Impact of ‘Organic' Pollutants on Coastal Waters, Gulf of Trieste

The main sources of potential ‘organic' pollutants (essentially pathogens, nutrients, floatables, suspended solids and detergents) discharged to the Gulf of Trieste by sewers and rivers are briefly reviewed; about 470,000 people live in the coastal area, and nearly 400,000 of them discharge sewage effluents to the Gulf. This brief review is followed by an evaluation of the impact of such discharges on the quality of marine waters, with reference to the impairment of uses such as bathing and shellfish cultivation. The sanitary and aesthetic aspects of faecal pollution which typically affect coastal waters are examined together with the water quality standards pertaining to bathing waters and shellfish cultivation areas; the extent of pollution of the coastal waters is determined. Experience gained at some wastewater treatment and disposal works is cited. On the whole, the Gulf of Trieste appears to be in a satisfactory condition: more than 85% of the shoreline (totalling 42 km in Yugoslavia and 93 km in Italy) is unpolluted, according to the pertaining standards. Ameliorations are, however, urgently needed in many respects. Recommendations regarding adequate forms of sewage treatment and disposal are made.