Common Excavation Work Plan
PROJECT ID: TUNDRA MINE PHASE 2 REMEDIATION
DATE OF SUBMISSION: February 15, 2011
SUBMITTED BY: Karen Lau (TLICHO)
SUBMITTED TO: Michael Bernardin (PWGSC)
INTRODUCTION
Herein is contained the details of TLICHO’s Common Excavation Work Plan for the
Tundra Mine Phase 2 Remediation Project.
REVISION LIST
The following table tracks the process of Common Excavation Work Plan revision and
ensures that all stakeholders have the most up to date copy. The table must be updated
each time a revision is made to the document.
Figure 1 Plan Revision Table
REVISION NO.
TLICHO REVIEW DATE CROWN REVIEW
DATE SECTIONS REVISED REVISION
DISTRIBUTION DATE
1 Dwight Grabke February
14, 2011
2
3
TUNDRA MINE PHASE 2
Common Excavation Work Plan
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Table of Contents Common Excavation Work Plan ................................................................................ 1 1 Equipment ................................................................................................................... 1 2 Methodology ............................................................................................................... 5
2.1 Work to follow Erosion, Sediment and Drainage Plan ....................................... 7 2.2 Excavation Areas near Identified Hydrocarbon Contamination Areas ............... 8
2.2.1 Bulldog Lake Jetty ........................................................................................ 12 2.3 Excavation of Tailings Dams (East Lower Dam and North Dam) ................... 12 2.4 Backfill and Re-grade of Excavation Areas ...................................................... 13
3 Quantities .................................................................................................................. 13
TUNDRA MINE PHASE 2
Common Excavation Work Plan
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Common Excavation Work Plan As all waste rock on-site may be Potentially Acid Generating (PAG) rock, TLICHO will
handle all waste rock as PAG rock to prevent contamination and impacts to the
environment. An original ground survey will be performed prior to any common
excavation work.
1 Equipment The Superintendent or Project Manager will determine the specific pieces of equipment
that will be dedicated to common excavation work once the field conditions have been
assessed. The following table summarizes the fleet of equipment that will be mobilized
into Tundra Mine on the 2011 winter road. Selected pieces of equipment from this list
will be available to perform this work.
Equipment will be dedicated to common excavation work to prevent any cross
contamination of areas.
TUNDRA MINE PHASE 2
Common Excavation Work Plan
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NO Unit # EQUIPMENT DESCRIPTION EQUIPMENT PURPOSE Equipment
Weight
Number
of Loads
Equipment
fuel burn
1 LV1 White Ford
XLT
2008 Ford F350 XLT
Superduty 4x4
Site transportation. 8500 lbs driven 100 L/day
2 LV2 White Ford
XLT
2008 Ford F350 XLT
Superduty 4x4
Site transportation. 8500 lbs driven 100 L/day
3 LV3 White Ford
XLT
2008 Ford F350 XLT
Superduty 4x4
Site transportation. 8500 lbs driven 100 L/day
4 LV4 White Ford
XLT
2008 Ford F350 XLT
Superduty 4x4
Site transportation. 8500 lbs driven 100 L/day
5 TCP1 Light Plant Ingersoll Rand L8,
8kw@60Hz
Power supply to CMTA
treatment facilities, Back-up
power supply for camp
2300 lbs 0.25 100 L/day
6 TCP2 Light Plant Ingersoll Rand L8,
8kw@60Hz
Power supply to CMTA
treatment facilities, Back-up
power supply for camp
2300 lbs 0.25 100 L/day
7 TCP4 Light Plant Ingersoll Rand L8,
8kw@60Hz
Power supply to CMTA
treatment facilities, Bac-up
power supply for camp
2300 lbs 0.25 100 L/day
8 TCP6 Light Plant Ingersoll Rand L8,
8kw@60Hz
Power supply to CMTA
treatment facilities, Back-up
power supply for camp
2300 lbs 0.25 100 L/day
9 TCP7 Light Plant Ingersoll Rand L8,
8kw@60Hz
Power supply to CMTA
treatment facilities, Back-up
power supply for camp
2300 lbs 0.25 100 L/day
10 TCP8 Light Plant Ingersoll Rand L8,
8kw@60Hz
Power supply to CMTA
treatment facilities, Back-up
power supply for camp
2300 lbs 0.25 100 L/day
TUNDRA MINE PHASE 2
Common Excavation Work Plan
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11 HV4 40D Rock
Truck
40 Tonne Rock Truck
S/NCATD400EC8PS01042
Hauling of Tailings Material
and Liner Cover
73000 lbs 1.00 375 L/day
12 HV5 40D Rock
Truck
40 Tonne Rock Truck
S/NCATD400ECL8PS0106
7
Hauling of Tailings Material
and Liner Cover
73000 lbs 1.00 375 L/day
13 HV1 2007 Rock
Truck
Caterpillar 730R 26.9 Yard
Capacity, 325HP
S/N:CAT00730AB1M0108
5
Hauling of Tailings Material
and Liner Cover
51000 lbs 1.00 360 L/day
14 HV2 2007 Rock
Truck
Caterpillar 730R 26.9 Yard
Capacity, 325HP
S/N:CAT00730HB1M0120
4
Hauling of Tailings Material
and Liner Cover
51000 lbs 1.00 360 L/day
15 HV3 2007 Rock
Truck
Caterpillar 730R 26.9 Yard
Capacity, 325HP
S/N:CAT00730CB1M0122
3
Hauling of Tailings Material
and Liner Cover
51000 lbs 1.00 360 L/day
16 HV6 966 Loader Caterpillar Diesel Engine,
325 HP motor,
bucket/forklifts
Loading and off-loading
trucks; materials
management; Loading Rock
Trucks; Feed screener
50000 lbs 1.00 200 L/day
17 EX1 345CL
Excavator
2008 - 380 HP Yard
Rock/Finishing Bucket 42'
Reach
Excavation/loading of
tailings material and waste
rock into trucks; Load
Trucks
90000 lbs 1.00 500 L/day
18 EX2 345CL
Excavator
2008 - 404 HP, Long
undercarriage, C/w 6m3
bucket, 46'1" Reach
Excavation/loading of
tailings material and waste
rock into trucks; Load
Trucks
90000 lbs 1.00 500 L/day
TUNDRA MINE PHASE 2
Common Excavation Work Plan
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19 EX3 EX300 LC
Hitachi
1998 - Hitachi 220 HP,
1.7m3 bucket, 32'2" reach
Excavation/loading of
tailings material and final
cover material
70850 lbs 1.00 200 L/day
20 EX4 315 Excavator 2007 - Caterpillar 115 HP,
27'7" Reach, digging depth
17'3"
Excavation/loading of
tailings material and final
cover material
17500 lbs 1.00 200 L/day
21 HV7 D6 Dozer 2008 - 258HP, Ripper, 12'
Blade width
Site and Tailings re-grading 47000 lbs 1.00 250 L/day
22 HV8 D6 Dozer 2008 - 258HP, Ripper, 12'
Blade width
Site and Tailings re-grading 47000 lbs 1.00 250 L/day
23 ME1 Vibroscreen 2007 SCM-55 Vibrotech
Equipment Inc
Sorting and blending
materials for final cover
27000 lbs 1.00
24 40D Rock
Truck
40 Tonne Rock Truck 73000 lbs 2.00 500 L/day
25 40D Rock
Truck
40 Tonne Rock Truck 73000 lbs 2.00 500 L/day
26 980 Loader Caterpillar Diesel Engine,
bucket/forklifts
95603 lbs 1.00 400 L/day
TUNDRA MINE PHASE 2
Common Excavation Work Plan
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2 Methodology As all waste rock on-site may be Potentially Acid Generating (PAG) rock, TLICHO will
handle all waste rock as PAG rock to prevent contamination and impacts to the
environment. Therefore, all waste rock excavated will be hauled from the excavation
area directly to its final disposal location, the tailings containment area (Lower Pond).
Waste rock will not be stockpiled anywhere else on-site.
An original ground survey will be taken prior to any excavation activities on-site. The
Departmental Representative will be notified prior to excavation activities on-site so that
they are present on-site during the work.
Excavation work will be under the supervision of the Civil Works Supervisor and the
Departmental Representative.
The areas for common excavation at Tundra Mine include waste rock at the Mill Area, at
East Lower Dam and at North Dam. The following figure shows the areas where waste
rock is identified for excavation as per the Issue for Construction drawing C8 (green
gridded areas).
TUNDRA MINE PHASE 2
Common Excavation Work Plan
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2.1 Work to follow Erosion, Sediment and Drainage Plan
All excavation work will adhere to the TLICHO Erosion, Sediment and Drainage Control
Plan to prevent sediment migration from land into the local water bodies, prevent
ponding water, and mitigate dust generation on-site during work.
To prevent sediment migration, excavations within 30 meters of a water body (ie.
Bulldog Lake) will follow the excavation procedures.
If there is a danger of a material spillage within 5 meters of a water body, it will trigger
the implementation of environmental protection supplies. The environmental protection
supplies include the following:
1. 3000 ft of silt fence
2. 1000 ft of silt curtains
3. 500 ft of sorbent booms
4. Spill Kits
Silt fence and silt curtains will be used as a preventative measure to prevent migration of
sediments into a water body. Sorbent booms and spill kits will be on hand to protect
water bodies from any uncontrolled release of contaminates. Access to shoreline
excavations by machinery should be limited to the top of the bank to minimize bank
erosion. Efforts will be made to retain riparian vegetation along the shoreline to
minimize erosion and enhance bank stability.
TLICHO’s site wide water management plan comprises of the following 5 areas where
we see a need for water management:
Controlling surface runoff from entering the excavation. TLICHO will pay
special attention to the potential of freshette impacts to the surface flow rates. The
surface runoff may be controlled utilizing surface ditches, earth dams,
Geosynthetic dams, culvert installation and pumping stations.
Controlling ground water. TLICHO will complete a preliminary drill hole with
the Minuteman drill to locate the sub-surface ground water table. The concern here
is that a high ground water table may quickly drain into the excavation creating a
significant environmental issue by contaminating water which may travel into the
adjacent ground water. In areas where the ground water table is higher than the
expected bottom of the excavation, TLICHO will implement the following
controls:
o ditching to divert ground water
o pumping to lower ground water
o locating the source and diverting the source of ground water
TUNDRA MINE PHASE 2
Common Excavation Work Plan
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Degradation of Permafrost. Any time ground is disturbed over permafrost,
especially when this changes surface or ground water characteristics, there is
significant potential for permafrost degradation. In-order to control permafrost
degradation, the ground and surface water must be properly managed. TLICHO
has a geotechnical engineer with over 20 years experience in cold regions who will
identify areas on-site where permafrost may be located. When permafrost is
encountered at an excavation site, all efforts will be made to divert any water
which may enter the excavation and propagate the degradation of permafrost. The
excavation site will be accessed as quickly as possible and recovered immediately
after work is completed. This will minimize the disturbance to the permafrost.
Precipitation Mitigation. TLICHO will not excavate during heavy rain. Areas
with a high potential for erosion will be inspected to ensure controls are in place
and maintained prior to anticipated rain events.
Plan for controlling sediments created by the excavation. TLICHO will install
silt curtains, silt fences and/or hydrocarbon booms to ensure that the excavations
will not impact the local water bodies or streams.
The water management plan will protect the environment from contaminants which will
be exposed during the excavation process as well as minimize the migration of sediments
due to water movement. When performing excavation work, a combination of the above
5 approaches will be utilized to control water, depending on what is encountered. The
construction supervisor will decide which control to implement in order to properly
manage water to prevent any sediment and erosion issues.
Dust and wind blown tailings are a concern on-site for worker health and safety during
the summer months when the roads and tailings pond are not frozen in and covered by a
layer of snow. Therefore, dust suppression will be on-going during the summer
construction season in areas of work activity. There will be a water truck on-site
dedicated to keeping dust to a minimum. It is anticipated that water will be sufficient for
dust control. If water isn’t sufficient, then we will utilize an environmentally friendly
chemical dust suppressant.
The dust suppressants that TLICHO have researched into include the following: soil-
sement from GeoEnvironmental; T.O.P from EnsSolutions; Dust Stop from Cypher
Environmental Ltd.; EnviroClear from The Amber Group. The availability, delivery time
and cost of these chemicals will play a factor in the selection process, as well as its
demonstrated effectiveness.
2.2 Excavation Areas near Identified Hydrocarbon Contamination Areas
An original ground survey will be performed prior to any common excavation work.
TUNDRA MINE PHASE 2
Common Excavation Work Plan
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There are areas identified to have hydrocarbon contamination on-site. The Civil Works
Supervisor will flag the perimeters of the areas identified to have hydrocarbon
contamination under the direction of the Departmental Representative. Prior to
excavation in these areas, workers will be trained to keep a 5 metre setback from the
hydrocarbon perimeters to prevent cross contamination. The Civil Works Supervisor will
be continually monitoring the excavations to ensure that the material excavated is free of
hydrocarbons.
A Petroflag sniffer will be on-site to aid in the identification of hydrocarbon
contaminated soil. The Civil Works Supervisor, or qualified designate will be trained to
operate the Petro flag sniffer.
If hydrocarbons are identified within any excavation, work will stop immediately and the
Departmental Representative will be notified for further instruction. Also, if we come
across buried debris in the excavation, work will stop immediately and the Departmental
Representative will be notified for further instruction.
All excavations will be sloped at a ratio of 2:1 to promote stability. This is a requirement
set within the Land Use Permit, Part C – 16. This ratio also has a built in contingency to
hold stability as the recommended slopes for most materials encountered on this site
identified for common excavation will maintain stability at a steeper slope (p. 105, Keller
& Sherar, Low-Volume Roads Engineering- Best Management Practices Field Guide).
TUNDRA MINE PHASE 2
Common Excavation Work Plan
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The Civil Works Supervisor will be continually monitoring the slopes and will consult
with the TLICHO Civil Engineer and Departmental Representative if stability is not
achieved with the current slope ratio. Work will stop immediately until a new slope is
derived.
TLICHO will excavate to the required depth as per the specifications, or as directed by
the Departmental Representative.
The following figure shows the areas identified to contain hydrocarbon excavation.
TUNDRA MINE PHASE 2
Common Excavation Work Plan
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2.2.1 Bulldog Lake Jetty
Excavation at this area will commence during open water season. The Department of
Fisheries and Ocean (DFO) will be notified and consulted on the best time to perform this
work so as to have the least impact on the fish in Bulldog Lake.
A silt curtain will be installed 3 meters all around the jetty to prevent silt migration into
Bulldog Lake. Then TLICHO will perform a fish salvage effort in the isolated area.
DFO will be consulted on best techniques for the impact fish at Bulldog Lake. During
construction, turbidity samples will be taken for continual monitoring. A threshold
turbidity will be set so that if readings surpasses the set point, work will stop immediately
and further erosion measures will be put in place to control sediment migration.
After excavation work has been deemed completed and satisfactory by the Departmental
Representative, turbidity samples will be taken on both sides of the silt curtain
installation. Once the turbidity levels are balanced between both sides, the silt curtains
will then be removed.
2.3 Excavation of Tailings Dams (East Lower Dam and North Dam)
An original ground survey will be performed prior to any common excavation work. The
Departmental Representative will be notified prior to excavation of the tailings dams.
TLICHO does not expect to excavate any part of the tailings dams until the majority of
the water in Lower Pond has been treated. Due to the topography of Lower Pond, it is
expected that the water level will decrease fastest from the South-East corner. Therefore,
the excavation can safely begin at the section of East Lower Dam between the East Upper
Dam road and the culvert at East Lower Dam. The rest of East Lower Dam and North
Dam are expected to remain in place until water has been treated to below the liner
installation elevation.
As a general rule of thumb, TLICHO will ensure that prior to the excavation of an area of
the tailings dam, it is no longer a functional barrier to retain water within that section of
Lower Pond.
Workers will be under the supervision of the Civil Works Supervisor. Workers will be
trained to stop work should they come across any buried debris or tailings in the
excavation area. The Civil Works Supervisor will be notified immediately. The
Departmental Representative will be sought for further instruction.
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Common Excavation Work Plan
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2.4 Backfill and Re-grade of Excavation Areas
The Departmental Representative will be notified to perform confirmatory samples to
indicate that there is no further contamination at the excavation area. After confirmation
from the Departmental Representative and approval is granted, excavated low areas will
be backfilled with Type A material. The areas will be backfilled and graded to provide
natural drainage and to prevent ponding water at the excavated area. Where areas are
identified that do not require backfill, grading will be performed graded to provide
natural drainage and to prevent ponding water at the excavated area.
Backfill and re-grade will be performed under the supervision of the Civil Works
Supervisor and direction from the Departmental Representative.
3 Quantities There is an estimated quantity of 104,173 cubic meters of common excavation on site.
An original ground survey of the entire site will be performed prior to any excavation
work in each respective area to accurately determine areas and volumes of waste rock to
be excavated.
TLICHO recognizes the maximum excavation tolerances from the design lines as
indicated in the specification drawings is 0.3 meters, as measured from the plane of the
excavations, unless otherwise directed by the Departmental Representative.
The Departmental Representative will verify material classification for these excavation
sites.
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