Table 20. PAR estimates (ANCOLD)
PAR
Stage 1
Stage 2
Mining operations
0
45
8 (1)
Township of Mt Morgan
0
Total
<1
53
(1) PAR corresponds to four properties identified within flood extents
Table 21. PAR Estimates (DETSI)
PAR
Stage 1
Stage 2
Mining operations
0
0
4 (1)
Township of Mt Morgan
0
Total
<1
4
(1) PAR corresponds to four properties identified within flood extents
4.3.2.2.4.
Consequence Classification ANCOLD
Table 22 presents the dam break CCA results as per the ANCOLD guidelines, considering the PAR
and overall severity of damage and loss. It is noted that ANCOLD specifically recommends that
consequence category for tailings dams is to be evaluated against the PAR rather than PLL due to the
nature of the released material and uncertainty in estimating fatality estimates for tailings outflow.
However, due to the expected displacement of water in the Open Pit, consideration of the PLL was also
deemed suitable for this assessment.
Table 22. Consequence Category Assessment for Upper Mundic Gully TSF
Embankment
PAR
PLL
Overall severity of damage and loss
Consequence category
Stage 1
<1
<0.1
Major
Significant
Stage 2
53
0.6
Major
High B
4.3.2.2.5.
Consequence Classification DETSI
Table 23 presents the dam break CCA results as per the DETSI guidelines, considering the PAR, PLL
and environmental significance for all assessed scenarios.
Table 23. Consequence Category Assessment for Upper Mundic Gully TSF – DETSI (Dam Break scenario)
PAR
Stage 1
Stage 2
Low People are not routinely present in the failure path and no loss of life is expected. Contamination of waters used for human consumption is not expected to affect human health.
Low A PAR of 4 with a PLL of less than 1 was estimated along the failure path. Contamination of waters used for human consumption is also not expected to affect human health.
Harm to humans (1)
General environmental harm
Low
Low
85
Wulguru Technical Services Pty Ltd – Supporting Information to Amend an Environmental Authority
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