Physicochemical and microbial quality of tanker-delivered drinking water in Tamale Metropolis, Ghana

Abstract. Commercial water tanker services provide an important alternative source of drinking water in rapidly urbanizing cities where piped water supply is inadequate. However, concerns remain regarding water quality deterioration during transportation and storage. This study assessed the physicochemical and microbial quality of water supplied by commercial tanker operators in the Tamale Metropolis, Ghana, and examined operational practices influencing water safety. A total of 54 water samples were collected from nine tanker operators and analysed using standard APHA methods, while structured questionnaires were administered to 50 operators to evaluate water sources, cleaning frequency, and hygiene practices. The results showed mean values of 30.16 ± 0.66 °C for temperature, 7.48 ± 0.31 for pH, 269.1 ± 0.04 NTU for turbidity, 126.49 ± 9.28 µS cm−1 for electrical conductivity, 0.073 ± 0.007 ppt for salinity, and 0.52 ± 0.42 mg L−1 for dissolved oxygen. Total and faecal coliform counts averaged 47.96 ± 104.90 and 40.59 ± 84.96 CFU/100 mL, respectively. While most physicochemical parameters complied with WHO (World Health Organization) drinking-water guidelines, turbidity exceeded the recommended limit in all samples, and oxidation–reduction potential values indicated inadequate disinfection. Total coliforms and faecal coliforms were detected in 38.9 % and 29.6 % of the samples, respectively, confirming post-treatment contamination during transportation and storage. Survey findings revealed that although most operators sourced water from the Ghana Water Company Limited, variations in cleaning frequency and hygiene practices likely contributed to the deterioration in water quality. These findings highlight the need for strengthened regulatory oversight, routine tanker inspection and disinfection, improved operator hygiene practices, and continuous water quality monitoring to safeguard public health.