Evaluation of the Water Quality of River Kaduna, Nigeria Using Water Quality Index

Twelve (12) water quality parameters (turbidity. TDS, pH, Cl" , EC, DO, BOD> COD, total nitrogen, total phosphorus, Fe and Mn) were analyzed in River Kaduna, Nigeria on a monthly basis for a period of one year in 15 sampling locations using standard methods. The data obtained were used to develop Water Quality Index (WQI) across the 15 sampling locations. The WQI revealed that the water quality of 4 sampling locations were poor as their index values ranged between 17.77 to 25.47. On the other hand, the generalized water quality of the remaining 11 sampling locations was marginal as the index values ranged between 44.95 to 60.80. The index values of the various sampling locations were thereafter used as weights in mapping the WQI of the entire sampled portion of the river using Inverse Distance Weighted (IDW) interpolation method. The WQI of the entire river was suggestively ranked marginal as 11 sampling locations out of 15 (73.3%) fell into the marginal category. Hence, regulatory agencies were advised to check the anthropogenic activities along the watershed with more emphasis at the hot spot areas or locations that recorded poor WQI.