Urban sanitation technology decision-making in developing countries: a critical analysis of process guides

Abstract

Planning for urban sanitation in developing contexts is one of the major development challenges of this century. Particularly, the relevance of a broad perspective in sanitation decision-making processes has been increasingly discussed. One possible contribution to achieve comprehensive decisions is through the use of planning guidelines, also called process guides. The present work first identified categories of relevant decision elements, namely: (a) the multi-sectoral approach, (b) the multiplicity of sustainable dimensions, (c) the system analysis perspective and (d) the co-existence of planning scales. Then, for each category, a comparative analysis of urban sanitation process guides was conducted with a focus on technology decision-making. It was found that the importance of considering those categories is increasingly reflected in process guides, although not always in a detailed supportive way. Recommendations are provided to increase the added value of process guides regarding technology selection, as well as, to better integrate them into urban planning.

Keywords:

• Decision-making
• developing countries
• planning
• process guides
• sanitation

1. Introduction

Globally, approximately 2.4 billion people (around 32% of the total population) still do not have access to improved sanitation facilities (WHO & UNICEF 2015), a situation which negatively impacts people’s health, social standing, livelihoods and ultimately economic development (Törnqvist et al. 2008). In particular, the inadequate provision of sanitation services in urban areas of developing countries is one of the major challenges of this century (Tayler 2008). Indeed, lack of sanitation services, coupled to the unprecedented growth of unplanned urban settlements, is a critical element to assuring sustainable urban development (Keivani 2010). This appalling situation is rooted in many causes, namely low income and education levels, institutional and political challenges, insecure tenure (Okurut & Charles 2014), the marginalisation of peri-urban poor, existing regulations and a general failure to take the local context into account (Hofmann 2011).

Poor planning, and particularly the inability to take into account the above-mentioned factors, has also been implicated among the reasons for failures in sanitation services in developing countries (Barnes et al. 2011). This mirrors what happens in urban planning in general, where the dominant form of planning, named rational or master planning, has been criticised for rigidity towards urban dynamics, disregard of peri-urban areas and little local buy-in, among other aspects (Watson 2009). Alternative approaches, such as communicative and deliberative ones which imply more cooperation and dialogue between stakeholders, have been suggested as more appropriate and have thus gained popularity (Richardson 2005). Planning has also been increasingly seen as an iterative, flexible and participatory process valuing other forms of non-technical knowledge and the involvement of the community (Allen 2003). Additionally, there has also been a trend towards more broad view of thinking in urban planning, e.g., considering complex issues like sustainability, a concept supported by the socio-ecological idealism planning theory (Lawrence 2000). Nevertheless, alternative approaches are rarely reflected in developing countries faced with weak local government capacity and lack of coordination between organisations and resources for planning (Smith & Jenkins 2015). In addition, the broad consideration of different aspects during planning processes may be very challenging, namely because interdependencies among decision elements can create trade-offs, muddle decisions and undermine the successful implementation of selected solutions. For example, the integration of comprehensive assessment tools, such as environmental impact assessment (EIA), into planning has been hampered by power structures and the fragile coalition of interests (Richardson 2005).

Despite difficulties in shifting planning practices, some of these newer planning theories are starting to find their way into the sanitation sector of developing countries. In fact, ideals of participation and communicative theory can already be found in sanitation planners and practitioners’ rhetoric (McConville et al. 2011). Sanitation planning approaches have been evolving from a more engineering focus, often based on prescribed technologies for presumed conditions that rarely exist (Lüthi & Parkinson 2011), to a wider multi-disciplinary focus (Kennedy-Walker et al. 2014). However, although the international community increasingly stresses the need to address sanitation from a holistic perspective, practicalities on the ground often make decision elements difficult to consider in a comprehensive way (Tiberghien et al. 2011). Consequently, it is important to first identify which decision elements are the most relevant ones to account for when planning sanitation solutions.

In addition, one way to overcome difficulties when planning with a broader view is to use process guides, which are documents describing steps decision-makers need to undergo when selecting sanitation solutions. The possible contribution of process guides to support comprehensive decisions results from their potential to raise relevant aspects and structure their consideration during planning processes. Sanitation process guides have been analysed through different perspectives, namely planning theory, stakeholders’ participation and their implementation on the ground (e.g., Palaniappan et al. 2008; Törnqvist et al. 2008; Peal et al. 2010; Barnes et al. 2011; McConville et al. 2011; Kennedy-Walker et al. 2014). It is therefore important to further assess such planning documents regarding the level of support they provide for the consideration of potentially relevant elements when taking sanitation decisions. Indeed, the way process guides are structured and the level of support provided for decision-making is believed to influence the adequacy of selected solutions. Decision-making, here referring specifically to the selection of sanitation technologies (i.e., dealing with wastewater and excreta), receives particular attention owing to its critical contribution to the success of the entire planning process and final implemented solutions.

Hence, this article aims to (a) identify which sanitation decision elements are potentially relevant for urban areas of developing countries, (b) evaluate the potential contribution and further improvements of process guides to support the consideration of such elements in decision-making and (c) integrate sanitation process guides into urban planning debates. As lack or inadequate access to sanitation significantly impacts the living conditions of urban communities, and because analysed topics are very much aligned with aspects of urban development, the present analysis is also expected to contribute to the wider debate on how to bring about sustainable urban development.

2. Methodology

From sanitation literature and discourses, groups of decision elements potentially relevant to consider when planning sanitation services were identified. They are referred to in this article as ‘categories of comprehensiveness’, meaning that each category comprises a broad group of related decision elements. The term ‘comprehensiveness’ here means the broad consideration of decision elements, not being associated with the traditional rational comprehensive planning theory. Other cross-cutting issues, such as participation and urban upgrading, are also frequently mentioned with regards to sanitation planning (e.g., Gomez & Nakat 2002; Butala et al. 2010). However, these issues can be seen as strategies for achieving comprehensiveness rather than specific categories of comprehensiveness and, therefore, they were excluded from analysis.

Then, based on Palaniappan et al. (2008), Peal et al. (2010) and further web-based research, around 50 sanitation process guides for developing countries were identified. Process guides were used for the present analysis due to their potential to guide the users through logical actions aiming at adequate decisions. Indeed, they describe a suggested set of steps (i.e., the ‘process’) that may be used by decision-makers to assess and improve sanitation conditions (Palaniappan et al. 2008). These planning guidelines are usually developed by international or research organizations. They commonly comprise the following steps: problem identification, definition of objectives, options design, selection of solutions and action plan for implementation (McConville et al. 2011). Other support resources excluded from this analysis owing to their reduced guidance for decision-making are, for instance, technical briefs presenting technology descriptions, or technical references providing guidance on how to carry out specific tasks like construction works.

Out of this initial list of sanitation process guides, five were shortlisted for analysis (Table 1) based on the following reasons: (1) they are applicable in urban or peri-urban contexts in developing countries and (2) they constitute a stepwise process including some form of guidance for technology decision-making, namely questions to orient decisions, tables, decision trees or procedures. The focus on urban areas results from the fact that the potential for disease, mortality and misfortune due to inadequate or absence of sanitation services is much greater in these challenging areas than in rural ones (Isunju et al. 2011). The second criteria implies that process guides introducing interesting planning concepts but which do not provide specific support for the technology selection were not considered in the analysis (e.g., strategic sanitation planning (Wright 1997), strategic planning for municipal sanitation (GHK, WEDC, WSP-SA 2000) or citywide sanitation strategies (WSP 2010)). With the exception of IWA (2006), the selected documents have been field-tested. A new version of IWA (2006) has been published recently. However, as it is less process-oriented than the previous version, it was not included in this analysis.

Table 1. Analysed urban sanitation process guides.

Authors	Year	Title
International Water Association (IWA)	2006	Sanitation 21. Simple Approaches to Complex Sanitation. A Draft Framework for Analysis
World Bank	2007	Principles of Town Water Supply and Sanitation. Part 2: Sanitation
Water and Sanitation Program (WSP)	2008	Technology Options for Urban Sanitation in India
Swiss Federal Institute of Aquatic Science and Technology (Eawag-Sandec)	2011	Community-Led Urban Environmental Sanitation Planning: CLUES – Complete Guidelines for Decision-Makers with 30 Tools
Program Solidarité Eau (pS-Eau) and Municipal Development Partnership (MDP)	2012	Concerted Municipal Strategy (CMS) – Methodological Guides (including one guide on how to select appropriate technical solutions for sanitation)

Then, a qualitative scoring system was defined (Table 2) in order to assess the level of support process guides provided for the comprehensive integration of issues related to the categories of comprehensiveness (here called decision elements), both in planning and decision-making processes. The first two scores, ‘⊘’ and ‘○’, assess whether or not there are references to the importance of the element under analysis in any step of process guides, i.e., from the situation analysis to the assessment of options or the preparation of a plan. This will allow acquiring a global perspective of the recognition of the element’s importance in the entire planning process. The scores in bold, ‘●’ and ‘●●’, specifically reflect the degree to which each element is integrated in technology decision-making.

Table 2. Scoring system and related meaning of scores.

Score	Meaning
⊘	There is no reference on the importance of the element in any step of the planning process
○	The importance of considering the element is mentioned but not specifically for decision-making
●	The importance of the element for decision-making is mentioned with reduced support on its incorporation into decisions
●●	The importance of the element for decision-making is mentioned with detailed support on its incorporation into decisions

The score ‘●●’ means that an element effectively receives more decision support regarding the selection of sanitation technologies, compared to the score ‘●’. Support is considered to be reduced when only few references or examples are presented on the importance of the incorporation of the element in technical decisions.

For each category of analysis, the scoring system allowed assessing the level of comprehensiveness in the process guides. Process guides showing higher levels of comprehensiveness were the ones whose decision elements were classified with higher scores. The scoring system also permitted the analysis of the relative guidance provided to the different decision elements under analysis. The elements receiving more guidance presented higher scores than the remaining ones.

3. Potentially relevant decision elements in sanitation planning

Based on the current literature, four ‘categories of comprehensiveness’ were defined for being potentially relevant in sanitation planning: (a) the multi-sectoral approach, (b) the multiplicity of sustainable dimensions, (c) the system analysis perspective and (d) the co-existence of planning scales. All of them are somehow aligned with general aspects of urban development planning.

The first defined category is the multi-sectoral approach. In urban planning, some agencies increasingly recognise that problems should not be solved sectorally but instead, solutions in different sectors may be mutually reinforced (Rossiter 2000). In particular, as sanitation systems are intrinsically linked to other components of the water cycle and other sectors of society, such as water supply and spatial planning (Isunju et al. 2011), the integration of sanitation-related sectors in decision-making seems to be crucial to capture their potential synergies, thus leading to more sustainable and cost-effective solutions (Lüthi et al. 2012).

The concept of sustainability has also flourished in urban planning literature (Rosales 2011). It has been accompanied by discussions on its application to the sanitation sector (e.g., Carter et al. 1999; Rosemarin et al. 2008). Indeed, although the primary objective of sanitation is public health improvement, many other sustainability elements, like socio-economic, institutional and environmental ones, are said to need urgent consideration to stem the trend of disrepair happening in the sector and to accelerate progress in sanitation coverage levels (Montgomery et al. 2009).

Another tool explored in planning is the system analysis, whereby, considering a physical or conceptual system composed of interrelated elements, decisions can be made about its optimal performance (ASCE 1986). In the sanitation sector, more and more emphasis is given to the need to look at all the segments of sanitation systems, from the user interface (i.e., a toilet or latrine) to the final disposal or reuse of the different generated waste products (Maurer et al. 2012). It is expected that by bearing in mind the sanitation system thinking, other relevant aspects become clearer, such as operation and maintenance issues and interactions among stakeholders (Lüthi et al. 2011).

Finally, the analysis of different urban planning scales also deserves attention in urban planning (e.g., Tayler 1998). Particularly in sanitation, the combination of city-wide and more localized scales has been increasingly discussed. On the one hand, small-scale activities may better meet communities’ expectations, but if isolated they may also compromise benefits at the city-wide level (Tayler 2008). Conversely, city-wide initiatives, often capital intensive, are associated with inertia that makes them slow to adapt to particular contexts (Nilsson 2006), and frequently fail to reach poor areas. However, they may contribute to solving problems at a wider scale, namely in terms of expertise and physical connections to municipal services or supply chains (Lüthi & Parkinson 2011).

After defining the categories of comprehensiveness, it was important to break them down into different decision elements (Table 3). For the category ‘multi-sectoral approach’, elements represent sectors that may constrain the adequacy of sanitation technologies, or with which there might be synergies of combined solutions. Rosemarin et al. (2008) is used as a basis for defining the elements of the category ‘multiplicity of sustainable dimensions’, because it is considered the broader proposed definition for the sector. The dimension ‘socio-cultural and institutional’ was broken down into two separate elements in order to better analyse their particularities. The elements of the category ‘system analysis perspective’ are based on the segmentation of sanitation systems found in Maurer et al. (2012), with some modifications, namely to differentiate dry sanitation systems whose main final product is sludge, from water-based systems which result in the production of wastewater. Finally, the category ‘co-existence of planning scales’ takes into account two different scales that are commonly found in planning literature: city-wide and localized small-scale.

Table 3. Categories and related elements potentially relevant in urban sanitation decision-making.

Category	Element	Definition
Multi-sectoral approach	Water supply	Possible constraints or synergies between selected sanitation technologies and existing or planned solutions within water supply, stormwater drainage, solid waste management, agriculture (due to the potential reuse of treated products), energy (potentially used or produced by sanitation systems) and spatial planning (land use and settlement patterns).
	Stormwater drainage
	Solid waste management
	Agriculture
	Energy
	Spatial planning
Multiplicity of sustainable dimensions	Technology and operation	Functionality and ease of construction, operation and maintenance, as well as, vulnerability and flexibility of technical elements to external factors.
	Financial and economic issues	Direct costs (construction, operation, maintenance and reinvestment) and the capacity of communities to pay, and external costs (e.g., environmental pollution) and benefits (e.g., increased agricultural productivity and employment creation).
	Institutional aspects	Compliance with legal framework and institutional settings.
	Socio-cultural aspects	Socio-cultural acceptance and appropriateness of the system, convenience and consideration of gender issues.
	Environment and natural resources	Environmental conditions, needed resources, emissions to the environment and potential of recycling and reuse of products.
	Health and hygiene	Risk of exposure to hazardous substances that can affect public health and hygiene aspects.
System analysis perspective	Interface /collection	Way in which the user accesses the sanitation system and the way of collecting and storing the generated products.
	Emptying	Method by which sludge is emptied from collection infrastructures.
	Transport	Method of transport of products (sludge/wastewater) from one segment of the supply chain to another.
	Treatment	Type and level of treatment of sludge/wastewater.
	Disposal/reuse	Method by which products (sludge/wastewater) are ultimately returned to the environment, as either useful resources or reduced-risk materials.
Co-existence of planning scales	City-wide scale	Centrally designed planning scale which takes a wider view of the entire city.
	Localized small-scale	Localized planning scale, usually community-led, not necessarily accounting for the wider scale.

4. Analysis of comprehensiveness in process guides

The process guides analysis identified the level of comprehensiveness of selected planning guides and the relative guidance provided to decision elements in each category of comprehensiveness. This section presents the most relevant observations to evaluate the potential contribution of process guides to support comprehensive decision-making.

4.1 Multi-sectoral approach

With the exception of World Bank (2007), the process guides acknowledge the importance of considering interactions between sanitation and all other related sectors under analysis (Table 4). When it comes to decision-making, however, the linkages across sanitation and other sectors are not fully elaborated. For instance, Eawag-Sandec (2011), which calls for coordinated sectoral actions, admits that in practical terms it might be advisable to deal with sectors separately for better traction. World Bank (2007) draws attention to the challenges caused by differences in responsibilities, institutional arrangements and scale of applied technologies from different sectors. Finally, pS-Eau (2012) even stresses the need to clearly focus on sanitation as it tends to be overlooked in favour of other sectors.

Table 4. Comprehensiveness of the multi-sectoral approach.

Process guide	Water supply	Stormwater drainage	Solid waste management	Agriculture	Energy	Spatial planning
IWA (2006)	○	○	○	○	○	○
World Bank (2007)	●●	⊘	⊘	●	⊘	○
WSP (2008)	●●	●	○	○	●	●●
Eawag-Sandec (2011)	●●	●●	●	●●	●●	●
pS-Eau (2012)	●●	○	○	●●	●●	●●

When comparing the relative guidance provided to linkages between sanitation and other related sectors, water supply is the one receiving more support, mainly based on the presentation of viable sanitation technologies according to water consumption levels (World Bank 2007; WSP 2008), the distinction between water-based or waterless systems (Eawag-Sandec 2011) and the definition of water requirements for the different technologies (pS-Eau 2012). Concerning agriculture and energy, information is provided on the potential of technologies to produce sanitation products that can be used as fertilizers or energy sources, as well as, on energy consumption requirements (Eawag-Sandec 2011; pS-Eau 2012). Regarding spatial planning, some decision factors for technology selection are presented for guidance, namely space constraints, land use, housing layout, tenure issues (WSP 2008), the distance between pits and the disposal or treatment site, the required surface area and the accessibility needed for emptying pits (pS-Eau 2012). Finally, stormwater drainage and solid waste management are the less considered sectors, both receiving most guidance in Eawag-Sandec (2011), in which stormwater is an input to technology systems templates, and references to tools for solid waste management are provided.

4.2 Multiplicity of sustainable dimensions

All analysed process guides recognize the relevance of all sustainability dimensions, either as representing factors that affect the outcome of sanitation investments, or as being part of an enabling environment representing the minimal requirements to conduct the planning (Table 5). The importance of considering possible interdependencies and trade-offs between sustainable dimensions is also generally stressed, warning that improvements in one aspect may be reduced if carried out in isolation. Eawag-Sandec (2011), in particular, provides a multi-criteria analysis procedure for technology selection.

Table 5. Comprehensiveness of the multiplicity of sustainable dimensions.

Process guide	Technology and operation	Financial and economic issues	Institutional aspects	Socio-cultural aspects	Environment and natural resources	Health and Hygiene
IWA (2006)	●	○	●	○	○	○
World Bank (2007)	●	○	○	○	○	○
WSP (2008)	●●	●●	○	●●	●●	●
Eawag-Sandec (2011)	●●	●●	●●	●●	●	●
pS-Eau (2012)	●●	●●	●●	●●	●●	○

Concerning technology and operation, the most considered sustainable dimension, various technologies are characterised, namely regarding operation and maintenance requirements, functionality and ease of construction (WSP 2008; Eawag-Sandec 2011; pS-Eau 2012). In financial and economic terms, guidance is provided on calculating technology life cycle costs (WSP 2008; Eawag-Sandec 2011), and approximate technology costs are provided (pS-Eau 2012). The process guides integrate social issues through community workshops together with information on organisational aspects (WSP 2008; Eawag-Sandec 2011), or by the inclusion of one selection criteria related to the technology social acceptance and a methodological guide on how to analyse users demand (pS-Eau 2012). Within the institutional dimension, the need to look at different interests likely to impact decisions in different domains, from the household to beyond the city, is stressed by IWA (2006). Also, support is provided on how to involve stakeholders in decision-making (Eawag-Sandec 2011; pS-Eau 2012), which is said to avoid potential conflicts with existing policies and regulations. Concerning the environmental dimension, factors are presented that may influence choices like the quantity of wastewater produced, soil type, groundwater depth, topography and some basic information regarding resources recovery (WSP 2008; Eawag-Sandec 2011; pS-Eau 2012). Finally, although recognized as a primary concern, health concerns are poorly represented in decision-making. Indeed, only references are provided, namely on the need to consider health aspects when water is reused in agriculture (WSP 2008), or to include municipal health officers as stakeholders (Eawag-Sandec 2011).

4.3 System analysis perspective

The level of comprehensiveness of the system analysis perspective seems to be high as all the corresponding decision elements (here referred as sanitation segments), i.e., from the user interface to the final disposal or reuse of the different generated waste products, are considered to be important by all process guides (Table 6). In fact, there is a general recognition that addressing only one particular segment may transfer the problem elsewhere, thereby, not offering the full intended benefits. However, this is not reflected in guidance to decision-making in all analysed guides. Furthermore, references were found on the relevance of looking at the interdependencies between segments. In this regard, Eawag-Sandec (2011) and pS-Eau (2012) guarantee the segment interdependency based on the definition of system templates or sanitation chains, respectively, which represent a combination of technologies along the segments of the sanitation supply chain, thus ensuring material flow compatibility and avoiding the need to consider every technology permutation.

Table 6. Comprehensiveness of the system analysis perspective.

Process guide	Interface/ Collection	Sludge				Wastewater
		Emptying	Transport	Treatment	Disposal/Reuse	Transport	Treatment	Disposal/Reuse
IWA (2006)	○	○	○	○	○	○	○	○
World Bank (2007)	●	●	○	○	○	●	●	●
WSP (2008)	●	○	○	○	○	●	●	○
Eawag-Sandec (2011)	●●	●●	●●	●●	●●	●●	●●	●●
pS-Eau (2012)	●●	●●	●●	●	○	●●	●●	●

The guidance provided on the user interface/collection and on the transport and treatment of wastewater segments is generally higher when compared to the other segments. Major forms of guidance include the enumeration of factors that might influence choice and some general guidance for technology selection in the form of examples, tables or simplified decision trees, although only for a few technologies (World Bank 2007; WSP 2008). As previously said, worth noting is the attention that Eawag-Sandec (2011) and pS-Eau (2012) place on the entire sanitation supply chain. In particular, Eawag-Sandec (2011) is meant to be used jointly with a Compendium of Sanitation Systems and Technologies (Tilley et al. 2014) which provides information about sanitation technologies along the full range of system segments. PowerPoint presentation slides about the compendium are provided to help planners familiarize with its related concepts. In pS-Eau (2012), technologies from each segment are compared for selection using technology fact sheets, pre-defined feasibility criteria and through various decision tables and diagrams.

4.4 Co-existence of planning scales

The analysed process guides either focus on the city-wide scale or the localised small-scale, i.e., neighbourhood scale (Table 7). This seems to be closely related to their respective target audiences. Additionally, the need to harmonize both planning scales receives little attention and limited guidance is provided on the coordination between these two scales. Eawag-Sandec (2011) is the process guide which mostly recognizes the relevance of both planning scales, highlighting the need for the local initiatives to complement and be supported by city-level services. It first analyses whether there is a productive working relationship between community-level initiatives and public sector agencies. It then stresses the need to identify the main links within city-wide infrastructures and existing municipal or private services. Also, IWA (2006) suggests identifying the pay-offs between stakeholder interests and factors influencing the identification of appropriate sanitation systems at different scale levels, but not many details are provided on how to deal with the localized small-scale.

Table 7. Comprehensiveness of the co-existence of planning scales.

Process guide	City-wide scale	Localized small-scale
IWA (2006)	●	○
World Bank (2007)	●	⊘
WSP (2008)	○	○
Eawag-Sandec (2011)	●	●●
pS-Eau (2012)	●●	⊘

All analysed process guides recognize the importance of the city-wide perspective, namely to guarantee that decisions do not cause deterioration of the wider environment. pS-Eau (2012) provides the most detailed guidance at the city-wide scale, encouraging the coherence in technology choices at town level. This document divides the town into homogeneous areas and identifies the most appropriate solution for each area, detecting whether it is possible to merge areas using similar sanitation solutions that may lead to economies of scale. For instance, vacuum trucks may need to meet the various requirements for more than one area. The location and construction of any wastewater treatment plant also need to be considered at the town scale. On the other hand, Eawag-Sandec (2011) is the only process guide especially dedicated to small-scale localized projects, providing detailed information on how to organize community workshops. It assumes the process is time-consuming, but affirms that it contributes to finding solutions better accepted by key stakeholders and better suited to the case-specific conditions.

5. Improvement of process guides to support comprehensive decisions

The analysed process guides are considered to be adequate starting points to assist in the consideration of the broad range of decision elements under study. This is particularly due to their ability to create awareness of certain aspects and to help structure decisions. Although there is no single process guide which provides supportive guidance to all decision elements, these documents seem to progressively recognise that addressing only some decision elements may just transfer problems elsewhere, leading to undesired results. Indeed, the more recent they are, the more elements receive decision-making guidance. Nevertheless, detailed support for the integration of decision elements into technology decision-making is not always provided, even when process guides acknowledge the importance of considering such elements at some point of the planning process. This section reflects on how to further develop existing process guides to better support comprehensive technology decision-making. Suggested improvements may be possibly undertaken by international organizations and research institutions involved in the development of existing process guides, as well as, entities enrolled in urban sanitation planning.

5.1 General suggested improvements

Simplified support tools within process guides (e.g., fact sheets, decision tables or decision trees) could be updated to provide more guidance for all decision elements. Generally speaking, they are considered to be useful, particularly due to their simplicity and user-friendliness. However, they do not cover all important decision elements, which may indicate an opportunity to further explore these tools. For example, the technology fact sheets, such as the ones found in WSP (2008), pS-Eau (2012) and referred to by Eawag-Sandec (2011), could be updated with additional information covering all decision elements. It is nevertheless acknowledged that technological innovation is an on-going process. Therefore, technology fact sheets could be worded in such a way as to allow for changes and additions to lists of recommended technologies. For instance, they could provide references for expected technological developments and set the general requirements that newly developed technologies should comply with, e.g., following international standards, such as ISO 24511:2007 (ISO 2007), or referring to national legislation, hopefully driven by the Best Available Technology (BAT) or the Best Available Technology Not Entailing Excessive Costs (BATNEEC) approaches. These approaches are expected to better ensure the affordability and the long-term performance of selected technologies. It should be stressed that on-site sanitation technologies typically found in developing countries need more research, namely for the definition of performance criteria, compared to the end-of-pipe solutions usually found in developed countries (Ujang & Henze 2006).

Providing links to other documentation or existing decision tools, e.g., the guidelines produced by WHO (2006) on the safe use of sanitation products or the cost-based decision tools applied to the sanitation sector (Fonseca et al. 2011), might also be relevant for helping process guides’ users to become familiar with certain issues and explore them in more detail. With the exception of Eawag-Sandec (2011), which provides a simplified multi-criteria procedure for technology selection, decision-support tools, such as multi-criteria analysis or life cycle assessment, are not explored in analysed process guides. Incorporating or referring to such decision tools is therefore another suggestion for improving process guides. In particular, multi-criteria analyses, which rate options against various criteria to come up with most appropriate solutions, have been increasingly applied in the sanitation sector of developing countries (e.g., Katukiza et al. 2010), and comprehensive lists of criteria and indicators are currently available in the literature (e.g., Garfì & Ferrer-Martí 2011). Other alternative decision methodologies may also be interesting to consider when upgrading process guides, such as methodologies focused on the participation of stakeholders rather than purely numerically focused analysis (Willetts et al. 2013), conceptual maps used as visualization tools for establishing the interconnectedness of all factors affecting sanitation systems (Tiberghien et al. 2011) or the capacity factor analysis model which assesses the community’s capacity to manage a sanitation service in order to assist in the selection of appropriate technologies (Bouabid & Louis 2015). Process guides’ users could then select which tools to use in accordance with the specific situation, namely data availability. For this to be effective, process guides should explain how to use these other resources and tools in a complementary way.

Additional real case applications of decision elements in decision-making processes could also be presented by process guides, including successful examples but also situations where there are lessons to be learnt from failures. This should be accompanied by a clear explanation of the context where such real cases occurred, since many challenges and solutions in the sanitation sector are site-specific. It is particularly recommended to take into account community practices which occur to compensate for the inefficiencies of the formal services but that remain unrecognised and unsupported (Hofmann 2011). For example, although not representing the most preferable solution in terms of public health, in some cases, manual emptying of pits might be the most viable solution, at least in the short-term. Process guides should then support planners to identify further improvements of existing local solutions rather than solely guiding planners to select new technologies. In the example provided, process guides could, for instance, suggest improving the manual emptying equipment in order to avoid human contact with faeces during emptying activities.

Finally, some further improvements in process guides can be identified to help guarantee that these documents actually facilitate effective decision-making, especially regarding the flexibility required to comply with different urban planning situations. First, they could further benefit from adapting to distinct levels of information available for decision-making. This would allow the process to be as comprehensive as possible without falling into disproportional resource-intensive, complex or even impossible analyses. In fact, data in developing countries is often scarce, of poor quality and it is usually not captured in the required form. Therefore, process guides could first provide detailed indicators for supporting technology selection based on numerical thresholds, e.g., water consumption levels (litres/capita/day). Nevertheless, it would be helpful if they also allow for a second level of guidance rather than blocking the planning process by unavailable data. In this example, users could be guided on technology selection based on more easily available information, such as the modality of water provision (stand post, yard tap or in-house connection). Complementary, efforts need to be continuously enforced by practitioners to improve available information. Second, planning documents could prompt the involvement of a broad range of stakeholders in order to consolidate taken decisions. A multi-disciplinary team would help to address common low levels of knowledge and skills of planners. Nevertheless, in cases where this is not possible, process guides should clearly advise for areas of expertise that are needed to analyse some particular aspects. For instance, they could advise users to look for the opinion of experts who would specifically assess the possibility of applying sludge to crops and identify irrigation practices appropriate for the wastewater quality expected to be obtained by the treatment technologies under analysis. Third, in order to comply with distinct governance structures, process guides should be compatible with different institutional frameworks and working conditions, while allowing for productive relationships between stakeholders. For example, instead of guiding the user to select a certain technology considering that it will be managed by the municipal entity, these planning documents should prompt the users for the selection of technologies taking into account other service provision models. Such potentially alternative models could include community initiatives or the involvement of the formal or informal private sector. Indeed, these alternative service provision models may be beneficial to compensate for inefficiencies of formal public services. Their consideration may actually broaden the range of appropriate technologies under discussion as it may influence, e.g., the adequacy of operation and maintenance procedures or the cost recovery of certain solutions.

5.2 Improvements applied to each category of analysis

It is considered preferable that process guides take a comprehensive approach and deal with all relevant decision elements due to their potential of awareness-raising, while helping users to select the elements which actually need deeper consideration in each particular situation. Nevertheless, prioritizing improvements on process guides may be particularly relevant when sufficient resources are not available to undertake the previously mentioned recommendations. In order to further suggest how process guides can be improved, it is interesting to compare with how each category of comprehensiveness is addressed in practice.

Within the multi-sectoral approach, the analysis of planning documents showed that linkages between sanitation and water supply are deemed most important to consider. This is probably justified by the historical recognition of water and sanitation interdependencies (Carter et al. 1999). In opposition, connections with other sectors, especially stormwater drainage and solid waste management, are less explored in process guides. This low consideration of multi-sectoral linkages is in-line with realities on the ground, where sectors are usually not integrated in planning processes or they are not institutionally close to each other (Lüthi et al. 2012). However, in certain contexts, the systematic consideration of other sectors might be crucial when planning sanitation solutions, particularly in cases where cross-sectoral relations are not obvious, or are affected by misconceptions. Therefore, users of process guides would benefit if they could follow an explicit and structured checklist of the situations where sanitation technologies are potentially affected by existing and planned solutions found in sanitation-related sectors, or situations where potential synergies of combined sectoral solutions may exist. As analysed sanitation-related sectors might be handled by distinct institutions, the suggested improvements could also help to involve stakeholders from different sectors earlier in the planning process.

Technical, economic and socio-cultural issues receive most guidance among the sustainability dimensions of analysed process guides, with a particular emphasis on technology management requirements, costs and community preferences. Those dimensions are actually viewed by the sector as critical to guarantee sustainability, although being often overlooked (Montgomery et al. 2009). Health is the least considered dimension in analysed guides. It seems that these documents assume that providing sanitation will lead to the achievement of health goals and, therefore, few orientations are provided. More detailed guidance was also expected to be found on the recovery of water, nutrients and energy, as current sanitation literature on sustainability emphasises recovery and reuse opportunities (e.g., Guest et al. 2009). This might result, among other reasons, from the fact that, besides the potential advantages of technologies allowing for resources recovery, such as source separating technologies, they are still considered immature and risky by most professionals (Larsen et al. 2009). However, it should not be forgotten that reuse of sanitation products without adequate treatment (e.g., untreated wastewater used for irrigation) occurs in many communities, a fact requiring serious consideration in decision-making. In order to facilitate the multi-dimensional approach, process guides need to clearly show the long-term implications of disregarding certain sustainability dimensions, for instance, by providing examples of successes and failures of past decisions. Adding information to technology fact sheets is believed to be an interesting way of supporting the analysis of sustainability dimensions. However, a balance is required so that fact sheets do not become overloaded with information. Providing references to further documentation describing technologies is an option to alleviate this problem. Particularly, the health dimension should be emphasised in order to judge technologies according to their expected health risks and the potential health gains to the communities. In this respect, further documentation to be referred to might include, for instance, the report from Stenström et al. (2011), which clearly presents the health risks associated with different sanitation technologies. Complementary methodologies and approaches might also be referred to, such as health impact and microbial risk methodologies, the recently developed rapid participatory sanitation system risk assessment methodology (Campos et al. 2015) or the multi-barrier approach applied by Sanitation Safety Plans (WHO 2015). Finally, the clear focus on the functions of the technologies under consideration (e.g., whether they provide low level or complete treatment) is critical so that planners compare options which actually provide similar outputs.

Regarding the system analysis, segments dealing with sludge are generally subjected to less guidance in analysed planning documents. This is in accordance with the lower attention provided to those segments in the field (Tayler 2008). Hence, it is important that process guides are able to clearly communicate the system concept such that all segments are considered, and water- and dry-based solutions are equally presented. Further applying the system schematics found in Eawag-Sandec (2011) and, additionally, developing decision trees to help select technologies based on system thinking is expected to avoid pre-conceived technical solutions that might not be adequate to certain areas. In addition, it may drive planners to think not only about the user requirements of the sanitation systems, but also the end opportunities of sanitation products. Process guides could also encourage planners to explore incremental technological solutions that could be upgraded over time, for instance, by providing examples of technologies which can be adapted to changing conditions, such as treatment plants that can be built in phases in order to accommodate to increased treatment requirements and budget availability.

Finally, in terms of relative guidance provided on planning scales, process guides are mainly applied at the city-wide scale, which is also the approach that dominates current sanitation planning (Lüthi et al. 2012). It is believed that process guides focusing on different scales are all valuable. This might be in agreement with the general need for combining methods and tools for environmental planning and management of peri-urban interfaces, ranging from the need to pay attention to the heterogeneity and power relations within communities, to broader dimensions of regional planning (Allen 2003). Another suggested improvement of process guides is to develop an explicit decision step which carefully assesses the replicability of existing small-scale localised solutions in the city under study. Localised solutions may include particular types of latrines/toilets which were introduced at a localised scale, such as the ones providing opportunities for the reuse of sanitation products, or the construction and management of transfer stations that temporarily collect faecal sludge in order to reduce travel times before final transportation to centralised treatment or disposal sites. Attention should be drawn to the context-specificity of solutions which may differ even between neighbourhoods.

Based on the present analysis, it then is suggested that priority improvements for sanitation process guides would be directed to the consideration of the ‘multiplicity of sustainable dimensions’ and the ‘system analysis perspective’ as those categories are usually important but not sufficiently tackled in the field. The ‘multi-sectoral approach’ and the ‘co-existence of planning scales’ are more context-specific.

It is also interesting to note that within the categories: ‘multiplicity of sustainable dimensions’, ‘system analysis approach’ and ‘co-existence of planning scales’, the inter-relationships between respective elements are said to be relevant to account for by analysed process guides. In this regards, a multi-criteria methodology accounting for sustainability aspects and the system template/sanitation chain concepts are suggested by these planning documents. Particularly, the compendium of technologies from Eawag-Sandec (2011) provides a significant contribution in the structuring of systematic analysis of sanitation technologies and helps to account for interactions among segments of the sanitation supply chain. However, for the ‘co-existence of planning scales’, more systematic guidance might be needed regarding harmonisation of both scales. For instance, independently of working small-scale or city-wide, process guides should encourage planners to ensure coherence and coordinated efforts in technology choice, while avoiding incompatible and fragmented solutions. One possible way to deal with this is to include a clear and explicit step in the decision-making process where the users have to follow a checklist of guided questions, namely to investigate if there are potential opportunities of physical connections to municipal services, existing expertise and supply chains. Synergies and economies of scales can also be further analysed by complementary communication and mapping tools that process guides may refer to. For instance, Shit Flow Diagrams may be used for visualizing the flow of faecal matter along multiple pathways from defecation to disposal or end-use (WSP 2014). The Sanitation Mapper is another freely available tool that enables the geographical representation of data by mapping sanitation facilities and their status to inform planning (Roma et al. 2013).

6. Integration of sanitation process guides into urban planning

The main point of using process guides is to facilitate planning. This is particularly important as inadequate planning often limits the success of urban development interventions. The present section intends to explore the integration of process guides into urban planning debates, both from a theoretical and a practical perspective.

6.1 Theoretical debates

The process-oriented and multi-actor nature of the analysed process guides is believed to facilitate the implementation of contemporary urban planning approaches. For instance, these planning documents may contribute to address power imbalances, as well as social and environmental justice principles (as defended by advocacy planning), to ease consensus building processes (as in deliberative planning), or to support dialogue and cope with uncertainty and conflicts (as in communicative planning). Furthermore, contrary to master planning which typically evaluates data from different disciplines separately, a ‘trans-disciplinary approach’ can be used when applying process guides so that mutual influences of data are analysed (Smith & Jenkins 2015). Additionally, the relevance of the ‘facilitator’ of a planning process, as considered in communication and collaboration planning theories (Lawrence 2000), is also reflected in some analysed process guides where support is provided to the person undertaking this role. The concept of ‘decision windows’ as developed by Stigt et al. (2013), meaning critical moments in which different interests are combined, can also be supported by sanitation process guides. In this sector, a ‘decision window’ might occur when structural institutional reforms are under way, when priority and budget are allocated to sanitation, or simply because a proactive person joins an organization. In fact, if it is not possible to gather all relevant stakeholders from the beginning of the planning process, planners can still make use of process guides to help identifying possible relevant decision elements and possible solutions, while at the same time, staying flexible enough to recognise and stimulate decision windows to cooperate with other planning areas and to reframe the original problem accordingly. At last, the advocacy for ‘pro-poor’ and more ‘inclusive’ urban planning approaches (Watson 2009) can also benefit from the use of sanitation process guides. Indeed, such planning documents are increasingly incorporating guidance to develop non-conventional urban solutions that are contextualised to poor areas.

6.2 Practical recommendations for urban planners

The present analysis can also provide insights to urban planners and managers, namely regarding the use of process guides, the balanced need for comprehensiveness and suggested key complementary actions required for successful decisions.

First of all, it would be important to understand the real use of analysed process guides. A complementary study analysing interviews to practitioners with international experience in sanitation concluded that besides the increased awareness of current alternatives to planning, the application of process guides has been quite limited, namely due to low dissemination or low interest from planners. This makes it difficult to analyse the real impacts of the use of process guides, their advantages and limitations. It is therefore important to promote the use of these planning documents, follow up on the cases where they are used and share lessons for future applications. Improved marketing that effectively reaches planners is suggested to increase use of process guides. For example, electronic versions or paper copies of these documents may be provided at conferences or international meetings and planning promotion campaigns targeted specifically at planners and decision-makers may be undertaken. It would also be relevant to regularly upgrade process guides in accordance with evolving needs in the sector. Furthermore, national or local governments could also adapt and develop their own guides, possibly translating them to local languages.

Second, when planning sanitation solutions, even in cases where process guides are used, it might be not only difficult but also irrelevant to be fully comprehensive. Indeed, not all decision elements are equally important in every situation. On the other hand, too many aspects to consider might end up complicating and possibly ruining the whole planning process. Therefore, it is underlined here that when applying process guides it is more important to identify most relevant elements rather than comprehensively include all of them. This is also expected to avoid highly resource-consuming data collection processes by excluding decision elements that are not locally prioritised. In practical terms, depending on the specific planning objectives, existing conditions and available resources, the first important question to be asked would be whether planning is to take place at the city-wide or small-scale, while keeping in mind the possible connections between both scales. Then, planners should identify the sectors, sustainability dimensions and segments of the supply chain that potentially affect or are affected by solutions needed for the local context, at the present and in the future. Accordingly, appropriate process guides would be selected. It would then be desirable if process guides label themselves with regards to the aspects that are explored in more detail and the contexts in which they are particularly applicable. Furthermore, if a particular process guide does not cover all important elements, some complementarity between more than one, as well as, additional resources and cooperation with stakeholders from different disciplinary expertise might be needed to support the planning process.

Finally, a supportive enabling environment is recognised as essential to guarantee the actual uptake of process guides and a successful planning and implementation process. Aspects increasingly discussed in the literature include prioritisation of sanitation by governments, support from international donors on institutional reforms, stronger inter-sectoral collaboration (Uwejamomere 2011), recognition of the potential role of the private sector in the provision of sanitation services and the urgent need to formally recognise poor communities under new governance regimes (Hofmann 2011). Indeed, although it is advocated in this article that process guides may help structuring planning and decision-making processes, it is also recognised that complementary actions for each category are needed as a crucial complement to the use of such planning documents (Table 8). Besides the specific measures identified for each category, some additional recommendations to practitioners and planners wishing to employ process guides include the need to allocate resources for planning, clarify roles of stakeholders involved in service provision, promote dialogue and cooperation, qualify practitioners competencies, formulate adequate policies and support the enforcement of laws.

Table 8. Complementary actions for successful planning against each category of comprehensiveness.

Category of comprehensiveness	Complementary actions for successful planning
Multi-sectoral approach	Guarantee that sanitation is not overlooked in favour of other sectors. Involve stakeholders from different sectors early in the planning process in order to design potential synergies of combined solutions. Lobby for sanitation when preparing urban development plans (e.g. considering implications from tenure issues on service accessibility, space needed for treatment sites, etc.).
Multiplicity of sustainable dimensions	Encourage multi-disciplinary teams, e.g. including municipal health officers. Promote public participation, namely through community workshops. Encourage the consideration of long-term implications of certain technologies, e.g., preparing and disseminating manuals in local languages describing technical operation and maintenance, life cycle costs, etc. Follow-up on the implementation of selected technologies.
System analysis perspective	Promote the system thinking such that all segments are considered, as well as, their interdependencies. Codify non-conventional but still appropriate technologies (e.g., on-site solutions, simplified sewers, if applicable) into national technical standards or regulations. Support the emphasis on the recovery and reuse opportunities of sanitation products.
Co-existence of planning scales	Acknowledge the importance of distinct service provision models (e.g. community-driven or informal providers). Assess urban dynamics (e.g. increased population density) and allow for flexible solutions at different scales. Support small-scale solutions, if appropriate, and facilitate exchange of experiences for collective learning. Investigate potential opportunities of economies of scale (e.g., physical connections), thus avoiding fragmented or incompatible solutions.

7. Conclusions

The present study first identified categories of decision elements potentially relevant to take into account when planning sanitation, sorted in four distinct categories: (a) the multi-sectoral approach, (b) the multiplicity of sustainable dimensions, (c) the system analysis perspective and (d) the co-existence of planning scales. These categories are important not only to help planners selecting sanitation technologies but also to adapt technological designs and identify complementary measures, for instance, on how to control health risks or reduce costs not completely dealt with by selected technologies.

The above-mentioned categories are increasingly acknowledged as crucial by the analysed urban sanitation process guides. These documents highlight the interconnectedness of elements affecting sanitation decisions and may play an important role to make certain aspects visible for policy-makers and practitioners. Nevertheless, decision support in the studied planning documents is not always provided in a detailed way that would support technology selection process.

It is therefore important that process guides are continuously improved, e.g., by international organizations and research institutions. The potential of support tools within analysed process guides, namely decision tables, decision trees, fact sheets and checklists, can be further explored taking advantage of their visually driven simplicity. In order to enrich process guides and avoid overloading them with excessive information, these planning documents may also refer to relevant documentation and existing decision-support tools, while explaining how to integrate these resources into the decision-making process. In addition, presenting real case studies might also be useful for planners. Increasing the flexibility of process guides to adapt to distinct levels of data availability, existing knowledge, working practices and institutional frameworks is also paramount. Priority improvements should be devoted to the consideration of the multiplicity of sustainable dimensions and the system analysis perspective, as those aspects are usually important and not sufficiently tackled in the field.

The present analysis also resonates with discussions around general urban planning theories and practices in developing countries. Indeed, the process-oriented and multi-actor nature of analysed process guides is expected to facilitate the implementation of modern forms of planning, such as collaborative and deliberative ones. However, in practical terms, the real uptake of these guides is quite limited, which justifies the need to explore options for increasing their use, e.g., improved marketing that effectively reaches planners. Selecting the appropriate process guides for the elements that are locally prioritised is also suggested. However, from an urban planner’s perspective, some limitations on the detailed guidance provided by process guides might mean that complementary support may be needed, e.g., by consulting further documentation or through cooperation with different disciplinary experts. Finally, it is paramount to recognise that, even when using these guides, an enabling environment is crucial to guarantee the successful planning and implementation of selected solutions, e.g., through appropriate policy frameworks and planning procedures.

In conclusion, increasing the added value of process guides and better integrating them into urban sanitation planning practices is believed to support planners undertake more efficient and locally adapted decisions. The presented suggestions are likely to be significant for other urban sectors of developing countries facing similar challenges, such as water supply and solid waste management (e.g., Guerrero et al. 2013). It is then expected to help dealing with the multi-faceted nature of urban sustainable development, with the ultimate goal to improve living conditions of urban communities in developing countries.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The work of the first author was supported by the Portuguese Foundation of Science and Technology (FCT) with the grant SFRH/BD/75785/2011.

Notes on contributors

A. Ramôa

Ana Ramôa is a doctoral student at Instituto Superior Técnico (University of Lisbon), Portugal. Her dissertation aims at developing a decision support methodology for improving sanitation services of peri-urban areas in developing countries integrating sustainability aspects and the system thinking (from the interface of the user with the sanitation system to the final destination of sanitation products).

C. Lüthi

Christoph Lüthi is head of the Department of Sanitation, Water and Solid Waste for Development (Sandec) at the Swiss Federal Institute of Aquatic Science and Technology (EAWAG). His research includes the validation of demand-driven community-based and strategic citywide planning approaches and the development of contextualised planning tools for urban infrastructure.

J. McConville

Jennifer McConville is a postdoc researcher at Chalmers Architecture, Chalmers University of Technology, Gothenburg, Sweden. Her research interests are related to processes of planning and decision-making with regards to urban sanitation and wastewater management. She works with concepts of sustainability, life-cycle thinking, participation and decision support frameworks to better shape planning processes.

J. Matos

José Saldanha Matos is full Professor at the School of Engineering of the University of Lisbon, Portugal, where he is coordinating the Sanitary Engineering group. He is fellow of the International Water Association and Vice President of the European Water Association. His main interests cover wastewater engineering for developing countries.