Using in situ sensors to monitor ecosystem health in freshwater catchments.

Freshwater eutrophication costs water companies approximately £54-96m annually in England and Wales. £1.5k per day per water treatment works. An excess of nutrients fertilises algal blooms that have negative impacts on ecosystem health, water quality, and eventually taste and odour. Treating the water after blooms have occurred is expensive, typically occurs after the problem has occurred, and risks longer term damage to the ecosystem. If treatment can be responsive, rather than predictive, then treatment costs may be reduced and ecosystem health improved. Predictive treatment, however, requires real-time monitoring of nutrient status of water bodies. Nutrients are typically assessed by water sampling and return to the laboratory for analysis, which even in the best case scenario may take several days. Technologies are now available for in situ monitoring of some nutrient species, notably nitrate and DOM, but their suitability for UK freshwater systems rather the ocean waters for which they were designed is poorly known. This project will assess several in situ sensing methods, to aid our project partners in developing the best predictive tools to control risks of eutrophication , taste and odour problems associated with geosmin production, and reducing associated water treatment costs and improving supply catchment ecosystem health.