Chemical and Ecotoxicological Characterization of Averno Lake

The scope of present paper is to carry out a model study on the lake Averno, a nearly water closed basin polluted by waste waters of nearby communities and by agricultural activities. Lake Averno is a natural basin in the Phlegrean Fields region about 15 km west of Naples (Italy). This lake was formed as a consequence of the collapsing of a large volcano, named Archiflegreo, which was active until historic times. The area around Phlegrean Fields presents signs of thermo-mineral spring streams (at Bagnoli, Pozzuoli and Lucrino) and natural (at Averno and Fusaro) spring streams (Martini et al. 1991; Celico et al. 1992). The water flowing into Lake Averno is essentially soft, with an average a flow rate of 42 dm3/s during the rainy seasons and almost zero in the summer months. The water basin is nearly elliptic (1000 m long and 700 m wide), covering a 0.54 km2 surface, and is 34 m deep at the center, with a total water volume of roughly 6.000.000 m3. A canal which is almost 1 km long links the lake to the sea, carrying both spring and rain waters to the Lucrino coast in the Gulf of Pozzuoli (Cortini and Scandone 1987). The discharge into the sea trough this canal and the sedimentation constitute outputs of lake pollutants. Around the crater terraces with citrus fruits and vineyards are irrigated with the lake water. However Lake Averno is heavily polluted by the urban waste waters from overflows of the collector that carries residual waters into the Cuma Plant.