To make the Seine River swimmable for the Paris 2024 Olympics, the City of Paris embarked on a €1.4B Swimming Plan and partnered with Fluidion for water quality management. Using ALERT Systems, Fluidion is successfully establishing a comprehensive dataset on the river's bacterial levels, and monitors water quality impacts of storm events, evaluates treatment initiatives, and provides scientific reports on factors affecting water quality. Their involvement supports Paris's goal of opening the Seine for public swimming by 2025.