What to Consider when Selecting Sanitation Technologies

An appropriate sanitation system is a compatible combination of appropriate technologies to provide a socially and environmentally acceptable service at an affordable cost. Appropriateness needs to be assessed through technical, geophysical, socio-cultural, financial and institutional factors as well as aspects related to skills and local capacity. Because of the many possible technology options and selection criteria, rapid decision-making difficult. A clear framework can help.

Key Actions

During the acute phase the priority is the installation of latrines (user interfaceUser InterfaceA term used to describe 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 on user preferences. and on-site storage) that are safe for the users and prevent public health risks from faecal waste (see also How to Design and Implement Appropriate and Sustainable Toilets?). During this phase consider socio-cultural preferences, geophysical factors such as the risk of flooding, the availability of funds and materials and how fast a solution is required. Both SaniTweaks (Oxfam 2022) and ExcretaExcretaRefers to human excrements consisting of urine and faeces. Disposal in Emergencies (Harvey 2007) provide simple checklists to answer these questions. The Initial Assessment must ensure that the information is collected along with the specific needs of the targeted communities. For instance, for vulnerable groups, simple add-ons like lighting or handrails at the stairs can make a big difference. How to Design and Implement Appropriate and Sustainable Toilets/Latrines also provides additional guidance.

The focus of the stabilisation phaseStabilisation PhaseThe stabilisation (or transition) phase usually starts after the first weeks/months of an emergency and can last six months or longer. The main focus is to increase sanitation service coverage and an incremental upgrade and improvement of temporary structures as well as to… is to move from communal to shared latrines and then to household latrines to provide a solution for the management of excretaExcretaRefers to human excrements consisting of urine and faeces. and faecal sludgeSludgeMixture 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,…. Aspects to consider in this phase include whether the infrastructure could be upgraded and the availability of service providers, trucks and equipment and whether the environment has access and space for on-site treatment or removal. See also the following pages for more details: How to Select Appropriate Emptying and Transport Technologies? and How to Select Appropriate Treatment Technologies?, It is advisable to consider design options for the superstructureSuperstructureThe above ground walls and roof built around a toilet or bathing facility to provide privacy and protection to the user. and the slab (user interfaceUser InterfaceA term used to describe 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 on user preferences.) and the pit (on-site storage) separately and to use locally available materials for each component where possible. Decisions about whether to integrate bathing units are taken in this phase and about how to deal with greywaterGreywaterTotal volume of water generated from washing food, clothes and dishware, as well as from bathing, but not from toilets (see blackwater). It may also contain traces of excreta (e.g. from washing diapers) and, therefore, some pathogens. Greywater accounts for approximately 65 % of… in general. If desludgingDesludgingThe process of removing the accumulated sludge from a storage or treatment facility. is needed, treatment focuses on safe containment and pathogenPathogenAn organism or other agent that causes disease. removal. In places where a system already exists but is damaged, the focus is on providing temporary emergency solutions while trying to rehabilitate the existing one. Often when the stabilisation phaseStabilisation PhaseThe stabilisation (or transition) phase usually starts after the first weeks/months of an emergency and can last six months or longer. The main focus is to increase sanitation service coverage and an incremental upgrade and improvement of temporary structures as well as to… is reached, there is hardly any budget remaining. Hence the best that can be achieved is simple pit latrines with household participationParticipationAims to empower people and involve them in decisions that affect their lives. Inclusive planning and participation are key ingredients to achieve sustainability in humanitarian interventions. They exceed consultation which involves seeking input from stakeholders. The different…. However, using the table above to plan for sanitation infrastructure along the entire sanitation value chainSanitation Value ChainA Sanitation Value Chain - usually referred to as Sanitation Service Chain - is defined as the combination of technologies and services that in combination manage sanitation products from their point of generation to the point of reuse or disposal. The hardware part of the… from the beginning can support additional fund-raising or handover to other providers.

In the recovery phaseRecovery PhaseThe recovery phase, sometimes referred to as the rehabilitation phase, aims to recreate or improve the pre-emergency situation of the affected population by increasingly incorporating development approaches and principles. This phase usually starts after, or sometimes during,…, the objective the aim is to establish a longer-term sanitation service with appropriate technologies along the entire service chain (including treatment and safe disposal or reuseReuseUse of recycled water or other sanitation products.) that can be operated and maintained either directly by the communityCommunityA group of people sharing something in common. or by public institutions or private service providers (see also Exit Strategy). In this phase, the focus is on the selection of appropriate Emptying and Transport, Treatmentand Safe Disposal or Use Technologies considering the Quantities of Faecal Sludge or compostCompostDecomposed organic matter that results from a controlled aerobic degradation process. Microorganisms (mainly bacteria and fungi) decompose the biodegradable waste components and produce an earth-like, odourless, brown/black material. Compost has excellent soil-conditioning…/ pit humusPit HumusTerm used to describe the nutrient-rich, hygienically improved, humic material that is generated in double pit technologies through dewatering and degradation. The various natural decomposition processes taking place in alternating pits can be both aerobic and anaerobic in…. The technology for treatment will depend on the latrines and collection services already in place. Establish Standards and look for synergies with the existing infrastructure and avoid creating inequalities with the host population. On-site facilities may need to be upgraded, safe treatment and disposal facilities put in place and Management Plans and Financial Plans developed according to the locally available budget, skills and capacities. GreywaterGreywaterTotal volume of water generated from washing food, clothes and dishware, as well as from bathing, but not from toilets (see blackwater). It may also contain traces of excreta (e.g. from washing diapers) and, therefore, some pathogens. Greywater accounts for approximately 65 % of… and Solid Waste Management should also be considered to avoid the dilution of faecal matter with greywaterGreywaterTotal volume of water generated from washing food, clothes and dishware, as well as from bathing, but not from toilets (see blackwater). It may also contain traces of excreta (e.g. from washing diapers) and, therefore, some pathogens. Greywater accounts for approximately 65 % of… and to ensure that solid waste does not end up in pits or clog drains. In some circumstances, reuseReuseUse of recycled water or other sanitation products. might be an option if demand exists.

Relevance/Importance

The appropriateness of sanitation technologies for the local context will directly influence the effectiveness and sustainability of an intervention. However, selecting locally appropriate sanitationAppropriate SanitationCombination of sanitation technologies that are compatible and provide a socially and environmentally acceptable level of service at affordable cost. This can be translated into geo-physical, technical, socio-cultural, legal, financial as well as criteria concerning capacity and… technologies and combine those into viable system configurations is a complex decision making problem. To adress this complexity, clear and transparent frameworks for technology selection are required.

Overview

Factors to consider for choosing a given type of system

For an overview on system template, see also What Different Sanitation Systems and Technologies Exist?.

1. WASH infrastructure and services already in place in the area (to use synergies and detect user preferences in terms of accessibility).
2. Institutional and regulatory environment (e.g. groundwaterGroundwaterWater that is located beneath the earth’s surface. protection or construction laws).
3. Preferences of the user groups to be served (socio-cultural acceptance, e.g. religious constraints such as the orientation of the user interfaceUser InterfaceA term used to describe 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 on user preferences.).
4. Demographics: number of users per user interfaceUser InterfaceA term used to describe 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 on user preferences., special requirements for children, women, elderly and disabled people.
5. Human and technical capacities available for collection of products, i.e. transport available on the area and potential partners from the host communities or other humanitarian aid organisation.
6. Synergies with infrastructure and services in host communities.
7. Possibilities for resource recovery (urineUrineThe 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… as fertiliser, compostCompostDecomposed organic matter that results from a controlled aerobic degradation process. Microorganisms (mainly bacteria and fungi) decompose the biodegradable waste components and produce an earth-like, odourless, brown/black material. Compost has excellent soil-conditioning…, effluentEffluentGeneral 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… for irrigation etc.).
8. Safety conditions.
9. Land use in the area (ex. Agricultural practices).

Based on these factors, it can already be identified, which type of system templates are potentially feasible, this will reduce the technology choice for the further steps of sanitation systemSanitation systemEffective network of people (community) and the systems of which they are a part, operating together to deliver sanitation services (IRC 2022). design.

Factors to Consider for Technology Selection

For an overview of technology options go to the Compendium and for a full list of technology selection criteria go to SaniChoice/Selection tools.

Socio-cultural:

• Religious beliefs
• Cleansing methods (ashers or wipers)
• Vulnerable groups (women, elderly, children, disabilities)
• Availability of finance
• Readiness for reuseReuseUse of recycled water or other sanitation products.

Geophysical:

• Ease of access for supply chain and staff (vehicular access to assess the feasibility of sewered or motorised collection)
• Soil-conditions for construction,
• Groundwater tableGroundwater TableThe level below the earth’s surface which is saturated with water. It corresponds to the level where water is found when a hole is dug or drilled. A groundwater table is not static and can vary by season, year or usage.
• Topography and slope
• Location and size of water sources, incl. availability of water for flushing, risk for groundwaterGroundwaterWater that is located beneath the earth’s surface. contamination
• Space availability on-site (for on-site storage, treatment, and disposal) and off-site (for centralised treatment and disposal)
• Climatic conditions – including rainfall patterns and risk of flooding, minimal and maximum temperature

Technical:

• Availability of water for flushing or transportation
• Electricity supply
• Availability of materials and workforces readily available for construction and regular repairs (e.g. concrete, pumps, pipes, etc)
• Availability of fuel if motorized transport is planned
• Technical maturity (technology readiness level TLR)

Managerial:

• Design, construction and operation and maintenanceOperation and MaintenanceRoutine or periodic tasks required to keep a sanitation process or system functioning according to performance requirements and to prevent delays, repairs or downtime. skills available/required

Specific to emergency:

1. Degree of urgency to inform the speed of implementation required
2. Scalability (expansion)
3. Lifetime and possibilities for upgrading

The factors above need to be evaluated in the baselineBaselineDetermines the starting point for subsequent monitoring. The term ‘baseline’ can refer to the situation before the emergency or provide initial data to compare with an ‘endline’ survey. assessment, see also: 2.1 Data Collection and Sources, 2.2 Context Analysis, 2.3 Needs Assessment and Analysis