With increasing concern regarding process emissions due to their high impact and reduction potential to reach NetZero, our presentation will provide feedback from activities related to GHG process and fugitive emissions (CH4 and N2O) delivered at scale on the wastewater treatment site of Lleida, Spain operated by Aqualia. We will provide global project outline and first results of 2 inter-related projects. Project 1: funded by local water authority Agència Catalana de l’Aigua (ACA): underway (will be completed 02/2027) • process emission campaigns using gas hoods on the biological treatment lanes (anaerobic and anoxic zones) • preliminary design of smart control system to minimise CH4 emissions based on deterministic models Project 2: LIFE ODYSSEY (starting 2026) This project will deliver smart monitoring and mitigation strategies for GHG and odour emissions in WWTPs. The project pursues a systemic approach that combines advanced digitalisation, bio-based technologies, and improved carbon accounting methodologies to enable climate-neutral and socially accepted wastewater utilities. The specific objectives are: 1. Monitor and predict emissions using AI-driven models 2. Optimise mitigation strategies: pilot and validate low-energy, bio-based solutions (biotrickling filters and biological oxidation) to reduce GHG and odours. 3. Develop digital tools for operators: create a digital toolbox integrating predictive models into WWTP monitoring systems, including an AI-driven conversational assistant (chatbot). 4. Refine carbon footprint methodologies