Steps for Technology Selection

Selecting locally appropriate sanitation technologies and combining them into viable sanitation systems can be complex: there are many aspects to consider and trade-offs to make. It helps to proceed in several steps. Additionally, it is an iterative process but already thinking in the first phase about the future for upgrading and hand-over. While in the initial phase, the focus is on providing safe community latrines (toilet user interfaces and on-site storage), as latrines fill up, appropriate technologies must be identified for on-site treatment, or transport and off-site treatment, safe disposal or use. Using a systematic assessment framework that includes the technology options and assessment criteria for each functional group along the sanitation chain and in different response phases, helps to eliminate inappropriate choices, consider the entire sanitation value chain and plan for incremental improvements over time.

Key Actions
  1. Focus on the safe containment of faeces to protect human health in the immediate response.
  2. Move as fast as possible from open defection to using shared latrines and on-site containments appropriate for the local context (e.g. shallow or deep trench latrines).
  3. During the stabilisation phase, organise Emptying and Transport (as pits are filling up and desludging is required) according to local skills and financial resources and consider Treatment Technologies that ensure Safe Disposal or Use Technologies.
  4. Identify specific solutions for difficult contexts as described in Specific Challenging Contexts. E.g. consider raised latrines or container-based solutions that are water-tight if there is a risk of flooding, the groundwater table is high or the soil conditions do not allow pits.
  5. Consider that selecting the most appropriate sanitation system configuration is an iterative process.
  6. Consider Inclusive Design (women, children, elderly people) and socio-cultural aspects when designing latrines (‘washers’ versus ‘wipers’).
  7. Consider the interlinkages with other services: consider solid waste management and greywater management to avoid its disposal in the pits. Use positive interactions through combining collection and treatment systems.
  8. Use urinals to reduce the volume of liquid entering on-site containments. Urine usually does not contain pathogens and hence some infiltration is acceptable.
  9. Consider potential synergies with the sanitation systems of host communities. Are there existing service providers (such as for Desludging or Mobile Toilets)?
  10. Take account of subsequent phases when selecting technologies for each phase. The long-term goal (beyond the humanitarian response) is to establish sustainable sanitation systems – systems that protect human health and the environment, that are technically appropriate, financially viable, socio-culturally and institutionally accepted and allow for resource recovery and reuse (SuSanA 2008). The development of an Exit Strategy together with the host communities and according to commonly agreed Standards crucial to guarantee the services for the future. Communities must be involved in the selection of land as early as possible: especially land for treatment is expensive, locations are controversial (nobody wants to live close to a faecal sludge treatment plant) and transportation distances should be optimised (see also Site Planning).

 

Relevance/Importance

Inappropriate sanitation or technology choices lead to misuse, a lack of ownership and resources for operation and maintenance and the failure of sanitation intervention; this has direct consequences for people and the environment.

Typical examples of inappropriate choices include flush toilets where there is no water, dry toilets where people use water for anal cleansing and flushing, pit latrines where there is a high groundwater table or no access for emptying, no space for the safe disposal of faecal sludge or activated sludge treatment when there is no energy supply or skills and finances for operation and maintenance. In addition to these technical and geophysical factors, the identification and selection of appropriate sanitation technologies require consideration of socio-cultural, financial and institutional aspects as well as skills and capacities. Systematically matching technology options with these different factors (see What to Consider When Selecting Sanitation Technologies) helps practitioners to identify more appropriate options.

Overview

Technology selection always requires an initial assessment of the WASH situation. Baseline assessment and the factors to consider for technology selection are described separately.

Technology selection can happen in the following steps:

  1. Identify two to three feasible system options based on the collected assessment data  and the system selection criteria (see What to Consider When Selecting Sanitation Technologies?). The Compendium of Sanitation Technologies in Emergencies provides a simple overview on technologies. SaniChoice provides an advanced technology appropriateness filter. You can also use simple guides and checklists such as those provided in OXFAM (2022) and Harvey (2007) or MacMahon et al. (2019). Key questions to ask:
    • Assess the initial situation including the number of users, identification of the WASH practices, preferences and needs of the user groups to be served, the geographical conditions, and the institutional and regulatory environment
    • Find out what WASH infrastructure already exists and can be integrated.
    • Find out what sanitation practices the target communities are used to and evaluate if these are appropriate and can be implemented.
    • If parts of a sanitation system already exist, think of whether and how to integrate them
  2. Based on the initial assessment, identify the five most important criteria for technology selection along the functional groups and emergency phases (see What to Consider When Selecting Sanitation Technologies?). Key questions to ask:
    • How much water is available and where?
    • What are the soil conditions?
    • How much space is available. onsite and off-site
    • How can facilities be accessed?
    • What kind of materials and skills are available for construction and operation and maintenance and what is their costs?
    • What are the financial resources available
  3. Rank the different sanitation technologies from each functional group according to their performance regarding the criteria (you can use a simple scale of “+”, “++”, and “+++”)
  4. Discuss the ranking with different stakeholders
  5. Finalise the sanitation system design by selecting a compatible set of locally appropriate sanitation technologies along the five functional group
  6. Document including links to existing services with the humanitarian context or the host communities as well as potentials for upgrading in future phases.
Author(s) (1)
Dorothee Spuhler
Swiss Federal Institute of Aquatic Science and Technology (Eawag)
Reviewer(s) / Contributor(s) (1)
Rob Gensch
German Toilet Organization (GTO)

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