Mapping groundwater quality degradation beneath growing rural towns in sub-Saharan Africa

Groundwater is often more reliable and less vulnerable to pollution than surface water, and more resilient to climate variability. Many expanding urban areas in sub-Saharan Africa (SSA) are dependent on groundwater for water-supply. However, urban groundwater is impacted by pollution from latrines, domestic waste and industrial activities. The change from rural to urban landuse causes dramatic changes in groundwater recharge, as well as in water quality and demand. Despite government and NGO efforts to increase access to safe groundwater, the most vulnerable in these areas still rely on inadequate sources of deteriorating quality. Safe water is important for domestic use, economic activities and industry, as well as public services. Groundwater resources beneath growing rural towns in SSA are poorly understood compared to large cities (e.g. Lusaka, Lagos and Dakar) and there has been a recent focus on rural settings. Given the large numbers of smaller but rapidly growing rural, groundwater-dependent towns in SSA, the development of effective strategies to protect the resource from inevitable contamination is a priority. This requires this resource to be effectively characterised and for practical tools to be developed for mapping risk to groundwater resources that can be used across SSA.

This proposal focuses on improving our understanding of the impact of urban development on groundwater quality in SSA. As part of this a groundwater risk mapping tool for use in different development scenarios will be develop and tested, enabling this approach to be used in other towns in SSA with minimal resources. As part of this work a comprehensive review of the current understanding, drawing on published and grey literature, of groundwater quality beneath urban centres across SSA will be assessed. An interdisciplinary pilot study will investigate groundwater quality beneath zones of contrasting development within a rural town and compare this with the quality of 'natural' water in adjacent rural settings. The comparison will be used to test the mapping approach. Zambia is a lower-middle income country in SSA, where it is estimated that around 30% of people don't have access to safe drinking water. This pilot study will include the collection of new microbiological and hydrochemical data. Water quality will be investigated in contrasting rainfall/recharge conditions to characterise contamination risk during intense rainfall. In-situ organic matter fluorescence techniques will be piloted as potential tools for tracking and screening for waste water pollution in groundwater. This study will test new methods and help develop a good scientific base for guiding research, policy and development for groundwater management rural towns in SSA. The outputs from this work will be novel, and have applications across SSA. This work will culminate in a workshop to disseminate and discuss findings with key stakeholders from Zambia and across SSA.

The proportion of the population living in urban centres in SSA is high (36%) and is growing rapidly in many countries. A large part of this growth is occurring in small expanding rural towns. There is a vital need for research on the impact of urbanisation on groundwater quality in this sector, compared to large cities in SSA, to manage the threat to these important water reserves.
The project will develop practical tools based on robust science to be used by a range of stakeholders for predicting and mapping groundwater quality degradation in growing urban centres under different development scenarios. These will include local government planning departments, NGOs, and agencies, or private bodies, with public water supply responsibilities. Examples of NGOs working in Zambia, and across SSA, on projects related to water, health, sanitation and education include WaterAid, Village Water, Care International and UNICEF.
In the context of growing urban centres, the project outputs will be used to provide underpinning evidence to distinguish roles of different sources and pathways of water contamination, and to enable prioritisation of measures to manage these most effectively. This will be achieved by providing a framework for developing a risk mapping tool where data can be collected easily and with minimum resources The majority of people in SSA rely on unimproved sanitation facilities [1] which are likely to contaminate key drinking water sources, particularly important local sources such as shallow aquifers. Under these circumstances the transmission of waterborne disease can be rapid leading to potentially high morbidity and mortality rates.
In the catalyst grant the beneficiaries will be the local population in the pilot study area from the identification of the factors which are contributing to degradation of their water supply. More broadly the work will benefit people moving into expanding rural towns in SSA by provision of better management of groundwater quality. The impact will come from economic benefits and improved public health.
Policy makers and managers will benefit from new insights into the key impacts of uncontrolled or poorly-planned activities on the quality of supplied water. For benefit to economists and social scientists the project results need to be accessible and digestible and the risk tool should provide a means for achieving this. The results would be of interest to the informed public and this will be addressed through web-based activities.
Key academic beneficiaries will include those investigating the occurrence, sources and pathways for pathogens and microorganic contaminants in groundwater in growing rural towns in SSA, as well as those developing rapid survey tools for characterising groundwater quality in these areas.
In addition, each participant, funded organisations, partners and others contacts made as part of the project will benefit from knowledge exchange. The project will help develop a network of researchers in SSA and UK focussed on important research topic.
The outputs from the project, including a framework for developing a risk assessment tool, will be developed in such a way that they will be applicable and of potential benefit to other growing towns across SSA. A systematic review of relevant literature, drawing on studies and experts from West and East Africa, will provide a valuable assessment of the state of knowledge in SSA.
Very few high quality studies have been carried out in this important and growing setting in SSA. The case study will provide a high quality data set from a growing town in SSA. This will enable a robust assessment of the risk mapping tool, as well as a baseline data set from this poorly researched setting in SSA. The high quality and novel research proposed will lead to open access peer reviewed papers in high impact journals.
[1] Graham, J. and M. Polizzotto, 2013. Environmental Health Perspectives. http://dx.doi.org/10.1289/ehp.1206028.