Abstract

This study investigated the microbial quality and physicochemical properties of borehole sources in Diobu, Port Harcourt, Rivers State, Nigeria. Water samples were collected at monthly intervals for a period of 12 calendar months (June 2023 to May, 2024), covering both the dry and wet seasons.  The physicochemical characteristics of the water samples were determined using standard analytical techniques. Bacterial isolation and total bacterial count was obtained using standard dilution and spread plate method; and bacterial identification was determined using standard microbiological techniques. The results revealed that the borehole water samples had pH values ranging from 6.23 to 6.38, temperatures from 27.15°C to 27.59°C, Electrical conductivity from 26.46 to 96.59µS /cm. Total suspended solids ranged from 2.07 to 2.64 mg/L, Total dissolved solids ranged from 1.64 to 2.06 mg/L, Turbidity from  1.55 to 1.71 NTU, Dissolved oxygen from 5.60 to 5.96mg/L, Biochemical Oxygen Demand from 34.1 to 53.7mg/L, Chemical Oxygen Demand from  61.13 to 92.80mg/L, Chloride ranged from 37.78 to 43.24mg/L, Salinity ranged from  2.51 to 3.51ppt and Total hardness ranged from 6.74 to 7.57mg/L. The mean total coliform counts ranged from 1.04±0.57^a ×10² to 8.67±4.41^a ×10² CFU/ml. The mean total faecal coliform counts ranged from 4.84±2.38^a ×10² to 8.55±5.28^a ×10²CFU/ml. The mean total Salmonella-Shigella counts ranged from 1.02±0.74^a ×10² to 2.69±1.72^b ×10² CFU/ml. The mean total Vibrio counts ranged from 0.98±0.76^a ×10² to 1.17±0.74^b ×10² CFU/ml. The identification of 14 bacteria genera which included pathogenic and opportunistic strains such as Klebsiella pneumoniae, Vibrio cholerae, Salmonella typhii, and Escherichia coli indicated the presence of faecal contamination in the groundwater, rendering it unsuitable for consumption without appropriate disinfection measures. Individuals who consume this water may experience a range of clinical symptoms, including cholera, gastrointestinal disorders, diarrhea, and typhoid fever. Consequently, it is crucial to implement appropriate