DISTRIBUTION OF SURFACTANT MARKERS IN SEDIMENTS FROM SANTA-MONICA BASIN, SOUTHERN CALIFORNIA

The effluent from the Joint Water Pollution Control Plant (Los Angeles, California) and sediment cores collected in a transect from the Los Angeles sewage treatment plants (i.e. Hyperion) to 50-60 km offshore in the Santa Monica Basin, were analysed for fossil hydrocarbons (UCM) and markers of major surfactant classes, namely, linear alkylbenzenes (LAB) (anionic), trialkylamines (TAM) (cationic), and nonylphenols (NP) (non-ionic). Relative concentrations of these markers vary from sewage effluents to sediments according to their stability and hydrophobicity. In this regard, NP were detected only in the sewage effluent, but the more hydrophobic components (e.g. UCM, LAB, and TAM) were abundant even in 900 m water depth samples, with a stratigraphic distribution reflecting variations in their temporal use.