K+S Salt Australia has continued to build on its commitment to local Traditional Owners, with the completion of the first in a series of Cultural Heritage surveys on the AshburtonRead more
Shipping channel “not an option” for Ashburton Salt project
There will be no dredging for a shipping channel
as part of the proposed Ashburton Salt project near Onslow, it has been confirmed by K+S Salt Australia.
The commitment was reinforced following further analysis of off-shore conditions near the proposed project, including the site of a proposed jetty.
“When we first visited Onslow in 2016, the community views on dredging were loud and clear – the community would not accept our project if we dredged a shipping channel,” said K+S Salt Australia Managing Director Gerrit Gödecke.
“We have always known a shipping channel would not be an option for this project.”
Instead, the German salt producer is proposing the use of a low-draft transhipper to transfer salt to deeper, offshore water for loading onto larger ocean-going ships.
While the proposed shipping point is directly on the ocean, not the Exmouth Gulf (there will be no shipping at all on the Exmouth Gulf), the near-shore water is still very shallow. A small berthing pocket would require dredging for use in low tide, however it would be very small and dredging spoils would be unloaded on land, not the ocean.
In details recently finalised, the scale of pocket dredging and also indicative transhipment impacts – have been defined, providing more detail about the exact nature of the salt export process.
How will the salt be shipped?
A small berthing pocket will be dredged with dredge spoil unloaded on land. This minimises turbidity (murky water) impacts to marine water quality and marine life. The dewatered dredge spoil will be used as construction material on site.
The planned dimensions of the berthing pocket are 200 m x 35 m x 2.5 m of seabed – roughly just over the size of four Olympic size swimming pools laid end to end. The total dredge volume is estimated to be 17,000 m3.
An area has been nominated for ocean-going vessels to anchor and enable loading from the transhipper at sea.
No permanent moorings are proposed within these areas. To choose the exact anchor locations, bathymetric and side scan sonar surveys, followed by video footage will be taken, to confirm the ocean floor is sand, with sparse to no sea grass or coral.
Final site selection will be done in consultation with Pilbara Port Authority. K+S is confident of achieving no BCH loss in the transhipment area.
The transhipper will be managed according to best practice, in consultation with Pilbara Port Authority to prevent collisions with marina fauna, spills or introduced species.
The kind of transhipper proposed travels at an average speed of 10-12 knots – much slower than many recreational and commercial vessels which can travel more than 40 knots.
K+S is investigating options to fuel the transhipper with natural gas instead of traditional fuel oil to further improve the environmental footprint of the operations.