StormFlux: Effect of Storm Babet on Pollution Fluxes from Remobilised Mine Wastes

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Historical wastes disposed in coastal zones are increasingly vulnerable to remobilisation via erosion and seawater inundation including ~2000 Ha of unprotected mining wastes dumped along the Northumbrian River Basin District Coast. Storm Babet, 18-21 Oct 2023, was highly unusual in that prolonged easterly winds caused extraordinarily high waves averaging >4m for six consecutive high tides. This led to mine wastes on the NE coastline being affected by extensive seawater flooding and erosion. This project aims to use Seaham Beach, a coastal waste site on the Co. Durham coast, as a case study location to explore the impact of damaging storms on coastal waste sites in terms of geomorphological behaviour, and potential pollution fluxes into adjacent ecosystems from the remobilised material. There is now an urgent need to sample and analyse this freshly exposed waste, alongside further measurements of geomorphic change, to determine (1) the pollution potential and geochemistry of the newly exposed waste, (2) the absolute flux of contaminant metals to the North Sea that occurred during Storm Babet, and (3) the short- to medium- term impacts of the storm event on adjacent beach environments. Given the rapidly changing geomorphic and geochemical nature of these beach-deposited wastes (e.g. as newly exposed wastes oxidise), there is a pressing need to undertake this research now, while the most significant changes to the waste, and impacts from its mobilisation, are most evident. This information will help inform local and national stakeholders on the potential behaviour of similar unprotected coastal wastes and their possible impacts on nearshore marine communities. More generally the data will assess how sediment erosion, in response to more intense storm events due to climate change, may lead to increasing waste mobilisation; this information is vital for re-evaluation of shoreline management plans, including consideration of improved sea defences.