~
RUSAL
. . . . . . AnallNI:-i1l
6th March 2012
Environmental Protection Agency
Office of Climate, Licensing & Resource Use
EPA Regional Inspectorate
P.O. Box 3000
Inniscarra,
Johnstown Castle Estate
Co. Cork
Co. Wexford
Attn: Ms Sonja Smith
Mr.Michael Owens
Review of existing IPPC License.
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Ref: IPPC P0035-05
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Ms Smith,
Further to Agency letter dated 24th November 2011 from your Mr. Owens to our Mr.Fleming re.
classification of the Bauxite Residue Disposal Area (BRDA) and further to Agency letter dated 28th March
2011 from your Mr. Owens to our Mr. Fleming re. BRDA stability monitoring and compliance with BREF
Management of Tailings 2009, Rusal Aughinish (RA) submit the following
Attachment 1. Describes particular BRDA Design and Operation and particular applicability of some
but not all aspects of the BREF to our BRDA here to emphasise that the BREF cannot prescribe a
one size fits all residue storage regulation.

Attachment 2. Summarises and updates with revised data and information the Aughinish rationale
that the BRDA should be categorised as “NOT Category A”

Attachment 3. Lists the Aughinish BRDA Stability Monitoring Programme and shows why it
complies with BAT as outlined in the BREF.
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
RA has since the commencement of its operation in 1983 adopted BAT in the form of thickened tailings
technology. Since 2008 we have further enhanced the BRDA operation (over and above any technique
described in the BREF) with the introduction of mud farming using amphirolls, an Australian alumina
industry developed technology. This has significantly enhanced the physical stability of the BRDA by
making the residue denser and stronger and thereby increasing its physical stability.
_________________________________________________________________________________________________________
Aughinish Island, Askeaton, Co Limerick – Ireland – Tel. +353 (0)61 604000 – Fax +353(0)61 604242 – www.rusal.com
DIRECTORS: K Bezzubov, D A Clancy, I Firyukov, D Goldberg, D Makarenko, A Shmalenko, K Strunnikov
Reg. in Ireland No.59982. Reg. Office: Aughinish Island, Askeaton, Co Limerick, Ireland
EPA Export 17-04-2012:03:54:23
RA has since July 2011 at a test scale and since January 2012 at a pilot scale introduced atmospheric
carbonation of the bauxite residue. The effect of this carbonation is to reduce the liquid phase alkalinity in
the red mud to ensure that both leachate and runoff from the BRDA pose less chemical risk to the external
environment.
RA has organised recently specific corrosivity testing of bauxite residue and its leachate and the results
indicate that neither bauxite residue nor its leachate is corrosive as defined in the Dangerous Substances
Directive.
In addition in order to enhance the physical stability of the overall BRDA structure and to reduce the risk of
any structural failure, RA has decided not to construct the Upper Level Interceptor Channel (ULIC) at Stage
6 originally designed to facilitate landscaping (see Figure 6.4 of original Breakout Study submitted in 2011).
Golder Associates recently revised the containment failure probability assessment to take account of
eliminating the ULIC and reported that the risk of BRDA containment failure reduces very significantly from
1 in 8,700 years to less than 1 in 400,000 years because the potential for blockage of spillways, overflow
pipes and channels has been consequently removed. As this ULIC feature has not been constructed to date,
that risk does not exist in 2012 but that risk had been accounted for in the 2006 Break-Out Study and
associated Risk Assessment.
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Furthermore RA indicates in Appendix 3 the extensive stability monitoring and visual inspections
undertaken in the existing BRDA. The particular instrument monitoring is undertaken on a quarterly basis by
Golder Associates as their recommended frequency. Golder Associates have proposed to Aughinish the
extent and frequency of stability instrument monitoring and site investigation frequency as adequate for
facility management given that the stability risk and in particular that the Aughinish BRDA is a stacked
thickened tailings facility and not a conventional tailings pond.
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Please note that the monitoring schedule listed in Table 4.15 page 400 of the BREF was adapted, (not
transcribed) by the original BREF drafting team from ICOLD Bulletin No. 104 “Monitoring of Tailings
Dams”. There is an extensive 14 page description in that bulletin of monitoring parameters for upstream
raised tailings (ponds) dams but lists none for stacked thickened tailings with no water storage. That original
bulletin does not mention or prescribe at all the monitoring frequencies. The BREF Table 4.15 description
also uses the term “typical” and “examples” and should not be regarded as prescriptive.
In conclusion, RusalAughinish contends that:


The proposed categorisation of the BRDA should be “NOT Category A”. The decision to remove the
upper level interceptor channel from the design re-enforces this.
The recommended type and frequency of BRDA stability monitoring tasks and visual inspections is
BAT and in compliance with BREF and is best defined by the judgement of competent independent
geotechnical experts because BREF Table 14.5 should not be interpreted as a one size fits all tailings
stability monitoring schedule.
Yours truly
Thomas Hartney
Consultant Engineer for Aughinish Alumina Ltd.
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Submission regarding Classification& Licensing of the Aughinish BRDA under the
Extractive Waste Directive (2006/21/EC)& EU Decision 2009/337.
Attachments
1. Description of Aughinish residue containment system & relationship toBAT
2. Updates with revised data forRusal Aughinish rationale that „NOT Category A‟ should apply
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3. Summary of Aughinish stability monitoring and compliancewith BAT as defined in BREF.
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1.1 Description of Aughinish residue containment system in relation to BREF
In summary the bauxite residue (tailings) containment at Aughinish uses a permeable upstreamstage raise method of construction to retain the residue and has an
interior (rather than perimeter) system of stacked residue deposition. Therefore the 2% sloping surface of the residue from the interior to the perimeter ensures that
water flows off the surface of the residue, drains through the permeable upstream walls and flows downwards into an external surface water collection drain.
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Therefore the leachate and rainfall are collected in a ground-level perimeter drainage channel; see Figure 1.1 which is outside the structural containment perimeter of
the residue. There is no storage of water on the existing BRDA. Currently 9 of the 10 permitted stages have been constructed on the Phase 1 BRDA.
Figure 1 .1Aughinish BRDA with structural containment of residue (tailings) shown in yellow.
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Table 1.1 Containment system described in BREF and contrast with scheme at Aughinish
Heading
Description
Contrast at Aughinish
Tailings
Dams
Describes tailings ponds with
percent solids 20 to 40%
2.4.2.2
Confining
dam
Permeable Dam (applicable)
2.4.2.4
Removal of
free water
2.4.2.5
Seepage Flow
3 systems described in
figures well as overflow
systems
Figure 2.46 on flat ground
2.4.3
Thickened
tailings.
Thickened tailings consolidated to 70 to
74% solids. Figure 2.26 does not
describe Aughinish‟s thickened tailings.
Retains (confines) the bauxite residue
but facilitates unimpeded drainage of
storm-water and leachate.
In contrast Aughinish uses totally
permeable stage raised walls to drain all
surface water away.
Seepage can be removed though the
permeable stage walls. Prevention of
seepage through/near the toe of the inner
wall (that could potentially undermine
conventional tailings dams) is not a
feature of the Aughinish design as the
wall is deliberately highly porous.
At Aughinish both walls are porous and
decants are not used as these have the
potential for blocking.
3.1.1.3.1
page 100
Under Figure
3.3 the text
reads 
3.1.1.3.3
page 107
Safety and
accident
prevention
4.4.10
Design Flood
for tailings
ponds
4.4.14
Monitoring of
Tailings
4.4.16
Dewatering
of tailings
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Figure 2.47 represents a
tailings in Australia with
impermeable dams and
decant tower
“ In both cases, the tailings
mature to 70% solids”
.
BREF
Section
2.4.2
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Sardinian alumina plant
tailings pond which has an
impermeable upstream wall
(page 105) has monthly
piezometer monitoring and
stability checks twice yearly.
These are based on “ponds”
and a low hazard pond would
have a 1 in 100 year flood
design
Extensive description of
types and frequency of
monitoring and inspections
Describes tailings ponds with
percent solids 20 to 40% and
indicates concerns with
regard to mobility if tailings
structures collapses
Since 2002 when that information
transmitted to EU for the BREF, the
residue solids has increased to 74% due
to introduction of mud farming using
“amphirolls”, so therefore it is more
solidified and more stable.
As Aughinish has more stable thickened
tailings which is solidified and hardened
by mud farming, Aughinish has quarterly
monitoring, quarterly stability reviews
and annual stability inspection audit.
Aughinish by contrast is a thickened
tailings with no water storage and has a 1
in 200 year flood resistant design.
See Attachment 3 below.
Thickened tailings consolidated to 70 to
74% solids; therefore risk of tailings
mobility is significantly reduced.
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Table 1.1 (Continued) Containment system in BREF and contrast with scheme at Aughinish
Heading
Description
Contrast at Aughinish
Thickened
tailings
4.6.1
Mitigation of
Accidents
Recommended as safer
option compared to slurry
disposal in conventional
tailings ponds.
Emergency Planning and
Response
4.6.2
Evaluation
and follow
up of
incidents
Describes requirements
4.6.3
Tailings pipe
line burst
Detection systems
required
4.7
5.2
EMS tools
BAT
Generic
Aughinish utilises thickened tailings disposal
but has enhanced this with the practise of
mud farming using amphirolls to consolidate
and increase the density of the residue.
Aughinish is accredited to the International
Safety Rating System (ISRS) and to ISO
14001 which addresses this issue and
Aughinish undertakes extensive emergency
planning to deal with such emergencies.
Aughinish employs an extensive system of
reporting, investigation and corrective action
follow-up system for both safety related and
environmental related incidents. Causes and
effects of accidents are clearly documented,
the learning outcomes are locked into our
information systems, and that there is follow
up to ensure that future incidents are
prevented.
Aughinish employs online pressure
monitoring, flow rate meter and density
monitoring and all report directly to the
relevant control room, so any pipeline failure
would be automatically detected by the
control room operator. However as the
scaling rate and wear rate of critical parts of
the pipe line is also monitored as part of the
Non Destructive Examination system at
Aughinish, pipe-line failure through rupture
would be a highly improbable event.
Aughinish EMS is certified to ISO 140001.
In addition to the original submission,
Aughinish has since July 2011 on a trial scale
and since January 2011 on a pilot scale
implemented atmospheric carbonation of
bauxite residue.
Residue carbonation will ensure that the
leachate and runoff generated will be more
benign than the un-treated leachate and
runoff.
BAT page 429 of BREF “is to neutralise
alkaline effluents with carbon dioxide.”
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BREF
Section
4.4.16.2
Implementation of BAT
for Residue Disposal at
Aughinish was listed in
Appendix C of original
submission to Agency in
February 2011.
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Attachment 2.0 Update of Rusal Aughinish rationale for classification as ‘NOT Category A’
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2.0 Update on why ‘Not Category A should apply to Aughinish BRDA
The previous submission to the Agency in February 2011 in relation to classification of the BRDA facility listed every relevant article and sub-article with EU
Decision 2009/337 and listed the Aughinish BRDA performance in relation to the classification criteria. The submission listed issues in relation to the risk and
consequences of containment failure as well as characterising the residue in relation to the Hazardous Waste Directive and Dangerous Substances Directives. The
original Aughinish Assessment is still valid but particular aspects will be updated (see Table 2.1) and the previous 2011 Summary Table submitted is now updated,
see Table 2.2 below.
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RA respond as follows to Agency letter dated 24th November 2011 which listed as an event “containment failure” that could cause a major accident leading to
1. non-negligible potential for loss of life OR
2. serious danger to human health OR
3. serious danger to the environment
Issue
Factor determining
Aughinish revised response
In light of the Agencies intention expressed in the letter of 24th November last, Aughinish and Golder
Associates have reviewed aspects of the Phase 1 and 2 BRDA which could lead to increased risk of
“containment failure”. RA has decided not to construct the Upper Level Interceptor Channel (ULIC) described
in the 2004 Design Report and in the related Breakout Study and Risk Assessment. This has removed the risk of
Containment
Risk of that event
water storage at height due to blockages of the culverts. The presence of water would increase the risk of mud
failure
mobility. By removing the ULIC the risk of red mud release reduces from 1.14 E-04 to 2.46 E-06. Therefore the
risk of failure has reduced from „Highly Unlikely‟ to less than „Highly Improbable‟. See attached Event Tree
Figures 2.1 & 2.2 replacing original Figures 8.1 & 8.2 in the original 2006 Breakout Study. The risk of failure
in Sector D near the Water Treatment Plant has reduced to 2.90 E-08.
The thickened tailings that are pumped to the BRDA are quickly consolidated and strengthened using the mud
farming “amphiroll”, see figure 2.1 attached. Therefore over the majority of the BRDA, the cross sectional
non-negligible
Human lives are threatened
depth does not contain slurry but compacted and strengthened solid residue. The compacted residue is capable
potential for
where slurry levels exceed 0.7
of supporting all common types of excavation plant as well as 4 wheel drive vehicles. Therefore the well farmed
loss of life
metres
residue is no longer slurry and will not readily flow out of the BRDA. Currently there is no public or third party
access to land outside the BRDA perimeter where any mud slurry from containment failure could flow to and
impact on human life.
The decision not to construct the Upper Level Interceptor Channel described above will also remove the risk of
non-negligible
Human lives are threatened
water levels exceeding 0.7 metres. This risk previously existed in the event that a culvert or spillway became
potential for
where water levels exceed 0.7 blocked. That original risk was assessed as 6.28 E-05 and is now reduced to zero by eliminating that ULIC from
loss of life
metres
the design. Currently there is no public or third party access to land outside the BRDA perimeter where runoff
water from the BRDA by containment failure could flow to and impact on human life.
Intensity of the potential
The bauxite residue and red mud leachate has been recently classified as Not Corrosive following specialist
serious danger
contaminant source strength is laboratory testing in compliance with the Dangerous Substances Directive, see Table 2.3. In addition, Rusal
to the
(NOT) decreasing significantly Aughinish has commenced atmospheric carbonation of the bauxite residue and therefore the risk of alkaline
environment
within a short time
contamination in both runoff and leachate will significantly decrease.
Table 2.1 Particular Response on Highly Improbable “containment failure” scenario”
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Issue
Comment
Conclusion
Risk of Structural
Integrity Failure
The annualised risk has been calculated at 2.46E-06 which is in
the „Highly Improbable‟ range especially given that the
remaining life of the BRDA is estimated to be just another 20
years until 2032.
This would not
trigger Category A
classification.
Potential for loss of
life or danger to
health
No members of the public are exposed to the residue as the
current BRDA is lower than either the public road, local
authority water treatment plant or the nature trails?
This would not
trigger Category A
classification.
Potential for serious
danger to the
environment
BRDA complies with all relevant aspects of BAT. Atmospheric
Carbonation reduces the liquid phase alkalinity. In the „Highly
Improbable‟ event of a failure, any remaining caustic leachate
from Bauxite Residue released to the environment would be
neutralised and buffered by the saline tidal estuary and the
brackish groundwater.
This would not
trigger Category A
classification.
Water and slurry
levels exceeding 0.7
metres above ground.
There is no water stored on the tailings because RA thickens
and stacks mud at a slope in contrast to the conventional
tailings ponds. Therefore there is no risk of water storage at
high levels.
Category A
classification not
triggered
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Mud layers are constantly consolidated, dried and strengthened
by the mud farming technology. The strengthened and
hardened residue is capable of supporting all common types of
excavation plant as well as 4 wheel drive vehicles. Therefore
the well farmed residue is no longer slurry and will not readily
flow out of the BRDA. Currently there is no public or third
party access to land outside the BRDA perimeter where any
mud slurry from containment failure could flow to and impact
on human life.
There is no water stored on the residue and therefore no water
velocity is generated. The absence of water on the residue
makes it extremely difficult for consolidated and hardened
residue to be mobilised. Currently there is no public or third
party access to land outside the BRDA perimeter where runoff
water from the BRDA by containment failure could flow to and
impact on human life
Category A
classification not
triggered
Hazardous Waste
content at end life
exceeding 5%.
The current hazardous waste salt cake 010307 represents just
over 1.5% of the total residue.
This would not
trigger Category A
classification.
Dangerous
Substances content
aqueous phase
during operation of
Facility
Recent testing has confirmed that bauxite residue and
associated leachate is Non Corrosive and therefore it will not
be classified within the Dangerous Substances Directives., see
extracts listed in Table 2.3
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Water and slurry
velocities exceed
0.5m/s
Red mud code 010309 is classified as Non Hazardous within
the EWC. And the recent laboratory analysis of bauxite residue
as Non Corrosive confirms that Aughinish‟s red mud is NOT
classified as Hazardous Waste
This would not
trigger Category A
classification.
Table 2.2 Update of Previous 2011 Submission Summary
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Figure 2.1 Amphiroll faming and subsequent Bulldozer Operations on solid residue at Aughinish
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Stld
S MMARY
°20110252TC C
I
The aim of the study was to assess the skin corrosion potential of COMPACTED RED MUD AFTER
AMPHIROLLING using an if! vitro skin corrosion model based on reconstructe{j human skin.
Firstly, a preliminary study was performed to identitY the possible interference between MTT and test
item. In a second phase, the main study involved 15 reconstruc.ted epidermis units (3 per group) as
describe{j below:
COMP CTED RED MUD AFTER
..MPHIROLLI G
Table t
In Vh.ro Skin Corrosion: HU111an Skin
Model Test
(OCDE 431
Treatment design
Groups
l'.umbco<
Dr
ConcmtratlCln lO be
Te:stitem
lest item
undiluted
.3 minute.s
I hour
3 minutes
N~ti\"e conuol
0.9%
0.9%
Positive control
undih.ned
.3 minute.s
I hour
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01-
nme
undilDted
Negative comml
BlllJ.gy, ;'j.-farch ':"'0,
Ex:P05U~
[~5ted
reeD 5tlucte:d
~pidermis. unilS
Test item and negati\'e control were applied topically for 3 minutes and I hour and positive control was
applied for 3 minutes to a three-dimensional human skin model. After rinsing of tissues, assay medium
was replaced by MTT-medium. Following 3 hours incubation. the formed blue fomlazan sa.lt was
extracted with isopropanol and the optical density was determined spectrophotometrically at 550nm ±
10 nm. The optic.al density values obtained for each group were used to calculate the percentage of cell
viability and consequently to classify the test item as corrosive or non-corrosive.
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RemIts:
SPO SOR:
Rus:3l1 ALlghinish Alumina
Aughinish .A.lumina Limited
Aughinish ]sland
Ask.~-aton
Co. Limerick
IRELAND
HI:SH 'G FACIU
Centre de Recherches. Biologiques CERB)
Chemin de ~ontifault
18800 B:3ILlgy
Flianc.e
Preliminar~' study:
Since MTT solution, did not tum blueJpurple when in contact with the test item for I hour (step I),
no interference between \iTT and test item was concluded. For this reason, the. second step of the
preliminary study was not undertaken .
. bin .tudy:
After 3 minutes of treatment, the positive control item showed a cell viability percentage 12.4%. As
expected and according to the OECD Guideline No.431, the positive control item was c1assitie{j as
corrosive. This result validated the ongoing sensitivit}' of the method used.
After 3 minutes and I hour of treatment with the undiluted test item, the percentage of cell viability
was 100% in both cases.
Under the experimental conditions adopted, COMPACTED RED MUD AFTER
A.\tPHIROLLI[liG was classified as non-curro.h·e on the Skin Ethic human reconstructed
epidermis.
AUDITED DRAFT RELEASE I
GLP
Primed date: lIt/arch 20, 2012
Table 2.3(1) Recent Corrosivity Testing indicates bauxite residue after amphirolling as Non Corrosive
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Page 8 on
CERB REPORT 20110254TClX
CERB REPORT 20110250TCUC
SUMMARY
SUMMARY
The aim or the study wa, 10 assei' the 'kin corrosion potential or RED MUD LEACIIATE FROM
BRDA PERIMETER using an in "llro skin corrosion model ba'ed on reconstructed human 'kin.
Fimly, • preliminary 'tudy wa, performed to iden,ify Il,e pOiSible interference between MIT .nd teit
item. In a 'econd phase, Il,e main 'tudy in\'olved 15 rec.an'truc,ed epidermis unit> (3 per group) as
deseri bed below,
Treatment design
The aim of ,he stud)' was to assess Ihe skin corrosion pOlential of COMPACTED RED M DAFTER
FARMING/CARBONATION using an In vitro skin corrosion model based on reconstructed human
skin.
Firstly, a preliminary study was performed to identify the possible interference between MTT and test
i'em. In a second phase, the main study involved 15 leconstructed epidemtis unil< (3 per group) as
described in Table 1.1, page 14.
Table I
~COllSlruCled
Treatment design
EXpOrufi! time
.
Concemration tLJ. be
mood
se
;)\un.lber 0:
~umtxrof
Groups
ru
Tahle I
eflbdemlisu"tts
l'\egl1l:i\'c oontrOl
POilti\'~ conool
0.9%
Trc:a.tment
rec()nstruc:ted
epidermis units
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I hour
0.9%
I hour
t1ndi ted
Te;t item .and negative conU'OI were applied topiCally for 3 minme; and I hour and posjt~\"e conU'OI was
applied for 3 minmes to a three-dimensional human ;kin modeL After rinsing ofti;sues, ass.ay medjum
was ,"placed by MTT-medium. Following 3 hours incubation, the blue formazan <alt fom'ed was
eXU'acled with isopropanol .nd the op,ical densi,y was detennined spectrophotometrically a, 550nm ±
10 nm. The optical densi'y values obtained for Mch g'oup we,e used '0 calcul.,e the perc"ntage of cell
nt
o
viab.lity and c.onsequently to cla;sify the I.e;t item as corrosive or non-corrosive.
[0
be:
E:x:po.5ure time:
TCSlitcm
TCSlitcm
Nceativc control
Negative control
Positive control
undiluted
undiluted
0.9%
3 minutes
1 hour
3 minutes
0.9%
1 hour
undiluted
3 minutes
Test item and negative control we," applied topically for 3 minutes and I hour and positive control was
applied for 3 minutes 10 a three-dimensional human skin model. After rinsing of tissues, assay medium
was replaced by },1TT-medium. Following 3 hours incubation, the blue ormazan salt formed was
extracted with isopropanol and the optical density was determined spectrophotometrically at 550nm =
10 nm. The. optical density values obtained for each group were used to calculate the percentage of cell
viability and consequeml)f to classify the lest ilem as corrosive or non·corrosive.
Co
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se
Results:
Prellmlna,")" study:
Since MTT solUlion did nOl turn blue/purple when in contac, with Ille teS! ilem fo' I hour ('tep I),
no interference between MTT and le;t item was concluded_ For this re-3son., the second Sltep of the
prelimin.ry <ludy w", not undertaken.
Concenrration
le5(~d
he
t1ndnut.ed
ot
T.estit.cm
Test jl~rn
Page 8 of2
~lajll study:
After 3 minu,e, of "eatment, the positive control item showed a c,,11 viability percentage of 1204%.
A' expected and .cc.arding to the OECD Guideline, 0.431, Il,e positive control i,em was classified as
corrosive. This result \ lidated the ongoing sensiti iry of the method u;ed.
After J minute,; and I hour of treatment with the undiluted teSI item, the percentage of ceU viability
w'as 100% i.n both cases.
Under the experimental eondltJeH15 adopted, RED ~'IUD LEACIIATE FRO'. ORDA
PERnlETER was classified as non-eorroslw on tlle SkJnEthle human reconstrueled eplderml'.
AUDITED DRAFT RELEASE I
GLP
PrlnlM dat": Marrh 20. 2012
Re.ults:
Preliminary stUd)':
Since MTT solution did not tum blue/purple when in contact with the te<l item for I hour (step I),
no interference between ~ITT and test item was concluded. For this reason, the second step of 'he
preliminary study was not undertaken.
i\lain study:
After 3 minutes of trealmem, the positive control item sho\ved a cell viabiliry percentage of 12.4%.
As expected and according to 'he OECD Guideline No.43 I, the positive control item was classified as
corrosive. This result validated the ongoing sensitivity o"'lhe method used.
Afler 3 minutes and I hour of treatment with the undiluted tesl item, the percentage of cell viability
was 100% in both cases.
Under the e.perimental condition. adopted, CO IPACTED RED MUD AFTER
FAR)II 'G/CARBONATIO:-; was classified as non-corro''''e on the SkinEthic human reconstructed epidermis.
Table 2.3(2) Recent Corrosivity Testing indicates red mud leachate & carbonated red mud as Non Corrosive
EPA Export 17-04-2012:03:54:24
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FIGURE 8.1
BRDA FAULT TREE: SECTORS A, B, C & F
UPPER PERIMETER INTERCEPTOR CHANNEL REMOVED
Figure 2.1 Revisions to original Breakout Study Figure 8.1 with Upper Level Interceptor Channel Removed.
EPA Export 17-04-2012:03:54:24
---
FIGURE 8.2
BRDA FAULT TREE: SECTORS 0 & E
UPPER PERIMETER INTERCEPTOR CHANNEL REMOVED
Co
n
se
nt
o
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"""''''''''BROA
Figure 2.2 Revisions to original Breakout Study Figure 8.2 with Upper Level Interceptor Channel Removed Sector D adjacent to Limerick County Council
Water Treatment Plant
EPA Export 17-04-2012:03:54:24
Attachment 3 BRDA Stability Monitoring.
3.1 Aughinish BRDA Stability Monitoring.
The stability monitoring function for the Aughinish BRDA has been contracted out to Golder Associates.
The function is implemented by the following
Total
29
Cassegrande
Standpipes
1APL
1APU
2APL
2APU
3APL
3APU
4APL
4APU
5APL
5APU
6APL
6APU
7APL
8APL
Push -in CPT
Standpipes
APT 11A
AAT12A
AAT 14A
CPT 1
APT 1A
APT 3A
CPT 4A
14
7
he
ru
se
.
Vibrating Wire
Piezometers
FGPZ 3c
FGPZ 7a
FGPZ 7c
FGPZ 8d
FGPZ 12a
FGPZ 13a
ot
Magnetic
Extensometers
1AIL
1AIU
2AIL
2AIU
3AIL
3AIU
4AIL
4AIU
5AIL
5AIU
6AIL
6AIU
7AIL
8AIL
1BIU
2BIU
to
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ny
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
Inclinometers
1AIL
1AIU
1BIL
1BIU
2AIL
2AIU
2BIL
2BIU
3AIL
3AIU
3BIL
3BIU
4AIL
4AIU
4BIL
4BIU
5AIL
5AIU
5BI
6AIL
6AIU
6BIL
6BIU
7AIL
7BI
8AIL
8BI
9BIL
9BIU
ns
en



Quarterly (3 monthly) monitoring of existing instruments Table 3.1 installed in the BRDA
Periodic site investigation using a mobile rig comprising Cone Penetration Testing (CPT) , and
residue sampling, see typical schedule of tests in Table 3.2
Quarterly review of that instrument monitoring data
Annual inspection of the BRDA , see Table 3.3
Compilation and assessment of all relevant stability data on an annual basis
Co


16
6
Table 3.1 Existing Stability Monitoring Instruments in the Phase1 BRDA.



Site Investigation Tasks
Cone Penetration Test (CPT) cone penetration
resistance with depth of the red mud
Mostap undisturbed sampling of red mud; and
Installation of push in standpipe piezometers.
Laboratory Analysis




Natural Moisture Content
Plasticity Index
Density
Undrained Triaxial Tests
Table 3.2 Planned Site Investigation & Laboratory Analysis of BRDA residue.
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Task
Stability Instrument Monitoring
Frequency
Quarterly
Data Review
Quarterly
Annual Inspection & Review
Annually
CPT rig Site Investigation Phase 1 BRDA prior to Stage 10
During 2013
First CPT Site Investigation in Phase 2 BRDA to avoid probe
penetration damage to the composite liner.
At Stage 3 raise residue filling
Every Second stage raise i.e.
Stage 5
Subsequent CPT Site Investigations in Phase 2 BRDA (as all static
stability parameters already derived from Phase 1 BRDA)
Stage 7
Stage 9
to
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Table 3.3 Golder Associates frequency of stability monitoring and assessments
Frequency
Daily
Weekly inspections of BRDA equipment by operators
Weekly
General conditions inspections by Aughinish engineer
Monthly
Co
ns
en
Task
Daily inspection by BRDA Supervisor
Environmental monitoring around perimeter of BRDA , dust deposition
, ground water and surface water sampling
Monthly
Table 3.4 Rusal Aughinish frequency of Logged Visual Inspections & Environmental Sampling
EPA Export 17-04-2012:03:54:24
Apply
Reason for Aughinish position
NO
Seepage through the dam cannot be measured or sampled as dam wall design is totally porous, and does not retain seepage
YES
YES
Position of Phreatic Surface in the bauxite residue is measured
Static pore pressures are measured
YES
Movement of tailings is measured using inclinometers and extensometers
NO
Seismicity is not measured by active instruments but issue has been assessed in the Breakout Study and annual risk of
trigger earthquake listed as 1 in 95,000 years
ot
he
ru
se
.
NO
BRDA is a thickened tailings stack and is not a pond. The Inner Wall and the current 9 upstream stages raise walls to date
comprise the overall Dam Walls
Water level cannot be measured as water not stored on or inside the dam
YES
Soil mechanics
YES
Tailings placement procedures
YES
undertake for tailings pond/dam
Visual inspections
Annual reviews
YES
YES
Independent audits
YES
Safety evaluations of existing
dams (SEED)
YES
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NO
Dynamic pore pressures and liquefaction are not considered relevant because of the low incidence and magnitude of
earthquakes at the site as stated above. The design report comprehensively evaluates the potential for residue bauxite to
liquefy and CPT testing is undertaken to assess the increase in strength and density of the material with time and stress
level. The probability of both dynamic and static liquefaction has been calculated in the Breakout Study
Soil Mechanics Penetrometers ,i.e. the Cone Penetration Testing Rig are used periodically at Aughinish prior to
construction of upstream raise walls
Tailings Placement Procedures are applied but Aughinish are specifically drafted for thickened tailings, upstream
construction and mud farming and not for the tailings “ponds” as outlined in the text of the ICOLD bulletin 104
Visual Inspections are undertaken and Aughinish uses a system of daily, weekly and monthly check sheets on our
computerised Business Performance Improvement System & inputted by the relevant operators, supervisor and engineer.
Golder Associates undertake both quarterly and annual reviews
Golder Associates are independent specialists & undertake the audits, their analysis are internally peer reviewed. Golder
and the BRDA design has also been peer reviewed by SLR on behalf of the Agency in 2004/05 and 2008
SEED In 2004 the Golder Associates design and geotechnical assessment of the BRDA was peer reviewed by SLR on
behalf of the Agency (Licensing). Again in 2008, the Agency (Enforcement) asked SLR to review the Golder Design in the
context of Condition 8.3.5 Essentially SLR have peer reviewed Golder‟s Design and also the Breakout Study and that
accounts as SEED
se
nt
o
Dynamic pore pressure and
liquefaction
Co
n
BAT requirement Section 5.2
page 432
BAT is to monitor in a tailings
pond/dam (Section 4.4.14.2)
The water level
Quality and quantity of seepage
flow through the dam (also
section 4.4.12)
position of the phreatic surface
Pore pressure
Movement of the dam crest and
tailings
Seismicity to ensure stability of
the dam and the supporting
strata
BREF table 4.15 page 400 & Section 5.2 Monitoring Stability page 432 is adapted (not transcribed) from ICOLD BULLETIN No. 104 “Monitoring of Tailings Dams “1996 and between
pages 21 and 49 for upstream raised tailings ponds and not for thickened tailings with porous dam design. There are no monitoring frequencies prescribed in this ICOLD documents
even for tailings ponds. Monitoring tasks and frequencies should be based on the judgement of the competent independent geotechnical experts. BREF cannot be prescriptive.
Table 3.5 Aughinish performance versus BREF BAT Section 5.2 page 432
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Aughinish
Frequency
Daily, weekly and
monthly
Instrument
Monitoring
Quarterly
Soil Mechanics
Penetrometers
using CPT rig
Only before every
second upstream
stage raise
constructed from
filled Stage 3 Raise
onwards in Phase 2
BRDA
Golder Associates
supervising CPT
rig sub-contractor.
Data review
Quarterly
Golder Associates
Annual
Inspection and
Review
Yearly
Golder Associates
Independent
Audit
Bi-annual
to
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Personnel
Aughinish Justification
Aughinish
personnel with
BRDA related
responsibilities &
experience.
Golder Associates
Aughinish use a system of daily and weekly
check sheets on our computerised Business
Performance Improvement System which are
filled in by the relevant operators,
supervisors (facilitators) and engineers.
Quarterly frequency is justified because
Aughinish BRDA is a compacted thickened
tailings and not a tailings pond.
Comprehensive data already collected in
Phase 1 BRDA and CPT rig cannot
commence below stage 3 in Phase 2 BRDA
to avoid damaging composite lining. The
frequency reflects Golder Associates
judgement based on the consolidated and
strengthened red mud data already assessed
in the Phase 1 BRDA and because no
dynamic pore pressures is observed in
consolidated red mud.
Quarterly frequency is justified because
Aughinish BRDA is a consolidated thickened
tailings and not a tailings pond.
Aughinish have contracted service to Golder
Associates to undertake annual inspection
and review which involves detailed site
inspection and collation of all quarterly
monitoring and site investigation data.
Golder Associates stability reports are peer
reviewed by appropriate experts within that
organization which is equivalent to
independent audits.
In addition SLR on behalf of the Agency
have peer reviewed the Aughinish design on
at least two occasions.
In 2004 the Golder Associates design and
geotechnical assessment of the BRDA was
peer reviewed by SLR on behalf of the
Agency (Licensing). Again in 2008, the
Agency (Enforcement) contracted SLR to
review the Golder Design in the context of
Condition 8.3.5. Essentially SLR have peer
reviewed Golders Design and Breakout
Study and that should provide the assurance
required by the Agency. As indicated above
all major Golder assessments are peer
reviewed. In addition GolderAssociates have
submitted in 2006 a Breakout Study for the
BRDA. Therefore Aughinish contend that the
proposed frequency of 20 years is adequate.
(SEED) Safety
Evaluation of
Existing Dams
15 to 20 years
Co
ns
en
Golder Associates
Team of
Independent
experts
ot
he
ru
se
.
Assessment
Type
Visual
Inspections
Table 3.6 BREF Table 4.15 & 4.17 & justification Aughinish frequency monitoring, inspections and
audits.
In conclusion Rusal Aughnish practice already complies extensively with BAT requirement in relation to
stability monitoring of the BRDA.
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