NASQAN: The design and implementation of a large-river suspended sediment and trace element flux programme

In 1996 the US Geological Survey (USGS) began a national flux-based water quality monitoring programme in the Mississippi, Columbia, Colorado, and Rio Grande basins. Suspended sediment flux estimates for periods greater than a year are generally accurate within ??15%. Discharge and suspended sediment concentrations varied much more than chemical levels. Most trace element concentrations are not elevated except Zn and Hg in the Ohio River, and Ag, Cu, Pb, Zn, Cd, Cr, Co, Ba, Mo, Sb, Hg, and Fe in the upper Columbia River, which is impacted by mining waste. The majority (???70%) of Cu, Zn, Cr, Ni, Ba, P, As, Fe, Mn, and Al are transported by suspended sediment; Sr transported seems dominated by the dissolved phase, whereas the transport of Li and TOC seem to be divided equally between both phases.In 1996 the US Geological Survey (USGS) began a national flux-based water quality monitoring programme in the Mississippi, Columbia, Colorado, and Rio Grande basins. Suspended sediment flux estimates for periods greater than a year are generally accurate within ??15%. Discharge and suspended sediment concentrations varied much more than chemical levels. Most trace element concentrations are not elevated except Zn and Hg in the Ohio River, and Ag, Cu, Pb, Zn, Cd, Cr, Co, Ba, Mo, Sb, Hg, and Fe in the upper Columbia River, which is impacted by mining waste. The majority (???70%) of Cu, Zn, Cr, Ni, Ba, P, As, Fe, Mn, and Al are transported by suspended sediment; Sr transported seems dominated by the dissolved phase, whereas the transport of Li and TOC seem to be divided equally between both phases.