Ann: Pre-Feasibility Study Completed for Mackay SOP Project, page-16

its written in the PFS:

The application of wet harvesting of the later stage waste salts and Potassium-bearing salts has delivered several key benefits to the Project, including:

• A lower overall operating cost per tonne of salt harvested that justifies the higher upfront capital;

• An increased overall recovery due to a portion of the Potassium-bearing brine entrained in waste salts in Ponds 2 and 3 being drained and pumped back into the pond system; and

• A decreased overall pond size due to Ponds 2, 3 and 4 not being taken off-line and dried prior to harvesting.