For the energy
balance two important positives were accounted: for the sub-system Raw water extraction, the production of 7
GWh/y of electricity in Balme hydroelectric plant, sold to external users and, for the sub-system Wastewater
treatment, the production of 36,5 GWh/y of electricity in the main WWTP in Castiglione T.se. This electricity is
produced from the combustion in CHP (Combined heat and Power) engines of biogas, produced during the
anaerobic digestion of the sludge (25,07 GWh/y), and methane (10,25 GWh/y) and is used within the plant.