University wastewater may contain conventional pollutants and contaminants of emerging concern that are difficult to manage in decentralized settings. This two-year case study evaluated the seasonal performance of a full-scale subsurface-flow ornamental constructed wetland treating wastewater at the Granja Pericos campus, Universidad de Sucre, Colombia, and quantified tissue distributions of nitrogen, phosphorus, and triclosan. The limestone-bed system was planted with Agapanthus sp., Alocasia sp., Canna hybrid, Cyperus papyrus, and Heliconia sp. Weekly triplicate influent and effluent samples collected during 2024–2025 were analyzed using standardized physicochemical and microbiological methods; tissue triclosan was quantified by ultra-performance liquid chromatography–tandem mass spectrometry. A season × year factorial design was used to evaluate temporal associations. Removal of biochemical oxygen demand, chemical oxygen demand, and total suspended solids was higher during dry periods. Nitrogen removal did not differ significantly between seasonal categories, whereas total phosphorus retention decreased during wet periods. Performance for biochemical oxygen demand and bacterial indicators was higher in 2025. Visual morphological counts indicated greater than 90% apparent retention of putative microplastic particles, although polymer identity was not confirmed spectroscopically. Triclosan occurred predominantly in roots and rhizomes or bulbs and was below the detection limit in stems and leaves. Phosphorus was highest in rhizomes or bulbs, whereas nitrogen occurred in above- and belowground tissues. The results provide site-specific evidence that a full-scale ornamental wetland can contribute to university wastewater treatment under variable tropical field conditions; causal hydraulic interpretation is limited because operational flow and hydraulic retention time were not measured directly.