The ENANTIA project addresses a critical knowledge gap in Environmental Risk Assessment (ERA): the enantioselectivity of the abiotic environmental fate of pollutants. While over 50% of Contaminants of Emerging Concern (CECs) are chiral, they are typically monitored as achiral mixtures, ignoring that enantiomers often exhibit distinct toxicity and persistence. While microbial activity is a known driver of enantiomeric enrichment, the role of abiotic pathways, such as pH-dependent hydrolysis, remains poorly characterized. This project aims to decouple chemical from biological fate mechanisms using fipronil as a model compound. The research plan is structured into two main pillars: 1) The development of high-sensitivity enantioselective analytical methods utilizing Solid Phase Extraction (SPE) coupled with HPLC-UV and GC-MS; 2) The characterization of hydrolytic degradation kinetics (OECD 111) and abiotic dissipation in synthetic buffers and natural surface waters across varying pH levels. By establishing a robust "chemical baseline," ENANTIA will provide essential mechanistic data to refine ERA frameworks and support evidence-based EU environmental policies.