| There is growing interest in decentralized and cluster-scale wastewater treatment, but knowledge of the effects of decentralization on treatment performance and by extension surface water quality is limited. This research demonstrates a method for using Generalized Linear Models to quantify the effects of facility size and capacity utilization on effluent BOD, TSS, and ammonia discharges from individual facilities as well as the aggregate of networks of facilities. Small and overloaded facilities have more frequent and longer permit violations. However, by dispersing the risk of violations across many facilities, decentralized networks have less variability than centralized networks of equivalent capacity and thus have fewer extreme events. By providing a method for prediction of typical treatment performance as well as the frequency and magnitude of variations, this research provides a valuable tool for wastewater managers considering decentralized treatment. |
