Nutrient Loading in a Mature Constructed Stormwater Wetland

Constructed stormwater wetlands (CSWs) are considered to be an effective part of green infrastructure to improve stormwater quality, however further research is needed to validate the CSWs ability to reduce nutrient loads. Past studies on the Villanova University CSW under baseflow conditions showed Total Nitrogen and Total Phosphorous had approximately 72% and 78% removal efficiency (by concentration) in the fall, respectively. For storm events, the removal efficiency (by concentration) of Total Phosphorous was 38%, but the results for Total Nitrogen were mixed, with a 1% increase in concentration through the CSW. The facility was again under study beginning in summer 2007 to evaluate water quality and quantity of a mature CSW under baseflow and storm conditions. The results confirm the treatment capability of Total Phosphorous under storm and baseflow conditions, and show an improvement in treatment of Total Nitrogen. The present work links discrete storm and baseflow samples to begin to integrate the fate and transport of pollutants to fully validate the nutrient reduction benefits of a CSW.