Risk assessment of hand-dug well water: a case study of Aflao in Ghana

Peri-urban and rural areas in developing countries like Ghana face challenges with access to quality potable water due to increasing groundwater contamination risks. This study assessed the risk of hand-dug well (HDW) water in Aflao using a cross-sectional survey of 400 wells based on WHO sanitary inspection checklists. Water samples from 20 wells were analysed for microbial contamination and heavy metals (HMs) (Pb, Cd, Cr, Ni, As) using membrane filtration and atomic absorption spectrometry. Results revealed that 37.3% of wells were within 10 m of latrines, 98% lacked concrete floors, 98.3% lacked covers, 88.5% had poor drainage, 31.8% were under trees, and all were shallow (<30 m). Microbial loads exceeded WHO guidelines (0 CFU/100 ml): total coliforms (579.7 ± 294.9 CFU/100 ml), faecal coliforms (32.6 ± 54.7 CFU/100 ml), and Escherichia coli (14.7 ± 21.7 CFU/100 ml) were detected in all samples. Sanitary risk factors, including latrine proximity, absence of covers, poor drainage, and shallow depth, were significantly associated with microbial contamination (p < 0.05; OR > 1). HMs were below detection limits (0.001–0.01 mg/l). Poor microbial quality and its association with sanitary risks confirmed that HDWs in Aflao are unsafe for consumption without treatment.