Salt pan near Onslow, Western Australia.

For the latest update on the Environmental Approvals Process please see Ashburton Salt and the Local Environment.

A sustainable industry

The concept of sustainability is embedded in the design and operation of new projects as a result of National and State Strategies, Agreements and legislation within Australia. Impacts on environmental values must be identified during an environmental impact assessment and avoided or minimised.

The design of solar salt works globally has advanced and best practice technology is required in the establishment of new projects. Examples in the way in which impacts are routinely avoided include:

  • Identification of important habitats and subsequent relocation and redesign of project infrastructure.
  • Use of conveyers rather than vehicle transport routes to reduce the project footprint, avoid collisions with animals and increase efficiency.
  • Screening seawater intake pump stations to avoid entrapment of marine animals.
  • Use of culverts in depressions intersected by linear infrastructure to maintain tidal flushing and stormwater flow paths.

The source of the solar salt product is renewable (seawater) and the production method is based upon naturally occurring processes (solar evaporation). Therefore it does not deplete non-renewable resources. Solar salt production has a long term lifespan thereby contributing to intergenerational equity.

The demand for high quality salt in the Asia pacific region is being driven by population growth and industrial demand. Australia has land areas suitable for large integrated facilities that can produce salt at competitive unit costs and sufficient volume to service the growing demand.

At the end of a solar salt field project’s life, should closure be warranted, the land within the project footprint can be easily decommissioned as the original earthworks and land disturbance is minimal in comparison to other mineral extractive industries.

Low Fossil Fuel Requirements

Solar salt production is one of the most efficient uses of solar energy, next to agriculture and forestry. Conversion of solar radiation into removal of water vapour from the brine has a 45% efficiency rate. Solar salt requires only a fraction of man-made energy compared with salt produced by solution mining and thermal evaporation.

Western Australia has the advantage of being the closest major salt producing state to the various Asia-Pacific customers with fewer carbon miles from the point of production to the consumer than alternative salt suppliers.

Habitat Creation

The majority of Australian solar salt fields are constructed on unvegetated and non-primary-productive supratidal salt flats. The environment of the salt flats is generally extremely hostile to life due to hypersaline groundwater and salt in the near surface sediments. The salt flats are generally devoid of flora and vegetation (except for occasional mainland remnants with the flats) and biological activity, and is not utilised by terrestrial fauna on any regular basis. The construction of solar salt fields involve flooding the salt flat with sea water creating an ecosystem that offers a number of unique ecological niches.

Studies on the ecology of solar salt fields have been an area of scientific interest for many years. A multi-tiered food chain is supported by the salt field ecosystem which is comparatively stable in comparison to the ephemeral fluctuations experienced in naturally saline or hyper saline coastal ecosystems (EuSalt, 2015). Salinity varies between the ponds from seawater to saturated brines offering a range of habitats.

Juvenile fish, mollusks and crustaceans are introduced by the pumping of sea water into the evaporator ponds wherein they grow rapidly and reproduce with few aquatic predators. Organisms of marine origin gradually disappear as they move from the initial ponds to more hypersaline environments. Other halophytic organisms develop in their place and, as there is no competition, they proliferate. Thus, a chain of organisms is developed in the evaporating ponds, similar to those of natural coastal wetlands.

Primary producers in a salt pan ecosystem consists of phytoplankton and to a lesser extent zooplankton communities which form an algal mat community on the bottom of the primary stage pond floors. The algal mat provides a home and food for a number of species of fishes, amphipods, copepods, larvae and juvenile crustaceans, molluscs and migratory and coastal birds.

Carribean flamingos on Inagua salt field

Protection of Habitats

In European countries solar salt fields are regarded as constructed ecosystems acting as natural wetlands and are recognized for their role in preserving habitat and so contributing to an overall strategy to reverse biodiversity loss (EUSalt, 2015).

References

  • European Salt Producers Association (EuSalt) (2015) Solar Salt Works & the Economic Value of Biodiversity Proceedings of the International Conference 2014
  • Davis J S., (1979) Biological Management of Solar Saltworks, In: Fifth International Symposium on Salt, Hamburg, Germany, pp. 265 – 268.
  • V.M. Sedivy (Sedivy) 2008, Environmental balance of salt production speaks in favour of solar saltworks. Salt Partners Ltd., Carl Spitteler Str. 102, Zurich, Switzerland; http://salt-partners.com/pdf/Santorini2006Paper.pdf
  • T D Sundararaj, M Ambika Devi, C Shanmugasundaram, Prof. Abdul A Rahman. 2006, Dynamics of solar saltworks ecosystem in India. Proceedings of the 1st International Conference on the Ecological Importance of Solar Saltworks (CEISSA06) Santorini Island, Greece. Available from: https://www.researchgate.net/publication/283070528_DYNAMICS_OF_SOLAR_SALTWORKS_ECOSYSTEM_IN_INDIA [accessed May 2, 2016].
  • Quashie A and Oppong D, 2006, Ghanaian Solar Saltworks: Promoting and Protecting the Ecology Proceedings of the 1st International Conference on the Ecological Importance of Solar Saltworks (CEISSA 06) 174, Santorini Island, Greece. www.srcosmos.gr/srcosmos/showpub.aspx?aa=7868
  • Food and Agriculture Organization of the United Nations (FAO) Available from: http://www.fao.org/fishery/en [accessed May 2, 2016]

This article was prepared by EnviroWorks, Perth, Western Australia, www.enviroworks.com.au

 

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