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periodic excavations of the bottom in compliance with the
classification regulation concerning water, waste and soil
[10], as well as the legislation relevant to dredging, like art.
48 of the Italian legislative decree of 24th January 2012 [7].
Favignana Harbour
The Favignana Harbour (Figure 2) is developed in the
sheltered inlet of Cala Principale (north central area of
Favignana Island). It is equipped with a pier about 110
m long, which extends to north-west. The smaller Molo
S. Bernardo stretches for about 85 meters in a southerly
direction. About 100 berths are available, 30 of which
dedicated to boats of travellers/ navigators. On the
seabed the Posidonia oceanica meadow is present. The
harbour of Favignana Island is located in the Marine
Protected Area, defined as “the buffer zone between the
valuable natural areas and external unprotected areas,
where the activities of enjoyment and sustainable use of
the sea of low environmental impact are permitted”.
Methods
Based on the complexity of sediments management and
the need to guarantee periodical dredging, as well as
to sustain tourism in the area (harbour, sports activities
and versus municipalities and tourist operators), a
simple and straightforward method was implemented
in four steps:
• implementation of conceptual model;
• sediments characterisation;
• technical and economic analysis of remediation
technologies;
• classification of sediments and management
scenarios.
Due to the low level of contamination of the Marine
Protected Area and the limited extension of the harbour
layout (i.e., volume to be dredged), the following
assumptions have been made:
• variation of contamination level with depth is
modest. It means that characterisation of superficial
sediment has been carried out to reduce the cost
of sampling and laboratory analysis in the first
exploratory phase of the work;
• on-shore management options have been taken
into account. So, the bioavailability and effects of
contamination on marine organisms have been
ignored as dredged material will not be in contact
with coastal marine water bodies, if reused.
,PSOHPHQWDWLRQRIFRQFHSWXDOPRGHO Research & development
Since marine sediments are potential targets of intentional
or accidental contamination, a detailed conceptual model
has been implemented. Four main contamination sources
were identified around the harbour basin and, for each
of them, a specific schedule of production activities was
compiled: (1) Florio’s factory; (2) Gas station; (3) Waste
Water discharge; (4) Boat repair (Camperia); see Figure 3.
For each of the potential source of contamination, the
transfer model and the final target have been identified.
The conceptual model is based on site-specific
reconstruction and the description of the contamination
transfer model. For each source, a schematic table
describes the route of transfer of potential contamination
and the following information:
• Name of the company;
• Site and type of business/production;
• Description of the area;
• Hydrogeological description;
• Type of pollutants (current and previous activities);
• Conceptual Model (sources, transfer and targets);
• Results of preliminary analysis of soils, land,
groundwater, marine waters.
FIGURE 3 Florio’s factory (green); Gas station (red);
Waste Water discharge (purple); Boat repair (orange)
39EAI Energia, Ambiente e Innovazione 4/2015