9th  IWA  Symposium  on  Systems  Analysis  and  Integrated  Assessment  14-­‐17  June  2015,  Gold  Coast,  Australia    

Development Of Prediction System Of Urban Runoff To Assist Treatment System Design And Operation Koo, Y.*, Seo, D.* * 99 Daehak-Ro,Yuseong, Daejeon, 305-764, Republic of Korea, Chungnam National University Keywords: Stormwater Treatment, Non-point Source, Suspended-Solids Removal, SWMM

Summary

This study aims to develop a modeling system to accurately predict flow rate and pollutant concentration in urban stormwater runoff. The SWMM(Storm Water Management Model) was used and the model was calibrated and verified using field data collected by automatic monitoring devices in the detention pond. The first flush treatment system developed by authors in separate study is consist of settling tank and filtration system using replaceable cartridge. Results of this system can be used in designing and operating first flush treatment system that can be installed in the field. Introduction

The development of drainage systems for stormwater and sewage also causes an increase in rapid surface runoff and reduces the amount of natural storage. Reduced infiltration may lead to reductions in groundwater recharge and the stream base flow. This urbanization can increase delivery of pollutant during storm events from basin area to water body by making flushing off of accumulated pollutant on surfaces easier. Urban nonpoint source pollution is rapidly becoming a significant contributor to water quality degradation as point source control has become better.

Figure 1. The Study Site; Gwanpyung-Cheon and its basin area, Daejeon, Korea and Conceptual Designand Proposed Location of First Flush Treatment System Various methods of treating stormwater in the basin area before the stormwater reaches the receiving body of water have been developed. However, these treatment methods tend to be costly to install and also to maintain. Authors developed an economical filter system using fabric filter medium (Koo. et. al, 2015). However, design and operation of the system requires information of inflow for both quality and quantity of water. SWMM can be effectively used for this purpose. The Gwanpyung-stream, a small urban stream in Daejeon, Korea was chosen as a study site shown in Figure 1. Results

SWMM(Storm Water Management Model) is constructed for a basin area for a detention pond as shown in Figure 1. In this study, the April 27, 2012 storm was selected for calibration to runoff and TSS of the watershed. Also June 8, 2012 storm was selected for verification. Model calibration and

9th  IWA  Symposium  on  Systems  Analysis  and  Integrated  Assessment  14-­‐17  June  2015,  Gold  Coast,  Australia    

verification were carried out using data obtained by automatic monitoring devices(Seo and Fang, 2012) as shown in Figure 2.

(a) Runoff and Water Quality(TSS) calibration results(2012.04.27)

(b) Runoff and Water Quality(TSS) verification results(2012.06.08)

Figure 2. SWMM calibration and verification results Discussion

After successful calibration and verification of the SWMM, it is possible to simulate the flows and TSS during any rainy weather for the basin area. The results can be successfully applied to design the first flush treatment system for determining appropriate size of settling facility and emptying time. Dependent upon the water level of the stream, it will be also possible to discharge treated water from the system. In the future, we plan to integrate this basin modeling, automatic monitoring and field management system together. It is expected this study will be helpful to develop efficient and effective water quality and quantity management of surface waters.

Acknowledgement

This research was supported by a grant (12-TI-C02) from Advanced Water Management Research Program funded by Ministry of Land, Infrastructure and Transport of Korean government. References Seo, D., Fang, T. (2012) Application of Automatic Stormwater Monitoring System and SWMM Model for Estimation of Urban Pollutant Loading During Storm Events. J. Korean Soc. Environ. Eng., 34(6), 373-381

Koo, Y., Kim, J., Kim, B. and Seo, D. (2015) Removel of Suspended Soilds from Stormwater Runoff Using a Fabric Filter System. J. Korean Soc. Environ. Eng., 37(3), 165~174