Case studies of data collection and decision-making for small low-income community water supply in Nepal

This project seeks to develop decision making tools to aid practitioners in Nepal to select appropriate improved water supply measures, using selected small low income communities as case studies. These include three rural communities (Bhalakhalak, Sonbarshi, Chamar Tolia) and a periurban squatter community near Kathmandu (Manohara). Household data was collected via questionnaires and site visits to assess the current practices and inform decision making. Standard water quality data was also collected to characterise water sources, several of which were deemed unsuitable for safe water supply. A decision framework, in the form of a ‘Yes/No’ decision tree, was then developed which incorporated site specific technical, demographic, and socioeconomic considerations and used literature information and local experience. It is hoped that the framework can be applied to decision making in other low income communities that face similar challenges

Evaluating the viability of establishing container-based sanitation in low-income settlements

Container-based sanitation (CBS) services operate in a number of low-income urban settlements across the globe, providing sanitation services where other on-site and off-site sanitation systems face logistical and environmental restrictions. The viability of each CBS service is influenced by a number of location specific factors. Drawing on an initial review of existing CBS services, this paper identifies and evaluates these factors in relation to establishing CBS in a new service location. By applying a weighted scoring matrix to these factors, the potential viability of CBS services has been assessed for urban informal settlements in Kathmandu Valley, Nepal. The viability of CBS services in these settlements was found to be most influenced by the current availability of basic sanitation facilities, the unfamiliarity with paying for sanitation services and the universally adopted practice of anal cleansing with water. The process and scoring matrix developed and subsequently applied in Nepal, are recommended as part of the pre-feasibility stage assessment where a CBS service is being considered as a sanitation option in new locations

The development of an onsite sanitation system based on vermifiltration: the ‘tiger toilet’

This paper describes the development of a novel onsite sanitation system based on vermifiltration, the ‘Tiger Toilet’. Initial laboratory experiments demonstrated that feed distribution was not required, a worm density of 2 kg/m2 could be used, worms preferred wetter environments, and system configuration did not affect effluent quality. Installing the first prototype in the UK proved that the process functioned when scaled, i.e., chemical oxygen demand and thermotolerant coliform reduction were found to be comparable with the laboratory results. Ten prototypes were then tested by households in rural India; all were working well after six months. The vermifilters were processing the amount of faeces entering the system on a daily basis, so faeces was not accumulating. It was estimated that they would require emptying after approximately five years, based on the depth of the vermicompost generated. With further development, it is believed that the Tiger Toilet has the potential to become a superior form of onsite sanitation, when compared with traditional onsite sanitation technologies