March 2021

Collaboration with Water4 on Water Chlorination Automation


Aquaya is starting a new project in Ghana in collaboration with Water4 and support from the Conrad N. Hilton Foundation.

Water4 has developed a new technology that automatically chlorinates water from handpumps.

Aquaya will provide an independent evaluation of the technology’s performance and also measure the willingness-to-pay of rural communities for this service.

Research Objectives

This study has three objectives:

1. Evaluate the technical performance of NuPump chlorinators under representative operating conditions in rural Ghana.

2. Assess potential impacts on water safety.

3. Evaluate the business case for deploying the NuPump at scale in rural Ghana.


Although handpump-fitted boreholes and shallow wells are the primary source of drinking water for approximately 40% of the population in sub-Saharan Africa , a large proportion of these systems supply water that does not meet national standards for microbial quality. Studies across Africa have found that 25% to 75% of boreholes and tubewells had detectable levels of fecal indicator bacteria and thus presented a risk of diarrheal diseases. Additionally, it is likely that water quality deteriorates during transport from the point of collection to the point of consumption and storage, further exacerbating this risk.

Chlorination is a widely used water treatment technique, especially at piped water systems. Chlorinating water can help remove existing contamination and provide residual protection against recontamination post-collection. While chlorination at handpumps is still relatively uncommon, passive chlorinators are a potential solution for improving water safety and protecting public health in rural African communities. Yet, few technologies exist for passive chlorination on handpumps, and half of them have shown limited technical performance.

Water4 has developed the NuPump, a new inline erosion handpump chlorinator that relies on a Klorman chlorine cartridge and a small sediment filter. Laboratory tests and initial field tests suggest that the NuPump can deliver free chlorine residuals of 0.1-1.6 mg/L. The purpose of this study is to independently assess the technical performance of the NuPump in rural Ghana and measure communities’ willingness-to-pay for handpump chlorination via the NuPump. Depending on the results of this study, Water4 and its Ghanaian subsidiary Access Development may deploy NuPumps across their customer communities.

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