Urban groundwater quality in sub-Saharan Africa: current status and implications for water security and public health

Abstract

Groundwater resources are important sources of drinking water in Africa, and they are hugely important in sustaining urban livelihoods and supporting a diverse range of commercial and agricultural activities. Groundwater has an important role in improving health in sub-Saharan Africa (SSA). An estimated 250 million people (40% of the total) live in urban centres across SSA. SSA has experienced a rapid expansion in urban populations since the 1950s, with increased population densities as well as expanding geographical coverage. Estimates suggest that the urban population in SSA will double between 2000 and 2030. The quality status of shallow urban groundwater resources is often very poor due to inadequate waste management and source protection, and poses a significant health risk to users, while deeper borehole sources often provide an important source of good quality drinking water. Given the growth in future demand from this finite resource, as well as potential changes in future climate in this region, a detailed understanding of both water quantity and quality is required to use this resource sustainably. This paper provides a comprehensive assessment of the water quality status, both microbial and chemical, of urban groundwater in SSA across a range of hydrogeological terrains and different groundwater point types. Lower storage basement terrains, which underlie a significant proportion of urban centres in SSA, are particularly vulnerable to contamination. The relationship between mean nitrate concentration and intrinsic aquifer pollution risk is assessed for urban centres across SSA. Current knowledge gaps are identified and future research needs highlighted.

Contribution A La Connaissance Hydrogéologique Et Hydrogéochimique Des Aquifères De La Région De Beni-Hassan (Rif Septentrional, Maroc)

“…Les eaux souterraines sont la plus grande et la plus importante ressource en eau en Afrique (Lapworth et al, 2017 ;MacDonald et al, 2012). Elle est souvent plus fiable, dans une proximité plus étroite aux utilisateurs, moins vulnérables à la pollution, et plus résilients à la variabilité de climat que l'eau de surface (Lapworth et al, 2013, Lapworth et al, 2017.…”

“…Elle est souvent plus fiable, dans une proximité plus étroite aux utilisateurs, moins vulnérables à la pollution, et plus résilients à la variabilité de climat que l'eau de surface (Lapworth et al, 2013, Lapworth et al, 2017. Dans ce contexte, le Maroc dispose de ressources en eau relativement importantes.…”

Groundwater as a strategic resource for improved resilience: a case study from peri-urban Accra

“…Three out of four of those surveyed considered water from their main source fit to drink: 80% did not treat their water-a practice that may pose a significant health risk especially if water is taken from shallow, dug wells that are generally prone to wastewater contamination (Machdar et al 2013;Lapworth et al 2017). Approximately half of those who had adopted a 'treatment' method said they let the water stand and settle.…”

“…Shallow, hand-dug wells are often microbially contaminated due to their placement and insufficient source protection including inadequate wastewater handling and solid waste management; a major challenge therefore remains in raising 1 3 6 Page 2 of 13 awareness connected to risks of consuming untreated groundwater from such (Akple et al 2011;Lapworth et al 2017;Okotto et al 2015). Nonetheless, in SSA groundwater is the major source of drinking water and has an important role in improving health and sustaining urban livelihoods (Adelana et al 2008;MacDonald et al 2012).…”

Complete Reduction of Hazardous Cr(VI) in Chromium Ore Processing Residue Dump Site

“…The chromium contaminated sites, which require remediation existing in various parts of the World are discussed briefly in the earlier works [15][16][17][18][19].…”