SEDIMENT AND HEAVY-METAL DISTRIBUTION AND TRANSPORT IN A COASTAL AREAAFFECTED BY A SUBMARINE OUTFALL IN THE BASQUE COUNTRY (NORTHERN SPAIN)

In 1989 a submarine outfall was brought into service in the coastal ar ea of Zarautz, in the Basque Country (north of Spain). The outfall dis charge point is located at similar to 35 m depth and similar to 1 km o ffshore. This work deals with the sediment dispersion and distribution patterns in the vicinity of an outfall. The methodological field proc edures included bathimetric surveys and sediment sampling for grain si ze characterization and analysis of organic matter content and heavy m etal concentrations. Sediment resuspension and transport paths were es timated. Small-sized sediments have been only deposited in the proximi ty of the outfall discharge point. Heavy metal distribution in the sed iments shows only minor influence of the outfall. Only under storm wea ther conditions sediments will get into suspension. Sediment transport studies suggest a net transport from the outfall discharge point to t he N-NW. It can be established that sediments discharged by the outfal l will not be transported coastwards; thus, water quality in this area will not be affected. (C) 1998 IAWQ. Published by Elsevier Science Lt d.