This needs to be put into perspective. The scheme mentioned is pumping
about 250 kL/day. This would be 90 mm depth of water over a square
kilometre, or around a 1m lowering of water table over a square kilometre.
If the water is of sea water salinity (40 000 mg/L) this
is an extraction rate of about 10T/day of salt, a 'drop in the ocean' of
Australia's
salinity problems. I doubt if there is a market for the vast quantities of
salt that need to be disposed of. There is only a limited market for high
grade salt, and the price of industrial grade salt would barely cover
freight.
I believe that evaporating basins in some
schemes are simply leaking brine back to the aquifer. Not really as bad as
it
sounds as the volume of water in storage has been reduced.
Australia's salinity problems are large, varied and complex. Both
tree-planting and engineering solutions ( bores, pumps and evaporating
basins) will be needed. There are no panaceas.
Robert Read
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