Lonza presents possible remediation options


Lonza is actively managing the company’s industrial legacy including contamination at a former landfill site in Gamsenried, Switzerland. High pollutant values were found in the groundwater downstream of the former landfill site, originating from deposits made between 1918 and 1978.

A preliminary study, conducted by Lonza, to identify possible remediation options for the former Gamsenried landfill was presented to the local authorities in July 2020.

In September 2020, the cantonal Department of the Environment, together with Lonza, presented the options for remediation including:

  • Reinforcement of the existing hydraulic protection via additional vertical retaining walls
  • Treatment of benzidine pollution in groundwater downstream of the landfill site
  • Priority remediation of landfill areas having the greatest impact on groundwater

In February 2021, Lonza submitted to the cantonal Department of the Environment a risk assessment according the Contaminated Sites Ordinance. The study concluded that the groundwater is the only relevant good which needs protection and that the impact on groundwater is mainly due to benzidine. As the remediation measures will last for a long time, the treatment of the benzidine plume downstream of the landfill through biosparging and the optimization of the existing hydraulic protection fence have to be completed as a first priority.

In June 2021, Lonza made a provision of 285 million Swiss francs to cover the first phase of the remediation. This will take around ten years to complete and will commence in 2023 or 2024. We have worked with our environmental experts to reach a reasonable cost estimate, and we believe this provision should cover the majority of total remediation costs. Addressing our legacy issues by investing in lasting solutions leaves us well-placed to push forward with our ambitious sustainability agenda.