Session FT 3.24
Emerging sanitation paradigms - economics and capacity building in ecosan
- International Water Association
The session dealt with three key areas of interest: how to understand and refine decision making around a broader suite of options; the economics and cost benefit analysis behind ecological systems and an appreciation of the capacity requirements for ecological sanitation and other systems.
- In particular, decision makers need a more informed basis (criteria) on which to advocate for mixed solutions – local actions will be more appropriate when boundary conditions between different technologies/systems are better understood.
- Concepts of, and training on, new approaches is lacking, and educational institutions need greater exposure to these concepts if long term paradigm shift is to be facilitated.
- A broader and mature debate about sanitation options is required. Although some solutions exist, there is a need for innovation to continue, as future challenges with sanitation cannot be adequately met through existing thinking.
- A thorough understanding and comparison of the economic aspects of different systems in different regions is sought. Current thinking in this regard is poorly developed, and the absence of economic analysis hinders advocacy for mixed solutions.
- There is a renewed interest in financing sanitation in the sector, with a host of initiatives seeking to create local funds for local initiatives. Sub-sovereign financing arrangements need to be examined to ensure optimal allocation of funds to local actions with potential to go to scale.
- New approaches and new criteria with regard to sanitation systems require a cadre of suitably trained and educated technicians and personnel, for all the MDGs, but especially those relating to water and sanitation.
Local Actions presented
Urine separation and re-use project at the main building of GTZ GmbH
Ms. Christine Werner, GTZ
The headquarters of GTZ are located in Eschborn, near Frankfurt am Main, Germany. The main building, a nine-storey office block, is currently under renovation, with work planned to finish at the beginning of 2006. Within the planned renovation measures, GTZ will implement a modern system for the separate collection and reuse of urine and possibly a treatment and reuse system for brownwater as an ecosan demonstration and research project.
The central part of the building, housing about 300 employees, the conference rooms and the restaurant is equipped with a urine separation system with the following characteristics :56 urine separation toilets, water flushed and waterless collection of urine, 25 waterless urinals with membrane stench traps, separate piping system for urine collection, 16 m³ urine collection and storage tanks in the basement of the building, urine treatment, nutrient recovery and reuse will be carried out within a research component of the work.
Two treatment options are planned for full scale implementation: treatment by prolonged storage, followed by direct agricultural use ; Precipitation of phosphorous and nitrogen from urine (MAP-precipitation), combined with ammonia stripping. Further treatment options will be tested on laboratory-scale and for demonstration purpose such as nutrient adsorption on zeolithes and thermal urine concentration. The implementation of a brownwater treatment (faeces and flush water) and reuse system is also currently being discussed.
Closed loop sanitation in Syria: Pilot implementation of a constructed wetland
Dr. Abir Mohamed, Damascus, Syria - Ministry of Housing and Utilities
The pilot plant serves the village of Haran Al-Awamied, in the Governorate of Rif Damascus, Syria. The village is located 40 km south east of Damascus. It has a semiarid climate, with 185 mm rainfall per year, falling within a four month period.This place fulfilled all the criteria such as disposal channels, wastewater quantity and enough room for building and expanding the project. Before the installation of the constructed wetland, wastewater was collected by a network of gravity sewers and used untreated for irrigation. The concerns of local authorities about introducing a new technology represented an initial difficulty, as did protests from local farmers who believed they would be deprived of the untreated wastewater for irrigation.
The plant involved the installation of a combined public sewer system in Haran Al-Awamied for the collection of rain and wastewater. This water is transported to a wastewater treatment plant, which has the capacity to treat the wastewater of 7000 inhabitants. It operates at a capacity of ca. 300 m³/d and the treated wastewater fulfilled the irrigation water quality set according to the Syrian Arab Organization for Standardization and Metrology (SASMO) data line “based on the WHO data line”. The treated water is collected in a tank and pumped to irrigate the agriculture near the plant. Thus the effluent from the wetlands is still used by the farmers. To avoid salinisation of the soil the use of mineral fertilisers is strictly controlled. The farmers were instructed to use fresh water and treated wastewater alternately for irrigation.
Navsarjan Ecosan Pilot Projects in Gujarat State, India
Johannes Heeb, Ahmedabad, India - Navsarjan Trust
A Vocational Training Institute called Dalit Shakti Kendra, DSK for short, was established near Sanand, Gujarat, in 1999. The institute comprises an administration & kitchen building, a workshop building, a common toilet centre, a hostel, a Community Training Centre and is used by ca. 250 students and a variable number of guests attending meetings and workshops. To overcome the drawbacks of the originally implemented wastewater treatment and disposal systems and to meet the needs of extension of the institute, a sanitation concept comprising the following components was developed:
• Greywater from the hostel and kitchen water will be treated in a treatment cum storage unit, which combines a reed bed and a storage tank. The pretreated water will be reused for irrigation purposes.
• Two double vault urine-separation vermicomposting toilet systems will be installed. Worms will facilitate composting of faeces; leachate and wash-water will be drained to an evapotranspiration bed. Source-separated urine will be collected and used as fertilizer after storage. Greywater from the washbasins will be used for subsurface irrigation of nearby plants.
• Mixed wastewater from the ground floor level and blackwater from the first floor level will be pretreated in an organic filter to remove solids. The pretreated water will be drained to an evapotranspiration / infiltration bed for reuse.
• Greywater from showers and wash basins at the first floor level will be discharged in separate pipings and reused for irrigation of nearby flowerbeds or greywater gardens. Distribution of the water will be done in mulch-filled absorption trenches with or without pretreatment in settling tanks.
For the time being Navsarjan is establishing primary schools in 4 talukas in Gujarat State. After completion each school will have a total capacity of 210 pupils and comprise 6 classrooms, toilet and shower facilities, an administration building, a kitchen building, a workshop building and staff quarters. A sanitation block has been designed to provide toilets and showers for pupils and staff, while allowing the recovery of urine, faeces and water for productive purposes. The cabins of the urine–separation compost toilets are designed in such a way that they double up as showers during the processing period.
ACTS Ecosan pilot project, Bangalore, India
Dr. Ken Ganakan, Bangalore, India - ACTS
Before 2001 the majority of households in Rajendra Nagar Slum, did not have their own toilets and residents had access to only one functioning communal toilet. Open defecating was a large option. Sexual harassment had been an associated problem as women were forced to defecate in the open field before dawn or after dusk. Soon a large housing complex came up in the open area used for defecation and women were put into a difficult situation for toilet use. In 2001 the local NGO ACTS, established an eco-friendly public toilet centre (source separation of urine, faeces and wash-water) and a co-composting site for faecal matter at ACTS Rayasandra Campus. Not just wanting to provide toilets, ACTS being an educational NGO, identified this as an ideal situation for experimenting with a scientifically based eco-toilet. Urine and faecal matter were separately collected in 120 litre plastic drums. Once a day the full drums were picked up and conveyed to the ACTS Rayasandra Campus where faecal matter was co-composted with waste paper from nearby IT companies and biodegradable waste in composting trenches and urine was applied to a banana plantation after storage. Wash-water produced at the toilet centre was drained to an infiltration bed in front of the toilet block. Water that didn’t trickle away was collected in a subsurface collection tank, which was emptied when full.
Although the ACTS ecosan toilet centre is successfully in operation for almost 4 years now, serving about 500 to 600 users per day, the originally designed logistics system was often discussed controversially. Hence a socially and culturally more acceptable, sustainable and hygienic safe collection, transportation and processing scheme has been developed and implemented. In the recently improved collection and logistics systems storage tanks replace the barrels for collection of urine and faeces. A truck, equipped with tanks and a pumping system, evacuates faeces and urine; therefore manual shifting of the drums is not necessary any longer. Urine and faeces are then transported to the Rayasandra Campus, where urine is stored in large tanks and faeces are treated in a biogas plant. Stored urine and digested slurry are used as fertilizers and soil amendment, respectively; whereas biogas is used for cooking. Due to the retention capacity of the biogas plant extension of the sanitation project on new public toilets is possible. Wash-water, produced at the public toilet centre, that isn’t taken up by the planted infiltration bed is now drained to a nearby municipal sewer.