Construction of new ZSC Lions’ ice hockey stadium, Zurich, Clearing the site of former allotments

The project

Location: Zurich-Altstetten (ZH)
Customer: Zurich City Council
Phases: Preliminary survey, submission and specialist support for neophyte, soil and earth remediation works
Duration: 2018-2019
Building costs: --


As the owner of the former allotments, Zurich City Council was responsible for clearing the site to allow the construction of the new ice hockey stadium. In addition to extensive neophyte deposits and heavily contaminated topsoil, the artificial infilling of former drainage channels was also an issue. Ecosens AG provided support to Zurich City Council at all stages of the project, from the preliminary survey and planning to implementation, in close collaboration with the client and main contractor.


Our services

  • Updating the survey of neophytes on the project site with the presence of more than 5 neophyte species, including Rhus typhina and Canadian goldenrod
  • Undertaking a supplementary preliminary survey of the contamination present (soil and earth)
  • Creating a process and decontamination plan in relation to neophytes, soil and earth
  • Inviting tenders for the neophyte clearance and disposal works prior to the actual site clearance, including contractor inspection
  • Supporting the tender process for the clearance of soil and earth from the site prior to the project-related excavation works
  • Specialist neophyte, soil and earthworks management, including final documentation for “independent monitoring”


  • A huge project site - 28,000 m2
  • A wide range of overlapping contamination sources: biological contamination from neophytes, top-soil and earth contamination due to prior use as allotments (fertilisers, pest control), contaminated earth resulting from artificial infilling (all types of extraneous material)
  • Project team coordination, as the client for the site clearance was not involved in the construction project but was responsible for bearing the costs
  • Complex triaging due to the wide range of sometimes overlapping contamination sources

Project manager:

Melanie Vögtli Co-divisional manager: Contaminated sites
MSc Environmental Engineering, ETH (Federal Institute of Technology) +41 44 839 47 71 More