A Semi-distributed Model for Predicting Faecal Coliform in Urban Stormwater by Integrating SWMM and MOPUS.

Xiaoshu Hou,Zhenyao Shen,Lei Chen,Yali Zhang,Jiali Qiu

doi:10.3390/ijerph16050847

Abstract

The microbial contamination of urban stormwater has an important impact on human health and stormwater reuse. This study develops an exploratory semi-distributed model, MOPUS_S, which can simulate faecal coliform levels in separate sewer systems in urban catchments. The MOPUS_S was built by coupling the SWMM model and the microbial MOPUS model. The parameters associated with the deposition and wash-off of microorganisms were more influential than those related to microorganism survival processes. Compared to other existing bacterial models, MOPUS_S showed comparable performance in predicting faecal coliform concentrations. The performance varied largely between rainfall events, with Nash-Sutcliffe efficiency (NSE) values ranging from −5.03 to 0.39 and R2 ranging from −0.02 to 0.83, respectively. The model simulation results for low and medium concentrations were better than those for the peak concentrations. Poor simulation results of peak concentrations obviously affect the overall model performance. In general, MOPUS_S could be capable of predicting the faecal coliform load in urban catchments and be a useful tool for urban stormwater management planning.

Highlights

As a major source of urban non-point source (NPS) pollution, stormwater runoff contains high concentrations of biological pollutants that are directly related to disease outbreaks, aquatic biological toxicity and water quality degradation [1,2]
The results revealed that the hydrologic model performs very well (NSE range during calibration: 0.854–0.920; Nash-Sutcliffe efficiency (NSE) range during validation: 0.737–0.912)
faecal coliform (FC) concentration ranged from 6.24 × 103 to 1.99 × 106 most probable number (MPN)/100 mL.The mean concentrations of FC across rainfall events ranged between 1.58 × 105 and 6.31 × 105 MPN/100 mL (Table 2)

Summary

Introduction

As a major source of urban non-point source (NPS) pollution, stormwater runoff contains high concentrations of biological pollutants that are directly related to disease outbreaks, aquatic biological toxicity and water quality degradation [1,2]. Of particular concern is contamination by microorganisms, especially pathogens, which are considered as a leading cause of impairment of rivers, streams, and estuaries around the world [3,4]. Investigating microorganisms in urban stormwater is very necessary for water quality management and stormwater reuse. The study of microorganisms in urban stormwater faces several challenges. It is really hard to accurately obtain the monitoring data of microorganisms due to high uncertainty related to stormwater sampling and analysis. Researchers suggest computer-based simulation as a practical method to study microorganisms in stormwater [11]

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Conclusion