The Use of Constructed Wetlands for Controlling NPS Runoff

The purpose of this study is to evaluate the use of constructed wetlands as a best management practice (BMP) by comparison of selected design parameters and pollutant removal efficiencies for three wetland sites. Analysis of stormwater samples for total suspended solids (TSS), chemical oxygen demand (COD), total phosphorus (TP), orthophosphate (OP), and zinc (Zn) indicates a wide range of average removal efficiencies ranging from –30 % (export of pollutant) to greater than 80 % (removal of pollutant) with significant variations between the three sites monitored. Data was also collected to document vegetative diversity and utilization of the wetlands as a habitat. A field scale wetland model (currently under development) utilizing the U.S.E.P.A. Water Quality Analysis Simulation Program (WASP) is described, along with a geographic information system (GIS) that has been developed as a resource for model input and storage of data pertaining to wetland sites.