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The 'Value at the end of the Sanitation Value-chain' (VeSV) project aims to develop and adopt business models for a low cost, safe method for the collection and processing of faecal sludge from pit latrines; a method that can be operated by local entrepreneurs and results in the production of a safe, high quality fertilizer that is desirable to farmers.
Background (text by Elisabeth Kvarnstrὂm)
Beginning in 2006, the BRAC WASH programme in Bangladesh has been dedicated to integrating sanitation, hygiene and water components in a programme targeting the poor and hardcore poor, and ensuring participation of women at all levels. With its predominant emphasis on sanitation and hygiene, the programme focuses on 248 Upazilas (sub-districts, with an average population of 300,000) in which the sanitation technology has been single and double-pit pour-flush latrines with water seal.
However, many of these pit latrines are filling up. Common practice for emptying of single-pit latrines, the most commonly occurring latrine type in the BRAC programme, is that the pit emptier is summoned when the pit is full, and he then empties the pit using a bucket and a rope. To suppress the smell, the pit emptier sometimes adds bleach or kerosene to the pit before starting the emptying. He then usually transfers the pit contents to an adjacent hole on the latrine owner’s land or to a hole on common land that many people may use for dumping of liquid faecal sludge. The hole is then covered by ash, soil etc., and the faecal sludge dewaters in that hole. Sometimes the liquid pit content gets disposed of on the latrine owner’s agricultural land. Common practice for emptying of double-pit latrines is to empty the first pit when the second pit is full.
This allows the first pit to have undisturbed storage for at least 1 year before the emptying. The pit emptier uses a hoe and spade to get the solid faecal sludge (the bio-solids) out of the pit. He then disposes of the sludge in a hole, in the same way as the liquid sludge above, also sometimes onto farmland. The disposal holes for liquid and solid faecal sludge are sometimes dug out and used as fertiliser.
From a sustainability perspective of the sanitation programme, it is BRAC’s intention to promote safe production of a marketable fertiliser from single and double-pit systems. Initial nutrient content studies of bio-solids from double-pit systems show that the bio-solids comply with the organic fertiliser standard of Bangladesh regarding total organic carbon, nitrogen, phosphorus but NOT for potassium, NOT on pH (too low pH) and NOT on moisture content (too high moisture content). Initial microbiological studies on bio-solids from double pits show that helminths are present, even after one year of undisturbed storage. It is reasonable to believe that the single-pit content, especially in cases where many families are dumping into the same hole, will have a higher incidence of helminth presence, as well as other pathogens.
To find solutions for these challenges the BRAC WASH II programme sent out a research call for proposals for one or several simple, low-cost, straightforward set-ups on production of faecal sludge-based fertiliser that meets WHO Guidelines for commercially viable faecal sludge reuse in agriculture and Bangladeshi standards for fertilisers, which is suitable for the different agro-climatic conditions in Bangladesh.
Four criteria were identified for the study:
- The secondary treatment technology shall produce a fertiliser that is desirable to the farmers and of adequate hygienic standard. The final product shall meet WHO Guidelines standards for faecal sludge on hygiene and standards for fertilisers in Bangladesh (organic or organo-chemical)
- To ensure commercially viable faecal sludge reuse, costs, including minimum construction and operation and maintenance costs in terms of finance, should be kept as low as possible
- Focus on the low-cost, simple secondary treatment technologies of faecal sludge from existing single and double pit latrines, which reduce helminth viability
- Common practice of existing pit emptying shall be the starting point of technology development, hence to use sludge that has been (i) dewatered in a double-pit or (ii)
- dewatered after emptying from a single pit, unless the Applicant can show that treatment on liquid sludge can meet all stipulated criteria
- Durability and sustainability of secondary treatment technology throughout the rainy season is desirable. The Applicant shall propose how the first step, in the single pit emptying, transfer to a common hole, can, in a very minimum cost way, be made more safe during the rainy season
- The suggested treatment method shall be possible to operate by local entrepreneurs
- Different technologies may be applicable for different agro-climatic zones of Bangladesh
Operator and downstream safety
- The secondary treatment technology O&M shall not cause harm to operators of the system (a hygienic O&M must be ensured)
- The fertiliser produced shall meet adequate hygienic and fertiliser standards for agricultural reuse and for consumers of fertilised produce. This entails proposing ways to eliminate the need for the pit emptiers to pour kerosene and/or bleach into the single pits before emptying, since kerosene and bleach will decrease the quality of the fertiliser
The VeSV project
The BRAC WASH II research call for secondary treatment options for faecal sludge was won by the School of Civil Engineering, University of Leeds, based in the United Kingdom. Their project is called Value at the end of the Sanitation Value-chain (VeSV).
The overall objective of the project is that business models will be developed and adopted for a low cost, safe method for the collection and processing of faecal sludge from pit latrines; a method that can be operated by local entrepreneurs and results in the production of a safe, high quality fertilizer that is desirable to farmers.
The University of Leeds is working together with three other partners: Bangladesh University of Engineering and Technology (BUET), NGO Forum for Public Health (Bangladesh), and IWMI International Water Management Institute (Sri Lanka).
The specific objectives of this project are to:
- Develop business models for conversion of faecal sludge into compost in such a way that the process and products are conducive to the needs of the various stakeholders and which will therefore be adopted and sustained because of demand and generation of revenue
- Characterize the sanitation value chain including the demand, supply and institutional arrangements for the production and use of faecal fertilizer, with a view to improving sanitation and supporting agricultural production
- Optimize the process of emptying pit latrines so that it is more efficient and safe for the operator
- Optimize the composting process including the drying and co-composting processes, so as to create a safe product that meets farmer/crop requirements in terms of nutrients and organic matter content
- To achieve widespread adoption of business models (in at least 5 Upazilas during the lifetime of the project and evidence that this is likely to increase to 50 over 5 years) and growth in sales
The project will run until 1 November 2014 and has a budget of € 325,000 (US$ 420,000)
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