Total metal concentrations in the Rhine water and metal partitioning between dissolved and particulate fractions. Bars are means obtained for both cofounded sites during the long-term monitoring (n = 45 water samples for both confounded sites ± SD) from March 2011 to July 2013. Thick lines are quality standards defined by European (full line) or French (emptied line) regulations. For Cd, Mn, Ni and Zn, concentrations were adapted by using a scaling factor.