Constructed Wetlands for Management of Urban Stormwater Runoff

In urban and suburban areas, stormwater runoff has been identified as a significant contributor to water quality impairment. The quality of the stormwater and the characteristics of the pollutants present are dependent on the types of surfaces the stormwater encounters. The scientific research within this field has been focused on pollutants such as nutrients, heavy metals, organic and particulate matter, herbicides, and polycyclic aromatic hydrocarbons. These constituents may pose risks to life forms along with technical and aesthetic problems and thus require implementation of management practices for mitigating stormwater pollution. Structural best management practices are now commonplace for stormwater management in urban developments and range from simple filter strips, to the latest green technology methods such as constructed wetlands. Physicochemical and biological properties of wetlands provide many positive attributes for remediating contaminants. Specifically, wetland stormwater treatment areas offer the advantages of water storage and peak-flow attenuation, nutrient cycling and burial, metal sequestration, sediment settling, and breakdown of organic compounds along with certain ancillary benefits such as recreational facilities as well as functioning as a wildlife habitat. In this context, the authors summarize information on stormwater and different structural best management practices used for stormwater treatment. They critically examine the potential of constructed wetlands for stormwater treatment by looking at the present research initiatives toward execution of this technology. Future considerations in choosing constructed wetlands as stormwater treatment systems are also highlighted by discussing benefits and inadequacies as well as economic facets of constructed wetlands.