An urban faecal pollution mapping tool for water quality protection and enhancement

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The global water and sanitation landscape has changed significantly in recent decades, but the complete infrastructure of sanitation service chain for managing excreta safely remains a challenge and faecal contamination of surface water in urban areas of many low and middle-income countries is a vital problem. Therefore, the risk of faecal pollution just shifting its location away from households to drains and surface waters. This is a concern for human health and aquatic life as well. The impact of the polluted waterbodies varies widely and often affects environmental health, e.g., breeding grounds for disease vectors in the absence of their predator, produce unpleasant odour, and become greenhouse gas emission sources. The UN Sustainable Development Goal 6 (target 3) aims to improve water quality by halving the proportion of untreated wastewater discharged to the environment by 2030. Also, a recent study led by the University of North Carolina, USA identified as a priority research area because of gaps in knowledge and ability to deal with it. If it is not dealt with, there will be consequences affecting all sector of life including health, agricultural yield and thereby low productivity leading to reduced affordability ending in a vicious cycle. Some countries are developing sanitation framework but often that is not integrating water quality into the policy. It is becoming a challenge for city authorities to manage various environmental health issues. Therefore, an integrated and spatial understanding of the sources, pathways and receptors of faecal pollution and assessment of environmental water quality is needed. However, there are some constraints to deal with faecal pollution in relation to water quality enhancement and protection, notably, lack of 1) water quality monitoring data, 2) proven geospatial technique for assessing water quality associated with faecal pollution and to map sanitation service chain, 3) simple planning tools which can integrate water quality and faecal pollution to facilitate necessary targeted intervention. This project will aim to fill some of these gaps by answering the following research question 'can an integrated spatial representation of sources, pathways and receptors (SPR) of faecal pollution in urban catchments be used to create a new planning tool for pollution prevention?' The project will use a wide range of data including field survey and satellite images to extract faecal SPR information and develop new water quality mapping methods and subsequently will establish the association between the two. The work will include 3 work-packages (WPs) each containing a few tasks. The WP1 will integrate geospatial information with spot field survey for a spatial-scale faecal SPR analysis, WP2 will identify a relation between water clarity parameters and faecal pollution and subsequently develop a water quality algorithm for satellite image analysis, and WP3 will develop a tier-based approach to integrate the faecal SPR and water quality degradation. The overall project will be carried out by a combination of computer-based data analysis, field survey, sampling and laboratory work in collaboration with the local partners in Bangladesh.The outcome of this project will provide an improved understanding of the link between environmental water quality and sanitation service provisions in a low and middle-income urban setting. The intended mapping tool would be as simple to use as possible and rely on readily available and easily acquirable data and will provide a practical guideline to the city planner in restoring water quality from faecal pollution to reduce the environmental health risk. Poor environmental water quality often is an indicator of poor sanitation in urban setting therefore this project has the scope to have an impact in both sectors which is a common problem in the global south.