Development of phosphorus loading control strategies for urbanizing watersheds

Phosphorus loading and accelerated eutrophication have negative effects on human and environmental health, and significant potential economic impacts. Increases in the frequency of algal blooms has been reported in several regions of Canada, with phosphorus loading from non-point urban and rural sources as suspected primary causes. Changes in trophic state within a water system influences the ability to use the water resource for recreational purposes, increases water treatment costs, and degrades aquatic biodiversity. Restrictions are currently being placed on new development in several regions of Canada based solely on phosphorus loading concerns. Within urbanizing watersheds, stormwater can be a major source of phosphorus to receiving water bodies. Treatment wetlands have been identified as a possible tool for mitigating phosphorus loading from urban stormwater due to their low maintenance requirements, resiliency, and aesthetic appeal. However, there are significant knowledge gaps with respect to the fate of phosphorus within stormwater wetlands, especially in cool climates. The short term goals of this research program are to identify mechanisms of phosphorus retention with stormwater treatment wetlands, and develop innovate design and operation approaches that can be used to optimize phosphorus removal in cool climate wetland systems. The research program will involve controlled laboratory experiments, field studies involving full scale stormwater wetland systems, and the development of a new, cool climate, process-based wetland model. The research activities will focus on a wetland system receiving stormwater from a new urban development in Halifax, that will serve as a \"Living Laboratory\". A diversity of students will be trained at the doctoral, masters and undergraduate levels, and will gain experience using state-of-the-art environmental monitoring instruments. This research will lead to the development of tools and design recommendations that can be directly used by stormwater engineers and municipal planners to ensure protection of valuable aquatic resources.