Fuss & O’Neill was hired by the Ontario Ministry of the Environment to assess the feasibility of using predictive modeling tools to aid decisions regarding public beach closures. The concentration of fecal indicator organisms (FIOs) has been the basis for recreational water quality standards, but delays in lab processing coupled with temporal and spatial variability associated with FIOs, prompted our client to look for an alternative.

Our team developed models for a variety of beaches on Lake Ontario, which included statistical analysis of environmental variables to determine candidate input or explanatory variables. We evaluated use of logistic regression and multiple linear regression, and assessed the feasibility of using the USEPA software Virtual Beach for implementation. Our team then authored a guidance document and created a user-friendly model interface.

Our model development for six Toronto beaches demonstrated that predictive models can be valuable tools to aid in beach closure decisions.