Pollutant load overspill minimization of interceptor sewer systems

This paper describes the development of an optimal pollution control model for interceptor sewer systems from conceptualization to detailed validation. The formulation of two optimization alternatives using a slug flow approach is presented. The models are tested on an idealized interceptor sewer system with a representative storm event to confirm the viability of the optimization techniques. A hydraulic verification routine is included and the WALLRUS hydrodynamic sewer flow simulation software is used to validate the results from the hydraulic verification routine. Application of the model to an existing interceptor sewer is presented. The results from the idealized test case show the viability of using Linear Programming and Dynamic Programming within the optimal pollution control models. The models give physically feasible solutions that can be validated using WALLRUS. Significant environmental improvements (in terms of pollutant load reduction to the receiving waters) can be achieved. The results illustrate the validity of the assumptions in the optimal control model formulation, and show that the slug flow approach provides a computationally efficient and sound formulation for the optimal control model and offers promise for practical implementation of optimal real time control.