The water sector in the UK has, by many measures, been very successful. In England and Wales, drinking water standards stands at over 99.9%, water pipe leakage is down by a third, sewer flooding reduced by more three quarters in the last 10 years and bathing water standards are at record high levels. This success has been achieved using a 19th century design approach based on the idea of plentiful resources, unrestrained demand and a stable climate. However, a perfect storm of climate change, increasing population, urbanisation, demographic shifts and tighter regulation is brewing! Each one of these challenges is a threat to the water sector and, taken in isolation, existing approaches may be able to cope. Taken together and compounded by the speed, size and uncertainty of change, the system is heading for failure unless something radical is done. The current way of working looks increasingly out of date and out of step with emerging thinking and best practice in some leading nations. This fellowship aims to meet these emerging challenges and global uncertainties head on by developing a new approach to water management in UK cities. The starting point is a new vision that is: Safe & SuRe. In a sense, our existing water systems are all about safety goals: public health, flood management and environmental protection. These are important and still need to be respected, but they are NOT sufficient to rise to the coming challenges. In the new world of rapid and uncertain change, water systems in cities must also be Sustainable and Resilient. Only a 'Safe & SuRe' system can be moulded, adapted and changed to face the emerging threats and resulting impacts. In this fellowship. my vision will be developed, tested and championed into practice over a period of 5 years. It will draw from multi-disciplinary collaboration with leading academics inside and outside the field. A comprehensive, quantitative evaluation framework will be developed to test in detail what options or strategies can contribute towards a Safe & SuRe water future, focussing on the challenges of water scarcity, urban flooding and river pollution. Recommendations and best practice guidance will be developed in conjunction with key stakeholders.

The majority of countries around the world maintain a disinfectant residual to control planktonic microbial contamination and/or regrowth within Drinking Water Distribution Systems (DWDS). Conversely, some European countries prohibit this practice because the residuals react to create disinfection by-products, which are regulated toxins with carcinogenic effects. Critically, the impact of disinfectant residuals on biofilms is unknown, including their role in creating a preferential environment for pathogens. Biofilms grow on all surfaces; they are a matrix of microbial cells embedded in extracellular polymeric substances. With biofilms massively dominating the organic content of DWDS, there is a need for a definitive investigation of the processes and impacts underlying DWDS disinfection and biofilm interactions such that all the risks and benefits of disinfection residual strategies can be understood and balanced. This balance is essential for the continued supply of safe drinking water, but with minimal use of energy and chemicals. The central provocative proposition is that disinfectant residuals promote a resistant biofilm that serves as a beneficial habitat for pathogens, allowing pathogens to proliferate and be sporadically mobilised into the water column where they then pose a risk to public health. This project will, for the first time, study and model the impact of disinfectant residual strategies on biofilms including pathogen sheltering, proliferation, and mobilisation to fill this important gap in DWDS knowledge. The potential sources of pathogens in our DWDS are increasing due to the ageing nature of this infrastructure, for example, via ingress at leaks during depressurisation events. Volumes of ingress and hence direct exposure risks are small but could seed pathogens into biofilm, with potential for proliferation and subsequent release. An integrated, iterative continuum of physical experiments and modelling is essential to deliver the ambition of the proposed research. We will make use of the latest developments in microbiology, internationally unique pilot scale experimental facilities, population biology and microbial risk assessment modelling to understand the interactions between the disinfection residuals, biofilms, pathogens and hydraulics of drinking water distribution systems. This research will combine globally renowned expertise in mathematical modelling, drinking water engineering, quantitative microbial risk assessment, and molecular microbial ecology to deliver this ambitious and transformative project. If the central proposition is proven, then current practice in the UK and the majority of the developed world could be increasing health risks through the use of disinfectant residuals. The evidence generated from this research will be central to comprehensive risk assessment. A likely outcome is that by testing the hypothesis, we will prove under what conditions the selective pressures on biofilms are unacceptable, and in so doing understand and enable optimisation of disinfection residuals types and concentrations for different treated water characteristics. Although focused on the impacts of disinfectant residuals and pathogens, the research will also generate wider knowledge of biofilm behaviour, interactions and impacts between biofilms and water quality within drinking water distribution systems in general and relevant to other domains. The impact of this research will be to deliver a step change in protecting public health whilst minimising chemical and energy use through well informed trade-offs between acute drinking water pathogen (currently unknown) and chronic disinfectant by-product (known and increasing) exposure. The ultimate beneficiaries will be the public, society and economy due to the intrinsic link between water quality and public health.

Understanding the impacts of environmental change and changing land use on biodiversity and how ecosystems work require comprehensive knowledge of communities and their ecology. Molecular biodiversity identification is emerging as a high throughput and cost effective alternative to traditional approaches and in particular, the analysis of environmental DNA (eDNA) provides an opportunity to measure biodiversity in space and time at unprecedented scales. Unlike DNA obtained through direct analysis of communities, eDNA refers to shed cells or free-DNA from organisms as they pass through an environment, or die and decay. eDNA is being applied for various uses such as identification and monitoring of endangered/invasive species and analysis of biodiversity. It is very clear that researchers can detect eDNA from a variety of natural environments and in particular, freshwater environments. However, understanding how those sources of eDNA relate to living biodiversity and associated ecological function in ecologically and socio-economically important river ecosystems is at the heart of the eDNA:LOFRESH proposal. Focusing on a range of exemplar experimental semi-natural and natural freshwater catchment systems from local to national scales, we will (a.) improve understanding of the movement, and persistence of lotic eDNA, (b.) quantify the relationship between lotic eDNA and the in situ community using different combinations of genetic and genomic approaches, (c.) improve methodological approaches for eDNA data acquisition and interpreting eDNA data using novel ecological and phylogenetic algorithms, (e.) develop and test new models relating lotic eDNA to stream biodiversity and ecosystem function and their variation in response to land use pressures. Over a 4 year period, five work packages (WPs) will be delivered by the Universities of Bangor, Birmingham, Cardiff and the Centre for Ecology and Hydrology. In WP1, we will use artificial stream channels in a series of experiments to assess the effects of a range of physical and chemical drivers on the loss of lotic eDNA and to compare and contrast genetic and genomic approaches for assessing known sources of lotic eDNA. In WP2, we will test our experimental findings from WP1 by tracking natural lentic (i.e. lake) and experimentally introduced control lotic eDNA through the natural stream network of the intensely studied Conwy River research catchment in north Wales. WP2 will also assess relationships between observed lotic eDNA and the in situ community in selected tributaries of the Conwy displaying a range of physicochemical characteristics and experiencing different land use pressures. WP3 will sample lotic eDNA in coordination with an on-going national survey in Wales to up-scale the experimental and catchment-scale findings of WP1 and WP2 to the Welsh landscape and national scales. WP4 will provide informatics support, but specifically, develop workflows to identify species level diversity in eDNA datasets. Finally, in WP5 we will further test our model findings, by manipulating the experimental stream systems with emulated land use pressures, quantify the ecosystem functions of decomposition and food web structure and test linkages with eDNA signals. Effective engagement with a broad range of stakeholder groups (government, end-users, environmental agencies) and project partners (research institutions and academic partners specialising in eDNA, sequencing and informatics) will optimise impact and research synergies of potentially transformative science throughout the consortium network.

Freshwater ecosystems provide critical ecosystem services that underpin human societies and wellbeing: including water purification, carbon capture, and the maintenance of sustainable fisheries. However, these ecosystems are under an increasing array of threats, both in the UK and worldwide, especially from a wide range of new and emerging chemical stressors (e.g. novel antibiotics and pesticides). Freshwater biosciences and applied ecology are under-equipped for dealing with these new threats: the evidence base is lacking, there is often little or no mechanistic understanding, or predictive capacity for anticipating how these novel chemicals will operate in the real world. This is particularly true for the ecosystems of the future that are being reshaped and constructed by climate and other environmental changes. Our project will address all these shortcomings by taken a radically different approach from the classical biomonitoring and ecotoxicology tools that have dominated for many decades. We aim to unearth the general rules by which emerging chemical stressors operate through, and alter, networks of interacting species - from microbes at the base of the food web, through to apex predators in the fish community at the top. This will involve the development of indicators of both proximate pollution, as the chemical first enters the biological system (commonly as a new food source for microbes), and also of its indirect effects as its impact propagates through the food web. For instance, we will be able to answer questions such as: if a new insecticide wipes out the invertebrates in the middle of the food web, does this trigger blooms of nuisance algae as they are no longer kept in check? To achieve this, we will develop a new suite of methods at the ecosystem level that combine lab and field experiments to detect the causal mechanisms that we currently do not understand. The experiments will be combined with mathematical modelling to predict ecosystem-level impacts. We will address both, contemporary ecosystems that could be under imminent threat from new chemical stressors, and ecosystems of the future that will emerge under different scenarios of land-use and climate change. This will provide a completely new paradigm in chemical stressor monitoring, based on using first principles to derive a novel means of predicting "ecological surprises" that commonly arise due to the inadequacies of our current simplistic approaches when dealing with the true biocomplexity of natural systems. Our scope is for our approach to serve as a diagnostic tool for management, with research findings, for example, supporting the selection of mitigation options that deliver reduction of ecological effects. This paradigm shift will allow far more robust predictions and therefore more informed management decisions about the freshwaters of the future. The work will bring together the field of pure and applied ecological science, to the mutual benefit of both sets of disciplines. Our proposal represents the first steps along this path to the more multidisciplinary perspective that is going to be critical for dealing with future threats to our ecosystems - from emerging chemical stressors in freshwaters to the growing list of other environmental threats looming on the horizon. Because the approach is general, it will not only pave the way for the next generation of ecological assessment in freshwaters, but it can also be adapted for applications in marine and terrestrial ecosystems.