Invited speaker: Graham Gagnon, PhD, P.Eng.
Over the past several decades there has been broad recognition that climate change is impacting drinking water supplies and our waters receiving wastewater in ways that we do not fully understand. In Atlantic Canada, our team at Dalhousie University has analyzed historical source water quality data, lake sediment cores, and has applied innovative analytical techniques (e.g., field flow fractionation) to demonstrate the following: pH is largely increasing; natural organic matter is not only increasing in concentration and changing in quality but is also impacting trace metal cycling; and algal and diatom blooms are occurring. These changes in surface water quality have resulted in operational challenges at many surface drinking water treatment plants in Atlantic Canada and have created awareness that a paradigm shift for plant design is required. Further, in Atlantic Canada, some wastewater treatment plants use surface waters as their receiving water for treated discharge, and it is expected that the aforementioned water quality changes such as algal blooms will be exacerbated in these circumstances. Accordingly, there is also a need to re-evaluate wastewater treatment plant design, particularly in light of changes to the Wastewater Systems Effluent Regulations (WSER) requirements (new limits of 25 mg/L TSS and 25 mg/L CBOD).
While there is broad recognition that new treatment strategies are required, this is balanced against the periodic nature of water quality dynamics along with the need to ensure carbon footprints are minimized and to foster a new wave of climate-based technologies. These new innovations must also meet increasingly stringent distributed drinking water quality and wastewater discharge requirements. The aim of this presentation is to provide an overview of the current state of knowledge and to describe a new strategic approach that acknowledges the disruption that is required to fully address climate change in the water sector.
Graham Gagnon, PhD, P.Eng., is the Associate Vice President Research at Dalhousie University, where he also serves as the NSERC – Halifax Water Industrial Research Chair in Water Quality & Treatment in the Centre for Water Resources Studies. Dr. Gagnon’s research program addresses emerging priorities for the water industry, which are addressed through fundamental research and translated into industry practice.