Original EA Amendment

PAR

Stage 1

Stage 2

It is expected that the outflow will reach areas of MSES, which may cause some impact to the existing ecosystem, but the area of damage is expected to be less than 1 km 2 . Low Harm to third-party assets in the failure path is expected to require less than $1 million or in rehabilitation, compensation, repair or rectification costs.

It is expected that the outflow will reach areas of MSES, which may cause some impact to the existing ecosystem, but the area of damage is expected to be less than 1 km 2 . Significant Harm to third-party assets in the failure path is expected to require $1 million or greater (but less than $10 million) in rehabilitation, compensation, repair or rectification costs.

General economic loss or property damage (2)

Overall consequence

Low

Significant

classification

(1) The PLL was calculated without the mining personnel

(2) General economic loss or proper damage does not include the holder’s own mine production, on-site

industrial or commercial assets or infrastructure solely for servicing the dam owner

4.3.2.2.6.

Environmental Spill/Failure to contain (Overtopping Consequence)

An embankment overtopping was deemed as non-credible for the proposed Upper Mundic Gully TSF,

given the storage design that allows containment of a 120-hr PMP storm volume. After such an extreme

storm, a subsequent storm of a sufficient magnitude to cause catastrophic damage or failure of the dam

is unlikely to occur prior to the water level being drawn down.

Therefore, the environmental spill/overtopping consequence has been based on a more frequent event

following a PMP storm, which is considered to be a credible failure scenario. Note, this scenario is not

expected to sufficiently erode the embankment to induce a breach. It is expected that any spills would

be largely attenuated by the OCP and contained in the downstream drainage infrastructure and Dee

River.

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Wulguru Technical Services Pty Ltd – Supporting Information to Amend an Environmental Authority

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