Contribution of physical factors to handpump borehole functionality in Africa

MacAllister, D.J. ORCID: https://orcid.org/0000-0001-8893-9634; Nedaw, D.; Kebede, S.; Mkandawire, T.; Makuluni, P.; Shaba, C.; Okullo, J.; Owor, M.; Carter, R.; Chilton, J.; Casey, V.; Fallas, H.; MacDonald, A.M. ORCID: https://orcid.org/0000-0001-6636-1499. 2022 Contribution of physical factors to handpump borehole functionality in Africa. Science of The Total Environment, 851, 158343. 10.1016/j.scitotenv.2022.158343

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Official URL: http://dx.doi.org/10.1016/j.scitotenv.2022.158343

Abstract/Summary

Handpumps are the main water supply for rural communities across sub-Saharan Africa. However, studies show that >25 % of handpumps are non-functional at any time. We present results from a systematic field study of handpump borehole functionality. The study was designed to investigate the contribution of physical factors to functionality outcomes, including; hydrogeology, borehole configuration, and handpump components. To achieve this, we deconstructed and examined 145 handpump boreholes in Ethiopia, Uganda and Malawi. Pumping tests showed that 19 % of boreholes were located in aquifers with transmissivity below the minimum required to sustain a handpump. Water levels, measured during the dry season, had a complex relationship with borehole configuration and transmissivity. The handpump cylinder was <10 m below the water table at 38 % of sites, which increases the risk of the handpump running dry during intensive use and/or in areas of low transmissivity. The water column was <20 m at 23 % of sites and screens were <10 m long at 29 % of sites and often sub-optimally positioned in the borehole. Borehole depth had no clear relationship with functionality. Using multinomial regression and four functionality categories (functional; unreliable; low yield; unreliable and low yield) as dependant variables, we found that transmissivity is a significant risk factor for the classification of handpump boreholes as low yield. The configuration of the borehole (e.g. cylinder position, screen/casing configuration and water column) is a statistically significant risk factor for the classification of handpump boreholes as unreliable. Handpump components were in poor overall condition but rising main pipes were a particular problem with 53 % of galvanised pipes corroded and 82 % of uPVC pipes damaged, with implications for handpump performance. Our study highlights the importance of; understanding aquifer properties, investing in borehole siting, construction (including supervision) and commissioning, and improving the quality of components and maintenance of handpumps.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	10.1016/j.scitotenv.2022.158343
ISSN:	00489697
Additional Keywords:	GroundwaterBGS, Groundwater
Date made live:	06 Sep 2022 13:09 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/533147

Item Type:

Publication - Article

Digital Object Identifier (DOI):

10.1016/j.scitotenv.2022.158343

ISSN:

00489697

Additional Keywords:

GroundwaterBGS, Groundwater

Date made live:

06 Sep 2022 13:09 +0 (UTC)

URI:

https://nora.nerc.ac.uk/id/eprint/533147