A four-stage constructed wetland system was tested for removing pollutants from wastewater over three years. The system, made up of different types of beds, showed high efficiency in removing suspended solids and organic compounds, with consistent results across seasons. On average, it removed 92.7% of suspended solids, 96.6% of BOD5, and 95% of COD. The treated water had lower levels of nitrogen and phosphorus compared to the untreated water.