Combined sewer overflows (CSOs) discharge organic micropollutants (MPs) into open water bodies, posing potential environmental threats. Knowledge of the numbers, sources, and dynamics of MPs during CSOs is scarce but crucial for assessing their impact and developing mitigation strategies. To shed light on the dynamics of dissolved organic MPs in CSOs, we conducted high-temporal-resolution sampling (10 min composite samples) followed by liquid chromatography high-resolution mass spectrometry analysis, both target (60 substances) and nontarget, at two CSO sites in a small [17 hectares reduced (ha