Production of systems for onsite treatment of wastewater is an expanding industry fostering more widespread application of reuse technology. This study evaluated the potential for constructed wetlands to remove micropollutants from industrial and household sources and, thereby, reduce their environmental impact resulting from toxicity, endocrine disruption, or physical interaction. Their removal during conventional treatment has been extensively studied, yet research on the performance of biofiltration and constructed wetlands in removing micropollutants is scarce. Through a column study scale model of a constructed wetlands onsite treatment system and parallel batch studies, the mechanisms by which micropollutants are removed were explored. The removal of steroid hormones, triclosan, and caffeine in these studies was measured using enzyme-linked immuno-sorbent assays, and was shown to improve in the presence of nitrifying bacteria. Diminished removal of co-contaminants was correlated with the presence of triclosan, possibly due to the latter's effect on suppression of microbial activity.