| Summary: | Antarctica is widely perceived as the most untouched continent on Earth. However, increasing anthropogenic presence in Antarctica is creating continual pressure on the pristine environment. To protect the Antarctic environment, monitoring and reporting procedures must be a priority for Nations wishing to conduct research on the continent. A significant contributor to environmental degradation is poor waste management and waste disposal, in particular the discharge of sewage and wastewater into the marine environment. This study provides information on the potential impact of Scott Base wastewater on the local marine environment, which can be used to improve operating systems and as a tool to ultimately reduce the environmental footprint of the base.
This study investigated the characteristics of the sewage from Scott Base, Antarctica, and the water quality within the wastewater discharge plume beneath the sea ice. Results from seawater analysis were then compared with Redvers (2000) to give an indication of how contamination levels have changed over the last decade. Results show that in the vicinity of the wastewater outfall, seawater samples contained no faecal coliforms or Escherichia coli. Nitrate-Nitrogen (NO3ˉ- N) concentrations were recorded up to 1.1 mg/L, while phosphate (PO43-) ranged from 0.28 to 0.45 mg/L. The pH ranged from 7.84 to 7.92. Dissolved oxygen ranged between 10.05 and 13.02 mg/L, and conductivity between 48.4 to 55.2 mS/cm. Concentrations of copper (Cu), manganese (Mn), and zinc (Zn) were greatest at sites within 30m of the outfall. Iron (Fe) and nickel (Ni) were detected at most sites within the plume. The general spatial extent of the plume is now approximately 50m long-shore, and 30m offshore. Compared to Redvers (2000) the current plume is more localised, with a reduction of approximately 100-125m long-shore and 10-20m offshore. Faecal coliforms have reduced to no longer be detected within the plume, while dissolved oxygen and total organic carbon concentrations in the plume have increased, and conductivity has decreased.
Soils surrounding Scott Base were also investigated as a potential source of trace metal (As, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) discharge to the marine environment. Total recoverable soil metal concentrations and readily leachable metal concentrations were measured. Sites were selected on the basis of being potential sources of contamination (fuel storage areas or refuelling areas), or potentially effecting the marine environment (shorelines). Results show that the greatest concentrations of metals and readily leachable metals were found primarily along the shoreline, and not necessarily where contamination related to current base activities is likely to occur. The results indicate that historic contamination may still persist in the terrestrial environment, and has the potential to be transported into the marine environment.
Domestic and drinking water samples were analysed for trace metals and nutrients to ensure that contaminants from the wastewater outfall were not entering the reverse osmosis plant. Results show that the drinking water meets New Zealand Drinking Water Standards (Ministry of Health, 2008).
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