CON MINE CLOSURE

1

• CON MINE CLOSURE RECLAMATION PLAN OVERVIEW
• February 22nd, 2007

2

• Current Status of the Closure Reclamation Plan
• All sections of the plan (with the exception of
  the reclamation cost estimate) have been reviewed
  by the Con Mine AR Working Group set up by the
  MVLWB in 2003
• The Working Group has met 20 times over the
  past 4 years to discuss technical details of the
  proposed reclamation plan for the Con Mine site
• The Working Group provided recommendations on
  each section of the Plan that led to Miramar
  revising each section prior to submission to the
  MVLWB

3

• Status of the Con Mine Closure Reclamation Plan
  
• Three public information sessions (open house
  style) were held in 2005/06 to present the
  content of each Section to the public and to
  elicit feedback
• In December of 2006 the MVLWB completed their
  review of all sections of the Reclamation Plan
  (except the reclamation cost estimate)
• The Board has given conditional approval to each
  section indicating what changes were needed to
  satisfy the MVLWB.
• Miramar has revised the Plan to incorporate these
  changes and formally re-submitted the Plan to the
  MVLWB at the end of January 2007 for final Board
  approval

4

• Status of the Con Mine Closure Reclamation Plan
  
• The MVLWB Board staff have indicated that this
  revised version of the Plan will be sent to the
  Working Group for one final review to confirm
  that the Boards conditions have been met this
  meeting.
• Once the Plan is approved, Miramar will implement
  the Plan starting in 2007, with most physical
  reclamation work completed by the end of 2009.
  Water treatment and post closure monitoring and
  maintenance will continue at least through 2031.
• Leased land held by Miramar can be returned to
  the GNWT starting in 2007.

5

• Status of the Reclamation Cost Estimate
• Miramar submitted a revised reclamation cost
  estimate to the MVLWB in December of 2007.
• Revised cost estimate is 12.5 million, not
  including work completed through 2006.
• 60 of this cost is direct physical reclamation
  while 40 is for ongoing water treatment and post
  closure monitoring and maintenance.
• MVLWB has asked INAC to review this cost estimate
  and provide the Board advice regarding any
  revision to reclamation security levels.

6

• Status of the Reclamation Cost Estimate
• Miramar currently has 10.0 million in security
  set aside for reclamation of the Con Mine
• 9.0 million in an environmental trust set aside
  for reclamation from the sale of the Bluefish
  hydro facility pledged to INAC under the Water
  License
• 1.0 million in a second trust set aside for
  reclamation from the sale of the Bluefish hydro
  facility
• Miramar estimates that it will spend an
  additional 4 million on final reclamation in
  2007. Consequently by the end of 2007, the amount
  held in two reclamation trusts will exceed the
  remaining estimated reclamation liability
• Final clean up and treatment of the remaining
  arsenic sludges through the autoclave is
  scheduled for completion by September of 2007
  leading the way for mill demolition in late 2007
  early 2008.

7

• Structure of the Con Mine Closure Reclamation
  Plan
• Table of Contents
• Introduction and History
• Site Infrastructure and Facilities
• Underground Workings
• Rat Lake
• Con Pond and Negus Pond
• Tailing Containment Areas (TCAs)
• Contaminated Soils
• Water Management
• Closure and Post Closure Site Monitoring
• Cost Summary and Schedule

8

• Public Information Session 1 - Held - June
  15th, 2005
• Sections Covered
• Introduction and History
• Site Infrastructure and Facilities
• Underground Workings
• Rat Lake
• Public Information Session 2 -Held October
  26th, 2005
• Sections Covered
• Con Pond and Negus Pond
• Tailing Containment Areas (TCAs)
• Historic Areas
• Recently Active Areas (Upper and Middle Pud)
• Public Information - Session 3 - Held March
  16th, 2006
• Sections Covered
• Contaminated Soils
• Water Management

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• The key reclamation objective is to return the
  minesite to a viable, and wherever practicable,
  self-sustaining ecosystem
• End land use objective is a mix of land suitable
  for industrial use mixed with open space
• Areas not impacted by mining could be used for
  other purposes pending appropriate setbacks
• There will be three sites designated as hazardous
  sites (Con and Negus Ponds and the hazardous
  materials storage site) that will be capped and
  thus not available for future land use

10

• Specific Reclamation Objectives
• Progressive Reclamation activities started in
  2002
• Mill area to be reclaimed to a standard suitable
  for future industrial land use
• Similarly the Shops/Office/Roads/Parking areas to
  be reclaimed to industrial land use standard
• Historic Tailing Areas to be drained, contoured
  and revegetated 35 hectares
• Upper and Middle Pud TCAs to be covered with 50
  to 60 cm of rock and vegetated 50 hectares

11

• Section 1 - Introduction
• History and Reclamation Objectives
• No Comments received from MVLWB and the Working
  Group.

12

• Section 2 - Infrastructure and Facilities
• All buildings on Site are to be removed, with
  potentially 3 exceptions
• Masonic Lodge
• One private residence
• Recreation Hall
• Exceptions subject to approval of the land owner
  (GNWT) - copies of letters from these 3
  interested parties have been submitted to Water
  Board.
• A procedure has been added that deals with the
  assessment of concrete foundations for
  contaminants.
• A procedure covering the removal of the timber
  and concrete crib at the boiler house at the Con
  dock has been added (Section 2.7). This procedure
  references DFO guidance to monitor the work to
  protect fish and commits to obtaining DFO
  approval of the detailed work plan prior to
  proceeding.

13
Mill Complex July 2005
Mill complex at present.
14
Mill Complex 2008 Projection
Mill complex removed - 2008
15

• Section 3 - Underground
• Mining ceased September 2003. Monitoring of
  water level and quality in mine has been carried
  out twice since then.
• In 2006, a procedure was developed to monitor
  minewater (level and quality) on an annual basis.
  This procedure is set out in detail in Sections
  8 and 9. Initially the minewater will be
  monitored at a minimum frequency of once each
  year, with the results reported to MVLWB and
  INAC. Information will be made public.
• In the summer of 2006 water was measured to at
  the 4700 foot level. At current flooding rates
  water is expected to equalize near surface in
  2014.
• Capping of shafts and raises in progress.

16

• Section 4 - Rat Lake
• The majority of the Rat Lake sediments were
  evaluated in 2003.
• A further 2,000 cubic meters were removed in
  2005.
• The Rat Lake Work Plan that detailed what was
  done and what results were obtained to the end of
  2005, has been submitted to the MVLWB (January
  2007).
• The last 100 cubic meters of contaminated
  material was removed in September 2006 and the
  tests results from that work are pending (report
  to be submitted to the MVLWB in March 2007).
• The Reference to the YASRC is added.
• MCML has included in the Plan commitments 10,16
  and 17. Section 4.1 and 4.2.

17

• Section 5 - Con and Negus Ponds
• Arsenic sludges have been removed and stockpiled
  in the Blend Plant for treatment in the
  Autoclave. The Autoclave will be commissioned in
  April 2007 and remain in service until all of the
  arsenic sludges have been treated.
• Con Pond has been cleaned and power washed to
  recover the remaining arsenic sludges.
• Cleaning of the Negus Pond will be completed in
  2007. As the gravel and boulders are removed,
  they will be washed and the wash water will go to
  the Autoclave as feed for the treatment of the
  arsenic sludges. Any gravel or boulders that
  have total arsenic over 340 mg/kg on the surface
  of the rock will be placed in the hazardous waste
  disposal site for permanent care and storage.

18

• Section 5 - Con and Negus Ponds
• The cleaned areas will be graded to direct
  surface runoff to the Middle Pud TCA
• Low permeability engineered cover has been
  designed for these two ponds with the objective
  of reducing infiltration to lt 2.
• Cover will include a Geosynthetic Clay Liner (low
  permeability liner) which has a clay core. As
  such, it is expected to have a long life (100
  years) as compared to synthetic liners (plastic /
  HDPE).
• The water quality of groundwater down gradient of
  the capped ponds will be assessed by monitoring
  wells.

19

• Section 5 - Con and Negus Ponds
• The GCL liner will be capped with a coarse gravel
  / cobble material that is both physically and
  chemically stable. As set out in Section 5.3.1,
  the gravel will be tested to confirm that the
  upper layer will have arsenic levels less than
  340 mg/kg of total arsenic.
• If needed, a quarry would be developed north of
  the water treatment plant to provide cover
  material. The quarry would be closed in a manner
  consistent with the Closure guidelines
  established by INAC for open pits or quarries
  (end of Section 5.3.1).
• A large boulder barrier will be constructed and
  maintained to prevent inadvertent access to these
  areas by motorized vehicles.

20
Con Pond July 2005
Con Pond in center of photograph
21
Con Pond at Closure in 2008
Con Pond with rock cover at closure
22
Negus Pond July 2005
23
Negus Pond at Closure in 2008
Negus Pond with rock cover. Large rock barrier
not shown for clarity.
24
Calcine Storage Area July 2005

• Calcine storage area cleaned out for waste
  storage

25
Hazardous Waste Storage Site September 2008

• Rock cap on hazardous waste storage site. Mill
  complex is removed from area at bottom of photo.

26
Hazardous Waste Site Cap Design

• Cover System for Hazardous Waste Disposal Site
  and Hazardous Waste Sites

27

• Section 6 - Tailing Containment Areas (TCAs)
  Historic and Recently Active
• Historic Negus, Neil Lake, Lower Pud Lake and
  Crank Lake TCAs will be drained, contoured and
  revegetated.
• Recently Active Upper Pud and Middle Pud TCAs
  will be capped with a minimum 50 to 60 cm layer
  of broken rock and then seeded and fertilized.
  Soil will be imported to create islands on the
  surface of the TCA to enhance the rate and
  success of vegetation establishment on the rock.

28

• Section 6 - Tailing Containment Areas (TCAs)
  Historic and Recently Active
• A section has been added to the Closure Plan to
  detail how vegetation success will be measured
  and what criteria will be used to determine when
  additional contingent measures are needed.
• Section 6.5.1. sets out a series of contingency
  plans that describe additional measures that will
  be taken by MCML if the vegetation cover is not
  successful within 4 to 5 years.

29

• Section 6 - Tailing Containment Areas (TCAs)
  Historic and Recently
  Active
• The details for the engineered cover to be placed
  on the Upper and Middle Pud TCA have been
  included in Section 6.5.1.
• The details outline the initial modeling used to
  check the design and present the material
  specifications that will needed to achieve the
  target infiltration (lt 7) for the cover.
• A test pad was developed in 2005 and is being
  monitored for physical stability. It was seeded
  at that time and is being used to evaluate
  vegetation success on the rockfill. Further
  studies are planned in 2007 to confirm the
  modeling used in the design.
• With the exception of rock outcrops, the surface
  area will be vegetated. Fertilizer will be added
  and the area over-seeded for the first several
  years to enhance success.

30
Neil Lake July 2005
31
Neil Lake 2010 Projection

• Neil Lake as revegetated in 2008, Kam Lake in
  background. Note Water Treatment Plant still in
  place.

32
Upper Pud - July 2005
33
Upper Pud - July 2010 Projection

• Upper Pud, capped with waste rock and gravel.
• Note vegetation starting to show.

34
Upper Pud 2015 Projection

• Vegetation cover now established on Upper Pud TCA

35
Cover Test Pad on Upper PudJune 2006
36
Test Pad for Vegetation on Mine Rock Cover
37

• Section 7
• Contaminated Soils
• Minesite has been impacted by 65 years of mining
• Areas of impact have been identified
• Site has been divided into 4 zones to facilitate
  closure and reclamation.
• The Zones are
• Zone 1 - Blend Plant/Negus Pond, Con Pond,
  Hazardous Waste Disposal Site
• Zone 2 Tailing Areas Upper Pud, Middle Pud,
  Lower Pud, Neil Lake, Negus Tailing, and Crank
  Lake
• Zone 3 Main mine lease with mill area,
  Robertson headframe, and area around tailing
  areas to north, west and south
• Zone 4 Rat Lake, Tin Can Hill, Con Camp and
  Dock, and Mosher Island.

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• Section 7
• Contaminated Soils
• Closure plan for Zone 1 is discussed in Section
  5.
• Closure plan for Zone 2 is discussed in Section
  6.
• Closure plan for Zones 3 and 4 are discussed
  here.
• The closure plan for Zone 3 is considered in 2
  parts.
• Area 1. Mill and headframe buildings will be
  removed. Impacted soil will be placed in the
  hazardous waste disposal site or the
  non-hazardous waste site as determined by
  testing. Area will be reclaimed to the NWT
  industrial use standard.
• Area 2. Soil in the areas to the north, west and
  south of Zone 2 (active tailing basins) will be
  tested. Site specific plans to close these areas
  will be developed based on the results of
  testing.

39

• Section 7
• Contaminated Soils
• The closure plan for Zone 4 (Rat Lake, Tin Can
  Hill and Con Dock) started with testing of soil
  at 8 sites identified as having arsenic
  contaminated soil. In addition to arsenic, all
  metals on the GNWT contaminated sites list were
  included in the testing program.
• If any metal on the list is exceeded and
  determined not to be naturally occurring, then
  the sites will be evaluated to determine if clean
  up is necessary. Data to date suggests, once the
  arsenic contaminated soils are removed or cleaned
  up, the other metals of concern are removed.
• The test results indicated that arsenic at 5 of
  the sites is naturally occurring mineralization
  not a result of mining. The others sites will
  be further investigated.
• The rest of Zone 4 was inspected and no other
  contaminated sites were identified. If
  additional sites are found in the next 4 years, a
  site specific closure plan will be developed for
  each area.

40

• Section 7
• Contaminated Soils
• In 2007, sites away from the main mine area
  mill and Robertson Headframe - will be tested to
  confirm the extent and type of arsenic that may
  be present in the soil.
• Water that collects in the excavations at the
  mill will be directed to construction sumps in
  the excavation area. These sumps will be pumped
  and the water directed to the Middle Pud TCA.
• Section 7.4 details the plan to clean up the mill
  site and clean the depressions in the rock
  surface once the mill is removed.

41

• Section 8
• Water Management
• Since the early 1980s surface water on site has
  been collected and directed to the Middle Pud TCA
  and then to the Water Treatment Plant.
• Water treated at the plant, and at nine sampling
  stations around the site, has been monitored
  under the Water License since the early 1980s.
• Regulatory limits for these contaminants are set
  out in the Water License and in federal MMER
  regulations. These will continue to be applied
  following Closure and will apply to minewater
  once it nears the surface. If the limits are
  exceeded, the minewater would be pumped to the
  Middle Pud TCA for treatment.

42
Map of Current SNP Sites
43

• Section 8
• Water Management
• Engineered structures control site surface
  drainage. The Closure Plan provides further
  improvement to the system.
• Offsite flows not directed to Middle Pud are
  minimal and have not been in contact with
  impacted areas.
• These flows are currently monitored by the
  Surveillance Network Program (SNP) under the NWT
  Water License.
• Rat Lake clean up is complete and a final report
  will be submitted in March 2007. The report
  includes the results of the speciation tests.

44

• Section 8
• Water Management
• The Closure Plan creates additional surface water
  monitoring stations and will monitor the quality
  of the minewater as it approaches the surface.
• Six groundwater monitoring wells have been
  installed and several more are included in the
  Closure Plan, including 2 deep wells adjacent to
  mine workings.
• Monitoring at these additional stations will
  continue and be required under future Water
  Licenses.

45

• Section 8
• Water Management
• Minewater and mine flooding.
• URS sampled underground minewater in 2004
• MCML sampled underground minewater in 2006.
• Mine flooded to 4700 Level as of September 2006.
• Minewater is expected to reach surface in late
  2014, thus Con Mine will take 11 years to flood.
• Water quality testing indicates minewater is
  relatively clean Zinc is only parameter above
  Water License limit.
• Closure Plan calls for installation of access
  points in the concrete caps at Robertson Shaft,
  C-1 Shaft, and 204Q Stope to allow for
  installation of pumps should it be necessary to
  pump and treat the minewater when it reaches
  surface.

46

• Section 9
• Closure and Post-Closure Monitoring
• Monitoring of the site is detailed in Section 9.1
  and includes geotechnical inspections of the
  tailing dams, closed hazardous sites, and water
  management facilities. The cost estimate
  (Section 10) anticipates that environmental
  monitoring would continue for 50 years, but the
  frequency of inspections would be reduced over
  time.
• Post-Closure monitoring is anticipated to
  continue unchanged for at least 25 years, or
  until water quality satisfies the Water License
  discharge limits and water treatment can be
  discontinued. The MMER and EEM programs would
  also continue to apply during that period.

47

• Section 9
• Closure and Post-Closure Monitoring
• The annual geotechnical inspection of the
  minesite includes the chemical and physical
  stability of the TCAs, plus all dams, dykes and
  drainage channels.
• The inspection will be expanded to include caps
  on the openings to surface, and the results of
  groundwater monitoring.
• A report of each inspection, and a plan outlining
  any required action, would be sent to the MVLWB,
  the INAC Inspector, and Environment Canada.

48

• Section 9
• Closure and Post-Closure Monitoring
• Federal Environmental Effects Monitoring (EEM)
  has been in effect since June 2002.
• Numerous parameters, including 36 metals, are
  routinely monitored.
• Post-Closure monitoring includes EEM and this
  will continue at least for the next 6 to 9 years.
• Other than arsenic, EEM has not detected any
  other metals at levels of concern.
• In addition to contaminants, EEM monitors the
  environmental effects of treated effluent on the
  receiving water, including fish and other biota.

49

• Section 10 Cost Summary Schedule
• Submitted to MVLWB in December 2006
• Remaining closure costs estimated at 12.5
  million

50

• 2007 Planned Reclamation
• Complete treatment of all remaining arsenic
  sludges.
• Decommission and start to remove Blend Plant
  structure.
• Begin dismantling and removal of remaining
  surface structures, including mill complex and
  headframes.
• Perform cycle 3 of minewater sampling
• Install remaining groundwater wells.

51

• 2008 Planned Reclamation
• Complete demolition and removal of remaining
  surface structures.
• Begin reclamation of Upper Pud TCA.
• Cap 204Q stope opening.
• Cap Robertson / C-1 Shaft openings.
• Perform cycle 4 of minewater sampling.
• Begin reclamation of Middle Pud TCA.
• Continue closure monitoring.

52

• 2009 Planned Reclamation
• Complete reclamation of Upper Pud TCA.
• Continue reclamation of Middle Pud TCA.
• Perform cycle 5 of minewater sampling.
• Complete any remaining tasks.
• Commence Post-Closure monitoring.

53

• 2010 Planned Reclamation
• Complete reclamation of Middle Pud TCA.
• Over seed and fertilize revegetated areas.
• Perform cycle 6 of minewater sampling.
• Complete any remaining tasks.
• Continue Post-Closure monitoring.

54

• Status of Con Mine Water License
• Current license expires on January 30th 2008
• Miramar will ask that the Water License be
  renewed to cover the period from January 2008
  thru December 2014 i.e. thru the 4 year
  physical reclamation period and into the start of
  the post closure monitoring period.
• The renewed license will allow for reclamation,
  ongoing water treatment and post closure
  monitoring and maintenance (no further mining or
  milling).
• This license period will allow the reclaimed site
  conditions to become stable. Subsequent Water
  Licenses will address the long term monitoring
  and maintenance requirements.
• Miramar will submit the application in 2007 once
  the Closure Plan has been approved.

55

• Questions?