Chemical and toxicological characterization of stormwater quality in the City of Saskatoon

来自降水事件和积雪融化的水以雨水的形式从城市景观中流出，并被收集在暴雨下水道中。城市化程度的提高和土壤的封堵导致了暴雨水量的增加。与此同时，全球雨水水质下降，雨水中检测到营养物质(氮、磷、有机物)、病原体(细菌和病毒)、盐类、金属以及多环芳烃和石油碳氢化合物等有机化学品等高浓度污染物。这些数量的增加和同时质量的下降给雨水管理带来了几个挑战，一方面涉及有效收集和分流雨水以保护市政基础设施，另一方面保护接收环境免受可能构成人类和环境健康风险的潜在有毒水的影响。以前的研究已经确定了有希望的战略，当雨水收集在雨水排放到环境中之前与卫生下水道分开的雨水管中时，对其进行初级处理，但关于导致接收环境脉冲暴露于高水平污染的降水事件的时间动态尚不清楚。萨斯卡通市是萨斯喀彻温省最大的直辖市。有一百多个独立的雨水下水道的排污口，其中许多未经处理直接排放到南萨斯喀彻温河。以前的研究使人们更好地了解了向河流的排放，并帮助确定了关键的排污口，以供进一步调查。然而，这项研究限于调查的排污口和污染物的数量，迫切需要可靠的数据来了解这些影响的时间动态。为了弥补这一差距，这项研究项目将首次生成萨斯卡通市雨水质量的详细化学和毒理学概况。这项研究将对城市雨水对河流生态系统的污染风险进行更可靠的评估，并帮助该市通过改进市政雨水管理为未来的监管做好准备。

Water originating from precipitation events and snowmelt runs off the urban landscape as stormwater and is collected in storm sewers. Increasing urbanization and sealing of soils have resulted in increased quantities of stormwater. At the same time, stormwater quality has dropped globally, and high concentrations of pollutants such as nutrients (nitrogen, phosphorus, organic matter), pathogens (bacteria and viruses), salts, metals, as well as organic chemicals such as polyaromatic and petroleum hydrocarbons have been detected in stormwater. These increases in quantity and concurrent decreases in quality result in several challenges for stormwater management related to the effective collection and diversion of stormwater to protect municipal infrastructure on the one hand, and protection of the receiving environment from potentially toxic waters that may pose a human and environmental health risks.Previous research has identified promising strategies to provide primary treatment of stormwater when it is collected in storm sewers that are separate from sanitary sewers prior to its release into the environment, but much remains unknown about the temporal dynamics of precipitation events that result in a pulsed exposure of the receiving environment to high levels of pollution. The City of Saskatoon is the largest municipality in Saskatchewan. There are over one hundred outfalls of separated storm sewers, many of which discharge directly into the South Saskatchewan River without treatment. Previous research has resulted in a better understanding of the discharges to the river and helped to identify key outfalls for further investigation. However, this research was limited in the number of investigated outfalls contaminants and, and reliable data to understand the temporal dynamics of these impacts are urgently needed. To bridge this gap, this research project will for the first time generate a detailed chemical and toxicological profile of stormwater quality in the City of Saskatoon. This research will result in a more reliable assessment of the risks of pollution from urban stormwater to the river ecosystem and help the City to prepare for future regulations through improved municipal stormwater management.