Controls on surface water quality in the River Clyde catchment, Scotland, UK, with particular reference to chromium and lead

Three collated geochemical surveys of surface water in the Clyde catchment have established the spatial variability in water composition, primarily under baseflow conditions. The waters are broadly pH-neutral to alkaline (maximum pH 8.7) in the lowlands, but mildly acidic in uplands on the catchment periphery. Electrical conductance is relatively high in lowland streams (maximum 8320μgL –1 ), with lower values in the uplands. Dissolved chromium...