Professional Assessment of Wastewater Reuse Standards and Practices in Industrial Zones in Ondo State

Industrial water reuse represents a critical strategy for addressing water scarcity and reducing the environmental burden of wastewater discharge in water-stressed states. This study professionally assesses wastewater reuse standards, technical practices, and regulatory frameworks in industrial zones in Ondo State, South West Nigeria, specifically targeting agro-industrial processors and oil palm mills. A professional survey combining facility audits and interviews with plant managers and environmental officers was conducted across twelve industries. Parameters include treated effluent quality, reuse applications, water balance assessments, and alignment with NESREA wastewater discharge and reuse guidelines. Selected reused water samples were tested for biochemical oxygen demand, total suspended solids, E. coli, pH, and nitrogen. Results indicate that only three of twelve assessed facilities have formal wastewater reuse programmes, primarily for irrigation of facility grounds and equipment washing. Effluent quality from these three facilities met NESREA Class I standards for non-potable industrial reuse. The remaining nine facilities discharge all effluent after primary or secondary treatment, representing a missed opportunity for water recovery estimated at 1,200 cubic metres per day across the industrial cluster. Regulatory frameworks do not currently incentivise reuse, nor do they impose reuse targets on water-intensive industries. The study recommends development of a state-level industrial water reuse policy, fiscal incentives for reuse infrastructure investment, and the establishment of water use efficiency benchmarks for the oil palm and agro-processing sectors. Keywords: wastewater reuse, industrial zones, Ondo State, effluent quality, water management