Tracking pollutants as continua throughout the Thames drainage basin

The state of UK river waters and their chemical contamination is of growing concern. Pesticides, pharmaceuticals, illegal drugs, plastic-related chemicals, and personal care products are now found throughout UK rivers. At toxic concentrations they have serious adverse impacts on the health of animals and plants that rely on rivers and on humans that use them. A crucial step towards improving the quality of our waterways is to identify the locations of toxic concentrations of chemicals and where they came from. A big challenge is developing the means (data and theory) to quantify chemical concentrations throughout entire drainage basins, which can have point and widespread sources of pollutants. Additionally, identifying sources of pollutants is complicated by the mixing and dispersal of chemicals as they move downstream.

To address these challenges, we will combine new, large, inventories of spot measurements of contaminants of emerging concern with newly developed computational models that will allow us to generate continuous predictions of chemical concentrations. This combination of state-of-the-art environmental monitoring data and computational techniques will allow us, for the first time, to generate continuous predictions of element concentrations throughout entire basins. Such continuous predictions will provide the knowledge necessary to identify all river reaches (not just those upstream of sample sites) with toxic chemical concentrations. They will be used to identify sources of pollutants, especially diffuse sources (e.g. agricultural runoff), which are currently very difficult to identify with existing monitoring techniques. In this project we will focus on the River Thames and its tributaries where the concentrations of >100 contaminants of emerging concern (CEC) have recently been measured by academics and the Environment Agency. The Thames drains the UK's most populous drainage basin and is a conduit for a large range of natural and man-made chemical that are inserted into its drainage network. The new maps of chemical concentrations will identify localities along rivers where urgent remediation is required, and, importantly, identify point (e.g. from waste water treatment plants) and wide-spread (e.g. pesticides from agriculture) sources of pollutants. In this proof-of-concept study, we will show how modern environmental monitoring techniques can be combined with cutting-edge computational techniques to generate transferable tools to quantify concentrations of diverse chemicals throughout drainage basin. The framework developed in this study will be used in future application of advanced techniques for continuous monitoring of drainage basins in the UK and beyond.