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Sources, dispersal and impacts of wastewater in Antarctica

Jonathan S Stark (1), Kathleen E. Conlan (2), Kevin A. Hughes (3), Stacy Kim (4), César C. Martins (5)

(1) Australian Antarctic Division, Kingston, Tasmania, Australia
(2) Canadian Museum of Nature, Ottawa, Ontario, Canada
(3) British Antarctic Survey, Natural Environment Research Council,  Cambridge, UK
(4) Moss Landing Marine Labs, California, USA
(5) Centro de Estudos do Mar, Universidade Federal do Paraná, Pontal do Paraná, Brazil

The discharge of sewage and wastewater into the Antarctic environment represents a serious and significant risk of environmental impacts that includes the introduction of non-native micro-organisms and pathogens, genetic pollution and accumulation of, and exposure to, contaminants. Wastewater discharges could lead to long term impacts on wildlife health, biodiversity and community structure in the vicinity of Antarctic stations. Treatment and disposal practices vary widely, as each Party to the Antarctic Treaty determines their own standards with varying interpretation of requirements under the Protocol on Environmental Protection. Further research and monitoring of the impacts of wastewater on Antarctic ecosystems will assist in quantifying the potential risks and impacts. Currently, no guidelines exist that describe permissible levels of bacteria, chemical and other contaminants being discharged from outfalls within the Treaty area, but their development would be beneficial in setting a baseline for monitoring. One of the highest priorities of the Committee for Environmental Protection (CEP) is addressing the introduction of non-native species. Wastewater discharge is a significant source of potential introductions, but advanced wastewater treatment could substantially reduce this and other associated risks.

The Protocol on Environmental Protection to the Antarctic Treaty permits the discharge of sewage and wastewater (hereafter referred to as wastewater) from Antarctic stations into the sea or into deep ice pits in non-coastal areas, when its removal from the region is not practically achievable (Annex III – Waste Disposal and Management). Wastewater has also been previously disposed of in inland areas, including burial in snow, discharged into inland streams and lakes and onto ice-free land1, 2, none of which now meet the requirements of the Protocol. In accordance with the Protocol, discharge into the sea must take into account the “assimilative capacity of the receiving marine environment”, and must be located, wherever practicable, where conditions exist for “initial dilution and rapid dispersal”, but these terms are not currently defined. The minimum level of treatment required is maceration, but only where station summer populations exceed c. 30. In practice a wide range of treatment technologies are used1, 3, 4, ranging from no treatment (e.g. at many smaller or seasonal stations) to advanced tertiary systems.

Figure 1. The McMurdo wastewater treatment plant is a substantial facility to serve a population that can exceed 1000 people and carries a higher than average solids load which requires substantial macerators on line.

Wastewater on Antarctic stations includes domestic (kitchens, showers, toilets) and light industrial sources wastewater from laboratories and mechanical workshops. Station wastewater has some similarities to standard municipal wastewater, for example, high microbiological loads5, however, several properties can differ: wastewater may be more concentrated (as there is no stormwater or runoff inputs and water use is generally restricted) while nutrients, Biological Oxygen Demand (BOD) and settleable solid levels may be higher5 and environmental degradation rates lower3. Wastewater quantity may also be highly variable due to seasonal cycles in station populations; however, volumes are generally small in comparison to domestic outfalls, ranging from several hundred to tens of thousands of litres per day, with notably higher volumes at larger stations (e.g. McMurdo Station6). The large variability in wastewater parameters may cause technical difficulties for those operating treatment plants year-round.  Contaminants detected in wastewater and around Antarctic stations include metals, persistent organic compounds (POPs), (such as polybrominated diphenyl ethers (PBDEs)7, 8) surfactants, hydrocarbons, endocrine disrupting compounds3, pharmaceutical compounds9 and microplastics10.

Figure 2. Clarity of the water discharged from the McMurdo wastewater treatment plant.

Antarctic wastewater studies have focused on measuring the distribution and extent of wastewater discharged into the marine environment. Five categories of wastewater dispersal tracers have been identified: human-associated enteric bacteria e.g. Escherichia coli, Enterococci, Clostridum perfringens and total coliforms3, 11-13; human biomarkers e.g. faecal sterols14-16; contaminants and sewage molecular markers e.g. hydrocarbons12, linear alkylbenzenes15, trace metals12, polybrominated diphenyl ethers (PBDEs)7, 8, 12; stable isotopes6; and pharmaceutical compounds and drugs9, 10. Wastewater tracers have been detected in seawater, marine sediments and biota, including fish and invertebrates16, up to 2 km from stations. Studies have been undertaken predominantly during the summer; however, during winter when coastal areas are covered by sea ice the dispersal conditions may be different13. In general, wastewater discharged from Antarctic outfalls predominantly flows along the shore, with less evidence for dispersal out to sea12, 17. Exceptions are for offshore disposal sites on ice shelves or permanent sea ice such as the airfields at McMurdo Station18.The detection of tracers in the environment, however, does not indicate whether any environmental impacts result from the discharge.

The Protocol states that precautions should be taken to prevent the introduction of non-native micro-organisms to Antarctica, although it does not specifically mention risks posed by wastewater. Wastewater discharge results in the release of large numbers of non-native micro-organisms, viruses and pathogens3 to the environment that may remain viable for extended periods2, 19, and may also present a substantial threat to indigenous microbial and macrofaunal species20. Wastewater may also contain mobile genetic elements, such as those encoding for antibiotic resistance21, 22, which have been found established in local bacterial and animal populations20, 21 and have been termed “genetic pollution”. Beyond establishing the presence of non-native microorganisms, there has been little research to determine their potential impacts. There are many records of disease associated pathogens (e.g. Salmonella) present in Antarctic wildlife including Adélie and macaroni penguins, skuas, fur seals, albatross and gulls3, although evidence of an anthropogenic source or any subsequent disease outbreaks is lacking. Human faecal bacteria have been found in Antarctic wildlife, (e.g. clams, fish, sea urchins and starfish) with a higher incidence closer to outfalls, indicating ingestion of wastewater, further confirmed by stable isotopes6. No disease symptoms have been reported3 but an increased incidence of internal organ abnormalities were reported for fish around an outfall23.

Figure 3. This sectional view of the wastewater treatment plant for Davis Station indicates the complexity of the engineering needed for treatment.

Our understanding of the environmental impacts of wastewater discharged into Antarctic ecosystems is relatively limited, but a comprehensive study at Australia’s Davis Station indicated a potentially wide range of significant impacts resulting from practices currently regarded as acceptable under the Protocol24. Marine benthic communities have been studied at McMurdo, Casey and Davis Stations as indicators of wastewater pollution. In general, impacts on the communities were correlated with scale of the wastewater discharge, with reduced species diversity and abundance and dominance by some opportunistic species25, 26. Ecotoxicological studies of wastewater are rare but indicate toxicity to Antarctic marine invertebrates at low concentrations, over exposures of several weeks5. Very little is known regarding the impacts of wastewater disposed to inland areas such as ice pits, freshwater lakes and streams or ice-free areas. Extremely low degradation rates and recent climate change may lead to exposure of historical wastes and long term pollution problems2.

The effectiveness of wastewater treatment facilities depends on the type and level of treatment. Traditional wastewater treatment removes nutrients (to prevent eutrophication) and reduces microorganism/pathogen concentrations. Antarctic marine waters are generally not nutrient limited but significant risks to the environment may be caused by contaminants and microorganisms5. Most station treatment systems remove nutrients and lower BOD, thereby reflecting secondary treatment processes described in the Protocol, (i.e. Rotary Biological Contactors). However, the removal of sewage microorganisms becomes more effective when employing more sophisticated treatment processes, with advanced tertiary treatment almost eliminating micro-organism/pathogen release and removing all contaminants3, 5.

Figure 5. The Davis Station wastewater outfall when the sea ice is in.

Currently, no specific guidelines for wastewater disposal or allowable levels of bacteria in discharges from outfalls have been agreed upon under the Protocol. Technologies for wastewater treatment, however, have improved markedly since the Protocol was signed in 1991, and advanced tertiary treatment is now the best procedure to minimize the full range of potential risks from wastewater discharge. The release of untreated sewage, with the associated non-native microorganisms, genetic elements, chemical contaminants and nutrients, remains a cause for substantial concern. Monitoring of existing outfalls/disposal areas and further research on their potential impacts, particularly those related to harmful contaminants (such as POPs), microbiological impacts, genetic pollution and wildlife health may help to quantify the risk and their potential impacts, along with more sensitive analytical techniques to detect low levels of sewage input in the Antarctic environment (e.g. 14. ‘Sufficient “initial dilution and rapid dispersal” to prevent impacts may not be achievable in Antarctic nearshore marine environments, but advanced treatment methodologies represent the best possible solution to mitigate the environmental risks associated with discharge.


ATCM VIII.  Recommendation VIII-11.  Code of Conduct for Antarctic Activities.  Included the requirement for human waste (as well as garbage and laundry effluents) to be macerated and flushed into the sea, where possible.


ATCM XII.  Recommendation XII-4.  Waste Disposal Code of Conduct.  The Parties noted that improvements in logistics and technology increase the feasibility of on-site treatment of human and other waste, and recommended that their Governments seek advice of their Antarctic operating agencies on the desirability and feasibility of revising the Code of Conduct for Antarctic Activities, particularly with respect to the increased potential for on-site treatment.


SATCM XI-4.  The Protocol and its first four Annexes adopted.  Annex III provides for:

•  Sewage to be removed from the Antarctic Treaty area to the maximum extent practicable.

•  No disposal of human waste [and other wastes] on to ice-free areas or into freshwater systems.

•  Sewage may affect the marine be discharged into the sea, taking into account the assimilative capacity of the receiving environment and provided that the discharge is rapidly diluted and dispersed.

•  Large quantities of sewage [from stations of 30 or more people] shall be treated at least by maceration.

•  The by-product of sewage treatment by the Rotary Biological Contactor process may be disposed to sea provided that it does not adversely affect the marine environment.


COMNAP Best Practice Guidelines to avoid waste water disposal at inland sites


Antarctic Environmental Officers workshop in Hobart on waste management


COMNAP Workshop in Christchurch on wastewater management


Publication of first comprehensive impact assessment of sewage discharge into the Antarctic marine environment24 by researchers at Australian Antarctic Division.


ATCM XXXIX/CEP XIX -BP008/CEP 13 – Installation of a new waste advanced water treatment facility at Australia’s Davis station

Other information:

1.  Connor, M.A., Wastewater treatment in Antarctica. Polar Record, 2008. 44(02): p. 165-171.

2. Hughes, K.A. and S.J. Nobbs, Long-term survival of human faecal microorganisms on the Antarctic Peninsula. Antarctic Science, 2004. 16(03): p. 293-297.

3. Smith, J.J. and M.J. Riddle, Sewage Disposal and Wildlife Health in Antarctica, in Health of Antarctic Wildlife, K.R. Kerry and M. Riddle, Editors. 2009, Springer Berlin Heidelberg: Berlin. p. 271-315.

4. Gröndahl, F., J. Sidenmark, and A. Thomsen, Survey of Waste Water Disposal Practices at Antarctic Research Stations. Polar Research, 2009. 28: p. 298-306.

5. Stark, J.S., et al., Physical, chemical, biological and ecotoxicological properties of wastewater discharged from Davis Station, Antarctica. Cold Regions Science and Technology, 2015. 113: p. 52-62.

6. Conlan, K.E., G.H. Rau, and R.G. Kvitek, δ13C and δ15N shifts in benthic invertebrates exposed to sewage from McMurdo Station, Antarctica. Marine Pollution Bulletin, 2006. 52: p. 1695-1707.

7. Hale, R.C., et al., Antarctic Research Bases: Local Sources of Polybrominated Diphenyl Ether (PBDE) Flame Retardants. Environmental Science & Technology, 2008. 42(5): p. 1452-1457.

8. Wild, S., et al., An Antarctic Research Station as a source of Brominated and Perfluorinated Persistent Organic Pollutants to the Local Environment. Environmental Science and Technology, 2015. 49: p. 103-112.

9. González-Alonso, S., et al., Occurrence of pharmaceutical, recreational and psychotropic drug residues in surface water on the northern Antarctic Peninsula region. Environmental Pollution, 2017. 229: p. 241-254.

10. Waller, C.L., et al., Microplastics in the Antarctic marine system: an emerging area of research. Science of The Total Environment, 2017. 598: p. 220-227.

11. Hughes, K.A. and A. Thompson, Distribution of sewage pollution around a maritime Antarctic research station indicated by faecal coliforms, Clostridium perfringens and faecal sterol markers. Environmental Pollution, 2004. 127(3): p. 315-321.

12. Stark, J.S., et al., Dispersal and dilution of wastewater from an ocean outfall at Davis Station, Antarctica, and resulting environmental contamination. Chemosphere, 2016. 152: p. 142-157.

13. Hughes, K.A., Influence of seasonal environmental variables on the distribution of presumptive fecal coliforms around an Antarctic research station. Applied and Environmental Microbiology, 2003. 69(8): p. 4884-4891.

14. Leeming, R., J.S. Stark, and J.J. Smith, Novel use of faecal sterols to assess human faecal contamination in Antarctica: a likelihood assessment matrix for environmental monitoring. Antarctic Science, 2015. 27: p. 31-43.

15. Martins, C.C., et al., Sewage organic markers in surface sediments around the Brazilian Antarctic station: Results from the 2009/10 austral summer and historical tendencies. Marine Pollution Bulletin, 2012. 64(12): p. 2867-2870.

16. Edwards, D.D., G.A. McFeters, and M.I. Venkatesan, Distribution of Clostridium perfringens and fecal sterols in a benthic coastal marine environment influenced by the sewage outfall from McMurdo Station, Antarctica. Applied and Environmental Microbiology, 1998. 64(7): p. 2596-2600.

17. McFeters, G.A., J.P. Barry, and J.P. Howington, Distribution of enteric bacteria in Antarctic seawater surrounding a sewage outfall. Water Research, 1993. 27(4): p. 645-650.

18. Haehnel, R.B., et al., McMurdo Consolidated Airfields Study, Phase I, Basis of Design, 2013, Cold Regions Research and Engineering Laboratory, US Army Engineer Research and Development Center: Hanover, NH, USA. p. 104.

19. Smith, J.J., J.P. Howington, and G.A. McFeters, Survival, physiological response and recovery of enteric bacteria exposed to a polar marine environment. Applied and Environmental Microbiology, 1994. 60(8): p. 2977-2984.

20. Power, M.L., et al., Escherichia coli out in the cold: Dissemination of human-derived bacteria into the Antarctic microbiome. Environmental Pollution, 2016. 215: p. 58–65.

21. Miller, R.V., K. Gammon, and M.J. Day, Antibiotic resistance among bacteria isolated from seawater and penguin fecal samples collected near Palmer Station, Antarctica. Canadian Journal of Microbiology, 2009. 55(1): p. 37-45.

22. Hernández, J., et al., Human-Associated Extended-Spectrum β-Lactamase in the Antarctic. Applied and Environmental Microbiology, 2012. 78(6): p. 2056-2058.

23. Corbett, P., et al., Direct evidence of histopathological impacts of wastewater discharge on resident Antarctic fish (Trematomus bernacchii) at Davis Station, East Antarctica. Marine Pollution Bulletin, 2014. 87: p. 48-56.

24. Stark, J.S., et al., The environmental impact of sewage and wastewater outfalls in Antarctica: an example from Davis station, East Antarctica. Water Research, 2016. 105: p. 602-614.

25. Conlan, K.E., et al., Benthic changes during 10 years of organic enrichment by McMurdo Station, Antarctica. Marine Pollution Bulletin, 2004. 49: p. 43-60.

26. Stark, J.S., M.J. Riddle, and R.D. Simpson, Human impacts in soft-sediment assemblages at Casey Station, East Antarctica: spatial variation, taxonomic resolution and data transformation. Austral Ecology, 2003. 28: p. 287-304.