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Research & development
FIGURE 2 Egadi archipelago and Favignana Harbour
above them due to the direct contact of many aquatic
organisms and following food web.
However, once present in water bodies, pollutants tend
to be absorbed by particulate matter and to settle onto
the bottom. Such process generates the formation of
contaminated sediments, defined as “soil, sand, minerals
and organic matter accumulated on the bottom of a water
body and containing toxic or hazardous substances at levels Law no. 84 of 1994 [7, 8, 9]. While the legislation tends
that may cause adverse effects on human health or the
environment” [5]. Accumulation of contaminants within
sediments can derive from natural or anthropogenic
sources. The natural mechanisms are identified with
volcanic eruptions, forest fires, the biosynthesis
performed by plants or bacteria and all phenomena
that exclude human impacts. However, natural processes
can lead to concentration exceeding the threshold of
contamination defined by national legislation. In some
sites, such abundance establishes a reference value of
natural background. Anthropogenic sources, however,
are represented by all the activities that produce and/
or use toxic or harmful substances and that can affect the
ecosystem in which they are issued [6]. Anthropogenic
contaminants may enter the aquatic environment through
punctual sources,such as industrial or civil discharges,or
from diffuse sources, such as runoff, erosion of farmland
treated with pesticides and atmospheric deposition. For
this reason, the conceptual model of contamination is
38 EAI Energia, Ambiente e Innovazione 4/2015
the preliminary part of the process of investigation and
remediation of the seabed.
The Italian current legislation is based on the Legislative
Decree no. 1 of 24th January 2012 (converted into Law no.
27 of 24th March 2012), in which Article 48 is referred to
“Dredging Rules” and re-writes the previous detailed
regulations regarding dredging, regulated by art. 5 of
to mitigate the environmental impact derived from the
movement of sediments in the coastal marine environment,
there are still strong references to the prevention of the
disposal of dredged material that should be applied to
harbour areas without the need to remove sediments
at the points where they are most polluted, which often
coincide with navigation channels, or internal parts of
the harbour, where hot spot are more abundant. Security
issues and maintenance dredging should be authorised
with simplified procedures, while we still suffer to adopt
best practices for sediments management in relation to
low levels of contamination.
The goal of ENEA was to implement a management model
of harbour sediments, which, after characterization and
possible treatment, may find reuse avoiding landfilling.
This strategy combines the need to avoid the silting of
coastal infrastructures, ensure the maintenance and permit
the transit and mooring of vessels, in order to provide the
tourist industry with a valuable natural resource through