealed vault, raised latrines that are entirely above ground have a high sludge accumulation rate. Storage facilities need regular emptying and a sludge management system is necessary. Raised Latrines with the pit partially below ground allow some of the effluent to percolate into the soil through the bottom and walls of the pit, while microbial action partially degrades the organic material. Raised Latrines can either be built as a single pit solution (with ventilation) or as a toilet block with several cubicles in a row and a trench or larger storage tank underneath. In toilet blocks ventilation is a challenge and thus odours and flies can become an issue.

General term for a liquid that leaves a technology, typically after blackwater or sludge has undergone solids separation or some other type of treatment. Effluent originates at either a collection and storage or a (semi-) centralised treatment technology. Depending on the type of treatment, the effluent may be completely sanitised or may require further treatment before it can be used or disposed of.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.Mixture of solids and liquids, containing mostly excreta and water, in combination with sand, grit, metals, trash and/or various chemical compounds. A distinction can be made between faecal sludge and wastewater sludge. Faecal sludge comes from on-site sanitation technologies, i.e. it has not been transported through a sewer. It can be raw or partially digested, a slurry or semisolid, and results from the collection and storage/treatment of excreta or blackwater, with or without greywater. Wastewater sludge (also referred to as sewage sludge) originates from sewer-based wastewater collection and (semi-)centralised treatment processes. The sludge composition will determine the type of treatment that is required and the end-use possibilities.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.Describes the type of toilet, pedestal, pan, or urinal that the user comes into contact with; it is the way users access the sanitation system. In many cases, the choice of user interface will depend on the availability of water and user preferences. Additionally, handwashing facilities have been included here with a dedicated technology information sheet as a constant reminder that each sanitation user interface needs to be equipped with handwashing facilities for optimal hygiene outcomes.Describes technologies for on-site collection, storage, and sometimes (pre-) treatment of the products generated at the user interface. The treatment provided by these technologies is often a function of storage and is usually passive (i.e. requires no energy input), except a few emerging technologies where additives are needed. Thus, products that are ‘treated’ by these technologies often require subsequent treatment before use and/or disposal. In the technology overview graphic, this functional group is subdivided into the two subgroups: “Collection/Storage” and “(Pre-)Treatment”. This allows a further classification for each of the listed technologies with regard to their function: collection and storage, (pre-) treatment only or both.Refers to the methods through which products are returned to the environment, either as useful resources or reduced-risk materials. Some products can also be cycled back into a system (e.g. by using treated greywater for flushing).A functional group is a grouping of technologies that have similar functions. The compendium proposes five different functional groups from which technologies can be chosen to build a sanitation system:
User interface (U), Collection and Storage/Treatment (S), Conveyance (C), (Semi-) Centralised Treatment (T), Use and/or Disposal (U).
A sanitation system is a multi-step process in which sanitation products such as human excreta and wastewater are managed from the point of generation to the point of use or ultimate disposal. It is a context-specific series of technologies and services for the management of these sanitation products, i.e. for their collection, containment, transport, treatment, transformation, use or disposal. A sanitation system comprises functional groups of technologies that can be selected according to context. By selecting technologies from each applicable functional group, considering the incoming and outgoing products, and the suitability of the technologies in a particular context, a logical, modular sanitation system can be designed. A sanitation system also includes the management and operation and maintenance (O & M) required to ensure that the system functions safely and sustainably. The utilisation of products derived from a sanitation system.
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.
A sanitation system in which excreta and wastewater are collected and stored or treated on the plot where they are generated.
An organism or other agent that causes disease.The movement of liquid through a filtering medium with the force of gravity.
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.

Waste matter that is transported through the sewer.
An open channel or closed pipe used to convey sewage. See C.3 and C.4
User interface used for urination and defecation. 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.18Used water from any combination of domestic, industrial, commercial or agricultural activities, surface runoff/stormwater, and any sewer inflow/infiltration.
Le terme général employé pour un liquide sortant d’une infrastructure, habituellement après que les eaux noires ou les boues ont subi une séparation de la fraction solide ou un autre type de traitement. L’effluent provient soit d’un processus de collecte et de stockage, soit d’une technologie de traitement. En fonction du type de traitement, l’effluent peut être complètement assaini ou nécessiter un autre traitement avant d’être utilisé ou rejeté.Composés d’urine et de fèces non-mélangées à de l’eau de chasse. Leur volume est peu important, mais ils sont concentrés en nutriments et en agents pathogènes. Selon la qualité des fèces, leur consistance peut être molle ou liquide.Waste matter that is transported through the sewer.

Design Considerations

Raised Latrines with pits partially below ground need pit lining (> 0.5 m) to ensure that the pit remains stable. To reduce odours and flies the latrine should be equipped with a ventilation pipe S.4 . Raised Latrines must be equipped with stairs or a ramp and corresponding handrails and, if necessary, structural support at the back. Drainage should be considered around the latrine so that rainwater does not enter the pit. In communal latrines, there should be separate latrines for men and women. The Raised Latrine platform usually does not exceed a maximum height of 1.5 m due to costs and user acceptance. The design must include arrangements for emptying.

Materials

If possible, materials should be used that are readily available and that can be sourced rapidly. The superstructure can be made from materials including bamboo, grass matting, wood, plastic or metal sheeting (though this often heats up the interior). The lining can be of concrete rings, bricks, stones, timber or sand bags. Several companies have developed variations of prefabricated Raised Latrines that can be delivered and assembled quickly.

The above ground walls and roof built around a toilet or bathing facility to provide privacy and protection to the user.
User interface used for urination and defecation.

Applicability

Raised Latrines are particularly suitable for flood prone areas, areas where pit digging is difficult or the water table is high and where construction of permanent structures is not allowed. They can be considered a viable solution in all stages of an emergency provided the technology is acceptable to the users. As no water is needed for operation it is also a solution for water scarce areas. They can be replicated quickly and implemented at scale if enough space is available. In areas with frequent flooding it can also be considered a permanent solution to increase longer-term resilience.

Operation and Maintenance

Operation and maintenance (O & M) requirements depend on which latrine design is used. Raised Latrines with a sealed containment facility fill up quickly and need regular emptying or replacement of storage facility and subsequent management of collected sludge. O & M tasks also include regular cleaning, conducting routine operational tasks (e.g. checking of availability of water, hygiene items, soap), providing advice on proper use, conducting minor repairs and monitoring the fill level. As latrines are often misused for solid waste disposal, which can affect later emptying, special awareness-raising measures should be considered. Public Raised Latrines tend to have a high sludge accumulation rate and will require frequent emptying. If regular desludging is needed, availability of and accessibility for desludging vehicles must be considered C.1 C.2 .

Mixture of solids and liquids, containing mostly excreta and water, in combination with sand, grit, metals, trash and/or various chemical compounds. A distinction can be made between faecal sludge and wastewater sludge. Faecal sludge comes from on-site sanitation technologies, i.e. it has not been transported through a sewer. It can be raw or partially digested, a slurry or semisolid, and results from the collection and storage/treatment of excreta or blackwater, with or without greywater. Wastewater sludge (also referred to as sewage sludge) originates from sewer-based wastewater collection and (semi-)centralised treatment processes. The sludge composition will determine the type of treatment that is required and the end-use possibilities.Describes technologies for on-site collection, storage, and sometimes (pre-) treatment of the products generated at the user interface. The treatment provided by these technologies is often a function of storage and is usually passive (i.e. requires no energy input), except a few emerging technologies where additives are needed. Thus, products that are ‘treated’ by these technologies often require subsequent treatment before use and/or disposal. In the technology overview graphic, this functional group is subdivided into the two subgroups: “Collection/Storage” and “(Pre-)Treatment”. This allows a further classification for each of the listed technologies with regard to their function: collection and storage, (pre-) treatment only or both.Refers to the methods through which products are returned to the environment, either as useful resources or reduced-risk materials. Some products can also be cycled back into a system (e.g. by using treated greywater for flushing).A functional group is a grouping of technologies that have similar functions. The compendium proposes five different functional groups from which technologies can be chosen to build a sanitation system:
User interface (U), Collection and Storage/Treatment (S), Conveyance (C), (Semi-) Centralised Treatment (T), Use and/or Disposal (U).
A sanitation system is a multi-step process in which sanitation products such as human excreta and wastewater are managed from the point of generation to the point of use or ultimate disposal. It is a context-specific series of technologies and services for the management of these sanitation products, i.e. for their collection, containment, transport, treatment, transformation, use or disposal. A sanitation system comprises functional groups of technologies that can be selected according to context. By selecting technologies from each applicable functional group, considering the incoming and outgoing products, and the suitability of the technologies in a particular context, a logical, modular sanitation system can be designed. A sanitation system also includes the management and operation and maintenance (O & M) required to ensure that the system functions safely and sustainably. The process of removing the accumulated sludge from a storage or treatment facility.
The utilisation of products derived from a sanitation system.
A sanitation system in which excreta and wastewater are collected and stored or treated on the plot where they are generated.
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.

Waste matter that is transported through the sewer.
An open channel or closed pipe used to convey sewage. See C.3 and C.4
Used water from any combination of domestic, industrial, commercial or agricultural activities, surface runoff/stormwater, and any sewer inflow/infiltration.
Waste matter that is transported through the sewer.

Health and Safety

If used and managed well, Raised Latrines can be considered a safe excreta containment technology. They need to be equipped with Handwashing Facilities U.7 and proper handwashing with soap after toilet use needs to be addressed as part of hygiene promotion activities X.12. For Raised Latrines partly below ground, groundwater contamination can be an issue and soil properties and the groundwater level should be assessed X.3 to identify the minimum distance to the next water source and limit exposure to microbial contamination. The Sphere minimum standards on excreta management should be consulted for further guidance. Emptying pits or replacing storage containers should be done in such a way that the risk of disease transmission is minimised (personal protective equipment and hygiene promotion for emptying personnel). Public latrines need additional illumination at night, security guards for protection and require accessibility for all users.

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.Water that is located beneath the earth’s surface.
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.User interface used for urination and defecation. 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.18Composés d’urine et de fèces non-mélangées à de l’eau de chasse. Leur volume est peu important, mais ils sont concentrés en nutriments et en agents pathogènes. Selon la qualité des fèces, leur consistance peut être molle ou liquide.

Costs

Building Raised Latrines is relatively inexpensive. Costs vary depending on availability and costs of local materials. Prefabricated versions may be more expensive (particularly costs for stockpiling and transporting) but can usually be implemented faster and with less dependency on local materials. Cost calculations need to reflect ongoing O & M requirements and follow-up costs such as regular desludging, transport, treatment and final disposal/ reuse of accumulating sludge. The cost of steps and access ramps for users can also push the cost up.

Mixture of solids and liquids, containing mostly excreta and water, in combination with sand, grit, metals, trash and/or various chemical compounds. A distinction can be made between faecal sludge and wastewater sludge. Faecal sludge comes from on-site sanitation technologies, i.e. it has not been transported through a sewer. It can be raw or partially digested, a slurry or semisolid, and results from the collection and storage/treatment of excreta or blackwater, with or without greywater. Wastewater sludge (also referred to as sewage sludge) originates from sewer-based wastewater collection and (semi-)centralised treatment processes. The sludge composition will determine the type of treatment that is required and the end-use possibilities.Describes technologies for on-site collection, storage, and sometimes (pre-) treatment of the products generated at the user interface. The treatment provided by these technologies is often a function of storage and is usually passive (i.e. requires no energy input), except a few emerging technologies where additives are needed. Thus, products that are ‘treated’ by these technologies often require subsequent treatment before use and/or disposal. In the technology overview graphic, this functional group is subdivided into the two subgroups: “Collection/Storage” and “(Pre-)Treatment”. This allows a further classification for each of the listed technologies with regard to their function: collection and storage, (pre-) treatment only or both.Refers to the methods through which products are returned to the environment, either as useful resources or reduced-risk materials. Some products can also be cycled back into a system (e.g. by using treated greywater for flushing).A functional group is a grouping of technologies that have similar functions. The compendium proposes five different functional groups from which technologies can be chosen to build a sanitation system:
User interface (U), Collection and Storage/Treatment (S), Conveyance (C), (Semi-) Centralised Treatment (T), Use and/or Disposal (U).
A sanitation system is a multi-step process in which sanitation products such as human excreta and wastewater are managed from the point of generation to the point of use or ultimate disposal. It is a context-specific series of technologies and services for the management of these sanitation products, i.e. for their collection, containment, transport, treatment, transformation, use or disposal. A sanitation system comprises functional groups of technologies that can be selected according to context. By selecting technologies from each applicable functional group, considering the incoming and outgoing products, and the suitability of the technologies in a particular context, a logical, modular sanitation system can be designed. A sanitation system also includes the management and operation and maintenance (O & M) required to ensure that the system functions safely and sustainably. The process of removing the accumulated sludge from a storage or treatment facility.
The utilisation of products derived from a sanitation system.
A sanitation system in which excreta and wastewater are collected and stored or treated on the plot where they are generated.
Use of recycled water or other sanitation products.
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.

Waste matter that is transported through the sewer.
An open channel or closed pipe used to convey sewage. See C.3 and C.4
Used water from any combination of domestic, industrial, commercial or agricultural activities, surface runoff/stormwater, and any sewer inflow/infiltration.
Waste matter that is transported through the sewer.

Social Considerations

Due to the raised design, Raised Latrines increase the risk of users being seen when going to the toilet. The location of the Raised Latrine may therefore be particularly important. Other design elements also need to reflect local user preferences (e.g. sitter vs. squatter, cleansing practices, direction, height, positioning etc.). Latrines need to be accessible to all, therefore ramps with a handrail and a turning space for wheelchairs at the latrine level may need to be considered X.10. O & M roles and responsibilities need to be agreed upon early on and closely linked to hygiene promotion activities X.12 to ensure appropriate use and O & M of facilities.

A person who prefers to sit on the toilet.A person who prefers to squat over the toilet.
User interface used for urination and defecation. A person who prefers to sit on the toilet.A person who prefers to squat over the toilet.

Fact Sheet Overview

Inputs

Excreta
Faeces

Outputs

Sludge

Response Phase

Acute Response + +
Stabilisation +
Recovery +

Challenging Ground Conditions

Suitable

Application Level

Household + +
Neighbourhood + +

Water-based or Dry Technology

Dry

Management Level

Household + +
Shared + +
Public + +

Technical Complexity

Low

Functional Group

Collection / Storage

Required Space

Little

Objectives & Key Features

• Excreta containment
• Alternative for challenging ground conditions

Strength & Weakness

  • Applicable in areas with challenging ground conditions and frequent flooding
  • Low (but variable) capital costs
  • Small land area required
  • Inclusive design is more difficult than for technologies that are not raised
  • Emptying costs may be significant compared to capital costs
  • Collected sludge requires further treatment
  • For above ground facilities emptying service needs to be in place from the design stage

Selected References

Overview on elevated and Raised Latrines

WEDC (2014): Pit latrines for special circumstances – Guide 29. WEDC, Loughborough, UK

WEDC (2017): Mobile Note 59 - Raised and Elevated Latrines. WEDC, Loughborough, UK

Calculating the size of Raised Latrines

UNHCR (2018): UNHCR WASH Manual – Raised Pit Latrines UNHCR, Geneva, Switzerland

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