Vol. 11, Issue 10, Part D (2025)

Abstract
Abattoir effluents are known sources of organic and microbial pollution that compromise both surface and groundwater quality, yet site-specific impacts remain underexplored in parts of Delta State. This study evaluated the effect of abattoir wastewater on water quality in Agbarho, Nigeria. Six sampling points were investigated: three along the receiving river (AGR1-AGR3) and three boreholes at increasing distances from the discharge point (AB1-AB3). Physicochemical and microbiological parameters were analyzed in triplicate and benchmarked against WHO, SON, and NESREA standards. Results revealed severe deterioration of surface waters, particularly at the discharge point (AGR2), where turbidity (14.85 NTU), BOD (4.22 mg/L), fecal coliforms (2.26 ×10³ cfu/mL), and E. coli (15.50 MPN/100 mL) exceeded guideline limits by up to threefold for turbidity and more than fifteenfold for microbial indicators. Although groundwater samples analyzed were within both international and local regulatory limits, AB1, the nearest borehole, showed ionic enrichment (EC 259.55 μS/cm, TDS 130.45 mg/L) and detectable coliforms, suggesting early infiltration. Statistical analysis confirmed significantly higher turbidity, BOD, and microbial loads in surface waters compared with groundwater (p<0.05). Exceedance factor analysis identified turbidity, BOD, and microbial indicators as the dominant risks. These findings highlight a dual concern: immediate health hazards from surface water use and progressive groundwater vulnerability. It is recommended that untreated effluent discharge be discontinued and replaced with primary treatment units and low-cost biological systems, while boreholes are reinforced through sanitary safeguards, setback assessments, and routine monitoring.