The Promise of Stormwater Phytotreatment

Planted stormwater systems represent the next substantive opportunity for treatment of stormwater (here termed “phytotreatment”) to produce high-quality runoff and maintain more natural runoff hydroperiods over large portions of urban watersheds. These systems are more than just “green” and aesthetically pleasing infiltration devices; they represent real, practicable opportunities for sequestering and/or degrading urban and industrial stormwater pollutants. When combined with the management of stormwater volumes that they provide, planted systems become the single most effective class of stormwater best management practices (BMPs) for improving the quality of stormwater runoff, reducing stormwater volumes to take pressure off of municipal infrastructure, and increasing the integrity of receiving waters. This paper describes the potential of a more holistic approach in the use of plants for stormwater treatment (phytotreatment) that recognizes the role of physical, horticultural, and plant/rhizosphere physiological processes in sequestering or degrading stormwater pollutants. We also describe challenges faced by the stormwater management community, along with guidance from colleagues versed in phytoremediation and plant ecology that would enable this approach to be more widely applied.