PHYSICOCHEMICAL AND HEAVY METAL CHARACTERIZATION OF DUMPSITE LEACHATE AFFECTING SURFACE WATER INTAKE POINTS IN CROSS RIVER STATE, NIGERIA

This study assessed the physicochemical, bacteriological, and heavy metal characteristics of dumpsite leachate affecting surface water quality in Cross River State, Nigeria. Mixed-method comparative cross-sectional design involving field sampling, laboratory analysis, and Geographic Information System (GIS) mapping was adopted. Water samples were collected from impact, intake, and control points in Ikom and Calabar during both wet and dry seasons and analyzed using standard World Health Organization (WHO) and Nigerian Industrial Standards (NIS) procedures. Data were analyzed using Analysis of Variance (ANOVA). The findings showed elevated concentrations of ammonia (4.16 mg/L), biochemical oxygen demand (18.25 mg/L), phosphate (3.81 mg/L), nitrate (60.50 mg/L), nitrite (0.18 mg/L), and sulfide (0.22 µg/L), exceeding permissible limits. Heavy metal analysis revealed high levels of copper (0.62 mg/L), chromium (1.16 mg/L), and manganese (1.05 mg/L), while other metals remained within acceptable standards. Total coliform and Escherichia coli counts were 600 CFU/100 mL and 311 CFU/100 mL, respectively. ANOVA indicated significant variations in water quality among sampling locations (F = 5.42, p = 0.008), confirming leachate influence on receiving waters. The study concludes that dumpsite leachate degrades surface water quality, poses environmental and public health risks, recommending stricter waste management, routine monitoring, and improved water treatment.