Analysis of the quality of drinking water at the well sites of the mini-AEP in the Maradi Region, Niger]

Abstract

In the Maradi Region, located in the central-southern part of Niger, groundwater is the main source of water supply for both the population and livestock. In rural areas, medium-depth boreholes (less than 250 meters deep) are drilled to extract water from the Hamadian Continental aquifers or Quaternary alluvium for the establishment of mini water supply systems, Autonomous Water Posts (PEA), and Pastoral Pumping Stations (SPP). However, among the numerous boreholes drilled, water with excessive levels of certain chemical elements (fluoride and nitrates) poses significant health risks for both people and animals. Despite previous studies conducted in the region regarding high levels of fluoride and nitrates in the water, knowledge remains limited. The present study aims to determine the quality of drinking water at the mini water supply systems in the Maradi Region for better implementation of new boreholes. The developed methodology is based on a literature review, the analysis of analytical results from water samples from 55 boreholes of mini water supply systems, and a counter-analysis of 7 water samples collected in 2024 from boreholes with high fluoride concentrations. The analysis and interpretation of the collected data allowed for the establishment of physicochemical parameters and the quality of water from the mini water supply boreholes in the region. The results indicate that the water collected from the mini water supply boreholes is generally of good quality for human consumption. However, high levels of fluoride and nitrates exceeding WHO and national quality standards were noted in some boreholes. Thematic maps of fluoride and nitrate levels at the regional scale have been developed. Regular monitoring of the water quality from these boreholes is necessary to safeguard public health and prevent waterborne diseases.