Artificially constructed wetlands offer a low cost treatment alternative to remove a number of pollutants found in effluent water from industry, mining, agriculture, and urban areas.  Wetlands can be used to mechanically remove suspended solids through sedimentation.  Dissolved nutrients, biochemical oxygen demand (BOD), heavy metals, and potentially harmful anthropogenic compounds can all be removed in constructed wetlands through geochemical and biological processes.  The anti-epileptic drug carbamazepine has been shown to be recalcitrant in sewer treatment facilities and in the environment.  Carbamazepine concentrations were monitored throughout a 1.2 ha constructed wetland.  Concentrations were linked to the hydraulics of the wetland and retention time.