CDOIF Guidance

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Page 12
Supplement to Guideline – ‘Environmental Risk Tolerability for COMAH Establishments’
Storage Terminal Example v0.0
Aggregate Unmitigated and Mitigated Failure Frequencies per Receptor
Receptor Type H01: Diesel
storage in T1
and T2; 2 x
10,000m3 semi-
buried tanks –
non pressure
vessels.
Maximum acute
release volume:
10,000m3 from a
catastrophic
failure
Chronic
releases from
the tank bases
can go
undetected for
some time.
1,000m3
H02: Receipt
of diesel by
vessel.
Receipts of
fuel from
vessels are
pumped to T1
and T2 via
on-board
vessel pumps
and a
foreshore
pump house.
Maximum
release
volume
10,000m3.
H04: Release of
fire-water
containing
aqueous film
forming foam
(AFFF) and
entrained
hydrocarbons
during
operations to
combat a major
fire.
Maximum
release volume
15,000m3, based
on current fire
water
requirement
Unmitigated total failure frequency
per scenario
2.76x10-1 years 6.57x10-03
years
1.48x10-03 years
Mitigated total failure frequency per
scenario
1.46x10-03 years 3.57x10-05
years
7.40x10-04 years
6 – widespread habitat
– non designated
water (adjacent
estuary)
Scenarios H01, H02
and H04 result in a
Consequence Level A
Aggregate
unmitigated
failure
frequency for
the
establishment
2.84x10-01 years
Aggregate
mitigated
failure
frequency for
the
establishment
2.24x10-03 years
8 – groundwater body
(non-drinking water
source) (groundwater
within the fractured
bedrock)
Scenarios (H01, H02
and H04) result in a
Consequence Level A
Aggregate
unmitigated
failure
frequency for
the
establishment
2.77x10-01 years
Aggregate
mitigated
failure
2.20x10-03 years