the negotiated procedure tender originating from the Qualification System, to award a three year contract for the technical, administrative and operational management service for the treatment plants of a vacuum sewerage system and sewerage pumping stations managed by AcegasApsAmga in the Pievese area, for a total of Euro "social clause" if envisaged by the Italian collective labour agreement for the sector, as identified on the basis of and according to the above criteria consistently with art.