In the negotiated procedure public tender for awarding the ordinary and extraordinary mechanical maintenance service care of the waste-to-energy plants and other waste treatment plants of Herambiente and other companies belonging to the Hera Group (including Hestambiente), for a total tender amount of around Euro the technical component, 25 were reserved for socio-environmental sustainability (training on safety and accident and injury trend, possession of ISO 14001 environmental, OHSAS 18001 safety and SA 8000 social responsibility certification) and 35 to other technical aspects (experience of the personnel).