Remediation

Colline Metallifere

Safety measures and remediation interventions on the ex-mining sites in Tuscany.

Montedison/EGAM

Origin of areas

700 ha

Surface area owned by Eni Rewind

1459 ha

Surface area of mining concession

€97 million

Environmental costs at 2023

The Colline Metallifere are located in the central-western part of Tuscany, covering the provinces of Livorno, Pisa, Siena and Grosseto. This area has been renowned since Etruscan times for its mineral reserves - hematite, pyrite, chalcopyrite, alum, stibnite, calamine, sphalerite, galena and cassiterite.

In 1899, Montecatini company at first took over the Fenice Capanne and Boccheggiano copper mines, and later the Gavorrano pyrite mine. When the Niccioleta mine began operations in 1930, Montecatini held the monopoly of pyrite in Italy. In 1967, following the merger with Edison in 1966, the business was taken over by Montedison and as of 1973 by Società Lavorazione minerali e Derivati – Solmine, of the EGAM (Ente Gestione Attività Minerarie) group. Progressively decommissioned, in 1978 the business was transferred ex lege to Eni, at that time a state enterprise.

Today, Eni Rewind holds four mining concessions in Tuscany, covering around 1460 hectares. The company owns 680 hectares of land, 360 of which are undergoing mining safety measures and soil and groundwater remediation interventions.

The environmental procedure

In 2009, we signed two programme agreements to begin safety measures and remediation works on the ex-mining sites: the procedural and programme Agreement for mining safety measures and environmental remediation of the mining sites and the contaminated areas in the Colline Metallifere, the Scarlino plains and the Municipality of Manciano, and the Final Agreement for safety measures and remediation interventions in the Merse Area. Specifically, the agreements covered:

the regeneration of the area through 26 environmental interventions and mining safety measures (18 led by Eni Rewind and 8 under mandate) covering around 360 hectares;
the reduction of the surface area or the withdrawal from the 4 mining concessions (Niccioleta, Fenice-Capanne, Accesa Serrabottini and Gavorrano-Rigoloccio) for a total of around 1460 hectares;
the characterisation and studies for the regeneration of the drainage tunnel waters in Niccioleta, Boccheggiano and Fenice Capanne and the waters from the Gavorrano - Rigoloccio mine;
the progressive divestment of the owned areas.

So far, we have completed 20 of the 26 programmed environmental interventions, 6 of which are already certified for the completed remediation, 2 with completed post-operam monitoring, while 12 are in the post-operam supervision phase. In 2021 and 2023 the project variants for the Bacini S. Giovanni in Gavorrano were approved, and in 2024 the implementation of the remediation interventions on the minor site of Montieri was authorised. In addition, there are 3 other projects under development or pending approval. Among these, the Merse Campiano site: after different proposals made since 2011 and a lengthy interaction with the authorities aimed at protecting the environmental and archaeological heritage, the new intervention planning stage is currently ongoing. For the Fenice Capanne site, the Cultural Interest Evaluation process (CIV), which led to the revision of the mining safety measure works, was completed in 2022. Lastly, the mining safety measures interventions for the new Niccioleta sites, presented in 2022, are undergoing approval.

The Niccioleta complex includes tailing ponds from mining activities, operational from the 1930s until 1992. The authorised environmental interventions, which we completed in 2019, comprised the site remediation and permanent safety measures, including the capping of area A7. With a view to listening to communities and enhancing the local areas, a feasibility study is currently underway for the installation of a photovoltaic park and the development of a network of foot and cycling paths.

This complex of 9 tailing ponds is part of the ore processing for the minerals extracted from the Gavorrano mine between 1910 and the late 1970s. The area is undergoing permanent safety interventions approved in 2019 (executive project for the reinforcement of embankment 9), with project variants in 2021 and 2023. Through dialogue with local institutions, Eni Rewind is committed to combining the environmental restoration works with the archeological valorisation of the mining site as well as the possible installation of a photovoltaic park in the older basins area.

To conserve the industrial mining memory and culture of the Colline Metallifere, in 2021 Eni Rewind completed the consolidation and redevelopment interventions of the Pozzo Roma headframe, an iron pylon tower built in the early 1960s and to date a symbol of Gavorrano mine. Today, Pozzo Roma falls within the museum network of the Gavorrano Natural Mining Park, in turn part of the vaster Technological and Archaeological Park of the Metalliferous Hills of Grosseto province.