Antarctic Sewage

This paper investigates waste water disposal in Antarctica and shows that more than half (52%) of the 71 research stations located in the largest pristine wilderness of the earth, still lack any form of waste and water treatment system (i.e. the process of removing physical, chemical and biological contaminants). A questionnaire, asking about the handling of waste and grey water, the type of sewage treatment and installation and operational costs, was sent out by the authors, to all 28 nations currently active in Antarctica. The results showed that 37% of the permanent stations and 69% of the summer stations completely lack any form of treatment facility and most of the stations that have a treatment system, installed it only during the past decade. The most common type is biological treatment (used by 20% of the stations), 10% of stations use macerations (which only removes solids such as waste, fats, oils and grease), another 10% use secondary biological treatment (i.e. the removal of dissolved organic matter using waterborne microorganisms) and only two stations (5%) use septic tanks. The study also shows that the treatment methods used at many stations are not efficient enough to reduce the likelihood of spreading introduced human-derived microbial pathogens to the environment. In fact, to handle the problem of microbial agents, only four stations use chemico-physical tertiary treatment systems, such as microfiltration, UV sterilization, chlorination, electric fields or ozone disinfection. Moreover, to be effective in Antarctica, depuration practices need to be adapted to local conditions, because some technologies, developed and commonly used in temperate areas, do not function in the harsh Antarctic environment. For this reason, stations with existing treatment systems often report operational problems and malfunctions, especially during periods of a high influx of people, when the plants are unable to cope with the high sewage input level (~100 litres per person per day). However, the summer climatic conditions in Antarctica, are no more extreme than conditions in Scandinavia, Greenland, Alaska and Canada, which have large populations and efficient waste water treatment.

In recent years there has been a continued growth in the number and size of stations and semi-permanent field camps in Antarctica. In the winter season approximately 1000 scientists and technicians carry out research and monitoring activities, while during the austral summer, which is also the most biologically sensitive period for terrestrial biota, the scientific community is estimated to comprise around 4000 people, to which must be added approximately 37500 tourists which visit Antarctica every summer. Most Antarctic stations are situated along the coastline, where accessibility is better and both research and tourism can noticeably increase the risk of introducing new humans infectious agents to the Antarctic flora and fauna. When waste and grey water containing microorganisms are released in the environment, microbes can remain viable in the low-temperature Antarctic conditions for prolonged periods and may have the potential to infect, cause disease, or become part of the gut flora of local bird, mammal, fish and marine invertebrates. Many studies have already detected well-known pathogens that may have been introduced by humans, such as Escherichia coli, Salmonella enteritidis, Salmonella typhimurium, Campylobacter jejuni and Pasteurella multocida, in both seal and bird populations. In addition to microorganisms, grey water, which comes from laundry, showers, sinks and washing dishes, may also contain fat, oil, detergents and other residues from personal hygiene products with surfactants that may be environmentally harmful. The organic enrichment by the sewage water from American McMurdo Station has already had a significant negative impact on the benthic community structure and high densities of coliform bacteria have been found along the shoreline outside the base.

Although the Protocol on environmental protection to the Antarctic Treaty states that the protection of the Antarctic environment is in the interest of mankind as a whole and it obliges all countries to apply and develop responsible waste management principles, much can still be done by the 28 nations operating the 82 research stations in Antarctica. The costs for installation and operation of waste water treatment systems are reasonable if compared with the overall cost of Antarctic research. The technology already exists for effective sewage treatment in the challenging polar conditions and thus, their use, coupled with a more efficient environmental monitoring, is necessary at all permanent and summer Antarctic research stations, in order to minimize the human impact on the most pristine continent on Earth and to protect it from human-derived infectious agents.

Reference:

Gröndahl, F., Sidenmark, J., Thomsen, A. (2008). Survey of waste water disposal practices at Antarctic research stations. Polar Research 28: 298-306.