The remediation strategy employed by EESI was multifaceted and adapted to the site's unique challenges. Initially, two contamination hotspots were excavated to a depth of 14 metres. The contaminated material was transported to a warehouse and treated using a Mobile Unit for Soil Treatment (MUST), where gas phase carbon tetrachloride and chloroform were captured. This treatment allowed the soil to be safely used for backfilling the excavations.
Following the removal of the hotspots, EESI addressed the residual soil and groundwater impacts with an innovative water treatment system. This system stimulated the degradation of the remaining chlorinated compounds through the activity of anaerobic microbes. The introduction of reducing bacteria, sourced from landfill cells and marine muds, was critical in this process. These bacteria, along with a slurry of simple sugars and nutrients, were injected into the ground to facilitate the degradation of the contaminants.
The remediation at the Akzo Nobel site was highly successful. Concentrations of hexavalent chromium, carbon tetrachloride, and trichloromethane were significantly reduced, ensuring the site's suitability for future commercial use. The innovative approach to bioremediation, especially the use of reducing bacteria, demonstrated EESI's capability in handling complex environmental challenges. The project also adhered to stringent environmental standards, with oversight from the EPA and an Auditor, ensuring compliance throughout the process.
The Environmental Earth Sciences International Group acknowledges the Traditional Custodians of country throughout Australia and their connections to land, sea and community. We pay our respect to their Elders past, present and emerging and extend that respect to all Aboriginal and Torres Strait Islander peoples today.
