PORR AG remediates contaminated factory site in Rum

Construction company PORR AG has concluded a significant environmental remediation project in Innsbruck, Austria. The project, carried out between 2011 and 2014, focused on cleaning up the old factory premises of the T5 Rum roofing felt factory, which had been in industrial use for decades.

The factory, primarily producing tar-based products like roofing felt, operated a coal tar oil distillation facility from 1908 to 1959. From 1960 onwards, crude oil was used as the raw material. This industrial activity left approximately 1.5 hectares of soil heavily contaminated with tar products and mineral oils. Particularly, polycyclic aromatic hydrocarbons (PAHs) at certain locations had caused a widespread contamination plume in the groundwater. Due to its risk potential, the site was classified as a priority 2 location.

The remediation project involved multiple measures. Heavily contaminated soil ("hot spots") was primarily removed through replacement bores and backfilling. To purify the groundwater, a system was installed incorporating extraction pumps, sand filters, and activated carbon filters. The purified water was either directed for industrial cooling purposes or returned to the groundwater. Additionally, a pilot trial using an "in situ" method was conducted to remediate the soil.

The remediation also included a pilot trial testing a hot water flushing system for areas inaccessible by large bores. In the trial, heated water (up to 70°C) was injected into the soil, increasing the mobility of contaminants for removal via extraction wells. This method is intended for continuous operation until 2022. In total, over 200,000 tons of soil and construction waste were processed in the project.