The main interventions for the expansion of the design solution are :
- construction of a new section of pre-treatment of wastewater in entrance, consisting of a sub-fund end grilling 3 mm, followed by a desander-longitudinal flow aerated oil separator;
- construction of a water tank of rainwater from 1100 M3, able to ensure the accumulation for more than 2 hours of maximum flow rate of rainfall in excess of the maximum flow started to organic (QPM-Qpb = 1.5·Q24);
- construction of two new lines of biological active sludge treatment, each of the potential of 11000 AE, a sub-fund of denitrification by 970 M3 and a nitrification by sector 1210 M3. each line also has a preliminary sector selection from anoxic 200 M3, bringing the total volume of the organic sector of each line to 2380 M3.
- retrofit of existing biological treatment line in order to implement the ventilation control logic in intermittent cycles (installation of submersible mixers in nitrification and aeration system, with provision of air diffusers in the second sector of denitrification).
- construction of two new secondary sedimentation tanks at the service of the new biological treatment lines, geometric size similar to the existing one (diameter of 21.0 m, volume of 866 M3);
- strengthening reagent dosing station service chemical phosphorous removal section tertiary chemistry, with replacing the determination of ferric chloride (the possibility to measure directly the three biological treatment tanks) and install the preparation and dosage of Polyelectrolyte solution;
- construction of a new channel of discharge of the effluent, to stay a UV disinfection system and monitor the outlet flow in Venturi-type meter;
- construction of a new pre-mechanized overflow sludge thickening (diameter of 9.0 m, volume of 259 M3) and installation of a dynamic continuous belt thickener to ensure a further densification;
- realization of a single-stage anaerobic digester, operating under mesophilic conditions, for the stabilization of mud (diameter of 14.0 m, useful volume 1850 M3);