Access to clean and safe drinking water is essential for human health and well-being. This study
evaluates the water quality of well water in Obudu Local Government Area, Cross River State,
Nigeria, by correlating the Water Quality Index (WQI) with various physical, chemical, and
bacteriological parameters. 65 well water samples were analysed using the Oregon WQI model,
incorporating parameters such as temperature, electrical conductivity, pH, turbidity, total dissolved
solids (TDS), heavy metals, and microbial contaminants. Results showed that temperature ranged
from 26.1–27.9°C, pH from 7.01–7.98, and electrical conductivity from 138.1–217.2 µS/cm, all
within acceptable World Health Organization (WHO) limits. However, concentrations of lead (0.01–
0.08 mg/L), Iron (1.90-5.32) and total hardness (120.5-202.3) exceeded the WHO standard of 0.01
mg/L, 0.3 mg/l and less than 150 respectively. Results of total Coliforms and faecal Coliforms were
too numerous to count (TNTC) in several wells, indicating contamination. WQI values ranged from
67.5 to 99.54, with some wells classified as poor to fair water quality (60–84 WQI), requiring
treatment before consumption. Using multiple linear regression analysis (MLRA) water quality via
WQI could be predicted by some physical, chemical and bacteriological parameters from Models 1-
4. Model1 with adjusted R² value of 0.873 provided the best correlation. Water treatment
interventions and sustainable management strategies are required to ensure safe drinking water for
the local population.