In the open procedure public tender for the service involving running and maintenance of the treatment plants, sewer lifting, imhoff pits, floodways and sludge dehydration (Emilia Romagna area) for a total annual tender amount of around Euro technical component, 3 were dedicated to environmental sustainability (ISO 14001 environmental certification), 36 to social sustainability (training of employees with regard to fire prevention and first aid, training of employees qualified as “supervisor”, OHSAS 18001 safety certification and SA 8000 social responsibility certification, employees with requisites for environments suspected to be polluted or confined areas and number of PES qualified employees) and 21 for other technical aspects (number and experience of the personnel made available).