PORR Completes Remediation of Contaminated Site

PORR AG has finalized the remediation of the contaminated site N68, formerly the "Krinninger roofing felt factory," located in Brunn am Gebirge, Austria. The project spanned from November 2014 to September 2015.

The site, previously housing a roofing felt factory established in 1888 before being absorbed by the Brunn Glass Factory, was identified with soil and groundwater contamination primarily due to residues from tar processing, including polycyclic aromatic hydrocarbons (PAC) and aliphatic hydrocarbons. Following environmental surveys, the site was officially declared contaminated and entered into the contaminated sites register in May 2012. Property owners Wiener Städtische Versicherung AG Vienna Insurance Group and Pilkington Austria GmbH established Brunn N68 Sanierungs GmbH, which commissioned PORR for the cleanup.

The scope of work included the removal and proper disposal of contaminated soil layers within a secured excavation pit. This involved dewatering and treating the groundwater, which was pumped out, passed through a sedimentation tank and activated carbon filters, and then discharged into the local recipient system meeting strict emission limit values. Concurrently, old factory parts and foundation elements found in the subsoil were demolished and removed.

Non-contaminated excavated material was recycled on-site using a recycling system to meet grade II standards for recycled building materials, as defined by the Austrian Building Material Recycling Association. This processed material was then used as backfill within the excavated area, outside the groundwater fluctuation zone. Layers of backfill were sampled and chemically analyzed before installation and compacted using appropriate equipment.