solution finder

27 April 2018

Sustainable Sanitation

Author/Compiled by
Katharina Conradin (seecon international gmbh)
Factsheet Block Title
Problems with current approaches to sanitation
Factsheet Block Body

On-site sanitation systems, such as pit latrines, or septic tanks etc. do form an incomplete barrier between users and the environment. Nutrients and pathogens infiltrate and contaminate water sources, hence posing a health risks (Source: CONRADIN 2007, adapted from WERNER).

On-site sanitation systems, such as pit latrines, or septic tanks etc. do form an incomplete barrier between users and the environment. Nutrients and pathogens infiltrate and contaminate water sources, hence posing a health risks (Source: CONRADIN 2007, adapted from WERNER).

Present conventional forms of wastewater management and sanitation fall either under the category of conventional waterborne or dry (pit) systems. In both cases, the design is based on the premise that excreta are waste, and that this waste should be disposed of. It is also assumed that the environment can safely assimilate this waste. These assumptions lead to linear flows of resources and wastes and often cause severe environmental pollution (see also water pollution). The technological developments that were once designed to solve the sanitation problem have become part of the problem, not the answer to it (ESREY 2000).


Conventional centralised systems

Linear end-of-pipe system, mixing all different kinds of wastewater. Source: WINBLAD and ESREY 2004

Linear end-of-pipe system, mixing all different kinds of wastewater. Source: WINBLAD and ESREY (2004)

On-site systems

In pit systems, which are abundant in many parts of the world, the toilet does form a barrier between human beings and excreta. Yet, this barrier is incomplete. Pit latrines are mostly designed to retain solids and infiltrate liquids. When liquids infiltrate, nutrients, and worse, pathogens also infiltrate. If there are large settlements, or if the toilets are built too close to water sources, this can lead to a severe pollution of ground and surface waters, as shown above. Consequences are a high prevalence of waterborne diseases.

Also conventional waterborne systems have their drawbacks. One of the largest is probably that they are linear “end-of-pipe” systems, which are constructed on the assumption that a treatment will take place at the end of the pipe. Yet, worldwide, more than 90% of the wastewater does not receive any treatment at all (CORCORAN et al. 2010), thus polluting an even larger amount of water. There are several other important drawbacks of centralised water-based sewerage (see also water pollution). Some of the most important are: 

  • Mixing different wastewater streams: In centralised systems, wastewater from a range of different sources (domestic, industrial, street runoff) gets mixed, thus creating a wastewater with properties that are hard to handle for any treatment plant — even high tech ones. The range of different harmful substances (heavy metals, chemical and medical residues etc.) contained in such wastewater makes it also difficult to recycle it.
  • Water use: Centralised sewage systems use a large amount of water; not only for flushing the toilet, but there also has to be a certain minimum water flow to ensure that the gravity operated sewers work. Water is getting an ever more scarce resource. According to the 2006 Human Development Report, “the scarcity at the heart of the global water crisis is rooted in power, poverty and inequality, not in physical availability” (UNDP 2006). In other words: there would be enough water for everyone, if it would be used wisely. Using water to flush toilets is definitely not the most sensible solution.
  • Energy consumption: Many centralised conventional sewage treatment plants are effective, but very expensive and plant usually highly energy intensive, which again adds to cost, and also makes them susceptible to failure.
  • Health risks: Wastewater, which is not treated and discharged into other surface water bodies, is a severe health risk to the people downstream using this water. “Unmanaged wastewater is a vector of disease, causing child mortality and reduced labour productivity, but receives a disproportionately low and often poorly targeted share of development aid and investment in developing countries. At least 1.8 million children under five years die every year due to water related disease, or one every 20 seconds (CORCORAN et al. 2010)” (see also health and hygiene issues).
  • Social acceptance: Many approaches to improve sanitary circumstances are well meant, but were largely planned top-down. Often, this can result in a non-acceptance of a system, leading to the fact that the sanitation systems are not well maintained, and do not function properly (see also socio-economic aspects).
  • Closing the loop: Yet, the largest drawbacks of centralised sewer system as they are used today is that they – in most cases – do not favour recycling of resources and thus closing the loop: Water (often groundwater) enters the water distribution system, and is essentially discharged into surface water, leading to groundwater depletion. And nutrients, which essentially come from the soil, are discharged into waterways, leading to soil depletion on the one hand and eutrophication on the other hand.
Factsheet Block Title
What is sustainable sanitation?
Factsheet Block Body

Drawbacks of centralised sewerage

Conventional approaches to wastewater management that regard wastewater as a waste, and often are dysfunctional, have serious drawbacks (Source: CONRADIN 2010).

Sustainable sanitation aims at overcoming these drawbacks. It is not a certain technology, but an approach with certain underlying principles. There are a number of technologies (see for instance sanitation systems) that can be used to make sanitation and wastewater management more sustainable. The term “sustainable sanitation” in principle denominates the same as ecological sanitation, though the latter has a stronger focus on source separation.

The first and foremost principle is probably the one to recognise that excreta and wastewater are not a waste, but a valuable resource that can be reused and recycled. This is actually — to speak in a simplified way — the very basis of sustainability: to use resources wisely and without impairing the possibilities of future generations to meet their own needs.

Sustainable sanitation can be defined more precisely (adapted from SUSANA 2008):

The main objective of any sanitation system is to protect and promote human health by providing a clean environment and breaking the cycle of disease. In order to be sustainable a sanitation system has to do this, and additionally be economically viable, socially acceptable, and technically and institutionally appropriate, and it should also protect the environment and the natural resources. This implies the following criteria:

  • Health and hygiene: The sanitation system must put an effective barrier between its user and the environment, and must prevent exposure that could affect public health at all points of the sanitation system: From the toilet, via the collection and treatment system, to the point of reuse or disposal and downstream populations — hence it also includes hygiene behaviour (see also health and hygiene issues).
  • Environment and natural resources: In order to be sustainable, the sanitation system must protect and respect the natural environment and resources. Wherever possible, the resources contained in excreta and wastewater (energy, nutrients, water) are recycled, thereby protecting other resources (e.g. by replacing fossil fuels through biogas). Should use little energy, water or other resources (e.g. for construction, operation and maintenance), and should produce as little harmful emissions to the environment as possible (both liquid, solid and gaseous) (see recharge and reuse).
  • Technology and operation: A sustainable sanitation system utilises a technology and a mode of operation that are well adapted to local circumstances. This includes the system’s functionality and the ease with which the entire system including the collection, transport, treatment and reuse and/or final disposal can be constructed, operated and monitored by the local community and/or the technical teams of the local utilities. Furthermore, the robustness of the system, its vulnerability towards power cuts, water shortages, floods, etc. and the flexibility and adaptability of its technical elements to the existing infrastructure and to demographic and socio-economic developments are important aspects to be evaluated (see implementation tools).
  • Financial and economic issues: The cost of a sanitation system must relate to the financial capacity of households, communities or institutions and includes not only the costs for construction, but also arising costs for operation, maintenance and necessary reinvestments of the system. Besides the evaluation of these direct costs also direct benefits e.g. from recycled products (soil conditioner, fertiliser, energy and reclaimed water) and external costs and benefits have to be taken into account. Such external costs are e.g. environmental pollution and health hazards, while benefits include increased agricultural productivity and subsistence economy, employment creation, improved health and reduced environmental risks (see financing).
  • Socio-cultural and institutional aspects: A sanitation system only lasts and can be sustainable if it is appropriate and accepted by the community. Again, this includes the whole sanitation system — i.e. not only toilets, but also maintenance and operation and the recharge and reuse system adopted. A sustainable sanitation system must hence be socially acceptable, convenient, respect gender issues and impacts on human dignity, consider impacts on food security. In regards to institution aspects, it must be in compliance with the legal framework and must make for stable and efficient institutional settings (see also sociocultural issues).

Most sanitation systems have been designed with these aspects in mind, but in practice they are failing far too often because some of the criteria are not met. In fact, there is probably no system that is absolutely sustainable. The concept of sustainability is more of a direction rather than a stage to reach. Nevertheless, it is crucial, that sanitation systems are evaluated carefully with regard to all dimensions of sustainability. Since there is no one-for-all sanitation solution, which fulfils the sustainability criteria in different circumstances to the same extent, this system evaluation will depend on the local framework and has to take into consideration existing environmental, technical, socio-cultural and economic conditions.

Taking into consideration the entire range of sustainability criteria, it is important to observe some basic principles when planning and implementing a sanitation system. These were already developed some years ago by a group of experts and were endorsed by the members of the Water Supply and Sanitation Collaborative Council as the “Bellagio Principles for Sustainable Sanitation” during its 5th Global Forum in November 2000 (EAWAG/SANDEC & WSSCC 2000):

  1. Human dignity, quality of life and environmental security at household level should be at the centre of any sanitation approach (see also sociocultural issues).
  2. In line with good governance principles, decision-making should involve participation of all stakeholders, especially the consumers and providers of services (see also creating an enabling environment).
  3. Waste should be considered a resource, and its management should be holistic and form part of integrated water resources, nutrient flow and waste management processes (see also IWRM).
  4. The domain in which environmental sanitation problems are resolved should be kept to the minimum practicable size (household, neighbourhood, community, town, district, catchments, and city) (see also community led urban environmental sanitation).
Factsheet Block Title
Conclusion
Factsheet Block Body

To summarise, sustainable sanitation is a simple approach: the most basic principle is that it considers wastewater and excreta not as a waste, but as a resource, that sanitation has to be socially acceptable and should be as economically viable as possible. There is no “one-fits-all” approach, much rather, the most adequate solution has to be found from case to case, considering climatic conditions, water availability, agricultural practices, socio-cultural preferences, affordability, safety, and technical prerequisites — just to name a few. 

Library References

Sick Water? The central role of wastewater management in sustainable development

This book not only identifies the threats to human and ecological health that water pollution has and highlights the consequences of inaction, but also presents opportunities, where appropriate policy and management responses over the short and longer term can trigger employment, support livelihoods, boost public and ecosystem health and contribute to more intelligent water management.

CORCORAN, E. ; NELLEMANN, C. ; BAKER, E. ; BOS, R. ; OSBORN, D. ; SAVELLI, H. (2010): Sick Water? The central role of wastewater management in sustainable development. A Rapid Response Assessment. United Nations Environment Programme (UNEP), UN-HABITAT, GRID-Arendal URL [Accessed: 05.05.2010] PDF

Summary Report of Bellagio Expert Consultation on Environmental Sanitation in the 21st Century

This report summarises the Bellagio principles, which can be considered a basis for sustainable sanitation approaches.

EAWAG ; SANDEC ; WSSCC (2000): Summary Report of Bellagio Expert Consultation on Environmental Sanitation in the 21st Century. Duebendorf & Geneva: Swiss Federal Institute for Aquatic Science and Technology EAWAG & Water Supply and Sanitation Collaborative Council URL [Accessed: 04.08.2010]

Ecological Sanitation - revised and enlarged edition

This book is one of the most fundamental and important books that defined the concept of ecological sanitation. The first version came out in 1998 - this version presents the findings of over ten years of research and development in ecological sanitation supported by SIDA (Swedish International Development Cooperation Agency).

WINBLAD, U. SIMPSON-HERBERT, M. (2004): Ecological Sanitation - revised and enlarged edition. (pdf presentation). Sweden: Stockholm Environment Institute URL [Accessed: 04.08.2010]
Further Readings

Estimating the Health Risk Associated with the Use of Ecological Sanitation Toilets in Malawi

Use of Ecological Sanitation (EcoSan) sludge is becoming popular due to increasing price of organic fertilizers in Malawi; however, there is little evidence on the associated risks. Quantitative microbiological risk assessment (QMRA) was done to determine health risks associated with use of EcoSan. Pathogens considered included Escherichia coli (E. coli), Salmonella, and soil transmitted helminths (STHs).

KUMWENDA, S. et al. (2017): Estimating the Health Risk Associated with the Use of Ecological Sanitation Toilets in Malawi. In: Journal of Environmental and Public Health: Volume 2016 URL [Accessed: 04.04.2018] PDF

Summary Report of Bellagio Expert Consultation on Environmental Sanitation in the 21st Century

This report summarises the Bellagio principles, which can be considered a basis for sustainable sanitation approaches.

EAWAG ; SANDEC ; WSSCC (2000): Summary Report of Bellagio Expert Consultation on Environmental Sanitation in the 21st Century. Duebendorf & Geneva: Swiss Federal Institute for Aquatic Science and Technology EAWAG & Water Supply and Sanitation Collaborative Council URL [Accessed: 04.08.2010]

Ecological Sanitation and Reuse of Wastewater. Ecosan. A Thinkpiece on ecological sanitation

This paper shows that there are comprehensive experiences and available technologies that meet new and sustainable sanitation requirements. Ecological sanitation constitutes a diversity of options for both rich and poor countries, from household level up to wastewater systems for mega-cities and needs to become recognised by decision-makers at all levels.

JENSSEN, P.D. HEEB, J. HUBA-MANG, E. GNANAKAN, K. WARNER, W. REFSGAARD, K. STENSTROEM, T.A. GUTERSTRAM, B. ALSEN, K.W. (2004): Ecological Sanitation and Reuse of Wastewater. Ecosan. A Thinkpiece on ecological sanitation. Norway: The Agricultural University of Norway URL [Accessed: 19.04.2010]

Ecological Sanitation - revised and enlarged edition

This book is one of the most fundamental and important books that defined the concept of ecological sanitation. The first version came out in 1998 - this version presents the findings of over ten years of research and development in ecological sanitation supported by SIDA (Swedish International Development Cooperation Agency).

WINBLAD, U. SIMPSON-HERBERT, M. (2004): Ecological Sanitation - revised and enlarged edition. (pdf presentation). Sweden: Stockholm Environment Institute URL [Accessed: 04.08.2010]

Sustainable Sanitation in cities: a framework for action

This book repared by partners of the Sustainable Sanitation Alliance (SuSanA) network is a real eye-opener. It takes a look at some of the methods that have worked well in the past, to guide us in solving the problems of the future. By addressing sanitation as a key element of the urban metabolism, and by linking sanitation with urban planning and neighbouring sectors like solid waste management or waste recycling, it allows for a holistic approach. In the cities of tomorrow, we will need to focus more on recycling energy. A good example being biogas generation from wastewater and sludges. Water will also become an increasingly scarce commodity. Greywater (from showers and sinks) can be treated in urban constructed wetlands or used to water and fertilise urban green spaces. Such examples of productive sanitation systems will form an integral part of infrastructure in sustainable cities.

LUETHI, C. PANESAR, A. SCHUETZE, T. NORSTROEM, A. MCCONVILLE, J. PARKINSON, J. SAYWELL, D. INGE, R. (2011): Sustainable Sanitation in cities: a framework for action. Sustainable Sanitation Alliance (SuSanA) & International Forum on Urbanism (IFoU), Papiroz Publishing House, The Netherlands URL [Accessed: 26.05.2019]

Sustainable Water and Waste-Water Management: Energy- and Material-Flow-Management - Quo vadis?

By taking the example of phosphorus, this essays shows that besides encompassing elaborate treatments to produce high quality water discharges to recipient bodies, the various substances brought into the water by human activities might also be extraordinarily valuable.

KIEFHABER, P. (2010): Sustainable Water and Waste-Water Management: Energy- and Material-Flow-Management - Quo vadis?. The Example 'Phosphorus-Recycling'. Kaiserslauten: Dr. Kiefhaber + zebe ingenieur consult gmbh

What Happens When the Pit is Full?

This seminar report helps people responsible for the sustainable operation of on-site sanitation systems. It shows new developments in the field and contains a lot of detailed information about Faecal Sludge Management (FSM).

WINSA (2011): What Happens When the Pit is Full?. Developments in On-Site Faecal Sludge Management (FSM). Durban: Water Information Network South Afrika (WINSA) URL [Accessed: 06.10.2011]

Construction of Ecological Sanitation Latrine

This document sets out the principles for adopting an ecological sanitation approach, as well as providing guidance on the construction ecological sanitation latrines and their operation. It is intended to support sanitation field practitioners and WaterAid in Nepal ’s partners in the delivery of appropriate services and technologies to fit the needs of different users. .It is also equally hoped that this document will be of value to other organisations and sector stakeholders involved in sanitation promotion and ecological sanitation.

WATER AID (2011): Construction of Ecological Sanitation Latrine. Kathmandu: Water Aid URL [Accessed: 19.10.2011]

Compilation of 13 Factsheets on Key Sustainable Sanitation Topics

This factsheet book is a compilation of 13 thematic factsheets which were produced by the eleven SuSanA working groups (WGs): WG1 - Capacity development; WG 2 - Finance and economics; WG 3 - Renewable energies and climate change; WG 4 - Sanitation systems, technology options, hygiene and health; WG 5 - Food security and productive sanitation systems; WG 6 - Cities and planning; WG 7 - Community, rural and schools (with gender and social aspects); WG 8 - Emergency and reconstruction situations; WG 9 - Sanitation as a business and public awareness; WG 10 - Operation and maintenance; WG 11 - Groundwater Protection. What makes these factsheets special is that they are multi-authored by people from different organisations and by free-lance consultants. The factsheets were developed in a long process involving many discussions and review loops which were mostly carried out in public, e.g. at working group meetings, with the working group mailing lists or, since July 2011, also in the open SuSanA discussion forum.

MUENCH, E. von ; INGLE, R. ; MBALO, D ; KAPPAUF, L. (2012): Compilation of 13 Factsheets on Key Sustainable Sanitation Topics. Eschborn: Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH URL [Accessed: 26.04.2019]

Ecodesign: The Bottom Line

There is no single design solution to sanitation. But there are universal principles for systematically and safely detoxifying human excreta, without contaminating, wasting or even using water. Ecological sanitation design — which is focused on sustainability through reuse and recycling — offers workable solutions that are gaining footholds around the world, as Nature explores on the following pages through the work of Peter Morgan in Zimbabwe, Ralf Otterpohl and his team in Germany, Shunmuga Paramasivan in India, and Ed Harrington and his colleagues in California.

NATURE (Editor) ; MORGAN, P. ; OTTERPOHL, R. ; PARAMASIVAN, S. ; HARRINGTON, E. (2012): Ecodesign: The Bottom Line. In: Nature: International Weekly Journal of Science: Volume 486 , 186-189. URL [Accessed: 19.06.2012]

Sanitation for All

Water pollution from sewage is causing great damage to India. The nation needs to complete its waste systems and reinvent toilet technologies.

NATURE (Editor) ; NARAIN, S. (2012): Sanitation for All. In: Nature: International Weekly Journal of Science: Volume 486 , 185. URL [Accessed: 19.06.2012]

Pit Latrines and Their Impacts on Groundwater Quality: a systematic Review

This study reviews empirical studies on the impact of pit latrines on groundwater quality and identifies knowledge gaps regarding the potential and consequences of groundwater contamination by latrines.

Graham, J. ; Polizotto, M.L. (2013): Pit Latrines and Their Impacts on Groundwater Quality: a systematic Review. Advance Publication. In: Environmental Health Perspectives: URL [Accessed: 09.04.2013]

Report of the Special Rapporteur on the Human Right to Safe Drinking Water and Sanitation, Catarina de Albuquerque

Focusing on sustainability in the realization the human rights to water and sanitation, the report examines how the rights to water and sanitation can and must be met for present and future generations. Using the human rights framework, the report analyses states’ common approaches to water and sanitation, particularly in adopting measures both during times of normalcy and during economic and financial crises, and shows how those approaches often fail to incorporate sustainability.

ALBUQUERQUE, C. (2013): Report of the Special Rapporteur on the Human Right to Safe Drinking Water and Sanitation, Catarina de Albuquerque. (=Report submitted to the General Assembly’s Human Rights Council, 24th session, July 11, 2013). Geneva: Office of the United Nations High Commissioner for Human Rights (OHCHR) URL [Accessed: 07.10.2013]
Case Studies

Eco Home for Sustainable Water Management- A Case Study in Kathmandu

This paper describes a case study of a house in Kathmandu where rainwater is used for all purposes including drinking, greywater is recycled for non drinkable purposes and human excreta is utilized as a fertilizer by adopting ecological sanitation technique.

SHRESTHA, R.R. (2010): Eco Home for Sustainable Water Management- A Case Study in Kathmandu. Kathmandu: United Nation Development Program (UNDP) URL [Accessed: 12.03.2019] PDF

Compilation of 27 Case Studies on Sustainable Sanitation Projects from Sub-Sahara Africa

The Sustainable Sanitation Alliance (SuSanA) publishes case studies of sustainable sanitation projects from around the world to demonstrate the wide range of available technologies for sustainable sanitation systems. This case study book only comprises those project examples which are from sub-Saharan African countries. These case studies are useful for decision makers, planners, researchers, engineers and the interested public. They have compiled descriptions of well-running projects as well as of less successful projects so that we can learn from past mistakes.

INGLE, R. MUENCH, E. von (2011): Compilation of 27 Case Studies on Sustainable Sanitation Projects from Sub-Sahara Africa. Eschborn: Sustainable Sanitation Alliance (SuSanA) URL [Accessed: 29.05.2012]

Use of Urine

A "Sustainable Sanitation Practice" journal by Ecosan Club, focussing on the use of urine and presenting some case studies.

ECOSAN CLUB (2010): Use of Urine. (= Sustainable Sanitation Pracice , 3 ). Vienna: Ecosan Club URL [Accessed: 05.08.2010]

Success Stories of Sustainable Sanitation Initiatives in India by ESF

ESF is working in the diversified sectors in rural, peri-urban and urban areas focusing on the agricultural sector, schools, communities, the Eco-village project, sanitation plans for pilgrimage towns and upcoming projects in local government bodies with a participatory approach and cost effective sustainable sanitation solutions. This document shows some examples.

THAKUR, P. PANSE, D. ESF (n.y): Success Stories of Sustainable Sanitation Initiatives in India by ESF. Pune: Ecosan Services Foundation (ESF) URL [Accessed: 22.06.2011]

Water Reuse

To meet the challenges extremely efficient water use is necessary to achieve overall improvements in water productivity. Multi-use systems will therefore be crucial in integrated water management. Different examples show how water can be reused and recycled and thus increasing water efficiency in urban, peri-urban and rural areas. Issue 11 of Sustainable Sanitation Practice (SSP) on „Water reuse“ shows 3 examples for the use of treated wastewater for irrigation in agriculture: (1.) The first paper presents results from a long-term study (agricultural wastewater reuse) carried out in Sicily, Italy. (2.) The second paper presents activities on water management in the Oasis of Figuig, Morocco. (3.) The third paper presents practical experiences from a feasibility study on technology selection for wastewater treatment and effluent reuse schemes in Anza village, Palestine.

MUELLEGGER, E. ; LANGERGRABER, G. (2012): Water Reuse. Vienna: EcoSan Club URL [Accessed: 18.07.2012]
Training Material
Awareness Raising Material

Sick Water? The central role of wastewater management in sustainable development

This book not only identifies the threats to human and ecological health that water pollution has and highlights the consequences of inaction, but also presents opportunities, where appropriate policy and management responses over the short and longer term can trigger employment, support livelihoods, boost public and ecosystem health and contribute to more intelligent water management.

CORCORAN, E. ; NELLEMANN, C. ; BAKER, E. ; BOS, R. ; OSBORN, D. ; SAVELLI, H. (2010): Sick Water? The central role of wastewater management in sustainable development. A Rapid Response Assessment. United Nations Environment Programme (UNEP), UN-HABITAT, GRID-Arendal URL [Accessed: 05.05.2010] PDF

Sanitation Now Money down the drain

This special issue of "Sanitation Now", a magazine on the global sanitation crisis published by the Stockholm Environment Institute, focuses on the millions of dollars that are lost through the lack of sanitation - such as costs caused through polluted water, diarrhoea related diseases and deaths, and losses in tourist income. Its baseline is that poor sanitation equals more poverty and a stunted economic growth.

SEI (2008): Sanitation Now Money down the drain. Stockholm: Stockholm Environment Institute URL [Accessed: 21.04.2012]

Waste? Not

Critical article on conventional end-of-pipe wastewater approaches, introducing some alternatives such as biogas digester, arborloos or the fossa alterna.

TUHUS-DUBROW (2008): Waste? Not. In: The Boston Globe: URL [Accessed: 21.02.2010]

Water Quality Factsheet

Thematic factsheet. Every day, 2 million tons of human wastes are disposed of in watercourses, and in developing countries 70 % of industrial wastes are dumped untreated into waters where they pollute the usable water supply. But not only industry contaminates our water resources, so do also agriculture. The contribution of the food sector to the production of organic water pollutants, are in high-income countries 40 % and in low-income countries 54 %.

UN Water UN Water (2013): Water Quality Factsheet. UN Water URL [Accessed: 09.04.2013]

Alternative Versions to