Page 4 - Grillini2015

would be suitable to rationally concentrate pumping
from the wells, to supplement the freshwater supply
currently coming from an aqueduct from Trapani [19-22].

Geology and hydrogeology of Favignana

With a length of 9 km (west to east) and a maximum FIGURE 2 The town of Favignana and the eastern plain Research & development
width of 4.3 km (north to south), the island of Favignana
extends over an area of 19.4 km2, along a 33 km long
coastline [23, 24]. It hosts a ridge of dolomite and
limestone oriented North to South -on top it stands Mt.
Santa Caterina (312 m a.s.l.)- and two plain areas west
and east of it, respectively (Figures 1 and 2).The ridge is
bounded on both sides by a system of faults which have
lowered the carbonate sequences, causing them to be
covered by more recent deposits, mainly calcarenite
[25-33].
Therefore, three hydrogeological basins should be
considered in Favignana (Figure 3), corresponding
to the two plains and the central ridge. The structural
discontinuity surfaces, bordering on both sides the
ridge itself, act as groundwater divide: only after heavy
rain periods some limited groundwater is allowed to
flow from the ridge toward the coastal plains.
In the western sector extensive outcrops of limestone
can be found, side-by-side with less widespread
calcarenite, as the evidence of a less deep lowering

FIGURE 1 Mt. Santa Caterina and the western plain FIGURE 3 Schematic hydrogeology of Favignana

of those rocks in this area [34-39]. As a consequence,
as it will be discussed later on, the groundwater in
this sector is somewhat different from the water in the
eastern sector: it is on average deeper and saltier.
In the eastern sector, instead, calcarenite covers the
whole area, with a thickness varying from two to thirty
meters. This rock has been extensively exploited
over the centuries as building material (called “Tufo”
all over Southern Italy) [40-44], to the extent that

21EAI Energia, Ambiente e Innovazione 4/2015