Process stress in municipal wastewater treatment processes: a new model for monitoring resilience

Although not-well-understood, process stress could provide a novel approach to resilience analyses in wastewater treatment processes by identifying the influence of a stressor on wastewater processes. This paper identifies how industry and academia view the concept of process stress in wastewater treatment processes. It also investigates how individuals, their role and education influence their decision bias and their propensity to use decision support tools. Survey results from 255 respondents showed that many wastewater professionals still have a preference to use personal or company-specific spreadsheets (33%), with a similar proportion of respondents using simulation and decision support tools (29%). The concept of process stress in wastewater treatment was well understood by industry and academic professionals as a variance from benchmarked conditions. This analogy of process stress means that it can be either, a positive or negative magnitude of variation from a benchmarked state, which expands on the approach taken in current resilience and benchmark simulation models. Therefore, the concept of process stress was a well understood by a vast majority of respondents, with 82% of respondents agreeing that an analytical tool that considers process stress would be a useful contribution to developing the understanding and management of process resilience. The study also highlights the requirement for a process stress analysis methodology, which builds on current resilience methods and separates the stressor (cause) from process stress (effect). Overall, this research has identified the requirement to measure and analyse stresses in wastewater treatment processes and recommends a strategy to develop this methodology.