South Australia’s opposition leader, Isobel Redmond, was quoted on 20 June 2011 in the Australian media as being “satisfied” that the Olympic Dam desalination plant will not cause any damage to the local environment, including the area’s giant cuttlefish population.
This follows publication in mid-May 2011 by mining company BHP Billington of a supplementary environmental impact statement (SEIS).
The SEIS addresses the environmental, social, cultural and economic issues raised in more than 4,000 public submissions on the draft EIS, which was released to the public in May 2009. BHP Billiton declares itself to be fully committed to “this important process” following more than five years of engagement with government, industry and community.
In the SEIS, BHP Billington reveals that it has decided to put the outfall pipe in tunnel to avoid blasting effects which would have been caused by trenching. The total length of the outfall pipe has also been extended by approximately 200 m beyond that shown in the draft EIS.
Both these changes are to reduce impacts on a regionally significant sponge community.
The SEIS refutes a large number of submissions related to the effect that the return water would have on the marine life around the outfall and on the general salinity of the Gulf of Spencer in which it will be sited. The main argument is that the diffuser design for the outfall would cause sufficient dilution within a short radius to make the difference in salinity insignificant.