철도 교량 강우유출수를 대상으로 한 비점오염원 저감시설의 성능평가

Concrete-paved railway bridges exhibit high imperviousness, causing the rapid discharge of accumulated non-point source pollutants during rainfall events. Without proper treatment, these pollutants are often directly discharged into nearby water bodies, raising concerns about water quality degradation. Despite this, few studies have assessed the pollutant removal performance of treatment facilities installed at railway infrastructure. This study aims to quantitatively evaluate the removal efficiency of non-point source pollutants using BMP(Best management Practice) facility installed at a subway bridge in the metropolitan area. Three rainfall events were monitored to calculate the event mean concentration (EMC) of influent and effluent, focusing on BOD, COD, TOC, TSS, TN, and TP. The results showed removal efficiencies up to 100% for COD and TP, and up to 64.8% and 71.0% for BOD and TOC, respectively. However, TSS exhibited a wide range of removal efficiencies, from 10.4% to 57.8%, indicating the facility has sensitivity to rainfall characteristics. This study provides empirical evidence supporting the need for runoff treatment systems at railway bridges and offers foundational data for future policy development and long-term performance monitoring.