EG Assignment 3, 4, and 5

Ecological sanitation: Principles, technologies and projectexamples for sustainable wastewater and excreta management C. Werner , A. Panesar, S.B. Ru ¨d, C.U. Olt Deutsche Gesellschaft fu ¨r Technische Zusammenarbeit (GTZ) GmbH, Sector Project Ecosan, Dag-Hammarskjo ¨ld-Weg 1-5, 65760 Eschborn Tel. þ49 61 96 79 4220; Fax þ49 61 96 79 80 4220; email: [email protected] Received 31 January 2008; revised accepted 15 May 2008 Abstract In order to reach the UN Millennium Development Goals for significantly reducing the number of people without access to adequate sanitation, new holistic concepts are needed, focusing on economically feasible closed-loop ecological sanitation sys- tems rather than on expensive end-of-pipe technologies, thus enabling all countries to finance and maintain sustainable sanitary systems. Such ecological sanitation systems advance a new philosophy of dealing with what to date has been considered as merely waste and wastewater. They are based on the systematic implementation of the reuse and recycling of nutrients, organics and water as a hygienically safe, closed-loop and holistic alternative to conventional solutions. Over the last few years an increasing number of pilot and demonstration ecosan projects have been implemented worldwide. These have contributed to the further development of a variety of ecosan technologies and operating and reuse options and have provided a large amount of experience with this new, holistic approach. In the following, the principles of ecological sanitation are presented, an overview on the range of ecosan tech- nologies is given and several successful ecological sanitation projects are described.

Keywords: Ecosan; Sustainability; Best practices; Project examples; Reuse 1. Introduction Current conventional approaches to wastewater management and sanitation fall under the category of either waterborne or dry systems. In both cases the sys- tem design is based on the premise that excreta is a waste, and that waste should be disposed. It also assumes that the environment can safely assimilate this waste. Unfortunately, many years of experience have shown that such conventional approaches are unable to make a significant impact on the sanitary backlog of nearly half of the world’s population, and even in cases where conventional approaches have succeeded in providing a functioning sanitary system; their long-term sustainability is questionable, as is their Corresponding author.

Presented at the Water and Sanitation in International Development and Disaster Relief (WSIDDR) International Workshop Edinburgh, Scotland, UK, 28–30 May 2008. Desalination 248 (2009) 392–401 0011-9164/09/$– See front matter © 2009 Published by Elsevier B.V.

doi:10.1016/j.desal.2008.05.080 appropriateness to address the MDGs. The main disad- vantages of conventional approaches to sanitation can be seen in Fig. 1.The main disadvantages of current, conventional approaches to sanitation are as follows, also showed in Fig. 1. Unsatisfactory purification or uncontrolled dis- charge of more than 90 %of wastewater worldwide Pollution of water bodies by nutrients, hazardous sub- stances, pathogens, pharmaceutics, hormones, etc.

Severe environmental damage and eutrophication of the water cycle Fig. 1. The main disadvantages of current, conventional approaches to sanitation (source: GTZ). C. Werner et al. / Desalination 248 (2009) 392–401 393 Consumption of precious water for transport ofwaste High investment, energy, operating and maintenance costs Frequent subsidisation of prosperous areas, and neglect of poor settlements Loss of valuable nutrients and trace elements con- tained in excrement through their discharge into water bodies Predominance of combined central systems, result- ing in problems with contaminated sewage sludge The modern misconception that human excreta are wastes with no useful purpose has resulted in the end- of-pipe sanitary systems that we have today. In nature however, there is no waste. All products of living things are used as raw materials by others as part of a cycle. Considering the environmental damage, the health risks, and the worsening water crisis, resulting from our present sanitary practices, a revolutionary rethink is urgently needed if we are to correct this mis- conception and realistically have a chance of achieving the Millennium Development Goals of providing sus- tainable sanitary services to over 1.2 billion people.

A new paradigm is required in sanitation, based on eco- system approaches and the closure of material flow cycles rather than on linear, expensive and energy intensive technologies. This paradigm must recognise human excreta and water from households not as a wastebutasaresourcethatshouldbemadeavailable for reuse [6].

2. Principles of ecosan Ecological sanitation is based on an overall view of material flows as part of an ecologically and economic- ally sustainable wastewater management system tai- lored to the needs of the users and to the respective local conditions. It does not favour a specific sanitation technology, but is rather a new philosophy in handling substances that have so far been seen simply as waste- water and water-carried waste for disposal. Ecological sanitation introduces the concept of sustainability and integrated, ecosystem oriented water and natural resources management to sanitation. The basic principle of ecosan is to close the nutrient loop between sanitation and agriculture with the objec- tives shown in Fig. 2. The advantages are as follows: Improvement of health by minimising the introduc- tion of pathogens from human excrement into the water cycle Promotion of recycling by safe, hygienic recovery and use of nutrients, organics, water and energy Conservation of resources (lower water consump- tion, chemical fertiliser substitution, minimal water pollution) Preference for modular, decentralised partial-flow systems for more appropriate cost-efficient solutions Possibility to integrate on-plot systems into houses, increasing user comfort, and security for women and girls Contribution to the preservation of soil fertility Promotion of a holistic, interdisciplinary approach (hygiene, water supply and sanitation, resource con- servation, environmental protection, urban planning, agriculture, irrigation, food security, small-business promotion) Closing the loop enables the recovery of organics, macro and micro nutrients, water, and energy con- tained in household wastewater and organic waste and their subsequent productive reuse – if necessary after adequate treatment – mainly in agriculture, or for other reuse options. An essential step in this cycle is the appropriate treatment and handling of the materials throughout the entire process, from collection to reuse, ensuring a series of barriers are erected that will reduce the risk of disease transmission within acceptable lim- its, thus providing comprehensive protection of human health [6].

3. Ecosan technologies As an integrated alternative, the implementation of an ecosan project requires an interdisciplinary approach that goes beyond the narrow disciplines and technological aspects of domestic water supply and wastewater management to address issues such as agri- cultural use, sociological aspects of acceptance and cultural appropriateness, health and hygiene, town planning, economic and small-enterprise promotion, institutional administration, and so on. Such an approach also makes a large contribution to the integrated management of water and other natural resources.

394 C. Werner et al. / Desalination 248 (2009) 392–401 Ecological sanitation opens up a wider range of sanitation options than those currently considered. To optimise cost efficient, high quality treatment and recy- cling options, two principles are very often applied in ecosan systems: Firstly, flow streams with different characteristics, such as faeces, urine and grey water (see Fig. 3), are often collected separately. This allows the application of specific treatment processes and optimises reuse.

Secondly, unnecessary dilution of the flow streams is avoided, for example by using dry, low flush or vacuum transport systems. This minimises the con- sumption of valuable drinking water and produces high concentrations of recyclables. Fig. 2. The advantages of implementing ecological sanitation (source: GTZ). C. Werner et al. / Desalination 248 (2009) 392–401 395 Rainwater harvesting and the treatment of organic domestic and garden wastes and of animal manure can also be integrated into ecosan concepts. Such a separa- tion of the flow streams also allows a better integration of the solid waste management sector, where there is already a great deal of experience in the logistics, treat- ment and marketing of discarded resources. As an example, the collection system of solid waste can be adopted to the collection of urine and faeces as well as experience in the field of marketing the recycled products. However, whilst often making treatment easier and less expensive, the separate collection and treatment of the flow stream is not a prerequisite in ecosan systems, and ecological sanitation is also possible in centralised and combined flow systems. Ecosan systems strive for resource efficiency. In reducing unnecessary water consumption and avoiding the contamination of water bodies, ecosan systems can have an impact on reducing the costs of raw water treat- ment and drinking water supply. Additionally, the recovery and agricultural use of the organics and nutri- ents contained in wastewater improves soil structure and fertility, increasing agricultural productivity and thus contributing to food security. The recovery of energy through the anaerobic digestion of faeces, organic waste and animal manure may also represent a significant step towards energy efficiency, providing biogas for cooking or electricity generation [6]. Yet, ecological sanitation systems are in many cases still far from overall sustainability due to various reasons: Due to the pilot character of many projects, the costs for Fig. 3. Separation of wastewater streams and examples of possible ecosan treatment elements (source: GTZ).

396 C. Werner et al. / Desalination 248 (2009) 392–401 introducing new innovative systems are often higher compared to already established treatment system. In addition, awareness raising campaigns and capacity buiding measures for ecological sanitation have to be provided frequently to overcome existing cultural con- straints towards the usage of treated excreta and wastewater.

4. Ecosan in practiceAs ecological sanitation does not prescribe a parti- cular technical solution, but rather tailors sanitary sys- tems to fit the needs of social, economic and environmental sustainability in a given context, a wide range of technologies can, and currently are, being used in ecological sanitation systems. These range from quite simple low-tech systems to sophisticated high-tech solutions. On the low-tech side, the use of system components such as simple dehydration toilets (either with or without urine separation) or composting toilets is common. For such systems, faeces and urine are most often collected and treated on site, with the recyclates being used locally, although an organised central collection and marketing of the recyclates is also possible. High-tech components of ecosan sys- tems include the use of vacuum technology to collect either black or brown water centrally with reduced water consumption, struvite precipitation for the recov- ery of nutrients, and membrane technology for the recovery of water for irrigation, industrial or domestic purposes. All these components can be put together with other treatment ecosan technologies, such as con- structed wetlands, treatment ponds, anaerobic digesters or soilisation basins for sludge treatment, to optimally address the treatment and resource recovery needs in a particular area. Ecosan systems are also of particular interest for international development and disaster relief. The fact that it is often possible to build them with local ressources, the flood protection of, e.g. the two chamber urine-diversion dehydration toilet com- pared to other low-cost sanitation systems like pit latrines and the ability to not only offer a first basic option but an enduring system which can be up- scaled and which can even produce benefits by the recovery of water, energy and nutrients, all make eco- logical sanitation methods highly interesting for sanita- tion projects in disaster relief. At present, pilot demonstration and up-scaling pro- jects are being implemented with the support of the GTZ-ecosan project in more than 40 countries, among them countries affected by post-war conflicts or natural disasters like Afghanistan, El Salvador, Eritrea and Nepal [4]. The programme mainly lays the foundations for projects by researching, preparing and elaborating a financing concept as well as supporting the elaboration of baseline-studies, feasibility studies and project pro- posals which may be submitted to financing agencies or investors.

4.1. Navsarjan primary schools project in Gujarat, India In 2005, Navsarjan Trust established three primary schools in rural areas of Gujarat. Each school has a total capacity of 210 pupils and comprises a sanitation building including toilets, showers and washing facilities. A sanitation bloc has been designed to provide toi- lets, showers, washing and laundry facilities to pupils and staff, while allowing the recovery of urine, faeces and water for productive purposes. The ecosan toilet block comprises eight single-vault-urine-separation dehydration toilets and four waterless urinals for the male pupils and staff members. The toilets are operated in batches to facilitate the harvest of the finished com- post. That means that only four toilets are in use at the same time and receive daily deposits until the dehydra- tion chamber below the squatting slab is ‘‘full’’ (see Fig. 4 for a backview of the toilet blocks including the dehydration chambers). The toilet cabins of the ‘‘closed’’ toilets are then used as showers. Addition- ally, a vertical flow filter treats greywater from bath- rooms, washbasins and the laundry area. The new bathrooms, greywater treatment system and reuse gar- dens were inaugurated on August 10th, 2006. The urine from the UD toilets and urinals is col- lected in a container and reused as fertiliser. The anal cleansing water from the toilets is infiltrated into a sub- surface irrigation of ornamental flowers. Treated grey- water is reused for irrigating the kitchen garden. The alternative use of the cabins as toilet or shower helps to reduce the interior space and therefore construction costs [3].

C. Werner et al. / Desalination 248 (2009) 392–401 397 This system offers a low-cost and enduring alterna- tive to conventional basic sanitation methods and is also applicable in disaster relief. In contrast to, e.g.

Ventilated Improved Pit Latrines, no hole has to be dug avoiding on the one hand groundwater pollution by infiltrating urine contaminated by feacal bacteria and making the system resistant against flooding. Further- more, food security of the users is improved by provid- ing a natural fertiliser and soil conditioner which can be used in local agriculture.

4.2. Model-project for constructed wetlands in Syria The village of Haran Al-Awamied is located south east of Damascus, Syria. The inhabitants are poor, with farming being the main source of income. The use of untreated wastewater from the existing gravity sewers for irrigation was common. The specified purpose of the GTZ-supported ecosan project in Haran Al- Awamied was therefore to make the use of wastewater for irrigation hygienically safe and to make best use of its fertilising effect. At the same time this project was intended as a model-project to adapt the technology to local conditions and to allow for the replication of the technology elsewhere in the country.

One result of the project was that the treatment space required per person was drastically reduced in comparison to European standards due the favourable climatic conditions in Syria. The implemented model-plant itself consists of bar screens and a sedi- mentation tank as a pre-treatment, two reed beds to treat the wastewater, and one reed bed for sludge humi- fication. The treatment efficiency of the treatment sys- tem is shown in Table 1. The treated water, about 300 m 3/d is collected in a tank for storage, and is pumped from the collection tank to the fields near the plant when needed, with the distribution being organised by the farmers. The improved availability of irrigation water con- taining valuable nutrients reduces farmer’s expenditure on commercial fertilisers. It contributes to higher yields in crop production, and increases the number of harvests from one to several per year. The reed plants of the constructed wetland are used for wicker and roof materials. The treated sludge is used as soil conditioner. This project started operation in November 2000.

As the constructed wetland provides the residents with this range of possibilities, they provide a great deal of support to ensure its correct functioning. Other moti- vating factors for choosing the reed beds as treatment option were the low costs, easy construction and simple operation and maintenance of the system. The construction and operation of the pilot con- structed wetland plant in Haran Al-Awamied has opened the gates for new innovative methods of waste- water treatment in Syria. Based on the success of the Fig. 4. Faeces dehydration chambers of the sanitation facility with ventilation pipes (source: ESF). Table 1 Analysis of treatment efficiency of constructed wetland in Haran-Al-Awamied, Syria, (source: GTZ) Parameter Unit Inlet Outlet Efficiency ( %) COD mg/L 446 70 84 BOD 5 mg/L 220 32 85 PO 4-P mg/L 19.3 6.1 68 398 C. Werner et al. / Desalination 248 (2009) 392–401 pilot plant the Syrian Government has decided to allo- cate more resources to build constructed wetlands in other regions of the country. The Ministry of Housing and Construction (MHC) prepared the planning documents for a program that would combine capacity development at governorate level with investment in about 20 additional plants [1].

4.3. EcoSanitation facility for Adrash Vidyaprakaash Sanstha’s College at Kulgaon Badlapur, IndiaThe ‘‘Adarsh Vidya Mandir School’’ is located in Badlapur town, in Maharashtra’s Thane district, about 68 km from Mumbai. The school accommodates about 11,000 students attending Primary School, Secondary School and Junior College or the ‘‘Adarsh Vidya- prasarak Sanstha’s College of Arts & Commerce’’. The city of Badlapur does not have a sewer system. So far, the school therefore depends on conventional on-site sanitation, consisting mainly of septic tanks followed by infiltration. Following some capacity building workshops orga- nised by the Indian Water Works Association IWWA in cooperation with GTZ, seecon and other partners, the city of Badlapur and the Adarsh School have taken the decision to refurbish the sanitation system of the school towards ecological sanitation. In August 2006, construction began for a sanitation building for the three-storied College of Arts & Commerce building with a total number of about 2700 students. The open ground that is located in the centre of the school premises is rented out on ca.

20 days per year for special programmes such as wedding ceremonies, which are attended by up to 1000 people each. The construction comprises a sanitation block with urinals for men and women, pour flush toilets and hand washing facilities. The urine is collected in two storage tanks and reused as fertiliser. The brownwater from the toilets is treated in a biogas settler tank (see Fig. 5). The biogas will be used for cooking. The pre-treated water is then added via a syphon tank into a vertical flow constructed wetland and then used for irrigation.

The greywater will be used on site for the beautifica- tion of the buildings with greywater gardens [5]. 4.4. GTZ headquarters main office building The main building of the GTZ headquarters is located in Eschborn, near Frankfurt am Main, Germany. When it became clear that the GTZ main office building was to be renovated, the GTZ ecosan team initiated and promoted the implementation of an ecosan demonstration and research project as part of the renovation. The renovation work began in 2004 and was finished in 2006. A modern system for the separate collection of urine is now being used by GTZ staff and a treatment and reuse system for brown water is in preparation. The main objectives of the project are to:

Reduce the emission of pathogens, organics, nutri- ents, and micro pollutants, such as pharmaceutical residues and hormones to the public sewer system and receiving waters Protect water resources Recover nutrients for agricultural use Demonstrate the implementation of the ecosan con- cept in an urban context Contribute to the international dissemination of eco- san by means of public presentations Research the technical, operational, legal, social, economic and agricultural aspects Develop ecosan technologies and operation for mod- ern urban buildings Within the renovation works, 56 urine separation toilets (model: Roediger NoMix) and 25 waterless urinals (model: Keramag Centaurus) were installed. Fig. 5. Biogas settler for brownwater treatment under construction (source: seecon). C. Werner et al. / Desalination 248 (2009) 392–401 399 In addition, separate urine and brownwater pipes and four urine tanks (see Fig. 6) with a total capacity of 10 m 3were built and the system started operation in July 2006. Some difficulties during planning and implementation of the innovative concept had to be overcome. For example, the tank overflow had to be shifted as the supplier did not deliver pressure-proven tanks and the odour trap of the waterless urinals had to be changed [2]. After several tests, the system is fully functioning since mid 2007 and urine is being collected, stored and transported to the University of Aachen where a solid mineral fertiliser is extracted from the urine. As Ger- man fertiliser law does not yet recognise urine as a fer- tiliser the use of urine for laboratory or field research is currently the only option of reusing urine in Germany.

5. Conclusion: challenges and outlook In recent years, many successful ecosan pro- grammes have been implemented in different countries in rural and sparsely settled urban areas. A great deal of experience has been made in these areas and a variety of solutions exists that can be recommended for wide- spread large-scale use in accordance with local physi- cal, cultural and socio-economic conditions. Although initial experiences with ecosan systems are available from densely populated urban areas and new projects for large-scale implementation are launched, further research and development is urgently required to gain the necessary experience in these more complex areas.

This knowledge would allow ecosan systems to be implemented on a large scale, to show case the techni- cal feasibility and the benefits of this new approach. In addition to this, there are several other challenges which need to be faced before ecological sanitation systems will be widely adopted:

Awareness of the alternatives offered by ecosan has to be increased Reuse needs to be integrated into sanitation planning processes from the very beginning Legal frameworks and technical standards need to be revised We need a full cost analysis and comparison of the environmental and health risks of all types of sanitation Innovation-friendly investors are required, as well as new financing instruments supporting private house- holds investment However, due to the huge potential shown, these challenges must be overcome. Ecological sanitation should be recognised as the new, promising, holistic and sustainable approach to provide safe and decent sanitation, reduce poverty, contribute to food security, preserve our environment and maintain the natural basis of life, in industrialised, developing and emerging countries. References [1] Sustainable Sanitation Alliance (SuSanA), Effluent Reuse from Constructed Wetland System, Haran Al-A- wamied, Syria, 2009; Available from: http://www. susa- na.org/images/documents/06-case-studies/en-susana-cs- syria-constructed-wetland-2009.pdf.

[2] Sustainable Sanitation Alliance (SuSanA), Urine and Brownwater Separation at GTZ Main Office Building, Eschborn, Germany, 2009; Available from: http:// www.susana.org/images/documents/06-case-studies/en- susana-cs-germany-eschborn-hausl-2009.pdf.

[3] Deutsche Gesellschaft fu ¨r Technische Zusammenarbeit (GTZ) GmbH, 022 – Urine-Diversion Dehydration Toi- let Centres at Navsarjan Boarding Schools, Gujarat, India, 2006; Available from: http://www.gtz.de/de/doku- mente/en-ecosan-pds-022-india-navsarjan-schools- 2007.pdf. Fig. 6. Urine tanks installed in the basement of the gtz main building, (source: GTZ).

400 C. Werner et al. / Desalination 248 (2009) 392–401 [4] H.P. Mang, C. Werner and S. Kimmich, Overview ofworldwide ecosan concepts and strategies, in: C. Werner et al., eds., Ecosan – Closing the Loop, Proceedings of the 2nd International Symposium on Ecological Sanita- tion, 7th–11th April, 2004, Lu ¨beck, Germany, pp. 785- 792; Available from: http://www.gtz.de/de/dokumente/ en-ecosan-symposium-luebeck-session-h-2004.pdf.

[5] M. Wafler and J. Heeb, Report on Case Studies of Ecosan Pilot Projects in India, Version 1, 2006; Available from: http://www2.gtz.de/Dokumente/oe44/ecosan/nl/en-eco- san-case-studies-draft-report-iesn-2006.pdf.

[6] C. Werner, Reasons for and principles of ecological sani- tation, in: C. Werner et al., eds., Ecosan – Closing the Loop, Proceedings of the 2nd International Symposium on Ecological Sanitation, 7th–11th April, 2004, Lu ¨beck, Germany, pp. 23-31; Available from: http://www.gtz.de/ de/dokumente/en-ecosan-symposium-luebeck-opening- session-2004.pdf. C. Werner et al. / Desalination 2 (200 ) 392–401 401 48 9