Developing a Framework for Wastewater Reuse in Canada: Using Quantitative Microbial Risk Assessment, Risk Communication, and Community Engagement for Evaluating Water-Fit-For-Purpose Reuse

Project funded by the Canadian Institutes of Health Research to the University of Alberta, CA (Prof Nicholas Ashbolt) 2017-2021 with 2.1 Million CAD. CARe (the Larsson group) is participating in the project with regards to antibiotic resistance research.

Drinking water treatment and sanitary waste management are considered the most important environmental public health achievements for infectious disease prevention. However, population growth, loss of environmental services and climate change are forcing communities to explore opportunities that treat municipal wastewater to allow its safe return for community uses or harvest rain/stormwater for various non-drinking water uses (all referred to here as wastewater reuse). There are also multiple synergies when wastewater reuse is considered within a broader, one-water approach that provides economic opportunities for society to reduce water service costs, provide resiliency to floods/droughts and promotes public health improvements while meeting future water demands. While wastewater reuse has been accepted in various arid, warm regions (including Arizona, California, Israel & Australia), Canada's cold climate poses uncharacterized challenges to wastewater treatment (e.g. sudden cold-water snowmelt events reducing treatment efficacy) and therefore uncertainty in the potential risks to human health posed by the recovered water. There is also a lack of international agreement on reuse guidelines/regulations that are protective of human health. Lastly, informed citizens are increasingly aware of new disease-causing agents produced by modern societies (e.g., antibiotic-resistant bacteria and respiratory pathogens that grow in distributed waters such as Legionella) and seek to engage in decision-making for new water services. Hence, water reuse strategies require an understanding of the public's perceptions and receptivity to wastewater reuse as well as technical understanding of how to control key hazards - major elements of the proposed participatory water reuse framework to engender trust in government and utilities to provide safe reuse water that communities seek to have in an equitable way to address Canada's $90 billion water service infrastructure deficit