Simulating water pollution accidents in Asan Lake: Toward proactive water pollution management

Abstract

As populations increase and new and diverse industries are developed, surface water pollution accidents have been increasing; moreover, the management and control of these accidents have become more difficult. To implement appropriate control measures, water pollution accidents must be responded to promptly and accurately. Therefore, prediction systems should be developed using a modeling approach based on-site monitoring data. This study established a water pollution accident prediction system based on the Environmental Fluid Dynamics Code Plus (EFDC+) for the Asan Lake watershed in Korea. The system was applied to reconstruct a real ethylenediamine (ED)–methyl ethyl ketone (MEK) spill event in 2024 with high hydrodynamic and water quality model reliability. Scenario analyses were conducted by varying discharge, season (winter vs. summer cultivation), and pollutant type (ED, MEK, or phenol). The results indicate that higher discharge led to earlier pollutant arrival, higher peak concentrations, and longer persistence. Summer stratification induced vertical concentration differences and prolonged stagnation in mid-downstream sections (M-4 and M-5). Phenol exceeded drinking-water criteria for >30 days in lake-like zones. Risk quotient evaluation indicated basin-wide risks for ED and phenol under certain conditions, and acute risks for MEK mainly near the upstream accident section. These findings provide a scientific basis for improving water pollution accident management and establishing proactive and post-accident response strategies. © 2026 The Authors