After a break which lasted several years, ENG reactivated and updated from 1999 plan of rehabilitation, modernization and development. Thus, in addition to investments of new rolling stock careers. All units have received an investment for rehabilitation and modernization of facilities in order to meet the demand of increasingly strong, particularly the sand for hydraulic concrete. Doubling the capacity of the unit Si Mustapha (wilaya of Boumerdes) (Plus 1 million tonnes) was decided. Setting Production is scheduled to current 3rd quarter of 2006. The new quarry of El Mallah (Wilaya de Ain Temouchent), with a capacity of 1 million tonnes per year will be operational current 4 th quarter of 2006. Sand production in this facility will be important. The decision to set up an additional capacity of 500,000 tonnes per year of sand in El Hachimia unit (wilaya of Bouira) was also taken. The production is scheduled for the 2nd quarter of 2007. Production capacity and product range of the calcium carbonate plant will be increased. The development of ornamental rocks will be strengthened through the subsidiary RoCaAl