Emerging contaminants (ECs) in drinking water raise growing concerns, yet their profiles and removal efficiencies in drinking water treatment plants (DWTPs) remain poorly understood. This study employed a combination of nontarget feature-based analysis and nontarget screening (NTS) to profile ECs in influent and effluent samples from eight DWTPs. A total of 12,049 and 15,885 molecular features were detected in summer and winter samples, respectively, reflecting the considerable chemical complexity present in these facilities. Molecular formula assignment and chemical classification revealed a notable increase in halogenated compounds and the dominance of organic acids/derivatives, benzenoids, organoheterocyclic compounds, organic nitrogen compounds, and lipids/lipid-like molecules at the superclass level. A tiered analytical strategy, integrating wide-scope, class-specific, and a SIRIUS-assisted NTS workflow, successfully identified 282 ECs in DWTP influents and effluents, with 99 % exhibiting median concentrations below 10 ng/L and including dozens of novel chlorinated disinfection by-products. Removal efficiencies for food additives, pesticides, and industrial chemicals were significantly higher in summer (35.9‒65.5 %) than in winter (-145‒37.8 %). Transformation products, particularly chlorinated organophosphorus compounds and 3,5-dibromo-4-hydroxybenzoic acid, displayed negative removal efficiencies. Tox21 screening identified 39 estrogenic disruptors, among which estrogen receptor agonists were removed at a median efficiency of 57.5 %. The transformation product 3,5-dibromo-4-hydroxybenzoic acid was flagged as the highest-priority compound. These findings highlight the persistent challenges in effectively eliminating ECs during drinking water treatment and emphasize the need for improved monitoring and mitigation strategies.