This week at Casey: 20 December 2019

At Casey this week: a bird’s eye view of the skiway, insight into the life of an AGSO, plus the low down on what the Remediation Team have been doing

Casey Aircraft Ground Support Officers

What a difference the weather makes down here and how it can really impact on day to day operations. Last season, due to poor flying and operational conditions at both Casey and Davis research stations, it took the Aircraft Ground Support Officers (AGSO) team 7 weeks to finally land a plane at the Ski Landing Area situated 10km east of Casey. This year, with very favorable conditions, the Ski Landing Area was fully operational within a week.

Our first day at the site was on 24 October 2019. Having a late start from our late arrival the night before, we found the runway threshold markers via GPS and started to mark out the center line. The following day we used a “dumpy level” to sight the northern and southern runway markers. This turned out to be a very accurate way to do it.

Once the runway was marked, we used a series of drag beam, land plane, and cut and groom procedures to produce a nice clean, flat surface for aircraft to use. This included a taxiway as well as an apron in front of our Operations Building. During this project the buildings were removed from their winter positions and place into the summer operational area.

On 29 October, the runway was ready to receive the first flight, a CHINARE Basler GCX. Two days later, a JKB Basler landed (they are contracted to fly with the Australian Antarctic Program each season).

Overall it has been a great start and really highlights how having good lines of communication and the support of all the work groups from Station makes things happen.

The AGSO Team this year is: Nathan Bourke, Russell Bradshaw, Dylan Scott, Ben Keyes and Dane Riley (Ben and Dane are based at Wilkins but have supported us in various stages) and Senior AGSO Dean Ahern.

 - AGSO Team 

A bird’s-eye view of the Casey ski landing area taken from a Basler
A bird’s-eye view of the Casey ski landing area taken from a Basler
(Photo: Russell Bradshaw)
A view of the ski landing area and taxiway taken from a Basler coming in to land
A view of the ski landing area and taxiway taken from a Basler coming in to land
(Photo: Russell Bradshaw)
the team assisting in digging a hole in the sea ice for the Tide Gauge calibration project at Casey
AGSO team assisting with Tide Gauge project
(Photo: Russell Bradshaw)
Two Baslers at the Casey ski landing area
Two Baslers at the Casey ski landing area
(Photo: Russell Bradshaw)
Two Baslers on the apron at the Casey ski landing area
Two Baslers on the apron at the Casey ski landing area
(Photo: Russell Bradshaw)
A view of the Casey ski landing area form the air
Another view of the Casey ski landing area form the air
(Photo: Russell Bradshaw)

Remediation at Casey

This season, the Remediation Team at Casey research station is focused on the clean up of four fuel spill sites at various stages of investigation, remediation and research. In December, we began a detailed investigation of the 2018 fuel spill at the Casey upper fuel farm. This included drilling through ice, down to bedrock in a grid that spans the area down gradient of the fuel spill. Vapour cartridges were installed, that once analysed, will give an indication of the extent of fuel migration below the ice. We encountered areas of snow and ice pack deeper than 4m and could only install pipework to this depth. Results from this investigation will inform us which areas to prioritize for future remediation activities, for example, how much ice will need to be dug out to access the impacted soil?  

Work has also continued on the 1999 fuel spill site where contaminated soils were undergoing treatment in the first generation of biopiles, originally built in 2011. Biopiles allow the natural bacteria in the soils to break down the fuels and use fuel as food. They are contained in bunded areas so that fertilizer and water can be recirculated through the soils. These soils have now been stockpiled for either reuse on station in approved environmentally managed applications or for further bioremediation treatment.

In the past few weeks, we took apart two biopiles and completed a detailed investigation of the geosynthetic barrier system that contains the contaminated soils and leachate (water). The design, construction and performance of barrier systems has been ongoing since 2010 with external university collaborators. We have completed drone flights to capture detailed photographs and maps of the barriers and foundation soils. With the doctors at Casey, we completed X-rays of the liners that show the presence or absence of water in the synthetic clay liner with void spaces being potential contaminant pathways.

One biopile was built on a relatively dry and coarse gravel foundation and another was built on a finer soil foundation that experiences a seasonal pulse of melt water running just below the barrier system. The learnings from these barrier designs, decommissioning studies and laboratory testing has helped us with the design of a new biopile to be constructed in January 2020. This will be the largest biopile built at Casey and will allow the small excavator to drive inside and turn soils (especially frozen soils) for enhancing bioremediation.  

Before the new biopile is built, our team must complete excavation of the remaining contaminated soils in the ground from the 2015 fuel spill. From our team’s collective soil remediation research and logistical experience, we know that the best method of containing and cleaning up fuel impacted soils is to get the soil out of the ground, into a biopile and encourage the natural bacteria to begin degrading the fuel. We have already successfully remediated two other areas impacted by this fuel spill: the area below the new Casey Utility Building and the sloped area that was the source zone of the fuel spill.

Our team is also completing work on soil biodiversity, ecological risk assessments, microbiology, ecosystem research and developing a framework for the Australian Antarctic Division (AAD) and other nations to guide soil reuse policy. The field team on the ground at Casey were able begin some of the soil sampling, mapping and investigative work at field sites a short distance from station.

It is important to note that less than 1% of the Antarctic continent is ice-free and soils are exposed. Essentially our greater team is aiming to answer the following questions:

  • How are soils, water, plants and animals (e.g. tiny invertebrates) impacted by humans in Antarctica? 
  • What types of remediation are possible and practical in Antarctica and other cold regions? 
  • When is the soil clean enough to be returned to the natural environment? 
This work involves many collaborators, AAD team members, trades workers, and Australian and international universities. We are a big project!

The AAD Remediation Team is very outdoorsy, enjoys long walks, an adventure, taking in the stunning views here at Casey, and spending time with each other. Pulling sleds and donning survival packs is a nice change of pace to our usual workday on station using heavy machinery, drones, shovels, pumps and Stanley knives.

 -AAD Remediation Team 

An excavator surrounded by shipping containers at main remediation site at Casey
The main remediation site at Casey
(Photo: Rebecca McWatters)
Textile covers pulled aside the biopile soil
Textile covers taken off the biopile soil as it warms for the summer season
(Photo: Rebecca McWatters)
The biopile barrier system showing the black high density polythene primary barrier and the beige geosynthetic clay liner (GCL) as the secondary barrier below
Investigations of the biopile barrier system during decommissioning showing the black high density polythene primary barrier and the beige geosynthetic clay liner (GCL) as the secondary barrier below
(Photo: Rebecca McWatters)
A man removing soil samples
Johan sampling the GCL barrier
(Photo: Rebecca McWatters)
A smiling woman standing in front of a loader
Bianca having fun on site while waiting on Johan to move the biopile soil using the loader
(Photo: Rebecca McWatters)
Two men and a woman removing the barrier specimens from the biopile
Bec, Bill and Johan removing the barrier specimens from a 10-year study of the biopile
(Photo: Rebecca McWatters)
A man and a woman sampling soils and recording GPS locations in the field
Anne and Bill sampling soils and recording GPS locations in the field
(Photo: Rebecca McWatters)