Il risanamento di Porto Torres

Environmental reclamation in Porto Torres

The implementation of the Nuraghe project and other environmental interventions continue for the completion of the reclamation activities at the Porto Torres site.

Reclamation and renewable energy

Since 2001, we have been engaged with Eni Rewind in an environmental clean-up of the Porto Torres industrial site. In 2010, we developed an environmental intervention plan, which was shared with the relevant authorities and local community and included in the Green Chemicals Protocol (2011). To ensure a sustainable approach to reclamation operations, the site has a plant for producing and distributing demineralised water. The recovery of water purified by groundwater treatment plants means the use of natural resources is limited. To further support reclamation operations for sustainability projects, Eni Rewind has made available 500 of the 1,200 hectares it owns. Porto Torres hosts the largest photovoltaic park ever made by Eni in its renewables development initiatives. With a capacity of 31 MW, the plant assures an annual production of 50 GWh, 70% of which is intended for the companies working on the industrial site, offering savings of around 26,000 tonnes of carbon dioxide every year. 

In 2019, we built a 10km barrier for groundwater reclamation. It works with 103 wells that extract water, which is then treated in 5 plants with a total flow rate of 340 m3 per hour (2.5 million m3 per year). Part of this, equal to 750,000 m3 in 2019, is subsequently sent to reverse osmosis plants, where demineralised water is produced, this is then reused in the Versalis plants, enhancing the value of the resource and reducing the use of natural resources. In Porto Torres we also use e-hyrec technology, patented by Eni Rewind. The automatic device, placed inside the wells, enables the selective separation of aqueous and oily water, recovering the hydrocarbon without extracting water, while traditional systems take a prominent part of water (about 70-80%). There is a consequent improvement in terms of the effectiveness and efficiency of groundwater reclamation.

The Nuraghe project and other interventions to complete the activities

Today, Eni Rewind has spent around 475 mln EUR on soil and groundwater remediation and decommissioning. Today it employs 70 people and, on average, around 250 outsourced companies (of which around 90% local). To complete the activities, a further expenditure of 373 million EUR is estimated, of which around 145 for plant management in the coming years. Among the main current works, the Nuraghe Project is of particular importance, as it represents an example of sustainable, zero-mileage remediation, performed in agreement with the local community and authorities. The works affect a surface area of around 30 hectares, and involve the removal and treatment of around 800,000 m3 of contaminated materials coming mainly from the ex-Minciaredda landfill, through a multi-purpose platform, which is already operational and equipped with all the plants and equipment required for soil decontamination. After treatment, the soils conforming to the remediation targets are reused to fill the excavations they came from, while non-conforming soils are taken to a specific permanent store on the site. The contaminated soils are then fully managed, reused or reallocated on site, in line with the principles of the circular economy, maximising the recovery of materials and, at the same time,  minimising the economic and environmental impacts linked to the handling of waste, which sometimes are sent event thousands of kilometres away.  Another important  project concerns groundwater remediation: currently, Eni Rewind is carrying out activities through a hydraulic confinement barrier around the whole site, running for 10 km, and 5 water treatment plants which will be upgraded by 2023 to increase their capacity by 30%.