## 3 Results and Discussion
### Pollution Assessment  
The results of the assessment of the single pollution index (P\({}_{\rm I}\)) and the Nemerow integrated pollution index (P\({}_{\rm N}\)) are shown in Table 15 and Figure 9 for the San Giuliano reservoir and Table 16 and Figure 10 for the San Giuliano reservoir.  
Regarding the San Giuliano reservoir, the Pi index shows that for all heavy metals and all sediments, the values are always less than 1, indicating a non-polluted condition of the sediments. An exception concerns the sediments SG_S5 and SG_S6, for which P\({}_{i}\) index values for Arsenic are between 2 and 3 and between 1 and 2, respectively. Therefore, it is possible to define that sediment SG_S5, regarding Arsenic, is moderately polluted, whereas sediment SG_S6 is low polluted.  
The Nemerow integrated pollution index P\({}_{\rm N}\) illustrates a similar condition to the one found above. All sediments, except SG_S5 and SG_S6, can be defined unpolluted, with values well below unity. In contrast, the sediments mentioned above have a P\({}_{\rm N}\) value between 1 and 2, i.e., they are, on the whole, low-polluted. However, the P\({}_{\rm N}\) index of sediment SG_S5 is close to 2, tending towards a moderately polluted condition.  
\begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline  & **As** & **Be** & **Co** & **Cr** & **Cu** & **Ni** & **Pb** & **Sb** & **TI** & **V** & **Zn** \\ \hline C\_B1 & 0.231 & 0.551 & 0.621 & 0.361 & 0.253 & 0.295 & 0.100 & 0.020 & 0.207 & 0.659 & 0.489 \\ C\_B2 & 0.198 &  
In the case of the Camastra sediments, the P\({}_{\rm i}\) index is always less than unity for all the parameters examined, and all the sediments sampled, indicating an unpolluted condition. For samples C_S3, C_S4, C_S8, C_S9, and C_S11, the single pollution index for Cobalt is between 1 and 2, indicating a low-pollution condition.  
However, Figure 10 shows that most of the sediments are unpolluted, except for samples C_S3, C_S4, C_S9, and C_S11, which are low polluted. In contrast to the single pollution index, therefore, overall, for sample C_S8, there is no polluted condition, although the P\({}_{\rm N}\) value is very close to unity (0.989); on the contrary, the sediments above slightly exceed the unity, settling at a value of about 1.1, indicating a low polluted condition.  
Overall, the findings of the analyses show that the heavy metal content is below the limit values fixed by the Italian Regulations, assumed to be the standards for sediment reuse. In other words, the sediment is substantially compatible, without prior treatment, for reuse in environmental recovery (as filling material for disused quarries, earth embankments, and dykes, reprofiling of riverbed morphometry, nourishment of shorelines and sandy shores, reconstruction of coastal morphologies) and for the construction of embankments and sub-bases, moving the dredged material outside the area of operation as by-products, by the compliance mentioned above with regulatory limits. Furthermore, considering that plants' uptake of Arsenic and Cobalt is not high, nor are there any potentially harmful effects for humans, it is also possible to hypothesize reuse in the agronomic field as inorganic fertilizer due to the low organic content. In conclusion, this research on the Camastra and San Giuliano reservoir sediments is the first step towards identifying potential alternative reuses to landfill disposal. In this regard, some research has already been started, mainly to verify the compatibility of sediments for reuse as aggregate and binder in the preparation of cement mortars, with preliminary evidence that was very encouraging [62].