A Submarine Tailings Disposal (STD) system operates on the northern flank of the Corinth Gulf, discharging bauxitic tailings on the shelf of the Gulf. A deposit of three high relief mounds has formed at a water depth of about 100 m. The surface of the mounds suffers from instabilities and tailings are transported as slumps down-slope. The tailings are dispersed on the shelf floor and are directed through the channels and canyons of the slope, to the basin floor where they form thin intercalating layers. Tailings have increased significantly the level of heavy metals in the study area.