Resilient submersible pumps for community water supply in East Africa

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Innovate UK
Innovate UK
Innovate UK
Innovate UK
Innovate UK

£293,915

March 31, 2020

Dec. 31, 2020

This project will address the need for a resilient groundwater pump for drinking water-supply, targeting Sustainable Development Goals (SDGs) 3 & 6.

The traditional approach to rural water provision in developing countries is to install handpumps in capped boreholes or hand-dug wells. Whilst handpumps have brought improved water to millions, they are labour intensive, maintenance intensive and suffer from under-developed supply chains of labour and parts. Often, they are not maintained and an estimated 1/4 of them don't work (Foster et al., 2019).

Solar-powered submersibles are an increasingly popular alternative to handpumps [RWSN], but they fall short during cloudy conditions or due to failures caused by silt/grit, overheating and dry-running. Unlike submersibles, surface-pumps raise water by suction from ground level. They are cheaper, more efficient, longer lasting and easier to swap-out and maintain than submersibles, in which motors and sliding seals must be submerged. However, they are limited to drawing water from within ~7m depth, representing <10% of cases (BGS,2011).

The "Impact Pump" is a novel "range extender" using acoustic phenomena to enable surface-pumps to access deep groundwater without fault-prone parts below ground. Related technologies have operated continuously for over a hundred years. Two years of field trials in smallholder irrigation have shown that failures are rare and constrained to the surface (drive)-pump, which can be swapped-out in under two minutes. Manual or fuel-driven drive-pumps can provide temporary backup. The Impact Pump is grit-tolerant, insensitive to water-level variations, and can run dry for extended periods without damage; self-priming when levels recover.

In this project, we will investigate whether these attributes can be advantageous in rural water service delivery. We will explore a range of implementation options based around a template field design. These will address variations in the commercial, social, institutional and environmental context associated with different sites, with a common aim of ensuring continuity of supply in the events of cloud cover or pump failure. The feasibility phase will also assess partnerships required to run a demonstrator and local supply chains for equipment and expertise. Two "breadboard" installations will be established by Thermofluidics and FundiFix near Kitui, Kenya. The project will determine whether the maintenance benefits already demonstrated in agriculture, can translate to water supply. If successful, demonstrators will be rolled-out in phase 2, showing substantial capacity for impact on rural water security, business and maintenance models, and the costs underpinning it, across the globe.