There is a compelling need for new technologies and approaches to help improve UK river water quality. Recent (2020) assessments revealed that only 36% of surface waters (rivers, lakes and coastal waters) in the UK are classified with 'high' or 'good' status. In England, only 14% of rivers exhibit 'good ecological status', whilst no rivers have attained 'good chemical status'. The poor state of UK rivers has implications for ecological and human health. Storm overflows discharge pollution, including sewage that contains bacterial pathogens, directly into rivers. For example, there were more than 400,000 of these discharges in England, amounting to 3.5 million hours. Freshwater recreation has never been more popular, and users are at increasing risk of exposure to bacterial pathogens, chemicals and toxic algal blooms. The challenge the project addresses The societal, legislative and economic challenges and implications of widespread poor river water quality are significant. In response, the UK's 25 Year Environment Plan, Environment Act 2021 and Storm Overflows Discharge Reduction Plan provide new political and legal frameworks (post-Brexit) designed to improve river and bathing water quality. For water assets, the aspiration is that by 2050 all inland storm overflows will only be permitted to discharge where no local adverse ecological impact can be demonstrated. Water companies are also required to significantly reduce harmful pathogens from storm overflows discharging near designated bathing waters by 2035. Section 82 of the Environment Act 2021 now requires the monitoring of water quality parameters up and down stream of all inland storm overflows and other assets. The estimated cost of delivering storm overflow targets is £60bn. Stark evidence shows that in situ water quality measurements are not taken at relevant temporal and spatial scales and that current sensing approaches are limited to the detection and monitoring of physical/chemical parameters only. This lack of data relating to organic pollution (sewage) and microbial (bacterial and algae) contamination are significant technical & scientific barriers to implementing evidence-driven infrastructure interventions. Evidence is urgently needed reassure stakeholders (e.g. public) that interventions are responding to, and managing the rapid changes to our freshwater ecosystems ultimately, improving ecological health.