ROCCH, the French Chemical Contaminant Monitoring Network,  regularly provides a new official dataset for assessing the chemical quality status of French coastal waters. Concentrations of trace metal elements and organic compounds were measured in samples of marine surface sediments collected in the English Channel and Bay of Biscay, during 3 campaigns over a period of 6 years. Samples of fine sediment material, from 200 to 250 monitoring stations, were freeze-dried and sieved prior to analysis. The Results were submitted to the international database of ICES (for the OSPAR Convention).