Analysis of efficiencies of runoff reduction and pollutant removal for subdividing design volume calculation in permeable pavement

In this study, the inflow/outflow event mean concentration (EMC) and pollutant removal efficiencies were analyzed. Based on the results of the analysis, a study was conducted on the necessity of estimating the appropriate design volume according to the characteristics of the permeable pavement. Therefore, this study analyses EMC and summation of loads (SOL) reduction efficiencies based on the monitoring results pertaining to 3 y. Analysis of pollutant removal efficiency and runoff reduction efficiency of filter-type permeable and crevice-type permeable pavements showed that biochemical oxygen demand, total organic carbon, and total suspended solid values increased from 2016 to 2018 for crevice-type permeable pavement. On the other hand, the filter-type permeable pavement was found to reduce the efficiency. In the case of crevice-type permeable pavement, the proper design was based on the storage, and the reduction efficiency increased due to this, while the filter-type permeable pavement is a facility that treats non-point pollutants by continual filtering. Therefore, it should be designed as water quality flow (WQ_F ), instead of erroneously designing it as water quality volume (WQ_V ). The obtained results are considered to be an important derivation factor when calculating the design capacity according to the type and characteristics of low impact development (LID) facilities.