The investigated site is located in northeast Piedmont, Italy,
near the town of Borgomanero, in the province of Novara, as reported
in Fig. 1. The area, now uncultivated and characterised by
a high environmental deterioration, was used as permanent meadow
and woodland in the past. The contamination occurred because
of the repeated floods of a small stream, which today has a
new course, caused by the insufficient size of the stream bed with
respect to the flow in rainy periods. The stream collected the
wastewaters of local industries, some of which operating in the
electroplating field, and its floods caused an accumulation of contaminants,
mainly of inorganic nature, in the soil. The extension of
the polluted area is estimated between 20 000 and 100 000 m2. The
core of the contaminated zone is about 3000 m2 wide: it is flat and
covered by a layer of black sludge about 1.50 m deep carried by the
floods, where a scant vegetation grows. The rest of the area is covered
by trees and spontaneous plants. The land in the zone is made
of alluvial deposits.