Yandi JSW & Oxbow

Rio Tinto Iron Ore’s Yandicoogina mine (operated on behalf of Hamersley Iron Pty Ltd),  is located in the East Pilbara region of Western Australia. A number of creeklines traverse the mine area, including Marillana, Yandicoogina, Phil’s and Weeli Wolli creeks.

The mine has been operating since 1996, and as part of mine operations dewatering of the Yandi JSE and Central pits has been necessary since 1998, with excess water discharged directly into adjacent creeklines. Rio Tinto is currently developing new deposits Junction South West (JSW) and Oxbow at Yandicoogina, with excess water from dewatering operations discharged to creeklines.

To support the proposed surface water and groundwater dependant ecosystems management plans required under Ministerial Statement 914 prior to discharging from JSW & Oxbow, Rio Tinto commissioned WRM to assist in the development of site-specific operational water quality guidelines, as per ANZECC/ARMCANZ (2000). The environmental approvals process for the JSW and Oxbow developments were the impetus to develop water quality guidelines (in addition to existing Yandi water license requirements), however, the new triggers will be applied to the entire Yandi operations in the future.

Data on the quality of groundwater discharged to creeklines were also used in a hazard analysis to assess potential risk to aquatic ecosystems.