**5. Conclusion**

The laboratory analysis results of the effluent samples indicated that metals and other contaminants from the effluents have compromised the River quality. The results of the physicochemical analysis showed that sulfate, phosphate, COD, and heavy metals such as Cr, Ni, Pb, Mn, As, and Cd were slightly higher than WHO and FEPA standards for drinking water, while the pH, Chloride, Nitrate, Nitrite, TDS, Conductivity, BOD, COD and some heavy metals such as Fe, Zn, Co were within the standard of WHO and FEPA, set for drinking water. The study, however, showed that some contaminants sampled were within statutory limits. It was also observed that sample A (Untreated effluent) and sample B (Treated effluent) had lower mean differences than sample C and sample D. Contamination factors follow a similar trend in metal contamination. At the same time, PLI index models confirmed that the effluents from the

different sampled locations were polluted, except for location D, which is unpolluted. The mean anthropogenic input for the sampled effluents for the individual metals followed the order As> Fe > Mn > Zn > Ni > Pb > Zn > Cr > Co > Cd. The ecological risk assessments for the heavy metals were at high ecological risk. Furthermore, the potential ecological index depicts As at extremely high risk, Pb at appreciable risk, Ni at moderate risk, and Cr, Mn, Co, Zn, and Cd at a low ecological risk level. Hence any significant increase would persuade environmental challenges. However, the present study recommends proper treatment of effluents before discharging to reduce their mean difference from the WHO standard and protect the health of the local population.
