NSERC Research Grants: Discovery Grants Program - Individual

Stormwater/snowmelt runoff flushes anthropogenic and natural pollutants accumulated on roads and other urban surfaces into storm sewers and then into receiving water bodies, posing significant threats to the water quality and ecosystem. This is particularly true for municipalities in Canada and the northern US where the large amounts of road de-icing salts/sands used in winter can potentially have a shock effect during spring runoff to the receiving water bodies, with chloride concentration reported as high as 600% over the Canadian acute exposure guideline. In the context of fast urbanization and climate change, such threats will be further intensified and complicated. The long-term goals of this program are to reveal and quantify the coupled impacts of urbanization and climate change to receiving water bodies and to research innovative ways to enhance the sustainability and resiliency of both cities and rivers/lakes to minimize such impacts. In the next 5 years, I will focus on urbanization impact to stormwater pollutant loadings and receiving river water quality using Edmonton and the North Saskatchewan River as an example. Two studies are proposed in the program. Aim 1 will research the less-reported temporospatial variability of stormwater loadings of common yet important pollutants (nutrients, sediments, salts), the un-reported relation of urbanization level with the loadings, and the overlooked potential shock effect of the loadings to receiving rivers during spring runoff. Aim 2 will quantify, for the first time, the loading of an emerging pollutant (microplastics, MPs) in urban stormwater, and investigate the unexplored hydrodynamic impact to MP transport and fate in rivers. Field monitoring is proposed at selected storm outfalls for Aim 1 and MP loading in Aim 2. Lab experiments will be conducted for Aim 2 on MP transport and re-suspension in a flume under different hydrodynamic conditions and with different MP properties (materials/densities, sizes and shapes). An innovative measurement technique for MP velocity and concentration will be developed based on particle image velocimetry, particle tracking velocimetry and planar laser-induced fluorescence. Numerical modeling will be conducted for pollutant loadings and river water quality in Aim 1, and MP transport and re-suspension in Aim 2. All the major devices/software listed in the proposal are available for use in the Water Resources Group at the UofA. The proposed research will generate innovative, original knowledge on urban stormwater pollutant loadings and transport and fate of MPs in water. The research results will be also useful in Canada's three levels of governments in making/adjusting numerous plans/policies on urban development and maximum total pollutant loadings to rivers/lakes, as well as on de-icing salts/sands and stormwater management. The research will train 7 HQP in areas that are highly desirable by consulting firms, utility companies and government sectors.