Industrial Contributions to Surface Water Pollution: A Physicochemical Study of the Ona River, Nigeria

Freshwater degradation in Nigeria remains a critical environmental and public health concern, driven by industrial effluents, agricultural inputs, and inadequate wastewater management. This study evaluated the physicochemical and bacteriological quality of the Ona River in the Oluyole Industrial Area of Ibadan. Water samples collected in June 2024 from upstream, industrial discharge points, and downstream residential zones were analyzed for thirteen parameters using APHA standard protocols. Elevated levels of TDS, EC, COD, BOD, manganese, and magnesium at industrial discharge sites frequently exceeded WHO and NIS limits, while DO values were consistently below recommended thresholds. Water Quality Index (WQI) scores indicated poor quality in industrial zones (Sumal: 43.2; Amir Plast: 47.3; P&G: 49.0) and moderate quality downstream (54.4). Coliforms were absent in industrial samples but detected in trace amounts at the residential site. Findings highlight the substantial influence of industrial effluents on water quality and associated community health risks. This study provides essential baseline data for water resource management, regulatory enforcement, and pollution control strategies.