초기강우 이후 발생 강우유출수의 대규모 저류를 위한 유입수 설계 수질농도 산정

초록

This research analyzed the water quality characteristics of urban stormwater runoff and quantified the differences in pollutant concentrations between the first flush and the post–first flush period, with the aim of presenting appropriate influent water quality ranges for designing large-scale underground storage facility. The analysis revealed that 50–80% of the total pollutant load occurred during the first flush, with high increases in TSS, COD, TN, TP, and heavy metals such as Zn, Cu, and Pb. In contrast, pollutant concentrations in the post–first flush period stabilized but still remained relatively high concentrations. The average design influent concentrations for large underground storage facilities were estimated as TSS 30–150mg/L, COD 25–80mg/L, TN 2–6mg/L, TP 0.20–0.80mg/L, and Zn 0.10–0.30mg/L. In addition, a review of Korean legislation and U.S., Japanese, and German case studies confirmed that large-scale underground storage facilities should serve not only for flood control but also as water quality management infrastructure. The findings of this study provide basic data for the design and operation of underground storage facilities aimed at simultaneously reducing urban flooding and improving water quality.

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