Oil Spill Remediation in a Very Cold Climate

By Nick Ackers

Two years ago this December, Tasmanian-based Loss Adjuster Nick Ackers left Hobart on the  Antarctic supply vessel “Aurora Australis” for Casey Station, Antarctica, along with 24 crew and 53 expeditioners.

Nick travelled as a guest of the Australian Antarctic Division (AAD) which Commonwealth Government Agency is responsible for managing activities in the Australian Antarctic Territory, as part of the 100 year anniversary to celebrate Sir Douglas Mawson’s first Australian led expedition to Antarctica. 

Casey Station is situated some 3,500kms south-west of Hobart on the eastern coast of Antarctica just outside the Antarctic Circle. Whilst limited air travel is available to Casey via the Wilkins Ice Runway, the AAD’s invitation to travel by sea enabled Nick to gain a much better perspective of the environmental and logistical challenges faced when operating in Antarctica.

Nick’s role includes adjustment of losses arising from fuel oil spills in the Sub-Antarctic (Macquarie Island) and the 42% of Antarctica controlled by the Commonwealth of Australia. It must be borne in mind that Antarctica is the coldest, driest and windiest continent on which human activity takes place. Living in that environment brings with it many challenges many of which can be life threatening.

The AAD is now a world-leading authority on managing fuel oil spills in Antarctica. This has developed from the requirements of the Antarctic Treaty that each country operating within the Antarctic Continent be responsible for cleaning up their own contamination.         

     

Some seven days after leaving Hobart the Aurora Australis sailed into the bay overlooked by Casey Station situated on the ridge line above. However, due to deteriorating weather conditions and the poor anchor holding ability in the bay, the Aurora Australis headed out to sea again for two days to ride out the storm. This was Nick’s first example of weather-induced delays when operating in Antarctica. The Aurora Australis returned to Casey Station and commenced unloading materials, supplies, equipment and personnel by barge from the ship to the nearby wharf; although this process was further dramatically delayed due to an ice flow which had blown into the bay during the recent storm, impeding efforts to discharge the cargo.

Upon landing ashore pedestrians were required to walk about 1km up to the Station which is a series of coloured buildings, the largest of which comprises living quarters, dining, social and accommodation facilities known as the “Red Shed” given its bright red colour.

Once at Casey Station, Nick was met by a team of three scientists principally involved in managing the fuel spill remediation site, who were stationed at Casey Station for approximately three months.

The Casey Station fuel spill involved some 10,000 litres of “Bergen” fuel having leaked from a ruptured delivery pipe between the main generator building and a holding tank external to the building.  Bergen fuel is a heavier fuel which has since been replaced by SAB (Special Antarctic Blend) diesel. Fortunately the spill had not migrated far and was initially contained by installing an impermeable barrier within the permafrost to about 1 metre deep around the down hill sides of the spill area.

Eventually the contaminated ground was excavated and placed into mounds formed on prepared ground. Preparation of this ground involved constructing a geo-synthetic clay liner on which a high density (impermeable) poly liner was placed to prevent any escape of fluid.

Once the pads were constructed the contaminated material was placed/formed into mounds. Within the mounds were a series of pipes to provide aeration, and covering the mound is geotextile fabric.

Bioremediation involves the artificial stimulation of microbial activity to eat away hydrocarbons (fuel) within the contaminated material. Whilst the microbes are naturally occurring they are effectively dormant for most of the year due to the very low temperature. Therefore, and given the limited time available for this to occur (generally November – February), the AAD has developed a system of pumping hot air and adding fertiliser nutrients (both liquid and granulated) which are incorporated into the mounds. Furthermore, as the summer period temperatures reach above 0°C the mounds are mechanically turned to improve aeration. This can occur 2-3 times per season.  

Due to the limited time frame each season the bioremediation process can take anywhere between 7-10 years to sufficiently decontaminate the mounds during which time Scientists, at least during the summer season, are actively monitoring, sampling, turning and testing the extent of the contamination and ensuring no escape of hydro carbons occurs into the surrounding pristine area.

Nick was away in Antarctica or travelling to and from Hobart for a total of five weeks, spending 2 days and 3 nights on the Antarctic Continent. The restricted availability of accommodation at Casey Station during the summer period when staff numbers can be in excess of 100 is one of the main limiting factors in the performance of non-essential activities on the Antarctic Continent. However, the logistics of moving equipment from Australia to Antarctica, generally via the Hobart-based AAD and staff is a very costly exercise and one which requires detailed planning and budgeting to minimise costs and maximise returns.

The above is presented as an example of Technical Assessing’s expertise particularly with respect to handling major losses involving technically challenging cases in remote locations combined with long tail demands.