A century ago waste or was collected in the major European cities, sometimes mixed with peat or lime, and used as fertiliser. In China the use of night soil or toilet waste has always been regarded as a valuable fertiliser resource for agri- and aquaculture.With the invention of the water toilet and development and installation of subterranean gravity sewer systems, these resources began being dis- charged to water. The water toilet improved the health in the homes, but caused eutrophication and severe pollution of waterways. This is threatening the ecological balance, even in the North sea, and also many drinking water sources in industrial and developing countries.If the water toilet had been invented today it would probably not have been certified as an environmentally friendly device. In cities water account for 20-40% of the water consumption (Gardner, 1997). This is often potable water purified and brought to the cities at high cost. This water is used to dilute a resource. Theoretically, the nutrients in domestic wastewater and organic waste are almost sufficient to fertilize all the crops needed to feed the . As much as 80-90% of the major plant nutrients (nitrogen, phosphorus and potassium) in wastewater are present in the toilet waste. If these nutrients are reclaimed they can be used locally as a fertiliser. And what if we at the same time could produce energy from the organic matter and save water!Technological alternatives to the conventional that provide the same comfort, save water and facilitates separate collection of toilet waste does exist. Vacuum- and gravity toilets that use only one liter (or even less) per flush has been developed. The treatment facilities for toilet waste can easily handle organic waste, hence, all domestic organic waste flows can be safely collected, reclaimed and turned into bio-energy and fertiliser. Several manufacturers provideurine separation toi- lets that are easily retrofitted in existing buildings, making collection possible. The urine, which is sterile in healthy humans needs only some storage time before it is hygienically safe to be used as fertiliser. Improvements in technologies facilitate dry sanitation and fecal composting. And furthermore: It provides a completely odorless toilet room.So, why do we not make use of these promising options? There are several reasons. The systems are relatively new. The possibilities to supplement and even replace traditional sewer systems with decentralised, resource saving systems are not widely known. Such, ecologically engineered systems that collect, sanitize and reuse waste resources are, with a few exceptions, not part of the curricula at engineering schools. When the engineers do not know, we cannot expect the decision makers to do so.How can ecological thinking be applied to wastewater engineering, and what kind of systems will evolve? This chapter clarify some design principles of ecological sanitation.We have not always thought of the consequences or impact that a conventional centralised wastewater treatment system has on the larger system that it operates within. Ecological engineering defined as: “The design of human society with nature for the benefit of both” seeks high system integration and is based on a holistic view (Ref). One of the key disci- plines of ecological engineering is ecological sanitation. The main design principles for systems based on ecological sanitation are: System approach (holistic): This means to consider the technical and the organisational structures as well as the people involved (Söderberg 2003). The technical structure shows the material and energy flows. It may include the separate collection of urine and feces at the household level and its recycling to fertiliser. However there is also an organisational, immaterial, structure; how are decisions performed, how is the re- sponsibility distributed, what is the strategy for communication with the users etc, who is paying for what – in total a structure for rules and procedures facilitating the participation of the stakeholders (households, the entrepreneurs, the administration and the policy makers). The stakeholders have their own behavior, values and interests that will determine the success of the chosen system Source separation of waste streams: This is often a logical consequence of the system analysis and facilitates better source control. Nutrient rich toilet waste is collected using extremely low flush and urine separating toilets or dry/composting toilets. This can be cotreated with other source separated organic wastes from domestic and agricultural sources. Recycling and resource efficiency: Recycling is often a consequence of ecological thinking. A century ago toilet waste or night soil was collected in the major European cities, sometimes mixed with peat or lime, and used as fertiliser. In China the use of night soil or toilet waste has always been regarded as a valuable fertiliser resource for agri- and aquaculture.With the invention of the water toilet and development and installation of subterranean gravity sewer systems, these resources began being dis- charged to water. The water toilet improved the health in the homes, but caused eutrophication and severe pollution of waterways. This is threatening the ecological balance, even in the North sea, and also many drinking water sources in industrial and developing countries.If the water toilet hadEcological been invented today it would probably notSanitation have been certified as an environmentally friendly device. In cities water toilets account for 20-40% of the water consumption (Gardner, 1997). This is often potable water purified and brought to the cities at high cost. This water is used to dilute a resource. Theoretically, the nutrients in domestic wastewater and organic waste are almost sufficient to fertilize all the crops needed to feed the world population. As much as 80-90% of the major plant nutrients (nitrogen, phosphorus and potassium) in wastewater areand present in the Reusetoilet waste. If these nutrients of are reclaimed Wastewater they can be used locally as a fertiliser. And what if we at the same time could produce energy from the organic matter and save water!Technological alternatives to the conventional sanitation that provide the same comfort,ecosan save water and facilitates separate collection of toilet waste does exist. Vacuum- and gravity toilets that use only one liter (or even less) per flush has been developed. The treatment facilities for toilet waste can easily handle organic waste, hence, all domestic organic waste flows can be safely collected, reclaimed and turned into bio-energy and fertiliser. Several manufacturers provideurine separation toi- lets that are Aeasily Thinkpiece retrofitted in existing on ecological buildings, making sanitation urine collection possible. The urine, which is sterile in healthy humans needs only some storage time before it is hygienically safe to be used as fertiliser. Improvements in compost technologies facilitate dry sanitation and fecal composting. And furthermore: It provides a completely odorless toilet room.So, why do we not make use of these promising options? There are several reasons. The systems are relatively new. The possibilities to supplement and even replace traditional sewer systems with decentralised, resource saving systems are not widely known. Such, ecologically engineered systems that collect, sanitize and reuse waste resources are,Petter with aD. few Jenssen exceptions, not part of the curricula at engineering schools. When the engineers do not know, we cannot expect the decision Johannesmakers to Heebdo so.How can ecological thinking be applied to wastewater engineering, and what kind of systems will evolve? This chapter clarifyElisabeth some design Huba-Mang principles of ecological sanitation.We have not always thought of the consequences or impact that a conventional centralised wastewaterKen Gnanakan treatment system has on the larger system that it operates within. Ecological engineering defined as: “The design of human societyWilliam with nature S. Warner for the benefit of both” seeks high system integration and is based on a holistic view (Ref). One of the key disci- plines of ecologicalKaren Refsgaardengineering is ecological sanitation. The main design principles for systems based on ecological sanitation are: System approach (holistic):Thor-Axel This Stenström means to consider the technical and the organisational structures as well as the people involved (Söderberg 2003). The technical structure shows the material and energy flows. It may include the separate collection of urine and feces at the household level Björn Guterstam and its recycling to fertiliser. However there is also an organisational, immaterial, structure; how are decisions performed, how is the re- sponsibility distributed,Knut Werner what Alsén is the strategy for communication with the users etc, who is paying for what – in total a structure for rules and procedures facilitating the participation of the stakeholders (households, the entrepreneurs, the administration and the policy makers). The stakeholders have their own behavior, values and interests that will determine the success of the chosen system Source separation of waste streams: This is often a logical consequence of the system analysis and facilitates better source control. Nutrient rich toilet waste is collected using extremely low flush and urine separating toilets or dry/composting toilets. This can be cotreated with otherMarch source 2004, separated Norway organic wastes from domestic and agricultural sources. Recycling and resource efficiency: Recycling is often a consequence of ecological thinking. But we need to recycle within spatially small loops and a suitable time frame to obtain an ecologically sound solution. Recycling is facilitated by decentralised, ecological sanitation. Decentralised treatment offers better source control and shorter transport distances. Decentralised concepts can be applied for urban and rural areas (see chapter 4). Resource efficiency means minimizing the use of input factors (buildings, pumps etc.), the operation of treatment systems and using natural systems, where solar energy is captured through photosynthesis, when possible.

2004 Ecosan

Contents Preface Abstract

1. Ecological Sanitation 4 The Agricultural University of Norway is heading the The challenges and opportunities given by the global community at the World Summit 2. Advantages and Challenges of Ecological Sanitation 6 development of ecological sanitation in Norway and was on (WSSD) and in the Millennium Development Goals (MDGs) 3. Ecological Sanitation in Practice 8 commissioned to write this ”Thinkpiece” by the Norwe- to improve livelihood for people and to restore the degraded environment are histori- 4. Culture, Gender and Poverty 12 gian Ministry of Environment. The text is the responsibil- cally unique. 5. Health aspects 14 ity of the authors. Investments in water supply, health, and sanitation will be given priority dur- Ecological sanitation is an option for all, but in ing the coming years. In order to meet requirements of , cost effective and this text the main focus is on developing countries. Suc- appropriate technologies must be introduced parallel with new attitudes, especially in cessful implementation of ecological sanitation requires the field of sanitation. a multidisciplinary approach, hence, we have invited This paper is a “Thinkpiece” to show that there are comprehensive experiences authors with a diverse background. and available technologies that meet new and requirements. Dr. Petter D. Jenssen is professor of environmen- Ecological sanitation constitutes a diversity of options for both rich and poor countries, tal engineering. Dr. Johannes Heeb has a major in natural from household level up to wastewater systems for mega-cities. The objective of this sciences and is chairman of the International Ecological paper is to show that ecological sanitation can play an important role in this context Engineering Society (IEES). Elisabeth Huba Mang has and that it needs to become recognised by decision makers at all levels. worked with ecological sanitation (ecosan) implementa- tion for 20 years in close cooperation with the German GTZ team, one of the most active groups implementing ecological sanitation world wide. Dr. Ken Gnanakan is heading the Indian NGO, ACTS, which is involved in devel- oping sanitary solutions for the slum population of . Dr. William Warner’s speciality is the cultural aspects of ecological sanitation. Dr. Karen Refsgaard is an ecologi- cal economist working with waste and wastewater. Dr. Björn Guterstam is an aquatic ecologist with experience in wastewater reuse in aquaculture. He is a network of- ficer for Global Water Partnership (GWP) regions in Asia. Professor Thor-Axel Stenström is an expert on health and hygiene and consults frequently for WHO. Journalist Knut Werner Alsén is responsible for editorial comments and layout. The authors thank Rune Vistad of the Norwegian Ministry of Environment, Ivar Jørgensen from Noragric and Florian Klingel from the GTZ for constructive com- ments.

The Agricultural University of Norway March 30, 2004

Professor Petter Deinboll Jenssen Ecosan

Page 3 Ecosan 2004 Ecosan

for concentrated toilet waste can eas- ily handle organic kitchen waste, hence, 1. Ecological Sanitation most domestic organic waste flows can be safely collected, reclaimed and turned AN OPTION FOR ALL into bio-energy and fertilisers. Several – manufacturers provide urine diverting toilets that are easily retrofitted in exist- ing buildings, making urine collection possible (8). Urine, needs only storage (time dependent on climate) before it is suit- able for use as a hygienic fertiliser (9). Most of the people in developing coun- supply. To reach the sanitation MDG more Recent improvements in compost technol- tries do not have access to safe sanitary attention and allocation of resources are ogy have made the treatment of human systems. If we are going to tackle this needed. The amount of resources needed waste, safe efficient and odourless (10). is strongly dependent on the choice of problem we have to leapfrog the central- Why are these options not widely technology. used? There are several reasons. The ised end-of-pipe sanitary systems of the The WSSD estimates that 2.4 systems are relatively new. The options industrial world. New affordable technolo- billion persons lack adequate sanitation to supplement and even replace tradi- gies based on ecological sanitation, which (2). Most people lacking sanitation live in tional sewer systems with inexpensive Water well (right) adjacent to an open sewer. save water, recycle local nutrients and developing countries. In addition, farmers decentralised, resource saving systems extract energy, open sustainable options in rural and urban areas experience short- are not widely known. With few excep- ages of water and nutrients in for all both in rich and in poor countries. ing countries. If the water toilet had been tions ecological engineering is not a part and aquaculture. It is therefore high time invented today it would probably not have of the curricula at engineering schools. If to look at safe reuse options for urban been certified as sanitation technology engineers are not aware of these devel- International Water and The United Nations, during the Millen- wastewater. Development Organizations meeting sustainability criteria. opments, we cannot expect the decision nium Summit in New York in 2000 and In order to meet the demands of with ecological sanitation on In cities, water toilets account makers to be aware of them either. the World Summit on Sustainable Devel- sanitation for all, prevent environmen- their agenda: for 20-40% of the water consumed (3). opment in Johannesburg (WSSD) in 2002, tal degradation, and to make long-term Potable water, a limiting factor for devel- SIDA, DANIDA, GTZ, Dutch Dev. developed a series of Millennium Devel- economically efficient investments, new opment, is misused to flush human waste Coop., WSP, WSSCC, IWA, Unicef, opment Goals (MDGs) aiming to achieve approaches to wastewater management UNEP,ATV/DVWK, NORAD where both water and the excreta should poverty eradication and sustainable must be implemented. Ecological Sani- be considered as a resource. Theoreti- development by rapidly increasing access tation is a promising approach whose cally, the nutrients in domestic wastewa- to basic requirements such as clean water, potential contribution for achieving the ter are almost sufficient to fertilize all the energy, health care, and the MDG’s is increasingly recognized among crops needed to feed the world population protection of . The specific international development organizations. (4). As much as 80-90% of the major target set for the provision of water sup- This paper gives an introduc- plant nutrients (nitrogen, phosphorus ply and sanitation services is to halve the tion to ecological sanitation as a tool for and potassium) in wastewater are present proportion of people without access to meeting the goals of urban sanitation as in the toilet waste (5). If these nutrients safe drinking water and adequate sanita- expressed in the MDGs tion by 2015. are reclaimed using hygienically safe The progress towards meeting pathways, they can be used locally as a the MDG sanitation target is the slowest The water born toilet paradigm fertiliser in . of all MDG’s, with an enormous gap exist- With the invention of the water toilet and ing between the intended coverage and subterranean gravity sewers the develop- Alternatives are on the market ment of sanitation systems moved from today’s reality (1). Water supply and sani- Technological alternatives to conventional decentralised to centralised wastewater tation are cornerstones of public health as sanitation that provide the same comfort, management. The water toilet improved well as social and economic well- save water and facilitate separate collec- health, but severely polluted waterways. being. Sanitation, however, receives less tion of toilet waste do exist (6). Vacuum At the same time the costs for sewage priority during planning, policymaking, and gravity toilets that use only one liter treatment started to exceed the range of budgeting, and implementation, while (or even less) per flush are on the market affordability for most people in develop- more resources are allocated to water (7). The downstream treatment facilities Ecosan

Page 5 Ecosan ��

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8 Impro v ed health by introducing 2. Advantages and Challenges ������������ �� ��������� new methods of handling faecal ������� matter ����� 8 Affordable s olutions with low ���������� capital and maintenance costs of Ecological Sanitation ���� �������� ����� 8 Increas ed f ood s ecurity by better ��������� �������� f ertilser availabilty ����� 8 Subs tantial water sa vings by using water saving toilets and reuse ������� of greywater ����� ����������� �������� 8 E c onomic dev elopment by genera- tion of local buisiness opportunities

��������� ��������� 8 B ioenergy production by inte- The UN Millennium Goal of supplying peo- �������� Advantages of ecological ������ ����� �������� ��������� grated solutions f or wastewater and ������� ������������ ple with safe drinking water and adequate ���������� organic waste sanitation ����� ����� 8 Stak eholder in v ol v ement and s ys- sanitation can be met with inexpensive Affordable options for all ����� ��������� tem acceptance ( considering social solutions that are well adapted to the Ecological sanitation reduces the need cultural, technical and environmen- ������������ local conditions. Sanitary systems used in for pipelines - the most expensive part tal issues ) of a traditional sewer network. Ecologi- ���������� developed countries are often too expen- ����� ������������ �� cal sanitation can provide both the poor �������� ���������� sive, require much maintenance and have ������������� ������ and the wealthy with sustainable sanitary System approach to ecological sanitation closes�� �loops������ �� �in��� wastewater��� management (10). a high water demand. systems at an affordable cost. It is difficult to give exact cost Recycling and saving resources tries favours conventional, centralised Ecological sanitation implies separating figures for ecological sanitation systems Design guidelines are needed 8 Ecological sanitation saves at least sanitary systems and must be revised to waste streams, saving water and energy, because the local conditions on which 20-40% of the domestic water consump- encompass ecological sanitation. This System approach nutrient recycling, cost efficiency, and the they rely vary greatly. General figures Ecological sanitation is a young tion (3). Adding water saving devices or means encouraging the implementation of integration of technology to environmen- from UNEP (11) show that the annual costs discipline. However, on a global recycling greywater makes it possible decentralised solutions and more focus on basis, much data and experience tal, organisational and social conditions. of ecological sanitation options are lower Actors Organisational to save even more water. This is of key promoting health and resource manage- is available. This comprehensive Structure In developing countries there than most conventional options. As an importance since water is a major limiting ment aspects. knowledge must be compiled as a is often no established infrastructure example the ecosan toilet system in Ban- basis for new design guidelines. factor for development in many countries. for wastewater handling. Water, money, galore has an annual cost per person of 8 In order to prepare the legal basis for Technical/ After filtration, greywater can be used for bioloical and fertilisers are scarce resources while 10USD. However, more cost comparisons ����������� ��� �������������� �� ������ ��� wider implementation of ecological sani- ������������� �������� ��� ����������� ������� structure irrigation,������ � �������� �groundwater��� ��� ������������ ����������� recharge. or even labour is cheap and available. These for different system options are needed. ���������� ���������� ��� ���������� ������� tation, performance-based�������� �regulations����������� ��� for production����������������� of potable water. ���������� �������������� ����� ���� conditions poorly match the characteris- for wastewater treatment systems should Planning sustainable wastewater 8 Ecological Sanitation is flexible, and tics of conventional wastewater systems 8 Ecological sanitation enables of 80- be introduced. This means that a system systems needs to integrate the organi- centralised can be combined with decen- sational system, the technical system, which are water intensive with a costly 90% of the nitrogen, phosphorus and has to meet requirements (e.g. discharge tralised, waterborne with dry sanitation, the users of the system and the inter- infrastructure. In addition conventional potassium in excreta and wastewater to limits, health and ) high-tech with low-tech, etc. By consid- actions between these (39). systems rely more on imported goods be recycled for agricultural use (5). This set by the authorities. Such regulations ering a much larger range of options, while ecological sanitation to a larger provides inexpensive local fertilisers that stimulate creativity and development of optimal and economic solutions can be extent utilises local resources. help long-term poverty alleviation through new systems because any system can be developed for each particular situation. Expensive conventional Moreover ecological sanitation enhanced food production and a series of used as long as it meets the requirements intrastructure systems are often locally managed with local business opportunities. and has been properly characterized. low transport costs, minor requirements Increasing health and dignity 8 Ecological sanitation eliminates large 8 Ecological sanitation facilitates energy 8 The water closet and centralised sew- Collection and transport account for water, and reuse of nutrients. These production from organic waste resources. for 80-90 % of the capital cost are some of the reasons why ecological quantities of , which is the ers are perceived as the ultimate solu- and more than 65 % of the annual sanitation may be more appropriate in main fraction carrying disease causing 8 Ecological sanitation creates local tion. This perception increases the gap cost of conventional wastewater organisms, and pollute water supplies business opportunities for construction, between rich and poor, specifically in handling facilities (12). low-income countries than conventional systems specifically for the poor in developing operation and maintenance of sanitary developing countries. Knowledge about countries. facilities and sale of fertiliser products. the concept of ecological sanitation must 8 Ecological toilet systems for the poor be communicated to engineers, decision enhance their dignity, quality of life and Challenges of ecological sanita- makers and stakeholders. health. tion and possible responses 8 Cultural taboos and attitudes can hinder the use of excreta-based fertilisers. Infor- 8 Existing legislation in many coun- mation is important to change this. Ecosan

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3. Ecological Sanitation in Practice

Ecological sanitation offers flexible solu- wastewater irrigation poses potential tions that are used in high tech environ- health problems that are not always prop- ments such as Volvo’s Conference centre erly dealt with. on the Swedish west coast, the slums of India Bangalore India and to treat wastewater A toilet centre provides sanitary facili- in mega cities in Asia and Australia. Below ties for 600 – 800 slum dwellers (19). are some examples from the rapidly grow- The urine is used as fertiliser after stor- age and the faecal matter is composted ing field of ecological sanitation. with wastepaper and garden waste and China used for soil amendment. In addition to China has a long tradition of effective improving public health the toilet centre management of natural resources. This enhances the dignity of women through includes reuse of garbage and human ex- eliminating sexual harassment associated creta in agriculture and aquaculture. The with the traditional practices of defecat- classical night soil system was reported to ing in the open. reuse as much as 90% in agriculture (13). The toilet centre, which gener- Wastewater fed aquaculture purifies water, produces food and provides green areas. Tradition therefore facilitates implemen- ates 200 t of urine and 100 t of faeces per tation of modern ecological sanitation in year, produces 50 t of compost, which in Wastewater aquaculture in Calcutta Lessons learned from Calcutta are that the China. turns yields 50 t of bananas. The project The main sewers of Calcutta began func- wastewater reuse system meets modern In 1998 70 households in the ru- has created 8 new full-time jobs. The tioning in 1875. In the 1930s sewage-fed criteria of sustainable development of a ral areas of Guangxi, installed new urine annual cost of the existing systems is ap- fish farming started in the extensive pond mega-city in terms of: proximately 10 USD per user. system used for wastewater treatment. diverting toilets and by the end of 2002 8 The Environment by providing low-cost The fisheries developed into the largest more than 100 000 households had simi- wastewater treatment, storm-water drain- single excreta-reuse aquaculture system lar toilets (14). This has paved the way for age and a green area as a lung for the city urban implementation in China (15). in the world with around 7,000 ha in the The reuse in aquaculture of 1940s, supplying the city markets with 8 Social and economic benefits, including wastewater from large cities started 10-12 tons of fish per day (14, 20). Today employment for about 17,000 poor people in 1951 in Wuhan, reaching about 20 the Calcutta Wetlands using wastewater and production of about 20 t of fish per 000 ha by the 1980’s (16). The reuse of both in agriculture and in aquaculture day for the urban poor (23) covers an area of about 12,000 ha, known wastewater in aquaculture systems has 8 Serving as a model to be replicated as the Waste Recycling Region (21). been linked to traditional concepts of elsewhere in India and other countries integrated farming and fish polycultures, Wastewater-fed aquaculture systems like which are seen as effective solutions to the Calcutta Wetlands represent control- 8 Reducing environmental impacts of meet a growing pollution problem in wa- lable public health risks (22) . This is due contamination from heavy metals from tercourses (17). Irrigation with municipal to a combination of long retention times, major industries, e.g. chromium from the high temperatures, high solar irradiance, tanneries in Calcutta (24) wastewater reached about 1.5 million ha Ecosan toiletcenter in Bangalore, India. in 1995 covering around 1% of the total high natural microbiological activity, cultivated land of China (18). However and adequate personal hygiene and food handling. Ecosan

Page 9 Ecosan 2004 Ecosan

Botswana for cattle and sheep. The public water The villages of East and West Hanahai are company Melbourne Water manages 54% located in Botswana’s Kalahari Desert. On- of its wastewater in 11,000 ha of ponds, site sanitation facilities allow the families wetlands and meadows, i.e., 500,000 to produce their own and cubic metres of wastewater per day. The fertiliser for their vegetable gardens (25). present livestock graze on 3,700 ha of The toilet systems collect urine and faeces pastures irrigated with raw or sedimented separately. sewage and 3,500 ha non-irrigated pastures. The livestock yield a substantial return of about 3 million Australian dol- lars per year, which significantly reduces the cost of sewage treatment. (27). Sweden In the Swedish capital of Stockholm, is used in several urban hous- ing areas, e.g. Palsternackan (50 apart- ments), Understenshöjden, (44 apart- ments), Gebers (30 apartments) and the newest Kullan (250 apartments). These Villagers meeting discussing ecological sanitation are all family homes and show that people easily adapt to the new system (8). After a period of awareness rais- ing, information sharing and mobilisation, which included meetings with the commu- Greywater treatment using a biofilter and for 100 persons in Oslo, the capital of Norway. nity chiefs and other events targeting all The effluent meets the current European swimming water standard with respect to indicator bacteria. women and men in the villages, 20 fami- lies volunteered to pilot the concept of ecological sanitation. All of them selected urine diverting dry toilets, to provide Germany Norway privacy and comfort. In Lübeck the condominiums at Flin- In Bergen, Norway’s second largest city, tenbreite (117 apartments) are served 42 condominiums collect blackwater us- South Africa by vacuum toilets. Household waste is ing 1-liter flush vacuum toilets and have After a successful pilot project involving Bokenäs, Volvos conference centre has source sepa- ground and added to the blackwater prior onsite greywater treatment. In Ås 24 stu- 12 families, a new medium-income hous- ration and biogas-production to . Greywater is dent flats (48 students) have an identical ing area for 3000 inhabitants in Kimberly On the Swedish west coast Volvo treated onsite in a planted filter bed (30). system (7). will be equipped with ecological sanita- has established a new conference centre In Germany compact mechanical greywa- Liquid composting provides a tion systems (26). (28) for 500 people where blackwater ter treatment systems for urban use are sanitised mixture of organic household 8 Urine is collected and will be used by and organic household waste are used for commercially available. waste and blackwater. Injecting the liquid the forestry department as fertiliser for biogas production and the greywater is fertiliser hydraulically into soil provides silviculture treated in a natural system. ���� equal yields to mineral fertiliser (32).

� ����

� When the blackwater is removed, � ���� In several Swedish cities nitrogen � � 8 Faecal matter is collected regularly for � ���� the remaining greywater meets drinking �

reducing wetlands are cost efficient ways � �

� ���� composting � water standards with respect to nitrogen, �

to meet increased water quality demands. � ���� � � 8 Greywater is treated in soak pits and � ��� swimming water standards with respect to � then drains to a wetland. bacteria, and is discharged to the storm- � � � � � � � � � �� �� � � �� �� � � �� � � �� �� � � �� �� water drain. The greywater treatment sys- � � � � � �� �� �� �� �� �� � � � � �� �� � � �� �� � � Australia �� �� tems are compact (1-2 sq. m per person) In Melbourne, the Werribee wastewater ���������� ���� ��� ����� �� ������������������ and can be landscaped (31). system was opened in 1897. Half of the Crop yields are similar for equal amounts of nitrogen wastewater from the 4 million citizens derived from urine and mineral fertiliser (29). is used for irrigation of pasture fields Ecosan

Page 1 1 Ecosan 2004 Ecosan

4. Culture, Gender and Poverty

Cultural aspects define important bound- integral dimension of Buddhism is rein- ary conditions for the implementation carnation, which promotes the harmoni- of ecological sanitation. It is crucial to ous concept of recycling life’s treasures; it is therefore not surprising that Buddhist develop sanitation systems together with cultures treat earthly resources similarly. the system users and emphasise gender issues. The Gender Approach Gender refers to the specific roles and re- Excrement naturally repels people. sponsibilities adopted by women and men ‘Natural’ in the sense that the repulsion in any society. It is related to how we are is an involuntary reaction. The reason is perceived and expected to think and act as much evolutionary as cultural. In the as women and men, because of the way course of human evolution, those unfor- society is organised, not because of our tunate to come in contact with excreta biological differences. A gender approach were exposed to a plethora of , implies that attitudes, roles and responsi- Ecological sanitation – by Dr. Ken Gnanakan: and consequently less likely to survive bilities of men and women are taken into than those who did not come into contact account. It requires an open mindedness The poor are the ones who suffer both because of water supply. Women have to line up for a bucket with excreta. Therefore, some assume that and aims at the fullest possible participa- their own “sins” and the “sins” of others. Not only full of water. Present unsheltered defaecation op- man’s instinctive repulsion is genetic in do they face the pollution of their own defecation, tions leave women exposed with a sense of shame tion of both women and men. nature. but often have to live beside water bodies that Poverty in India is also a caste issue. The lower When introducing ecological Despite our instinctive repulsion have been released from urban sewers. Access to the caste, generally, the poorer. Hence these are sanitation it is important to train the clean water and proper sanitation is therefore a confined to undignified jobs like handling the towards excreta, culture influences our whole family so that the responsibility of necessary precursor to development. Lack of clean sewage of the rich; even drinking their wastewater. attitudes towards handling (33). Religions operation will not be a burden only to the water and adequate sanitation contribute to peo- “Night-soil” or sewage carrying was the job of the vary considerably in addressing excreta. ple remaining in the poverty trap. Some 1.1 billion lowest caste condemned to such occupations. women. In the Bible, the act of elimination is men- people – one sixth of the world’s population – do Women’s role in decision-making in all ecological How does ecological sanitation tioned only once, and it does not address not have access to safe water and 2,4 billion lack sanitation projects must be increased. Women contribute to a new understanding of basic sanitation. should be shown to be equal partners with men the subject of using excreta for agricul- gender roles? Both men and women are Water and sanitation are major factors in the community. Further, involving both women tural purposes. producers of waste, contaminating the in the health status of populations. Conventional and men in ecological sanitation initiatives can The Koran, however, prescribes toilets have been guilty of converting massive increase project effectiveness. This is mainly water and the soil. It is significant that strict procedures to limit contact with quantities of clean water into ‘blackwater’. In de- because women normally take on more social the ecosan toilet can improve health, gen- faecal material, including its use in agri- veloping countries 90 % of this sewage is flushed responsibility than men. Men tend not to be com- erate fertiliser, and consequently increase into surface waters, polluting rivers, lakes and mitted to such initiatives. culture, because excrement is considered family income. Both the sanitation and the coastal areas. This has contributed to the spread of Water, health, sanitation, agricultural impure. agricultural aspect can increase women’s disease mainly amongst the poor. and nutritional aspects have to be integrated. The principal Hindu text that A basic issue in poverty is that of Ecological sanitation propagates recycling princi- power to control their own lives. Instead details the code of conduct for rituals, the identity and dignity. The poor often lack identity ples in a very powerful way. The implementation of a producer of waste, she becomes a Artha Veda, clearly specifies the use of as humans, and therefore lose their dignity. Water of a material-flow-oriented recycling process as a producer of resources, which can benefit and sanitation are factors that highlight this in- holistic alternative to conventional solutions is the water for personal hygiene. But nowhere herself and her family. dignity even more. While the rich can be identified key to such practices. The poor, as well as the rich, do we find excrement included more in a with their bottles of mineral water, the poor must will be able to observe the wider ecological issues religious context than in Buddhism. An be content with polluted water from any source, as they focus attention on this basic problem. mostly contaminated by the rich. Most houses will have no direct Ecosan

Page 1 3 Ecosan 2004 Ecosan

5. Health aspects – A SYSTEMS VIEW

The introduction of a new sanitation household installation instead of being approach needs to demonstrate that the part of a centralised system. This is a general requirement of reducing the po- fundamental difference from a barrier perspective. To ensure the necessary tential for disease transmission is feasible safety against transmission it and valid. is essential to have simple installation, handling and management guidelines. For The most important criterion of eco- this reason WHO is currently planning the logical sanitation, as for all sanitation publication of guidelines for the safe use approaches, is that the system forms a of excreta and greywater in agriculture, barrier against the spread of diseases which will provide a reliable basis for caused by pathogens in human excreta. planning ecological sanitation projects This is also one of the basic aims in con- International research on patho- ventional “flush and discharge” or “drop gen destruction in sanitation systems and store” sanitation systems which have show that the dry sanitation systems well-known drawbacks in downstream or may give an equal or higher reduction groundwater contamination, eutrophica- of pathogens than conventional systems tion, and long-term destruction of fresh- and a high reduction in the subsequent water ecosystems, coastal areas and loss risk of exposure (34). Low flush gravity Slum dwellers defecate into open sewers and play along open sewers. of plant nutrients. or vacuum toilet systems, with or without Ecological sanitation implies urine separation, provide as good hygiene separate, often dry, handling of the faecal as traditional water toilets, but facilitate matter, with the objective to recycle the local collection and subsequent fertiliser bacteria, that some guidelines are based make it possible to recycle nutrients back resources contained in it back to agri- and energy (biogas) production. Manage- on, may multiply (35). These, therefore, into agriculture. This represents an impor- culture. By not introducing human waste ment routines that ensure acceptable risk overestimate the faecal load and associ- tant contribution to . into the , contamination of reduction exist. ated risks of greywater use (35). Viral Wastewater recirculation and reuse on superficial and ground water bodies can For large systems, urine storage contamination may pose a potential risk agricultural land has recently been largely be avoided. From a public health point of regulations even in a cold climate give and their reduction to acceptable risk lev- practiced in many developing regions. view, this is an important achievement. high level protection prior to agricultural els has been calculated, dependent on the Although nutrients are also reused here, a Ecological sanitation faces specific chal- application on all crops (9). Similarly the type of greywater discharge (35). A 3-log much larger potential threat exists (both lenges to counteract pathogen transmis- treatment of the faecal fraction either reduction, as suggested, with respect to through direct contact for the farmers and sion in the handling of the material and in dry or anaerobically (biogas reactor) bacteria can be obtained by simple treat- due to industrial pollution) than when the use of the “products” on agricultural or aerobically (liquid composting) can ment systems (31, 36). source-separation and reuse is practiced. land for food production. The system provide pathogen reduction in compliance Ecological sanitation has a large The reuse of wastewater will also con- should be efficient both when it is intro- with existing regulations for application potential impact in the reduction of risks tinue to develop, but there is a need to duced, and in the long run. to agricultural land. The soil also acts as a in poor countries. The health risks linked include other options than conventional With dry handling of the faeces barrier with further pathogen reduction. to poor sanitation severely affects the wastewater treatment, to minimise the as in some ecological sanitation systems, Greywater has been perceived as rela- ability of families to improve their liveli- negative impacts both on health and the the primary treatment has moved to the tively free of pathogens but the indicator hoods. Ecological sanitation will reduce environment of untreated wastewater ir- health risks, improve access to water and rigation (37, 38). Ecosan

Page 1 5 Ecosan 2004 Ecosan

Literature and Links

1. Winpenny, J. 2003. “Camdessus Report”, Financing Wa- of the Governing Council/ Global Ministerial Environ- 21. Ghosh, D. 1996. Turning around for a community based Proc. 2nd int. symp. ecological sanitation, Lübeck Apr. ter for All, Report to the World Panel on Financing Water ment Forum Jeju, Republic of Korea, 29-31 March 2004. technology, towards a wetland option for wastewater 7-11. 2003, GTZ, Germany, pp:875-881. Infrastructure. Global Water Partnership, World Water UNEP/GCSS.VIII/INF/4 treatment and resource recovery that is less expensive, Council, and Third World Water Forum, ISBN 92-95017- farmer centered and ecologically balanced. Calcutta 32. Morken, J. 1998. Direct ground injection - a novel 01-3 (available for downloading on www.gwpforum.org). 12. Otis, R. 1996. Small diameter gravity sewers:experi- Metropolitan Water and Sanitation Authority, 21pp. method of slurry injection. Landwards, winter 1998, pp. ence in the United States. In Low-Cost (D. 4-7. 2. WEHAB, 2002. A framework for action on water and Mara, ed.), pp. 123-133. Chichester: John Wiley and Sons. 22. Strauss, M. 1996. Health (Pathogen) considerations sanitation. World Summit on Sustainable Development, regarding the use of human waste in aquaculture. In: 33. Warner, W. 2000. The influence of religion on waste- Johannesburg, August 2002, 40 pp. 13. Edwards, P. 1992. Reuse of human wastes in aquacul- Staudenmann, J., A. Schönborn, and Etnier C (Eds.). Re- water treatment: a consideration for sanitation experts. ture, a technical review. UNDP-World Bank, Water and cycling the Resource, Ecological Engineering for Waste- Water 21 Aug: 11-136 3. Gardner, G. 1997. Recycling organic waste: From urban Sanitation Program, 350 pp. water Treatment, Environmental Research Forum Vols. pollutant to farm resource. Worldwatch Institute paper 5-6 (1996) pp. 83-98. Transtec Publications, Switzerland 34. Stenström T.A. 2001. Reduction efficiency of index 135. 58p. 14. EcoSanRes. 2003. Guangxi Autonomous Region, China. pathogens in dry sanitation systems compared with EcoSanRes. URL: http://www.ecosanres.org/asia.htm 23. Edwards, P. 2000. Wastewater-fed aquaculture: state traditional and alternative wastewater treatment 4. Wolgast, M. 1992. Rena Vatten.: omtankar i kretslopp. (07.10.2003) of the art. In: B.B. Jana, R.D. Banerjee, B. Guterstam, J. systems. Proc. First Int. Conf.on Ecological sanitation. Creanom 187p. Heeb (Eds.) Waste recycling and resource management www.ecosanres.org. 15. Black, M. 2002. Official conference report. -Re in the developing world, University of Kalyani, India and 5. Vinnerås B. 2002. Possibilities for sustainable nutrient port on first international conference on ecological International Ecological Engineering Society, Switzer- 35. Ottoson J. (2003). Hygiene aspects of greywater and recycling by faecal separation combined with urine di- sanitation, Nanning, China, 5 – 8 November 2001. land. pp. 37-49. greywater reuse. Licenciate thesis. Royal Institute of version. Doctoral Thesis. Swedish University of agricul- China. URL: http://www.ecosanres.org/PDF%20files/ Technology/Swedish Institute for Infectious Disease tural Sciences, Uppsala. Nanning%20Conf%20report% 20% 20final.pdf 24. Biswas, J.K. and Santra, S.C. 2000. Heavy metal levels Control. Stockholm. (23.10.2003) in marketable vegetables and fishes in Calcutta Met- 6. Werner. C., Avendaño V., Demsat S., Eicher I., Hernandez L., ropolitan area, India. In: B.B. Jana, R.D. Banerjee, B. 36. Siegrist, R.L., E.J. Tyler and P.D. Jenssen. 2000. Design Jung C., Kraus S., Lacayo I., Neupane K., Rabiega A. & Wafler 16. Edwards, P. 2000. Wastewater-fed aquaculture: state Guterstam, J. Heeb (Eds.) Waste recycling and resource and performance of onsite wastewater soil absorption M. 2004. Ecosan – closing the loop. Proc. 2nd int. symp. of the art. In: B.B. Jana, R.D. Banerjee, B. Guterstam, J. management in the developing world, University of systems. Report presented at National Research Needs ecological sanitation, Lübeck Apr. 7-11. 2003, GTZ, Esch- Heeb (Eds.) Waste recycling and resource management Kalyani, India and International Ecological Engineering Conference Risk-Based Decision Making for Onsite born, Germany, 1004p.ISBN 3-00-012791-7. in the developing world, University of Kalyani, India and Society, Switzerland. pp. 371-376. Wastewater Treatment, St. Louis, Missouri,19-20 May International Ecological Engineering Society, Switzer- 2000. USEPA, Electric Power Research Inst. Community 7. Jenssen P.D., Heyerdahl P.H., Warner W.S. and Greatorex J.M. land. pp. 37-49. 25. Werner C., H.P Mang and V. Kesser 2004. Key activities, Env. Center, National Decentralised Water Resources 2003. Local recycling of wastewater and wet organic services and current pilot projects of the international ecosan Capacity Development Project. waste – a step towards the zero emission community. 17. Li, S. 1997. Aquaculture and its role in ecological programme of GTZ.. In C. Werner et al. (eds). Ecosan – closing Paper presented at the 8th International Conference on wastewater treatment. In Etnier, C. and Guterstam, B. the loop. Proc. 2nd int. symp. ecological sanitation, Lübeck Apr. 37. Ensink, J.H.J., van der Hoek, W., Matsuno, Y., Munir, S, and ; Lemnos Greece 6 – 12. Sept. (Eds.), Ecological engineering for wastewater treatment. 7-11. 2003, GTZ, Eschborn, Germany, pp: 75-82. Aslam M.R. 2002. The use of untreated wastewater in peri- 2003. www.ecosan.no Proceedings of the International Conference at Stensund in Pakistan: Risks and opportunities, Folk College, Sweden, 24-28 March, 1991. 2nd Edition, 26. SIPU International 2002. Hull Street Integrated Housing International Water Management Institute, Research 8. Johansson M., Jönsson H., Gruvberger C., Dalemo M. & CRC Press Boca Raton, USA, pp. 37-49. Project, Kimberley, South Africa. SIDA. Stockholm. Report 64. Sonesson U. 2001. Urine separation – closing the nutrient cycle (English version of report originally published in 18. Ou, Z.Q. and Sun, T.H. 1996. From irrigation to ecologi- 27. Melbourne Water 2001. Infostream. Western Treatment 38. IWMI, 2003. Confronting the Realities of Wastewater Swedish). Stockholm Water Company. Stockholm, Swe- cal engineering treatment for wastewater in China. In: Plant, PO Box 2251 Werribee, Victoria 3030, Australia. Reuse in Agriculture, Water Policy Briefing, Issue 9, pp den. Available at: http://stockholmvatten.se/pdf_arkiv/ Staudenmann, J., A. Schönborn, and Etnier C (Eds.). Website: www.melbournewater.com.au 1-8, International Water Management Institute, Colombo, english/Urinsep_eng.pdf Recycling the Resource, Ecological Engineering for Sri Lanka, www.iwmi.org/health Wastewater Treatment, Environmental Research Forum 28. Bokenäs. www.bokenas.com 9. Höglund C. 2001. Evaluation of microbial health risks Vols. 5-6 (1996) pp. 25-34. 39. Urban Water, 2001. Urban Water Progress Report Re- associated with the reuse of source-separated human 29. Cottis, T. 2000. Kildesortert humanurin – god gjødsel, port 2001:4 Chalmers University of Technology, Sweden urine. PhD Dissertation, Stockholm 19. Heeb, J. 2004. Source separation – new toilets for Indi- god økologi? I Økologisk landbruk – Innovasjon 2000. ISSN 1650-3791 an Slums. In C. Werner et al. (eds). Ecosan – closing the Høgskolen i Hedmark, Rapport nr. 7-2000, pp. 91-102. 10. Werner, C., P.A. Fall, J. Schlick and H.P. Mang 2004. Rea- loop. Proc. 2nd int. symp. ecological sanitation, Lübeck Links: sons fior and principles of ecological sanitation. In C. Apr. 7-11. 2003, GTZ, Eschborn, Germany, pp:155-162. 30. Behnke, S.M. 2004. Vacuum sewers an element in www.ecosan.no Werner et al. (eds). Ecosan – closing the loop. Proc. 2nd ecosan systems. In C. Werner et al. (eds). Ecosan – clos- www.iwmi.org int. symp. ecological sanitation, Lübeck Apr. 7-11. 2003, 20. Ghosh, D. 1997. Ecosystems approach to low-cost ing the loop. Proc. 2nd int. symp. ecological sanitation, www.ecosanres.org GTZ, Eschborn, Germany, pp-23-30. sanitation in India: Where people know better. In Etnier, Lübeck Apr. 7-11. 2003, GTZ, Eschborn, Germany, pp: www.melbournewater.com.au C. and Guterstam, B. (Eds.), Ecological engineering for 479-482 and 982. www.bokenas.com 11. UNEP 2004. Financing wastewater collection and wastewater treatment. Proceedings of the International http://stockholmvatten.se treatment in relation to the Millennium Development Conference at Stensund Folk College, Sweden, 24-28 31. Jenssen, P. D. and L. Vråle. 2004. Greywater treatment in www.gwpforum.org Goals and World Summit on Sustainable Development March, 1991. 2nd Edition, CRC Press Boca Raton, USA, combined biofilter/constructed wetlands in cold climate www.gtz.de targets on water and sanitation. Eighth special session pp. 51-65. In: C. Werner et al. (eds.). Ecosan – closing the loop. www.iees.ch Ecosan

Page 1 7 Ecosan A century ago toilet waste or night soil was collected in the major European cities, sometimes mixed with peat or lime, and used as fertiliser. In China the use of night soil or toilet waste has always been regarded as a valuable fertiliser resource for agri- and aquaculture.With the invention of the water toilet and development and installation of subterranean gravity sewer systems, these resources began being dis- charged to water. The water toilet improved the health in the homes, but caused eutrophication and severe pollution of waterways. This is threatening the ecological balance, even in the North sea, and also many drinking water sources in industrial and developing countries.If the water toilet had been invented today it would probably not have been certified as an environmentally friendly device. In cities water toilets account for 20-40% of the water consumption (Gardner, 1997). This is often potable water purified and brought to the cities at high cost. This water is used to dilute a resource. Theoretically, the nutrients in domestic wastewater and organic waste are almost sufficient to fertilize all the crops needed to feed the world population. As much as 80-90% of the major plant nutrients (nitrogen, phosphorus and potassium) in wastewater are present in the toilet waste. If these nutrients are reclaimed they can be used locally as a fertiliser. And what if we at the same time could produce energy from the organic matter and save water!Technological alternatives to the conventional sanitation that provide the same comfort, save water and facilitates separate collection of toilet waste does exist. Vacuum- and gravity toilets that use only one liter (or even less) per flush has been developed. The treatment facilities for toilet waste can easily handle organic waste, hence, all domestic organic waste flows can be safely collected, reclaimed and turned into bio-energy and fertiliser. Several manufacturers provideurine separation toi- lets that are easily retrofitted in existing buildings, making urine collection possible. The urine, which is sterile in healthy humans needs only some storage time before it is hygienically safe to be used as fertiliser. Improvements in compost technologies facilitate dry sanitation and fecal composting. And furthermore: It provides a completely odorless toilet room.So, why do we not make use of these promising options? There are several reasons. The systems are relatively new. The possibilities to supplement and even replace traditional sewer systems with decentralised, resource saving systems are not widely known. Such, ecologically engineered systems that collect, sanitize and reuse waste resources are, with a few exceptions, not part of the curricula at engineering schools. When the engineers do not know, we cannot expect the decision makers to do so.How can ecological thinking be applied to wastewater engineering, and what kind of systems will evolve? This chapter clarify some design principles of ecological sanitation.We have not always thought of the consequences or impact that a conventional centralised wastewater treatment system has on the larger system that it operates within. Ecological engineering defined as: “The design of human society with nature for the benefit of both” seeks high system integration and is based on a holistic view (Ref). One of the key disci- plines of ecological engineering is ecological sanitation. The main design principles for systems based on ecological sanitation are: System approach (holistic): This means to consider the technical and the organisational structures as well as the people involved (Söderberg 2003). The technical structure shows the material and energy flows. It may include the separate collection of urine and feces at the household level and its recycling to fertiliser. However there is also an organisational, immaterial, structure; how are decisions performed, how is the re- sponsibility distributed, what is the strategy for communication with the users etc, who is paying for what – in total a structure for rules and procedures facilitating the participation of the stakeholders (households, the entrepreneurs, the administration and the policy makers). The stakeholders have their own behavior, values and interests that will determine the success of the chosen system Source separation of waste streams: This is often a logical consequence of the system analysis and facilitates better source control. Nutrient rich toilet waste is collected using extremely low flush and urine separating toilets or dry/composting toilets. This can be cotreated with other source separated organic wastes from domestic and agricultural sources. Recycling and resource efficiency: Recycling is often a consequence of ecological thinking. But we need to recycle within spatially small loops and a suitable time frame to obtain an ecologically sound solution. Recycling is facilitated by decentralised, ecological sanitation. Decentralised treatment offers better source control and shorter transport distances. Decentralised concepts can be applied for urban and rural areas (see chapter 4). Resource efficiency means minimizing the use of input factors (buildings, pumps etc.), the operation of treatment systems and using natural systems, where solar energy is captured through photosynthesis, when Apossible. century ago toilet waste or night soil was collected in the major European cities, sometimes mixed with peat or lime, and used as fertiliser. In China the use of night soil or toilet waste has always been regarded as a valuable fertiliser resource for agri- and aquaculture.With the invention of the water toilet and development and installation of subterranean gravity sewer systems, these resources began being dis- charged to water. The water toilet improved the health in the homes, but caused eutrophication and severe pollution of waterways. This is threatening the ecological balance, even in the North sea, and also many drinking water sources in industrial and developing countries.If the water toilet had been invented today it would probably not have been certified as an environmentally friendly device. In cities water toilets account for 20-40% of the water consumption (Gardner, 1997). This is often potable water purified and brought to the cities at high cost. This water is used to dilute a resource. Theoretically, the nutrients in domestic wastewater and organic waste are almost sufficient to fertilize all the crops needed to feed the world population. As much as 80-90% of the major plant nutrients (nitrogen, phosphorus and potassium) in wastewater are present in the toilet waste. If these nutrients are reclaimed they can be used locally as a fertiliser. And what if we at the same time could produce energy from the organic matter and save water!Technological alternatives to the conventional sanitation that provide the same comfort, save water and facilitates separate collection of toilet waste does exist. Vacuum- and gravity toilets that use only one liter (or even less) per flush has been developed. The treatment facilities for toilet waste can easily handle organic waste, hence, all domestic organic waste flows can be safely collected, reclaimed and turned into bio-energy and fertiliser. Several manufacturers provideurine separation toi- lets that areA easily Thinkpiece retrofitted in onexisting ecological buildings, making sanitation urine collection possible. The urine, which is sterile in healthy humans needs only some storage time before it is hygienically safe to be used as fertiliser. Improvements in compost technologies facilitate dry sanitation and fecal composting. And furthermore: It provides a completely odorless toilet room.So, why do we not make use of these promising options? There are several reasons. The systems are relatively new. The possibilities to supplement and even replace traditional sewer systems with decentralised, resource saving systems are not widely known. Such, ecologically engineered systems that collect, sanitize and reuse waste resources are, with a few exceptions, not part of the curricula at engineering schools. When the engineers do not know, we cannot expect the decision makers to do so.How can ecological thinking be applied to wastewater engineering, and what kind of systems will evolve? This chapter clarify some design principles of ecological sanitation.We have not always thought of the consequences or impact that a conventional centralised wastewater treatment system has on the larger system that it operates within. Ecological engineering defined as: “The design of human society with nature for the benefit of both” seeks high system integration and is based on a holistic view (Ref). One of the key disci- plines of ecological engineering is ecological sanitation. The main design principles for systems based on ecological sanitation are: System approach (holistic): This means to consider the technical and the organisational structures as well as the people involved (Söderberg 2003). The technical structure shows the material and energy flows. It may include the separate collection of urine and feces at the household level and its recycling to fertiliser. However there is also an organisational, immaterial, structure; how are decisions performed, how is the re- sponsibility distributed, what is the strategy for communication with the users etc, who is paying for what – in total a structure for rules and procedures facilitating the participation of the stakeholders (households, the entrepreneurs, the administration and the policy makers). The stakeholders have their own behavior, values and interests that will determine the success of the chosen system Source separation of waste streams: This is often a logical consequence of the system analysis and facilitates better source control. Nutrient rich toilet waste is collected using extremely low flush and urine separating toilets or dry/composting toilets. This can be cotreated with other source separated organic wastes fromDesign: domestic Knut Werner and agriculturalAlsén Photo: Johannes sources. Heeb, Recycling Elisabeth and Huba-Mang, resource Petter efficiency: D. Jenssen and Recycling Knut Werner is Alsénoften a consequence of ecological thinking. But we need to recycle within spatially small loops and a suitable time frame to obtain an ecologically sound solution. Recycling is facilitated by decentralised, ecological sanitation. Decentralised treatment offers better source control and shorter transport distances. Decentralised concepts can be applied for urban and rural areas (see chapter 4). Resource efficiency means minimizing the use of input factors (buildings, pumps etc.), the operation of treatment systems and using natural systems, where solar energy is captured through photosynthesis, when possible.