1
Workshop on Assessing Liabilities and Funding Options
November 2-3, 2005Embassy West Hotel and
Conference CentreOttawa, Ontario
Objectives• To present and discuss approaches for
assessing liability and funding options at orphaned/ abandoned mines, and share relevant experiences and examples
• To develop a better understanding of the issues
• To explore different approaches to dealing with the issues; and
• Identify areas for further work by NOAMI.
Agenda
Day 1 - Morning
8:45 – 10:30 Case StudiesGiant MineBritannia MineKam Kotia Mine
10:30 – 10:45 Break
10:45 – 12:15 Panel on Technical Site Assessment
12:15 1:15 Lunch
Agenda
Day 1 - Afternoon
1:15 – 2:15 Panel on Accounting and Reportingon Liabilities
2:15 – 2:30 Break
2:30 – 4:45 Perspectives on AssessingCommunity and Health Impacts
5:00 - 6:30 Informal Reception
AgendaDay 2
8:30 – 10:30 Presentation and Discussion on Funding Options Paper
10:30 – 10:45 Break
10:45 – 13:00 Panel on Funding Options
13:00 – 14:00 Lunch
14:00 – 16:00 Roll-up Discussion and Next Steps
16:00 - 16:15 Closing Remarks
1
NOAMI Conference November 2005
Challenges and best practices related to assessing liabilities and funding options
Giant Mine Remediation Project
W. S. MitchellManager Giant Mine Remediation Project
60
Giant Mine Location
CON MINE
Original Giant Mine “A” Shaft (1945)
Background
§ Giant Mine is over 50 years old§ The Mine was established in 1948 on federal
land; in 1970 administration of the land was transferred to the Commissioner
§ Site within the Yellowknife City limits§ Approximately 237,000 tonnes of highly toxic
arsenic trioxide dust is stored underground and there is arsenic contamination on surface
§ Underground storage is located near or under Ingraham Trail, adjacent to mill/roaster
§ City holds an existing lease on former Town site, but is not responsible for environmental liabilities that existed prior to it obtaining its lease in 2000
Background§ 1999 - Royal Oak Mines forced into receivership
§ Indian and Northern Affairs Canada (INAC) entered into an agreement with Miramar to provide ongoing care and maintenance of Giant Mine –agreement also allowed Miramar to operate mine on reduced scale
§ Miramar indemnified for existing condition of mine
§ Agreement allowed INAC and Technical Advisor to:
Assess liabilities and develop options with public input for the management of the underground arsenic trioxide
Technical AdvisorTechnical Advisornn Competitive contracting process: SRK Consulting Competitive contracting process: SRK Consulting
retained, with retained, with SenesSenes Consulting, Lakefield Research and Consulting, Lakefield Research and HG Engineering on the teamHG Engineering on the team
nn Main objectives of Technical Advisor:Main objectives of Technical Advisor:nn provide broadprovide broad--based, neutral, technical advice on based, neutral, technical advice on
identification of preferred, longidentification of preferred, long--term arsenic trioxide term arsenic trioxide management planmanagement plan
nn identify and recommend, with rationale, preferred identify and recommend, with rationale, preferred management management option(soption(s) to DIAND) to DIAND
nn assist DIANDassist DIAND in assessment of liabilitiesin assessment of liabilitiesnn assist DIAND with workshops and public consultationsassist DIAND with workshops and public consultationsnn assist DIAND in Risk Assessment assist DIAND in Risk Assessment -- Canadian Risk Canadian Risk
Management Standard CSAManagement Standard CSA--Q850Q850
2
Assessing LiabilitiesLiabilities arising from legacy of mining activity at Giant Mine ØSurface• Buildings with severe arsenic contamination, asbestos
insulation
• Decaying mine infrastructure
• Tailings impoundments, sludge settling and polishing ponds
• Contaminated surficial materials (arsenic and hydrocarbon)
• Miscellaneous junk piles
• Underground mine openings
ØUnderground• 237,000 tonnes toxic arsenic trioxide dust stored in sealed
rock chambers
Giant Mine Surface Elements2002 Air Photograph
N
Arsenic trioxide dust in storage underground is enclosed completely in rock – all access drifts sealed by thick cement bulkheads
“ C” Headframe
2000
S
1000
S
0 N
1000
N
“ B” ShaftVentilation Intake
UBCPortal
5000
6000
250 LEVEL
425 LEVEL
100 LEVEL
5500575 LEVEL
C212
C10
C9 #15
#14
#12
#11
B230
B234
B208
B233
B235
B236
B214
B213
B212
Arsenic Chambers Long Section: 10 chambers & 5 stopes
Independent Peer Review Panel
• To provide INAC with expert, independent peer review of management alternatives for the arsenic trioxide currently stored underground at the Giant Mine, beginning with a review of the Draft Final Report entitled "Arsenic Trioxide Management Alternatives - Giant Mine" by SRK Consulting Inc.
• Role subsequently expanded to include review of integrated underground and surface Giant Mine Remediation Plan
• Review by GNWT• Review by expert federal departments
– Environment Canada– Fisheries– Health Canada
• Community Alliance kept informed of progress on Remediation Plan
Addressing Liabilities - Giant Mine Remediation Plan:Integrated arsenic trioxide dust management Project Description and Abandonment and Restoration plan
3
§ There is no possibility of previous owners cleaning up the site
§ Different Jurisdictions
§ Difficult to apportion responsibilities and liabilities between governments
§ Expectation to proceed with remediation
§ Integrated remediation plan for surface and underground
Funding Options
DIAND Jurisdiction§ Administration of mines
and minerals§ Administrative control of
beds of bodies of water§ Water management
GNWT Jurisdiction§ Administration and control
of Commissioners land§ Mine inspections and mine
safety§ Highway§ Public health
Jurisdictional Responsibilities Canada and GNWT
Cooperation Agreement Fundamentals
§ Acknowledge different legislative and administrative responsibilities for the Giant Mine site
§ No transfer of responsibility
§ Liability allocation set aside
§ Agree to be co-proponents of remediation plan
§ Recognition that remediation of Giant Mine is a priority for the public
§ Agree to cost share
§ The Agreement covers the Giant Mine remediation project only. It does not set a precedent for other mines on Commissioner's Land
Cooperation Agreement -Main Components
§ Care and Maintenance
• Interim joint office and cost share between GNWT and DIAND
§ Remediation Plan (integrated surface and underground)
§ Administration of Project
§ Financial Cost-Share
Remediation Plan§ Parties agree to finalize a remediation
plan including surface and subsurface components for submission to regulatory agencies
§ Plan will include former Town Site
§ Parties agree that in situ freezing of arsenic trioxide dust is the preferred option for addressing the underground arsenic trioxide at the site
§ Parties agree to cooperate in all aspects of regulatory filings and environmental assessment
§ Remediate surface of the site to GNWT Industrial Standards
Mine Site Integrated Remediation Estimated Costs
§ Costs over next 3 years including the Care and Maintenance ~ $30M§ Currently estimated cost of
remediation $280 - $330 million - 1/3 surface ($100m) and 2/3 Underground ($200m)
4
Financial Cost-Share
§ GNWT to contribute $23m over 10 years towards care and maintenance and remediation of surface only
§ Canada acknowledges long term responsibility of arsenic trioxide dust stored underground
§ GNWT to provide right of access and possession by appropriate land tenure instrument at no cost to Canada
§ GNWT will contribute up to $250,000 annually towards the cost of the interim office
§ GNWT will make best efforts to provide other in-kind services
Next steps :
§Finalize Remediation Plan and IPRP review report
§Regulatory Board Review ( 2 years)• Additional public input• Possible Full Environmental Assessment
Giant Mine Remediation Project
Diane WalshAdministrativeCoordinator
Bill MitchellProject Manager
Mark LiskowichHead, Technical andEnvironmental Services
Manny LimProject Specialist
Alex GlowachProject Specialist
Mark CronkEngineer PWGSC
Rosanna MassimiEnvironmental Scientist
For more detailed information:http://giant.gc.ca
Ben NordahnMining Technical
Specialist
1
Britannia MineRemediation Project
Assessment of Costs and Liabilitiesat Beginning of Project and at Current Time
Barry Azevedo, PEng. MASc.Britannia Mine Remediation ProjectCrown Contaminated Sites BranchBC Ministry of Agriculture & Lands
Ho
we
So
und Britannia Creek
MillBuilding
BritanniaBeach Mineral Creek
Jane
Cre
ek
4100Portal
Jane BasinGlory Hole& Open Pit Complex
M i n e r a l R i d g e
2200Portal
Furry CreekWorkings
1 km
• 1905 – mine begins production
• 1920s – largest producing copper mine in Commonwealth; metal recovery from mine drainage
• 1970 – Pollution Control Act becomes effective
• 1973 – mine owners ordered to obtain permit (lime treatment)
• 1974 – mine closes; mine owner ordered to maintain metal recovery system
• 1979 – mine sold to real estate developer
BriefHistory
• 1981 –works not being maintained; initiation of period of studies and monitoring to characterise impact and define liability (EC, DFO, BCMEM, BCMOE)
• 1997 – EC and BCMOE jointly fund pilot plant testing and conceptual design of HDS lime treatment of mine water
• 1997 – Contaminated Sites Regulation becomes effective
• 2001 – $30M settlement with historical mine operators; initiation of remediation
• 2003 – Agreement with current land owner
• 2005 – Award of WTPcontract
4100 L
2700L
4100 Portal
4100 Plug
Mineral Creek
Britannia Creek
Maximum
Allowable
Mine
Flooding
Limit
HoweSound
Britannia Beach Townsite
Hom
esta
ke
Blu
ff
Vic
tori
a
3D Cutaway of Mine from Southwest
Jane Basin
Fai
rvie
w
Jane
2200 Portal
B r i t a n n i a C r e e k
Howe Sound
contaminatedsediments
4100 portal acidic metal drainage
contaminatedfill and groundwater
2200 portal acidicmetal drainage
Mill
metal sulphideore body
contaminated wasterock and groundwater
Post-Mining Conditions
2
Project Management Structure (~1999)
Steering CommitteeProvince-Environment Canada (co-chairs)
BC Ministry of Energy and Mines,BC Ministry of Finance
Legal CounselBC Ministry of Attorney General
Technical Advisory CommitteeProvince (chair), Environment Canada,
BC Ministry of Energy and Mines,BC Ministry of Environment,
Squamish Lilllooet Regional District, Environmental Mining Council of BC
later:Contracted Project Manager,
Britannia Beach Historical Society,land developer,
Natural Resources Canada,Squamish First Nation
Provincial Goals• Environmental goal
– to reduce pollution from Mine into Howe Sound
• Financial goal– Minimize cost to taxpayers by maximizing opportunity for cost
recovery through:• legal means• landowner contributions / development revenues• infrastructure grant
• Development goal– Optimize development capability of land (subject to costs)
• Operational goal– Long term operation of remedial works by party other than
Province
mine safety?
Britannia C
reek
3D Cutaway of Mine with Remedial Actions
Jane Basin
WTP
Fan Remediation
2200 Plug (UBC 2001)
4100 Plug
Mine InflowDiversions
$ 680,000 Annual O&M - Fan
$ 1,770,000 Annual O&M - WTP
$ -Legal
$ -Administration
$ -Project Management
$ -Mine Safety
$ -Mine Inflow Diversions
$ -AA Remediation
$ 15,000,000 Marine Remediation
$ 1,375,000 JB Road Upgrade
$ 10,600,000 Fan Remediation
$ 11,569,964 WTP Capital
2001 Estimated Costs
Nominal Total Costover 20 years
= $99.3M
NPV Total Costover 20 years
= $75.9M
• Persons responsible for remediation of a contaminated site include: a current owner/operator, and a previous owner/operator.
• A responsible person is absolutely, retroactively, and joint & severally liable
• 1998 assessment of corporate history identified several existing companies that were successors to the historical mine owners and operators
BC Environmental Protection Act (formerly Waste Management Act) and the
Contaminated Sites Regulation (1997)
Britannia Mine andReclamation Corp.
current site owners: BBPL, BBHS, Makin, Tanac, BCR, BC Crown
parties indemnified by Province: ARCO, BP/Dome, Canzinco, Intalco, Alcoa, Alumax, Howmet, Pechiney
Britannia BayProperties Ltd. BC
20012003
Britannia Mine Successorship of
Corporate Ownership
3
white space
BC MOE(EMA Regulator)
Historical PotentialResponsible Parties
(Arco, Alcoa,Ivaco, others)
Province of BC(Remediator)
Copper BeachEstates Ltd.
(Property Owner)
Other PRPs(Museum, BCR,
MoT)
Remediation – 2001 Relationship of Relevant Parties
historical owner agreement- to Province: $30M- from Province: indemnification- settlement preferable to legalbattle
CBEL memorandum of agreement- to Province: $5M, Jane Basin Road construction, 50% of site development profits, annual property surcharges, and limited property (total est. value of $30.9M)- to CBEL: indemnification, noobjection to development
infrastructurefund (Canada,BC, SLRD,CBEL)- to Province$15 million
Britannia Beach community- ongoing public meetings
- website, feedback- progress reports
Remediation Plan
WTP feasibility design (AMEC)
Mine Hydrogeology – mine drainage investigations (SRK and KC)
Contaminated SitesInvestigation –remediation plan (URS)
mine drainage flowand quality
groundwater flowand quality
Drainage diversionsand equalizationthrough minestorage
Plant final design,procurement, andconstruction (EPCOR)
Soil and Groundwater Remediation works
Flood Risk Assessment (WMC)
sitinginformation
Project Management (Golder)
EM/RA (EVS-Golder)
blank
BC MOE(EMA Regulator)
Historical PotentialResponsible Parties
(Arco, Alcoa,Ivaco, others)
BC MAL Province of BC(Remediator)
Britannia BayProperties Ltd.
(Property Developer)
Other PRPs(Museum, BCR,
MoT)
Remediation – 2003 Relationship of Relevant Parties
historical owner agreement- to Province: $30 million- from Province: indemnification
BBPL agreement- 440 acres of land needed for remediation- 8996 acres of mineral claims- 32.9 acres for highway RoW- environmental levy on development- timber and access rights- estimated value of $5M- to BBPL: no objection to development, limited environmental liability
2001 2003
Britannia Beach community- ongoing public meetings
- website, feedback- progress reports
blank
provincial contribution- projected cost of $99.3M - private contributions of $35M- province commitment =$64.3M
WTP ProcurementA Public-Private Partnership
• Decision to proceed with WTP procurement through a P3 in late 2003– risk transfer, cost effective, DBFO 20 year contract
• RFEI, RFP processes in 2004• EPCOR awarded contract in late 2004
– design (Stantec), construction (LSI), finance and operation (EPCOR)– performance-based monthly payments for repayment of capital,
operating, financing, and profit costs (must meet permit criteria)– no payments until plant is operational– $27M NPV ($60M nominal) contract vs traditional projected cost of
$39M NPV ($70M)– hydroelectric plant to provide 30% of electric needs– WTP design capacity of 1,050 m3/hour (based on mine storage)
WTP Under Construction- Commissioning October 21, 2005- Full operation in early November
Contaminated Soil Disposalinto East Bluff Glory Hole
4100 Portal and Aditunder Rehabilitation
Contaminated GroundwaterPumping Well Pipe Array
$ 200,000 $ 680,000 Annual O&M - Fan
$ 1,212,000 $ 1,770,000 Annual O&M - WTP
$ 701,105 $ -Legal
$ 1,885,161 $ -Administration
$ 4,506,514 $ -Project Management
$ 800,000 $ -Mine Safety
$ 423,620 $ -Mine Inflow Diversions
$ 2,000,000 $ -AA Remediation
$ -$ 15,000,000 Marine Remediation
$ 541,909 $ 1,375,000 JB Road Upgrade
$ 6,966,366 $ 10,600,000 Fan Remediation
$ 26,031,000 $ 11,569,964 WTP Capital
20052001Comparison of Estimated Costs
4
2001 Cost Estimates Compared to 2005 Cost Estimates
$-
$5,000,000
$10,000,000
$15,000,000
$20,000,000
$25,000,000
$30,000,000
WTP C
apital
Fan R
emed
iation
JB Roa
d Upg
rade
Marine
Remed
iation
AA Remed
iation
Mine In
flow Dive
rsions
Genera
l Mine
Safety
Projec
t Man
agem
ent
Adminis
tration Le
gal
Annua
l O&M - W
TP
Annua
l O&M - F
an
Unconsidered Costs in 2001 Budget
• WTP Capital: feasibility assessment, flood assessment, site demolition, residential development, access road, sludge filter plant,wtp site remediation, outfall location, building architecture, water supply, profit
• Fan Remediation: contaminated soil excavation and disposal
• AA Remediation: investigation and remediation
• Mine Inflow Diversions: East Bluff diversion
• Mine Safety: open raises, 4100 wye, ore bin, mine manager
• Project Management: project management, owner’s engineer, construction management
• Administration: staff salaries and expenses
• Legal
Dismissed Costs in 2005 Budget
• WTP Capital: Jane Basin sludge disposal cell study and construction,
• Marine Remediation ($15 million!!!)
Outstanding Liabilities
• Five large abandoned water reservoir dams on Britannia Creek• Jane Basin Rock Block (20,000,000 m3)• Loss of hydraulic continuity between mine ore body and 4100 portal (mine
drainage exits at another location into Britannia Creek or Furry Creek• Excessive WTP bypasses despite mine storage (weather dependent)• 3250 overflow into Mineral Creek despite mine storage (weather and mine
working collapses)• Open portals, raises, derelict structures, fall hazards• Marine sediment contamination• Upland waste rock dumps at mine portals – undefined remediation (RA)• Outfall location instability• Adjacent residential growth
Summary• indemnification to historical mine operators has resulted
in provincial taxpayer covering additional substantial remediation costs of $64.3M (nominal)
• the project is on budget as set in 2001 ($99.3M, nominal)• the project is on budget due to some early conservative
assumptions, and cost effective WTP procurement• there are substantial outstanding liabilities which may
impact budget• the WTP is ahead of schedule, with no over-budget risk
on contract items
Barry Azevedo, PEng. MASc.Managing Engineer, Britannia Mine Remediation Project
Crown Contaminated Sites Branch, BC Ministry of Agriculture & Lands 10470-152nd Street, Surrey BC V3R 0Y3
tel:(604) 582-5309 cel: (604) 612-8536 fax:(604) 584-9751email: [email protected]: www.britanniamine.ca
Estimated Total Inflows to Mine (including flows that reported to 2200 level)
0
200
400
600
800
1000
1200
1977
Jan
01
1978
Jan
01
1979
Jan
01
1980
Jan
01
1980
Dec
31
1981
Dec
31
1982
Dec
31
1983
Dec
31
1984
Dec
30
1985
Dec
30
1986
Dec
30
1987
Dec
30
1988
Dec
29
1989
Dec
29
1990
Dec
29
1991
Dec
29
1992
Dec
28
1993
Dec
28
1994
Dec
28
1995
Dec
28
1996
Dec
27
1997
Dec
27
1998
Dec
27
1999
Dec
27
2000
Dec
26
2001
Dec
26
Month
Min
e In
flo
w (
L/s
)
-500
0
500
1000
1500
2000
2500
3000
3500
4000
4500
SW
E (
mm
)
Mine Inflows
Design Capacity
Hydraulic Capacity
SWE
Estimated Total Inflows to Mine
5
No. of Days of untreated pipe discharge per event
0
5
10
15
20
25
30
35
40
45
50
1977
Jan
01
1978
Jan
01
1979
Jan
01
1980
Jan
01
1981
Jan
01
1982
Jan
01
1983
Jan
01
1984
Jan
01
1985
Jan
01
1986
Jan
01
1987
Jan
01
1988
Jan
01
1989
Jan
01
1990
Jan
01
1991
Jan
01
1992
Jan
01
1993
Jan
01
1994
Jan
01
1995
Jan
01
1996
Jan
01
1997
Jan
01
1998
Jan
01
1999
Jan
01
2000
Jan
01
2001
Jan
01
2002
Jan
01
Date
No
. of D
ays
of u
ntr
eate
d d
isch
arg
e p
er e
ven
t (co
ntr
olle
d a
nd
u
nco
ntr
olle
d)
Projected Number of Days of Untreated Discharge per Event Utilizing Last 25
years of Hydrology Data
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
Date
50
40
30
20
10
0
Num
be
r of D
ays
of U
ntr
ea
ted
Disc
ha
rge
Ball Diamond18.7%
East Mill Slope1.0%
Sedimentation Pond(Waste Rock)
0.4%
West Mill Slope3.7%
Sedimentation Pond (Launder Sediment)
6.1%
Settling Pond12.2%
Concentrate Pile18.7%
Museum 4.7%
Mill Settling Pond6.2%
Mill area E of Hwy11.4%
Product Building0.3%
Concentrate Wharf Tailings
6.7%
Concentrate Building9.3%
Subsurface Deposits56%
Surface Deposits43%
Mill Building<1%
Loading Sources to Howe Sound
Britannia Fan Area Remediation OptionsBritannia Fan Area Remediation Options
South Alluvial Fan (Mill):Copper and Zinc: up to 90 kg/day each
North Alluvial Fan:Copper and Zinc: up to 5 kg/day each
Estimated Daily Metals Loading
Mine Workings Total:Copper and Zinc around300 kg/day each
4100 Level
Groundwater flow
Mine water flow
From 2200 Levelvia Britannia Creek – UBC 2001
Howe Sound
Bedrock
Alluvium and Fill
Contaminated sediments (tailings)
2200 Level Waste Dump
blank
Permit Level Development Table
100%100%100%100%96HRLC50
8.5-109.5upper pH
6.56.5lower pH
30103025-7525TSS
(mg/L)
0.010.0020.0010.01-0.100.00010.050.01Cd (mg/L),
0.40.40.20.1-1.00.110.2Mn (mg/L),
110.50.5-1.00.10.50.2Al (mg/L),
0.200.50.0310.2-1.00.019-0.0950.30.15Zn (mg/L),
0.10.30.010.3-1.00.05-0.30.50.01Fe (mg/L),
0.10.40.020.60.05-0.30.002-0.010.20.05Cu (mg/L),
(total)(diss)(total)(diss)(diss)(total)(total)(diss)
permitpermitdesigndesign(total)PCOcriteria
WTPWTPMMERMiningambient1999permit
parameter
Jane Basin
Upper Jane Creek
Pipe(s)Weir/flowcapture structure
East Bluff Diversion
Lower Jane Creek
6
Settling Pond andNortheast Fan Piles
Sedimentation Pond
Concentrater Pile
East Mill Slope
Summary of Fan Area Remedial Work
Contaminated StormwaterCollection System
Groundwater PumpingSystem
Existing Deep Outfall
Stormwater Sewer to Deep Outfall
Ore Bin
Jane Basin Access Road
• INSERT JB ROAD MAP
Jane Basin Access Road Plan
WTP Location & Access Road
Upper Bridge
Lower Bridge
Highway 99 AccessNew Road Section
11
Mineral Development & Lands Branch, MNDM 59
The Rehabilitation of The Rehabilitation of OntarioOntario’’s Kam Kotia Mine:s Kam Kotia Mine:
An Abandoned Acid An Abandoned Acid Generating Tailings SiteGenerating Tailings Site
Christopher D. HamblinChristopher D. Hamblin
Project ManagerProject Manager
Abandoned Mines Rehabilitation FundAbandoned Mines Rehabilitation Fund
Ministry of Northern Development & MinesMinistry of Northern Development & Mines
Mineral Development & Lands Branch, MNDM
WHAT IS KAM KOTIA?WHAT IS KAM KOTIA?
l Kam Kotia is a former Cu/Zn mine near Timmins, Ontario
l There are about 6 million tonnes of unmanaged acid generating tailings covering more than 500 ha
l Environmental impacts are locally significant– acidic leachate– dusting– aesthetics– physical safety
Mineral Development & Lands Branch, MNDM
MINING HISTORYMINING HISTORY
l Principle exploration 1926-1928, exploration shaft
l Mining * 1943-1944 - 169,000 tonnes open pitl Mining 1961-1972 - 5,840,000 tonnes, mainly
undergroundl Production 6.6 MT @ 1.1% Cu, 1.17% Zn,
0.10 oz/Ag
* Mining in 1943-1944 carried out on behalf of Wartime Metals Corporation, a Federal Government Agency. Cu sold to Metals Reserve Company. Washington, which paid operating costs and royalty.
Mineral Development & Lands Branch, MNDM
(NUT)(NUT)
((NITNIT))
((SUTSUT))
Mineral Development & Lands Branch, MNDM Mineral Development & Lands Branch, MNDM
22
Mineral Development & Lands Branch, MNDM
HYDROLOGYHYDROLOGY
l North and East seeps, with a pH of 2-3, drain NUT, east half of NIT and north half of plant site to the Kamiskotia River in the north.
l South seep drains SUT, south half of NIT and plant site to Little Kamiskotia River in the south, which had a pH 0f 3.5 to 4 prior to rehabilitation beginning on the site.
Mineral Development & Lands Branch, MNDM
Mineral Development & Lands Branch, MNDM Mineral Development & Lands Branch, MNDM
• The total rehabilitation of the abandoned Kam Kotia Mine site is to be conducted as a proposed five-phase program.
• This rehabilitation plan was developed during fiscal 2000/01, and predicted a total rehabilitation cost of more than $41 million.
• The cost estimates were as follows, including a 30% contingency:
• Phase “A”: $4.985 million• Phase “B”: $3.285 million• Phase “C”: $8.190 million• Phase “D”: $3.372 million• Phase “E”: $11.766 million• Effluent treatment for 50 years: $9.698 million
BACKGROUND
Mineral Development & Lands Branch, MNDM
• In the fall of 2000, a funding commitment for $9.0 million was made to conduct Phases “A” and “B”.
• This money was to come from the $20 million available during the last two years of the original 4-year Abandoned Mines Rehabilitation Fund.
PHASES “A” AND “B”
Mineral Development & Lands Branch, MNDM
• Phase “A” involved the construction of a Lime Addition Treatment Plant, as well as all of its required infrastructure, and the construction of a new NUT impoundment dam structure.
• The combined cost of these Phase “A” bids was $9.85 million, and the work was completed by July 2002.
• Realized that the combined costs of Phases “A” and “B” would approach $14 million.
PHASE “A”
33
Mineral Development & Lands Branch, MNDM Mineral Development & Lands Branch, MNDM
Mineral Development & Lands Branch, MNDM Mineral Development & Lands Branch, MNDM
Mineral Development & Lands Branch, MNDM Mineral Development & Lands Branch, MNDM
• Phase “B” involved the relocation of the SUT tailings to within the new NUT impoundment area.
• Upon completion of the work, more than 340,000 m3
of SUT tailings had been relocated and buffered with Envirolime, at a cost of $3.4 million.
• Phase “B” work was completed by mid-March 2003.
PHASE “B”
44
Mineral Development & Lands Branch, MNDM
• The bid prices for the Phase “B” work resulted in a cost overrun of $142,991.26 over the total amount available for Phases “A” and “B”.
• Savings were attained by having the contractor reduce the total area of clearing and grubbing required and by cancelling the seeding of the SUT area after the removal of the tailings.
• Although seeding was not done, agricultural lime was still spread over the peat/soil surface to buffer residual acidity.
• The final cost of Phases “A” and “B” was 4,111.88 below the expenditure cap.
PHASE “B”
Mineral Development & Lands Branch, MNDM
Mineral Development & Lands Branch, MNDM Mineral Development & Lands Branch, MNDM
Mineral Development & Lands Branch, MNDM
• Phase “C” involved the relocation of the NUT tailings to within the new NUT impoundment area.
• Upon completion of the work, more than 611,000 m3 of NUT tailings had been relocated and buffered with Envirolime, at a cost of $6.9 million.
• The Phase “C” work was completed by late-March, 2004.
PHASE “C"
Mineral Development & Lands Branch, MNDM
55
Mineral Development & Lands Branch, MNDM
However…..
…. in abandoned mine rehabilitation,like any construction project, .…
Things donThings don’’t always go t always go exactly as planned!exactly as planned!
Mineral Development & Lands Branch, MNDM
• Timmins received two years of anomalously high precipitation.
• The NUT Impoundment Area filled with 500,000 to 700,000 m3 of water at a pH of about 2.8, and containing very high acidity and metals.
• In order not to delay the project, a decision was made to stack the NUT tailings in the impoundment area during Phase “C”.
Contaminated NUT Area Water
Mineral Development & Lands Branch, MNDM Mineral Development & Lands Branch, MNDM
• Efforts were made to conduct the “in-situ” treatment of the NUT “Pond” during the winter of 2003/04.
• 706 tonnes of lime were added to the Pond, followed by over 2,000 tonnes of caustic (e.g. NaOH).
• Managed to raise the pH sufficiently to allow the discharge of the contaminated water for ~ 3 hours.
• Eventually ceased the treatment after having spent $1.8 million.
Contaminated NUT Area Water
Mineral Development & Lands Branch, MNDM
Contaminated NUT Area Water
• A contract was awarded earlier this year to conduct the treatment and discharge of the contaminated NUT water and to place the stacked NUT tailings into their proper location.
• The work is currently being conducted.
• The treatment method is based on the recommendations of a consultant that studied the various ways to deal with this water, and involves neutralization with caustic and filtering of the resulting sludge using geotextile bags.
• The final cost of this contract will be over $9.0 million.
Mineral Development & Lands Branch, MNDM
66
Mineral Development & Lands Branch, MNDM Mineral Development & Lands Branch, MNDM
Mineral Development & Lands Branch, MNDM Mineral Development & Lands Branch, MNDM
Mineral Development & Lands Branch, MNDM
NIT Area Cover
• The NIT area “dry” cover was to have been built as part of Phase “E”.
• In order for the KKM rehabilitation work to continue, the first two layers of that cover – the capillary break – were constructed during the winter of 2004/05, at a cost of $3.4 million.
Mineral Development & Lands Branch, MNDM
77
Mineral Development & Lands Branch, MNDM Mineral Development & Lands Branch, MNDM
Mineral Development & Lands Branch, MNDM
Miscellaneous Rehabilitation
• The first partnership project between MNDM and the OMA (the Ontario Mining Association) was conducted on the Kam Kotia Mine site during the fall of 2003.
• The project involved the vegetation of the NUT impoundment dam structures, which had been deleted as a cost saving measure during Phase “A”.
• The project cost of $276,000 was shared equally between the two partners.
Mineral Development & Lands Branch, MNDM
Rehabilitation Yet To Be Done ...
• Complete the NIT cover – this work is expected to cost more than $10 million, so it will have to be conducted during two separate fiscal years.
• Collect the remainder of the unimpounded tailings.
• Conduct Phase “D”, which involves the construction of the “moist” cover over the NUT impoundment area.
• Conduct the remainder of Phase “E”, which will include the rehabilitation of the open pit and all of the physical hazards on the site, such as the shaft and the thin crown pillar.
Mineral Development & Lands Branch, MNDM
The final cost for the rehabilitation of the Kam Kotia The final cost for the rehabilitation of the Kam Kotia Mine site is now expected to be in the range ofMine site is now expected to be in the range of……....
$55 million$55 million
Mineral Development & Lands Branch, MNDM
Recommendations
(aka – What would I have done differently?)
If you are planning on undertaking an abandoned mine rehabilitation project of a similar size and scope:
1. Try to diversify your funding sources by involving other governments, agencies or partnerships:
• MNDM was unsuccessful when it approached the Federal government for assistance.
• The OMA partnered with MNDM on the revegetation of the NUT impoundment dams.
88
Mineral Development & Lands Branch, MNDM
Recommendations (cont’d)
2. Build a “contingency” allowance into your bids so that you can deal with the unforeseen – a 50% cost increase is not unusual:
• The latest RFT for the treatment and discharge of the contaminated NUT water had a contingency allowance of $250,000 built into the bid forms.
• The bidders each show what their mark-up percentage will be on that contingency allowance.
• The cost of that contingency [e.g. contingency + (contingency x mark-up)] becomes part of the contractor’s total bid price.
Mineral Development & Lands Branch, MNDM
3. Once you start a rehabilitation project it’s hard to “back off”. Be prepared to stay the course:
• The five-phased approach at Kam Kotia was supposed to have allowed MNDM to end or pause the project after any phase, with no loss of the benefits already achieved.
• In reality, discontinuing rehabilitation on an environmental project like Kam Kotia will probably draw the negative attention of the environmental regulators, environmental NGOs, and/or the public.
Recommendations (cont’d)
Mineral Development & Lands Branch, MNDM
Recommendations (cont’d)
4. Be prepared to “think outside of the box”.
5. Expect the unexpected.
6. We live in Canada! Weather will probably have a negative impact on your project at some point!!
7. Have fun with your projects. Remember that you are making things better.
1
Top Down Process for Top Down Process for Mine Closure PlanningMine Closure Planning
Daryl HockleySRK Consulting Inc.Nov. 2, 2005
Top Down ProcessTop Down Process1. Identify all possible closure methods2. Identify factors by which methods will be
evaluated3. Try to evaluate methods using available
information only4. Make decisions where results are clear5. Initiate investigations only where not clear6. Re-evaluate & stop when decisions are clear
14 Waste Rock piles250 M tonnes600 hectares
Absetzerhalde150 M tonnes
Nordhalde 60 M tonnes
pH 2.7SO4 10,000 mg/L
Ronneburg District Ronneburg District –– East GermanyEast Germany 1. Identify possible methods
n “Representative options”:– Perpetual water treatment (only)– Cover waste rock in place– Relocate waste rock to pit
2. Identify evaluation factors 2. Identify evaluation factors n Cost
– Capital costs– Long-term water treatment costs
n Risk– Human and ecological– Radiological to workers
n Acceptance– Regulations and commitments– Local public
n Cost estimates based on conceptual designs only
n Human health risk assessments based on available data and comparison to other cases
n Assessed acceptance based on review of regulations, effect on land values, and feedback from public meetings
3. Use available information (only) 3. Use available information (only) to evaluate optionsto evaluate options
2
0 1 2 3 4 5
Absetzerhalde
Nordhalde
Kegelhalde Paitzdorf
Kegelhalde Reust
Halde Beerwalde
Halde Drosen
Halde 4
Halde 370
Halde 381/Schurf 12/13
Halde 377
Halde Korbussen
Schutzdamm
Treat Water Cover Relocate to Pit
4. Make decisions when results 4. Make decisions when results are clearare clear 5. Investigate only the uncertainties 5. Investigate only the uncertainties
that prevent decisionsthat prevent decisions
0 100 200 300 400 500 600 700 800Transverse lenght (m)
0
20
40
60
80
100
120
140
Rel
ativ
ehe
ight
(m)
XPY
0.9900.9800.9700.9600.9500.9400.9300.9200.9100.9000.8900.8800.8700.8600.850
Pyrite Fraction and Oxidation Rate
0,15 kg Py/m3⋅year
Mid-February
0 100 200 300 400 500 600 700 800Transverse lenght (m)
0
20
40
60
80
100
120
140
Rel
ativ
ehe
ight
(m)
XOAIR
0.2100.1950.1800.1650.1500.1350.1200.1050.0900.0750.0600.0450.0300.0150.000
Oxygen Concentration and Flux
2,0 kg/m2⋅year
Mid-February
0 100 200 300 400 500 600 700 800Transverse Lenght (m)
0
20
40
60
80
100
120
140
Rel
ativ
ehe
ight
(m)
T1817161514131211109876543
Temperature and Gas Velocity
0,3 m/day
Mid-February
6. Re6. Re--evaluate and stop investigations evaluate and stop investigations when decision is clearwhen decision is clear
Decision: Relocate to pit
In situ measures unlikely to improve water quality
Refinements since 1994Refinements since 1994• North American mine closure
– More transparency– Broader consultation– Particularly when publicly funded
• Use of workshops at key points in project– Technical workshops – identification of options– Stakeholder workshops – evaluation factors– Joint workshops – decision making and
identification of critical uncertainties
25 Abandoned Yukon Mines 199625 Abandoned Yukon Mines 1996--9898 Arctic Gold & Silver, Yukon, 1998Arctic Gold & Silver, Yukon, 1998--9999
3
Giant Mine Arsenic Trioxide 2001Giant Mine Arsenic Trioxide 2001--0303 ColomacColomac Mine, NWT, 2001Mine, NWT, 2001--20042004
Island Copper Mine, BC, 2002Island Copper Mine, BC, 2002--20042004 Faro Mine, Yukon, 2003Faro Mine, Yukon, 2003--PresentPresent
San Manuel Mine, Arizona, 2001San Manuel Mine, Arizona, 2001--0404 FlinFlin FlonFlon Metallurgical Complex, 2005Metallurgical Complex, 2005
4
Red Dog Mine, Alaska, 2004Red Dog Mine, Alaska, 2004--PresentPresent ConclusionsConclusions• Mine closure is about making decisions• The top down process applies a decision
analysis framework:– Transparent and replicable– Defensible choices– Effective management of technical inputs
1
SEFRSIGNIFICANT ENGINEERING FAILURE RISK
John Brodie, P. Eng.Faro Mine Closure Project Technical Manager
Brodie Consulting Ltd.
SEFRPURPOSE1. Identify issues not captured in standard
approach to contaminated sites2. Aid in setting priorities for remediation3. Identify need for monitoring & interim
mitigative strategiesFocus on critical components of abandoned
mines
SEFR
RISK = PROBABILITY x CONSEQUENCE• 4 Steps
– Identification of potential failures– Assessment of probability of failure– Estimation of consequences– Conversion of probability and consequences
into numeric values to obtain risk rating
SEFR
• Step 1 – Identification of potential failures– Focus on major concerns– Avoid developing closure solutions– “what could happen without proper closure
work”
SEFR
• Identification of potential failures– Dams– Spillways and diversions– Bulkheads– Crown pillars– Waste dump slopes
SEFR
• Step 2 - Assessment of probability of failure– Semi-quantitative assessment (data is often
insufficient)– Conservative opinion of qualified professionals who
have working knowledge of the site (sites)– Common issue is dams and spillways
• 5 main failure modes– Piping, static or seismic slope failure, hydraulic failure, overtop
2
SEFR – Probability of Failure
Piping Failure
Static Slope Failure
Siesmic Slope Failure
Hydrologic Failure
Other Failures FAILURE
SITE 1 in : 1 in : 1 in : 1 in : 1 in : COMMENTSGIANT MINE
NW tailings 833 1000 1000 1001:20 event (2001 precip) nearly filled pond, no spillway
N-C-S tailings 347 200 475 100water accum. In North pond could cause dam failure
Polishing pond 347 200 100 50no spillway, dam founded on tailings, failure leads to sludges in mine
Crown Pillars 1000short term stability believed to be OK, long term is ?able
SEFR – Risk Rating
PROBABILITY Rank
very high > 1:10 10high 1:100 - 1:10 9moderate 1:500 - 1:100 5
low 1:1000 - 1:500 2
very low <1:1000 1
SEFR
Step 3 - Estimation of consequences• 3 areas of impact
– Fatality– Environmental impact– Remediation cost
• Other areas – legal, private or First Nations land
SEFR
Consequence Rating
FATALITIES ENVIRONMENTAL REMEDIATION Rankvery high more than one fatality irreversible impacts > $10 million 10high one fatality reversible impacts $2.5 - $10 million 9
moderate irreversible injury Imminent impacts offsite$0.5 - $2.5 million 5
low hospital treatment low site impact $100,000 - $0.5 million 2very low no medical treatment no percieved impact <$100,000 1
SEFR
FATALITYENVIRON
MENTREMEDIATION
SITEGIANT MINENW tailings very low high highN-C-S tailings very low mod highPolishing pond very low mod highCrown Pillars very low high very high
Step 4 – Numeric Risk RatingMultiply Probability Rank x Consequence
RankTABLE 4 RISK MATRIX
ConsequenceProbability very low low moderate high very high
very high 10 20 50 90 100
high 9 18 45 81 90moderate 5 10 25 45 50
low 2 4 10 18 20
very low 1 2 5 9 10
3
SEFR
PROBABILITY OF FAILURE RISK
Probability Description Rating Consequence Description Rank SCOREDESCRIPTIVE
RANKINGSITEGIANT MINE
N-C-S tailings 1:100 high 9 high high 9 81 highremediation
CONSEQUENCE
SEFR
• Use the risk ranking to:– Capture risks not commonly part of
contaminated site assessment– Aid in identifying which sites should be
remediated first– Identify need for monitoring and pre-
reclamation mitigation efforts