The olive pomace oil is the principal by-product in the olive oil sector. Nonetheless, the production uses olive bagasse after the primary extraction, it also produces by-products and effluents that need a strategic approach to possible reuse and treatment. This study aimed at the characterization of the effluent from an olive pomace oil extractor industry and to investigate the application of physicochemical pre-treatments for future water reuse. The physicochemical characterization shows high amounts of BOD and COD for the effluent freshly produced (E1) and effluent collected from storage tanks(E2) in the industrial plant. Other parameters were evaluated: Phosphorus, Organic nitrogen and Ammonia, FOG, Phenolic compounds, Alkalinity, TS, TDS and TSS, and Biodegradability (Zahn-Wellens Test). E2 shows the storage tanks were able to reduce 55% of TS and TDS, 77.5% of COD and69% of BOD when compared with E1. Compared with the Portuguese legislation, these effluents cannot be discharged to water bodies and need treatments, such as coagulation and flocculation as tested in this work. Aluminium Sulphate was shown to work at best as a coagulant in the minimum concentration of 10 g/L and pH 5, RIFLOC F45 (4 mg/L) was used as a flocculant. After the treatment, it was observed a remotion of 95.6% of turbidity, 76,4%of COD,76,7% of TSS, and 85.4% of PhC when compared with E2. A sampling campaign was carried out on the Tua river to assess its water quality, and samples were taken at four different points to assess the impact of the effluent discharge, with none of the evaluated parameters presenting values higher than those recommended by the Law-Decree nº236/98 from the Portuguese Legislation.