The remediation team is back at Casey this season working on many different projects. The early season team consists of six members brought in from around the world and different universities.
One of the main projects for the team this season is a continuation of the remediation of the 1999 fuel spill at the main powerhouse fuel tank. The clean-up approach required a low-cost technique suitable for Antarctic conditions and was the first major instance in Antarctica of a comprehensive remediation strategy. Key aspects of this strategy involve managing a contaminated site using Permeable Reactive Barriers (PRBs) and biopiles. The PRBs, built in 2005 and 2011, are positioned in the ground and intercept the fuel (hydrocarbon) plumes moving from the source through the soil. It is then directed to the bioremediation treatment zone of the barrier. The PRB is equipped with sensors and sampling ports to log data, sample groundwater and investigate the performance of the barrier treatment material at removing hydrocarbons from the groundwater.
Over the past two seasons, excavation of contaminated soil at this spill site was completed and all soil was placed in the biopiles. The biopiles are contained treatment cells employing engineered liner systems to prevent migration of contaminants out of the cells to the surrounding environment. Within the cells, both bioremediation (where natural microorganisms in soil degrade hydrocarbons) and aeration of the soil occur.
The remediation team arrived back to the site in early November to discover that both PRB and biopiles were buried deep in the snow. Many days were spent shovelling snow using heavy plant and manual labour. A few enthusiastic fellow expeditioners also lent a hand in digging. After more than a week of digging, a few broken shovels, a blizzard, and then more digging because of it, the team was finally ready to peel back the covers off the biopiles and take the first soil samples of the season. It proved to be a tougher task than shovelling heavy snow, as the soil within the biopiles was frozen. The team persevered and completed the task. Now they are set to spend time focusing on another remediation site that is part of the team’s project schedule this season. And in the meantime, it will give the biopiles and PRBs time to thaw out.