SEA CHANGE Australia's love of coastal living is leading to some
serious environmental problems, as more and more Australians are
choosing to build along coastal areas. This is leading to the
leaching of acid soils, which is degrading our coastline, marine
life and infra-structure. Australian coastal soils have a high
Pyrite content and when disturbed through excavation and
construction is leading to the natural production of sulphuric
acid, which is then washed down to the rivers and sea causing
heavy environmental damage. What is Pyrite? Pyrite (FeS2) is a
common mineral found in soils around the coast of Australia. It
is brass yellow in colour and has a metallic lustre. In
industry, Pyrite is used to manufacture sulphuric acid (H2S04),
which is widely used in the production of fertilisers, steel,
explosives and petrochemicals. In soil Pyrite is relatively
benign, but when disturbed and exposed, it reacts with oxygen
and water in the environment to produce sulphuric acid. ?One
tonne of pyrite gives 1.6 tonnes of sulphuric acid. How much
Pyrite do we have? Australia has some 40,000 sq km of coastline
and CSIRO research has estimated there is one billion tonnes of
pyrite in Australia's coastal soils, potentially leading to
serious environmental degradation in the near future as our
coasts are opened up to more and more development What are the
effects of sulphuric acid on the environment? Sulphuric acid is
toxic to aquatic life and organisms and can destroy
infrastructure leading to costly repairs. It is known to: ?Kill
fish; ?Release potentially dangerous arsenic and aluminium in
shellfish such as oysters, which are later consumed; ?Eat away
at concrete bridges, structures and footings; ?Eat away at road
structures and steel structures such as bridge pylons. What are
we doing to fix the problem? ?The CSIRO are undertaking studies
to map where the reactive soils occur. They are determining what
are the properties of the soil, then mapping key "hotspots".
?Some State Governments are putting planning policies in place
to limit the development of these key sensitive areas. ?Where
the damage has already occurred, state governments are
rehabilitating the soils and the environment, which is extremely
costly. Government Policies Victoria, Queensland, NSW and South
Australia have government planning policies in place. ?The South
Australian Government has only put in place limited "fringe"
policy and needs to address the issue on a broader scale. ?In
West Australia, Northern Territory and Tasmania no such policies
exist. As an island country, it is imperative that these
planning policies are introduced in key sensitive areas.
Rehabilitation Rehabilitation is a large task and already in
parts of Cairns and South Australia, small areas are costing
millions of dollars to repair.
About the author:
Tobi Nagy is a small business develoment consultant and a
specialist on developing sustainable systems. His website can be
found at http://www.sustainable-development.net
|
