From the 1930s, the Caffaro plant in Brescia, northern Italy, was the country’s main producer of polychlorinated biphenyls (PCBs).
Widely used throughout the 20th century in industrial products, PCBs are a group of highly carcinogenic chemicals toxic to both human and environmental health.
According to studies, the former plant contains a significant concentration of PCBs – up to 100 times above the legal threshold – as well as other polluting chemicals. This makes Caffaro-Brescia one of the most environmentally hazardous brownfield sites in Italy today.
To ensure the protection of wildlife and local communities, our team was appointed to design a decommissioning and remediation strategy for the polluted site for a public tender.
Our role was to assess the feasibility of the project, limit environmental impact, and make sure it was approvable by the public authorities and stakeholders involved. We also ensured that the project was agile enough so that it could be carried out in phases once public funds became available.
Addressing the toxic legacy of PCBs
Despite a global ban on the production of PCBs in the late 1970s, their presence continues to pose a threat. For the nearby residents of Brescia, of which 25,000 are believed to be directly impacted, the contamination of vast tracts of land has led to increased rates of cancer and health problems.
Besides PCBs, the soil and groundwater contain other toxic chemicals such as hexavalent chromium. As a result, the area is now classified as a ‘Site of National Priority’ for remediation.
In the past 20 years, groundwater contamination has been managed at the site by extracting large amounts of water from the industrial wells. But without addressing the contamination spread in the subsoil, the groundwater is at risk.
We took a phased approach to this project in preparation for it to go out to public tender. This involved helping the Brescia-Caffaro Commissioner, who manages the site, prepare the decommissioning, remediation and permanent safety measures project at the Caffaro site.
This process included getting the necessary approvals, ensuring both technical and cost feasibility, defining the amount of the capital cost required, and developing the final design so that the initial works can go ahead.
Site-specific remediation techniques
Our remediation strategy focused on removing deep sources of contamination identified beneath the surface of the site, using a combination of in situ and ex situ remediation techniques such as soil replacement and soil stabilisation.
While in situ (or onsite) methods treat the contaminated soil or water in its original location, ex situ methods involve removing the contaminated substances from the site and treating them elsewhere.
As the site is near a residential area, safety was a crucial factor in this project. The challenge for our team was to design a secure demolition of the old plant, where hazardous chemical products were made and modified several times during its operational lifetime of more than a century.
Our remediation strategy focused on removing deep sources of contamination identified beneath the surface of the site, using a combination of in situ and ex situ remediation techniques.
Feasibility, sustainability and safety
Thanks to our expertise in remediation design, we were able to devise a strategy that was both financially and environmentally sustainable. This will ensure that the work can be completed within a reasonable time frame and budget, that any negative environmental impact is avoided, and that the highest safest standards are adhered to throughout.
Besides protecting human and ecological health, this much-needed clean-up project will bring multiple benefits to the region once complete – helping to create a safer and more livable environment for generations to come.