LONG-TERM EXTRACTABLE COMPOUNDS SCREENING IN SURFACE-WATER TO PREVENTACCIDENTAL ORGANIC POLLUTION

The organic composition of surface water (a canal network fed by the R hone river, France) was studied over a period of 3 years. The spatial and temporal evolution of extractable organic compounds was determined by monitoring the water of the principal canal (72 km long) over 3 ye ars and 139 compounds were detected at the ng/l concentration level. U sing these data the organic fingerprints were constructed for every sa mpling point. These fingerprints depend on sampling dates and climatic conditions. Analysed compounds were classified according to two crite ria: appearance frequency and average concentration. Three classes wer e defined, corresponding to: organic background, occasional component and chronic component. The preponderance of organic background, corres ponding to the natural organic fingerprint, indicates the high quality of this surface water. The proportion of some chemical families were calculated in order to assess their anthropogenic impact on the water. This study produced a databank which was useful as a reference for th e monitoring and checking of water quality. Any anomaly disturbing org anic fingerprints can thus rapidly be detected and identified by compa rison with the databank, making better crisis management possible. (C) 1997 Elsevier Science B.V.