1. © NERC All rights reserved Groundwater dependence and threats in urban Sub-Saharan Africa (SSA) James Sorensen

2. © NERC All rights reserved Urban population By 2050 the urban population of SSA is projected to increase from 40 to nearly 60% and exceed 1.26 billion (UN, 2011). Natural woman

3. © NERC All rights reserved The rapid growth of many urban areas has overwhelmed the ability of many local authorities to provide basic infrastructure 60% of the SSA urban population lives in informal settlements and slums (UN-Habitat, 2010) Wikimedia

4. © NERC All rights reserved Threats to urban groundwater Impacts of wastewater - 70% population unconnected to reticulated sewerage network - 80% wastewater is discharged directly to surface waters or soil (Nyenje et al. 2011) Threats: enteric pathogens and chemical waste Kenedy Mayumbelo

5. © NERC All rights reserved Study site Kabwe, Zambia Heavily groundwater dependent Self-supply wide-spread from shallow wells Ageing sewer network; restricted to 11% of properties in informal settlements and slums >100 water supplies sampled across the city

6. © NERC All rights reserved Tryptophan – indicator of bacterial quality of water? Common indicator – thermotolerant coliforms (TTCs) Rapid, reagentless measurement using a fluorimeter Measured thermotolerant coliforms and many indicators at >100 water supplies What was the best indicator of TTCs? Tryptophan! For both presence/absence and number of thermotolerant coliforms Sorensen et al. (submitted). In-situ tryptophan sensing: a rapid indicator of faecal contamination in drinking water supplies. Water Research. Abs Present

7. © NERC All rights reserved Emerging Organic Contaminants Unsurprisingly from 40 sites, contaminants most prevalent in shallow hand-dug wells Good news - Concentrations were below researched toxic levels DEET was widespread, but at low concentrations Potential use as a wastewater indicator Sorensen et al. 2014. Emerging contaminants in urban groundwater sources in Africa. Water Research.

8. © NERC All rights reserved Do TTCs identify the presence of pathogens? Filtered sample collection in field from 40 sites, preservation, assay analysis for suite of pathogens Work in progress… Opportunistic pathogens in c. 70% of supplies Vibrio cholera in >40%

9. © NERC All rights reserved Conclusions Urban populations are growing rapidly in SSA and the majority of this population resides in informal settlements or slums Tryptophan-like fluorimeters offer a solution to practitioners for the rapid indication of faecal contamination and potential enteric pathogens Emerging contaminants may be posing threats to people and the aquatic environment in SSA and could require future regulation