Water quality modelling, risk analysis and decision-making: an integrated study

Falling detection limits, the proliferation of chemical contaminants and the rising population densities of the world’s watersheds are erasing the traditional conception of wastewater and drinking water as demarcated academic disciplines. This increased interconnectedness reflects increased awareness of the extent to which human activities impact water resources and to what extent these impacts are felt downstream. This text integrates the candidate’s contributions to the fields of industrial-scale wastewater treatment, municipal-scale wastewater management planning, and drinking water management and regulation made during his postgraduate studies. The collected works constitute a novel civil engineering dissertation that challenges the historic compartmentalization of subfields in water resources management. 1) A new type of wastewater treatment system is modelled with traditional computational fluid dynamics (“CFD”) methods in order to optimize operating conditions and design features and to model its principal hydrodynamic characteristics. 2) Risk analysis techniques are used to build a decision model for municipal-scale management of wastewater discharged to highly transient water bodies. A risk analysis framework uses environmental and economic impact valuations to translate CFD model output into concrete decisions about infrastructure investment. 3) The claim that improved analytical ability leads to stricter regulations than justified by available toxicological data is evaluated with respect to drinking water. The relationships between historical and present maximum contaminant levels and goals are evaluated, and the overall drinking water regulatory apparatus is outlined. Analytical ability is demonstrated to have a weak effect on resulting regulation, and the tightening of regulations is shown to be unlikely in the absence of updates to the underlying toxicological model. 4) Drinking water regulatory structures are compared with respect to their ability to protect public health in light of several widely reported outbreaks in Canada since 2000. Claims of inadequate government intervention and proposed alternative regulatory arrangements are contextualized using principles of risk perception and evaluated using principles of risk analysis. 5) Drinking water regulation in the United States is deconstructed to understand to what extent the landscape of rules and standards reflects the balancing of risks with the costs and benefits of treatment. The research points to risk biases that make low-risk, high-occurrence contaminants more likely to be regulated than high-risk, low-occurrence contaminants. Decentralization along the lines of the Canadian model is shown to have the potential to improve water quality outcomes in a way that is consistent with risk valuations already established

Aligning evidence generation and use across health, development, and environment

© 2019 The Authors Although health, development, and environment challenges are interconnected, evidence remains fractured across sectors due to methodological and conceptual differences in research and practice. Aligned methods are needed to support Sustainable Development Goal advances and similar agendas. The Bridge Collaborative, an emergent research-practice collaboration, presents principles and recommendations that help harmonize methods for evidence generation and use. Recommendations were generated in the context of designing and evaluating evidence of impact for interventions related to five global challenges (stabilizing the global climate, making food production sustainable, decreasing air pollution and respiratory disease, improving sanitation and water security, and solving hunger and malnutrition) and serve as a starting point for further iteration and testing in a broader set of contexts and disciplines. We adopted six principles and emphasize three methodological recommendations: (1) creation of compatible results chains, (2) consideration of all relevant types of evidence, and (3) evaluation of strength of evidence using a unified rubric. We provide detailed suggestions for how these recommendations can be applied in practice, streamlining efforts to apply multi-objective approaches and/or synthesize evidence in multidisciplinary or transdisciplinary teams. These recommendations advance the necessary process of reconciling existing evidence standards in health, development, and environment, and initiate a common basis for integrated evidence generation and use in research, practice, and policy design