The Use of Wastewater Models in Managing Risk

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In the field of wastewater treatment, in spite of many advances over the past 30 years, we are still using design approaches that imply that we work in a well-defined, stationary environment. We typically account for the unpredictability by incorporating generous safety factors in our designs, which often result in overdesigned or inefficient plants. In the current regulatory environment of extremely low effluent nutrient standards, cost pressures, climate change, and energy optimization, a new design approach is required that provides us with an understanding of what are the main sources of uncertainty and quantifies the risk of non-compliance.

The DOUT Group has been working on uncertainty analysis in the field of wastewater treatment for the past 10 years. Even though the bulk of the work for the upcoming STR was completed in the first five years following the group’s formation, work on the DOUT uncertainty analysis framework has continued with case studies and post graduate academic work.

This webinar will present and illustrate the findings of the IWA/WEF Design and Operations Uncertainty Task Group (DOUT Group).  The group will present the key elements of the STR, including such considerations as contract delivery mechanisms and stakeholder perspectives. This webinar will focus on method that we can apply now to include uncertainty analysis in our projects. Specifically, how to identify project specific sources of uncertainty and prioritize them, use of dynamic models to explicitly account for variability, how to incorporate statistical descriptions of major model inputs, how to translate safety factors to Probability Density Functions and how to express model results in terms of statistical watershed criteria.


  • Lorenzo BenedettiWaterways d.o.o
  • Evangelina BeliaPrimodal Inc.
  • Bruce JohnsonJacobs
  • Peter VanrolleghemUniversité Laval
  • John Copp (moderator), Primodal Inc.

There will be 2.0 Professional Development Hours (PDHs) offered for this webcast. Please check with your state accreditation agency to determine if you qualify.