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Public Information Booklet
Saline water from the desalination process will be discharged into the sea at a rate and a
location where it can be shown that there will be minimal impact on the marine
environment/saltwater country.
Questions:
� Can you please provide some more information on desalination?
� How does the desalination process work? How does the process affect the
sea?
There are two different ways desalination of salty water can be achieved in order to get
fresh water. This can be either by vacuum distillation (basically boiling water and
condensing the steam to make fresh water) or via reverse osmosis where water is
pumped to a very high pressure and pumped through a membrane with very small holes
in it that lets the fresh water pass through but not the salt.
Independent of the method used to produce the fresh water there will be a waste steam
of salty water (called brine) that needs to be managed. This water has nothing extra
added to it so if the water was extracted from the ocean, then the brine is just sea water,
but it is twice as salty. This ëextraí salty water quickly mixes with the ocean and is diluted
back to normal salt levels (typically within tens of metres of the outfall location where it is
put back in the ocean).
If the source water used is from the Wallal deep aquifer then less brine will be produced
and the brine that is produced will be less salty (even less salty than the sea). This is
because the Wallal water has much less salt in it (only one tenth of the salt that the ocean
has). As a result, the brine from treatment of the Wallal is much easier than the
management of the brine from sea water. If a fresh water source is used (e.g. shallow
ground water) then there would be almost no brine to manage at all.
5.7. General Issues
Construction Materials Requirements
Question - What construction materials/rock is required for foundations and other
construction/Precinct needs and where will it be sourced from?
The range of potential construction materials required for the civil and marine
components of the project includes: rock for sub-sea pipeline stabilisation/protection
works, armour and core for breakwater development, concrete aggregate for marine and
plant structures, bulk fill materials for onshore earthworks, potable water resources and
pavement materials for road construction.
It is recognised that on the Dampier Peninsula, the availability of suitable materials for
these purposes is likely to be limited and will require evaluation and negotiation with
Traditional Owners and authorities. Although still to be assessed, possible locations in
the Kimberley to source construction materials may include Nillibubbacca quarry and
Cockatoo and/or Koolan Islands.
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