Analytical Study of Groundwater Contamination from Industrial Effluent Discharge in Kaduna River Corridor, Kaduna State

Industrial effluent discharge to the Kaduna River and its floodplain from Kaduna metropolis' textile, food processing, and tannery industries creates potential groundwater contamination pathways that threaten domestic water supply for communities along the river corridor. This study analytically investigates groundwater contamination from industrial effluent discharge in the Kaduna River corridor. A hydrochemical investigation was designed to characterise contamination extent and identify contaminant sources. Groundwater samples from 28 boreholes and wells along a 15 km corridor of the Kaduna River downstream of the Kaduna industrial area were collected and analysed for heavy metals (lead, cadmium, chromium, zinc, copper), physical-chemical parameters, and organic indicators (COD, BOD, oil and grease). Stable isotope analysis (delta-18O and delta-2H) differentiated groundwater recharge sources. Spatial contaminant distribution was mapped using kriging interpolation in ArcGIS. Results indicate that lead concentrations exceed the WHO drinking water guideline of 10 micrograms per litre in 64 percent of samples within 2 km of discharge points. Chromium from tannery waste is elevated above WHO limits in 32 percent of samples. Isotope mixing indicates that 15 to 35 percent of groundwater within the immediate river floodplain is derived from river bank filtrate, which carries industrial contamination. The study maps contaminated zones and recommends groundwater exclusion zones for potable use within 1.5 km of confirmed discharge locations.

Keywords: groundwater contamination, industrial effluent, Kaduna River, hydrochemical investigation, Kaduna State