Stream sediment background concentrations in mineralised catchments in Northern Ireland: assessment of ‘pressures’ on water bodies in fulfilment of Water Framework Directive objectives

An approach for deriving sediment background metal and metalloid element concentrations using systematically collected geochemical survey data is demonstrated in the mineralised area associated with the Ordovician-Silurian rocks in counties Down and Armagh in Northern Ireland. Operationally-defined background ranges can be used for improving the assessment of the environmental pressures posed by historical mining on impacted catchments and establishing feasible catchment restoration goals. Deriving pre-mining baselines provides essential information for any proposed mineral development project, with direct benefit to the mineral sector and industry.