A recent paper reports the effect of abstraction method on microbial communities and pathogen risks in shallow groundwater supplies, based on work carried out across several locations and seasons in Kenya.
The study used qPCR and 16S rRNA sequencing to characterise pathogenic indicator species and bacterial communities in three sand-dam aquifers across seasons and between various abstraction methods. Faecal and opportunistic environmental pathogens were detected in all samples.
Models indicated that contamination mainly arises from unsealed abstraction points such as open wells and cracked hand pumps. In contrast, natural sand filtration effectively limited dispersal of species between sample points.
Abstraction method had more influence on microbial community structure than seasonal or local factors. Microbial community composition showed adaptation to the local environment in different sampling points, which remained consistent between sites and seasons. Samples from well-maintained hand pumps had the lowest abundance of pathogen indicators, suggesting growth-limiting conditions and effective in-dam filtration.
Dr Francis Hassard, Reader in Public Health Microbiology at Cranfield University and a co-author on the study, said: “How we abstract groundwater matters for its microbial quality, highlighting the need to bring microbial ecology into the design and management of safer water supplies”.
Dr Hassard has also worked extensively on new developments in slow sand filtration systems: see the short animation on these, and for more information follow the WB WG News tag.
Abstraction method shapes microbial ecology and pathogen risk in water from shallow aquifers. Duncan, R., Ijaz, U.Z., Cholet, F., Keating, C., Koci, O., Quinn, R., Russell, J., Hassard, F., Parker, A. and Smith, C.J., 2026. Total Environment Microbiology, p.100074
