Ranking stormwater control strategies under uncertainty: the River Cam case study

Monte Carlo simulations taking uncertainty in model parameters into account were performed on a river water quality model. The simulation results were used to rank wastewater treatment plant control strategies according to th eir impacts on river water quality. This impact is estimated by the maximum ammonium concentration and by the duration of dissolved oxygen concentrati on below 4 g/m(3) at the downstream boundary of the system. The strategies were classified according to the previous criteria using 4 ranking methods, one of them being based on the concept of stochastic dominance. Results ar e presented for a case study based on a 10 km stretch of the River Cam as i t passes through the city of Cambridge in Eastern England. It was found tha t ranking was robust in face of uncertainty in the parameter values for the control strategies considered as being superior in terms of river water qu ality impacts.