premier gold mines hardrock inc. project description ... · 2014 by premier gold mines hardrock...

Premier Gold Mines Hardrock Inc. Project Description Report Addendum

Prepared for: Canadian Environmental Assessment Agency

Prepared by: Stantec Consulting Ltd. 70 Southgate Drive, Suite 1 Guelph ON N1E 7B8

Premier Gold Mines Limited Suite 200, 1100 Russell Street Thunder Bay, Ontario P7B 5N2

File No. 160960946 July 28, 2014

Sign-off Sheet

This report has been prepared by Stantec Consulting Ltd. (Stantec) for the sole benefit of Premier Gold Mines Hardrock Inc. (Premier). The report may not be relied upon by any other person or entity, other than for its intended purposes, without the express written consent of Stantec or Premier.

This report was undertaken exclusively for the purpose outlined herein and was limited to the scope and purpose specifically expressed in this report. This report cannot be used or applied under any circumstances to another location or situation or for any other purpose without further evaluation of the data and related limitations. Any use of this report by a third party, or any reliance on decisions made based upon it, are the responsibility of such third parties. Stantec and Premier accept no responsibility for damages, if any, suffered by any third party as a result of decisions made or actions taken based on this report.

Stantec makes no representation or warranty with respect to this report, other than the work was undertaken by trained professional and technical staff in accordance with generally accepted engineering and scientific practices current at the time the work was performed. Any information or facts provided by others and referred to or used in the preparation of this report were assumed by Stantec to be accurate. Conclusions presented in this report should not be construed as legal advice.

The information provided in this report was compiled from existing documents and data provided by Premier and by applying currently accepted industry standard mitigation and prevention principles. This report represents the best professional judgment of Stantec personnel available at the time of its preparation. Stantec reserves the right to modify the contents of this report, in whole or in part, to reflect any new information that becomes available. If any conditions become apparent that differ significantly from our understanding of conditions as presented in this report, we request that we be notified immediately to reassess the conclusions provided herein.

Prepared by (signature)

Fiona Christiansen, Regional Technical Leader (Central Canada), Environmental Assessment Stantec Consulting Ltd.

Reviewed by (signature)

Amiel Blajchman, Director, Environment, Aboriginal and Community Affairs Premier Gold Mines Limited

PREMIER GOLD MINES HARDROCK INC. PROJECT DESCRIPTION REPORT ADDENDUM

Table of Contents

1.0 INTRODUCTION ...........................................................................................................1.1 1.1 OBJECTIVES ..................................................................................................................... 1.1

2.0 UPDATED PROPOSED FACILITIES, INFRASTRUCTURE, AND ACTIVITIES .......................2.1

LIST OF APPENDICES Appendix A Preliminary General Layout (Current as of July 28th 2014) Appendix B Comparison Table of Key Updates

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Introduction July 28, 2014

1.0 INTRODUCTION

A Project Description Report was submitted to the Canadian Environmental Assessment Agency (CEAA) on April 23rd 2014 by Premier Gold Mines Hardrock Inc. (Premier), formerly Premier Gold Mines Limited. Following submission of the Project Description Report (and open house events held in June 2014), additional resource estimate and engineering studies have been completed by Premier as the Project planning phase continues to advance.

Feasibility studies have ultimately resulted in the identification of a larger pit shell and updates to associated infrastructure. The general footprint of the Project remains relatively unchanged and in some areas the footprint has been tightened, for example by moving the Tailings Management Facility closer to the open pit. Some additional infrastructure components, such as a power supply and generation facility and liquefied natural gas (LNG) facility have been added to the Project (generally sited in the same area as the Processing Plant). Updated preliminary layouts are provided in Appendix A.

1.1 OBJECTIVES

This addendum provides amended descriptions for key project components and activities (as presented in Section 2.3.3 of the Project Description Report April 2014). A tabular summary of the key changes within this Section, comparing April 2014 Project Description Section to Addendum Submission, is provided in Appendix B.

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Updated Proposed Facilities, Infrastructure, and Activities July 28, 2014

2.0 UPDATED PROPOSED FACILITIES, INFRASTRUCTURE, AND ACTIVITIES

The key Project components are expected to include:

• open pit;

• waste rock storage areas;

• raw ore stockpile;

• crushing plant primary and secondary stage;

• crushed ore stockpile process plant;

• tailings management facility;

• mine water treatment facility;

• sewage treatment facility;

• internal access roads and pipelines;

• buildings and yards (administration and dry building, assay lab building, mine maintenance shop, reagent storage building;

• explosives manufacturing and storage;

• water distribution system (including fresh water pumping station, potable water distribution, fire water distribution, reclaim water pumping station);

• fuel supply, conversion, storage and distribution system;

• power generation and distribution system; and

• domestic solid waste handling facility;

At this time a temporary construction camp is not anticipated, however the need will be confirmed as the Project progresses.

Key activities that will need to be undertaken prior to construction include property acquisitions, Highway 11 re-alignment and potential relocation of the Ministry of Transportation (MTO) patrol yard, watercourse realignments, vegetation clearing, a relocation of a portion of the historic MacLeod tailings, a relocation of the Hydro One Networks Inc (HONI) substation and associated overhead power lines and the construction of a natural gas pipeline (at this time the owner/operator is anticipated to be Union Gas).




Key Project Components

Open Pit

As stated in Section 1.0, feasibility studies have ultimately resulted in the identification of a larger pit shell than was original identified in the April 2014 Project Description.

Mining of the Hardrock deposit has been designed as an open pit with a total tonnage of 670,330 kt. Planned production will be 4,380,000 tonnes per year (4.38 tpy) or 12,000 tpd of mineralized material processed at the mill during the first three years, and 10,950,000 tonnes per year (10.95M tpy) or up to 30,000 tpd of mineralized material processed at the mill starting during the fourth year, for 365 days per year of mill operation and mine operation.

The increase in production will not be possible without the mill expansion. The increase in production is anticipated to occur during the third year, with year four representing the first year of full production. The total amount of mineralized material to be processed during the first three years will be 13,140,000 tonnes, for a total of 460,000 ounces of gold. During years 4-15, 130,360,000 tonnes of mineralized material will be mined and; 4,347,000 ounces of gold will be milled. The estimated Life of Mine (LOM) for the Project is anticipated to be 15 years (however this could range between 12-15 years depending on the price of gold), in the last two year of operation mining, drilling and blasting will cease and, the mineralized material stockpile will be the primary supply for the mill and will account for most of the production. This schedule will yield a total of 143,500,000 tonnes of mineralized material at an average grade of 1.05 g Au/t diluted.

The pit slopes will be designed for safety based on applicable industry standards. The benches in the rock will be developed by blasting. Pumps will likely be required for pit dewatering.

The mining method will be a conventional shovel and truck type operation. Ore, mine rock and overburden removed from the open pit will be trucked to the surface. Ramp widths will be designed to accommodate the necessary heavy equipment. One type of truck is likely to be required for the Project (200 tonnes). The use of diesel shovels and/or electric shovels will be evaluated.

During pre-production, 30,000,000 tonnes of waste, 12,500,000 tonnes of overburden and 6,500,000 tonnes of mineralized material will be mined. This amount of waste will cover the need to start the construction of the dyke, tailings management facility, roads and parking area.

The type of explosive used for the Project will be emulsion. Non-electric detonators will be used. An explosive manufacturing and storage facility will likely be constructed on-site considering the volume of explosives needed each year.

Waste Rock Storage Areas

Waste rock has been classified as falling into one of two categories, inert non-acid generating (NAG), and reactive potentially acid generating/metal leaching (PAG/ML). Co-disposal of




PAG/ML rock with NAG rock is assumed at this time. A detailed waste rock management plan will determine runoff treatment options to meet regulatory effluent requirements. Other disposal options may also be considered as appropriate.

The open pit mine plan estimates approximately 505 kt of waste rock and 22 kt of overburden will be generated over the LOM. Waste rock will generally be stored around the perimeter of the open pit. A phased waste rock deposition approach may be considered as appropriate. Material is assumed to be placed on the pad at a maximum height of 90 m with a 10 m bench every 10 m. The location of the storage area was selected to be reasonably close to the open pit to minimize the overall Project environmental footprint. The area was also considered to have suitable foundation conditions with appropriate land tenure. The final location of waste rock will be confirmed as the Project progresses.

Raw Ore Stockpile

An ore stockpile will be generally located west of the open pit capable of storing up to 144 kt of mineralized material. Preliminary ARD/ML testing indicated that approximately 19% of the ore could be ARD/ML, it has been assumed at this time that the ore storage pads will be lined with an impermeable membrane, with runoff collected and sent to the water treatment plant prior to discharge to the environment. As the Project progresses and more information on ARD/ML is acquired, the need for lined ore pads and treatment of runoff may be eliminated.

Mill Feed Storage Area and Crushing Plant

A truck dump and primary crusher will be generally located east of the mill and adjacent to the open pit road. The dump will be capable of handling up to 200 tonne trucks. The primary crusher will feed the secondary crusher and then the crushed ore stockpile generally located east of the process plant. The crushed ore stockpile is a fully enclosed area and will accommodate 47,000 tonnes of total ore capacity (27,000 tonnes live capacity), providing about one day of live storage for the mill. Ore will be transported to the mill by conveyors.

Ore Milling and Processing Plant

The mill will include tertiary ore crushing, ball milling, carbon-in-leach, cyanide destruction, carbon stripping, electrowinning, and refining. The mill will be built in two stages: Phase 1 will be capable of processing up to 12,000 tpd of ore and Phase 2 will bring the plant capacity up to 30,000 tpd.

Ore processing will be carried out by conventional methods using a combination of gravity separation and cyanidation for gold recovery, followed by in-plant cyanide destruction using the SO2/air oxidation process. Tailings will be pumped via a slurry pipeline to the TMF located approximately 5 km from the process plant. On-going ore processing plant water requirements will be derived from water recycled from the TMF. There will also be a need for additional surface water takings, likely from Kenogamisis Lake (amounts to be determined by operational




water balance). Excess site water will be treated and discharged to Kenogamisis Lake. Such discharge will meet applicable federal and provincial effluent discharge requirements.

Tailings Management Facility

The TMF site selection process was generally carried out in accordance with Environment Canada’s “Guidelines for the Assessment of Alternatives for Mine Waste Disposal” (Environment Canada, 2011). The location of the TMF considered technically and economically feasible alternatives, the use of natural topography for containment and ensuring all tailings storage is located in a single location. The location also considered the Project’s environmental footprint and existing land tenure.

The TMF for the Project was conceptually designed to satisfy the design criteria of 150 Mt of tailings, dry density of 1.44 t/m3 and volume of 104.5 Mm3

The TMF will also be constructed in a number of stages, with Stage 1 having capacity to store the tailings production at a milling rate of 12,000 tpd, and the relocated historic MacLeod tailings from stripping activities required for open pit construction (estimated to be 1.32 Mt). Subsequent raises, to provide additional storage capacity, will be carried out to coincide with operations, but will likely be done on a two year cycle, and consist of downstream raises. All tailings will be assumed to be PAG and stored subaqueous in the TMF.

Based on available information of subsurface soils, it is not likely that suitable impermeable soils will be available in the area for dam construction and therefore it has been assumed that rockfill gravity structures will be required with an upstream impermeable membrane and seepage cutoff. Rockfill will be sourced from NAG mine waste rock.

All containment structures for the TMF will be designed in accordance with:

• Canadian Dam Association Dam Safety Guidelines;

• Ontario Dam Safety Guidelines ; and

• MNR Lakes and Rivers Improvement Act requirements.




Preliminary consultation on the location of the TMF presented in the April 2014 Project Description indicated initial comments/concerns, particularly from aboriginal communities, regarding the proposed in-filling of Lake A-322. Premier maintains their continued intent in ensuring the protection, conservation and wise management of the environment. Therefore, in response to comments and concerns raised, and the evolution of the Project, Premier has identified an alternative location for the TMF. The proposed TMF location is still considered to be preliminary and will be subject to further evaluation through the MMER alternatives assessment process that will be undertaken in parallel with the Federal EA process.

Mine Water Treatment Facility

Process water treatment is anticipated for mine contact water on-site, ore pad runoff, waste rock pile runoff, and any excess from the TMF discharge.

As cyanide in tailings will be destroyed in the mill using the Air/SO2 treatment method, the parameters of concern will likely be arsenic, metals (likely copper from the Air/SO2 treatment), TSS, and potentially ammonia. It has been assumed that water treatment will be carried out using a high density sludge clarifier / thickener system. Any excess ammonia will be treated by a typical acidification/degassing system. The effluent will at a minimum meet MMER Schedule 4 limits. As the Project progresses and the flows and concentrations of effluent parameters are better understood, further refinement of the best treatment strategy will be possible.

Internal Access Roads and Pipelines

The main access to the Project will be via the western leg of the existing Highway 11. This access to the Project site will be used by personnel, material deliveries, and haulage trucks transporting material to the mill. Upgrades to the road will not be required as it is assumed to be currently rated for the loads expected. The road will be maintained by Premier personnel year round.

Premier will also own and maintain internal site roads which will link the main site facilities. Large haul truck traffic and other site vehicular traffic will be separated where appropriate.

Pipelines will be needed to transport and dispose of water/waste between various facilities, including the open pit, mill/processing plant and TMF. A pipeline will also be constructed to provide freshwater for potable and process requirements. A on-site gas pipeline will also be required to supply the power plant. It is anticipated that excess treated effluent from the TMF will be pumped via pipeline to the receiving water after a downstream polishing pond. The location and dimensions of pipelines will be confirmed as the Project progresses.




Parking Areas

Two parking areas have been provided for the Project, including:

• a parking facility at the entrance of the plant site for the mine operations and maintenance crews, offices/work areas for all mine technical, supervisor, and management personnel, and mine rescue equipment maintenance and storage;

• a parking area for the open pit equipment close to the mine maintenance shop.

Mine Dry, Office Building and Assay Lab

A two-storey 50 m x 22 m mine dry and office building has been included for this Project. The mine dry will be capable of accommodating 300 people and the office building will be comprised of conference rooms, washroom facilities, mine rescue, first aid and filing rooms as well as office for management staff, operating, geology, engineering and administration personnel.

An assay lab will be built as a separate building located between the Administration building and the mine maintenance shop.

Mine maintenance Shop and Warehouse Building

The shop and warehouse building will be approximately 100 m x 30 m. The shop will have seven bays to service open pit trucks and other surface equipment. It will be equipped with an overhead crane and will provide adequate space for the storage of maintenance tool cabinets and other items required for maintaining the mobile fleet.

The warehouse will be located in the back of the shop and will store mobile equipment parts and other material required throughout the life of the mine. The repair shop will also have adequate space for office/desks to manage the maintenance of the open pit fleet.

Explosives Storage and Manufacturing

Explosives needed for Project development will be prepared in a dedicated explosives manufacturing facility. This facility will be located a safe distance from the open pit. The distance between the various buildings that make up the facility (ammonium nitrate storage, emulsion plant, explosives magazines) will be established in accordance with the “Quantity Distance Principles User’s Manual” (Natural Resources Canada, 1995). The facility will be licensed under the Explosives Act.

Water Distribution System

The water distribution system will provide fire water and service water to all of the surface buildings on the mine site. This system will also provide water for mining personnel working at the mine, for eyewash, safety shower, hand washing, toilets, and possibly for drinking water.




The plant site will be connected to the Geraldton municipal potable water system. Upgrades to the current municipal distribution system are required.

Sewage Treatment Facility

The Ontario Building Code requires wastewater systems with flow rates of greater than 10,000 L/d regulated by the Ministry of the Environment and Climate Change (MOECC) under the Ontario Water Resources Act require an Environmental Compliance Approval (ECA). Based on projections of 300 shift workers and assigning an average unit flow rate of 250 L/person-day, the average sanitary wastewater flow rate would be approximately 75,000 L/d. At this flow rate, a subsurface disposal system would be classified as a Large Subsurface Disposal System. At this time it has been assumed that a package treatment plant will be required with a permitted discharge consisting of an outfall pipe and diffuser to the selected surface water receiver (likely Kenogamisis Lake). The effluent will be treated to meet regulatory requirements.

Fuel Supply, Conversion, Storage and Distribution

Tanker trucks would deliver diesel fuel and gasoline to the site on an as-needed basis for use by heavy equipment and Project vehicles. LNG is also being considered as a potential fuel source. It is anticipated that LNG will be trucked to site during the first few years of mining, however in the longer term a small scale LNG facility may be required. If it is determined that a LNG facility is required it is anticipated that trucking will occur for approximately the first 3 years of operation or until the LNG facility is constructed. If an LNG facility is not required trucking will occur for the LOM. The LNG facility will be located in relatively close proximity to the power plant. The anticipated processing capacity of the LNG facility is 20 metric tons per day with a storage capacity of 450 tons (14 days of storage on site) at full operation (assuming a density of 550 kg/m3 for LNG). Fuels would be stored in approved above-ground storage tanks equipped with secondary containment in accordance with provincial regulations and standards. All fuel storage and distribution infrastructure would be constructed to modern engineering standards and would be approved under provincial legislation requirements. Stationary mine equipment would be fueled with a fuel-dispensing truck. The precise requirements for on-site fuelling will be determined during the Feasibility Study.

Power Generation and Distribution System

Power for the Project will be generated on-site; up to 56 MW of installed power generation capacity is anticipated to be required for the Project at full operation. 20 to 25 MW are anticipated to be required for Phase 1 and 35 to 40 MW are anticipated to be required for Phase 2 (assuming 40 MW of running capacity and 16MW of standby capacity). A new Project substation will also be required on-site. The power plant will be fueled by natural gas.

All site primary power distribution will be via overhead lines, with local outdoor type e-houses for transformers and load centres at each point of utilization.




General site lighting will be a combination of power line pole mounted fixtures and building mounted fixtures at the offices, shop, and other miscellaneous buildings.

Domestic and Solid Waste Handling Facility

Non-hazardous domestic solid waste may be deposited in an on-site landfill, unless a suitable off-site landfill with sufficient capacity can be found. Hazardous solid and liquid waste will be hauled off-site by a licensed contractor.

Solid waste will be collected in steel bins and recycled and reused to the extent practical. Paper and cardboard will be recycled; waste steel will be sold as scrap; wood and plastic will be salvaged and recycled where possible. Non-hazardous domestic solid waste may be deposited in an on-site landfill, unless a suitable off-site landfill with sufficient capacity can be found. Recyclable solid materials and garbage may be collected by a local contractor for recycling or disposal of the garbage.

All waste disposal shall be undertaken in accordance with existing regulations. Contractors shall be required to conduct all day-to-day operations in such a manner as to avoid creating any unpleasant appearances or any conditions that will be detrimental to the surrounding area.

The contractor shall ensure that waste oils, fuels, and hazardous wastes (if any) shall be handled in a safe manner. Contractors will be required to transport, store and handle all such substances as recommended by the suppliers and/or manufacturers and in compliance with all applicable federal, provincial or municipal regulations.

Key Project Activities

Existing Property Acquisitions

Premier intends to acquire existing properties, some of which are currently inhabited, as a result of the Project. This includes 37 houses and 5 vacant lots in the MacLeod Townsite, a public park in the MacLeod Townsite, 12 houses and 11 vacant lots in the Hardrock Townsite, a police station, a discovery centre, a headframe and a gas station/general store. Site remediation associated with the gas station and the historic MacLeod tailings will be evaluated by Premier. Premier anticipates that some holes on the Kenogamisis Golf Club course will likely need to be relocated as a result of the Project. Premier currently owns the golf course property and leases it to the Municipality.

Realignment of Highway 11 and Potential Relocation of MTO Patrol Yard

As the ore deposit is partially located underneath Highway 11, realignment of a portion of the existing Highway 11 is required to accommodate the proposed open pit. A Highway 11 feasibility route study was undertaken by Stantec in July 2013. The Study identified and assessed alternative routes around the open pit. The Study provides a framework for future discussion with




the MTO, and provides recommendations to carry-forward more detailed studies to confirm a recommended route for Highway 11. This new road will continue to by-pass the Project, connect with Michael Power Blvd and will provide access to Geraldton.

As Project planning continues to advance, mining feasibility studies have identified a 500m safety setback from the open pit. A highway corridor has been identified for evaluating re-alignment options. Re-location of the MTO Patrol Yard may also be required depending on selection of the preferred highway alignment.

Watercourse Realignments

The Project has been developed in order to select watercourse realignments with the aim of minimizing the overall environmental effects to flow regimes, water transfer between subwatersheds, fish and fish habitat, and to maximize Project efficiencies.

As part of the proposed development of the TMF Goldfield Creek will be diverted/re-aligned The SW Arm Tributary located within the footprint of the proposed waste rock storage area may also be re-aligned along with a number of smaller watercourses generally located within the golf course area. Where re-alignments are not possible, in-filing may be considered. Realignments will require further investigation and review as engineering studies are advanced.

Historic MacLeod Tailings

A portion of the historic MacLeod tailings will likely be required to be relocated as a result of the Project. At this time, it is anticipated that the tailings will be stripped and placed into the TMF.

HONI Substation and Associate Overhead Transmission Lines

A potential relocation of the HONI substation and associated overhead power lines is also anticipated to be required as a result of the proximity of the open pit, discussions with HONI are ongoing.

Natural Gas Pipeline

Discussions are ongoing with TCPL and Union Gas to confirm the need for a new gas distribution pipeline. If the need for this pipeline is confirmed it is assumed that the existing distribution line, located to the west of Geraldton, would be twinned. It is anticipated that the line would be approximately 10 km in length. At this time is has been assumed that the owner/operator for this pipeline would be Union Gas. This will be confirmed as the Project progresses.



Appendix A

Preliminary General Layout (Current as of July 28th 2014)

PRELIMINARY

CONSTRUCTIONNOT FOR

IN PROGRESS

FOR COMMENTS

UNDER REVISION 0E

N

N

PRELIMINARY

CONSTRUCTIONNOT FOR

IN PROGRESS

FOR COMMENTS

UNDER REVISION 0B

NOTE :NAD83 DATUM - UTM ZONE 16 -CONTOUR INTERVAL : 5m. CONTOURS FROM AMEC SMOOTH CONTOURS 14-06-27


Appendix B

Comparison Table of Key Updates

Comparison of Proposed Facilities, Infrastructure, and Activities Appendix B

Key Project Component Project Description (April 2014) Addendum Submission – Key Changes (July 2014)

Open Pit 3,650,000 tonnes per year (3.65 tpy)

10,000 tpd of mineralized material processed

at the mill during the first three years, and up

to 18,000 tpd of mineralized material

processed at the mill starting the third year

During pre-production, 1,230,000 tonnes of

waste, 400,000 tonnes of overburden and

200,000 tonnes of mineralized material will be

mined.

The estimated LOM for the Project will be 15

years, with 13 years to mine the open pit.

This schedule will yield a total of

89,332,152 tonnes of mineralized material at

an average grade of 1.185 g Au/t diluted.

The total amount of mineralized material to

be processed during the first two years will be

7,300,000 tonnes, for a total of 465,693 ounces

of gold. Year 3 represents the first year of full

production (up to 18,000 tpd).During years 3-

13, 72,270,000 tonnes of mineralized material

will be mined and; 2,783,369 ounces of gold

will be milled. During the years 14-15 only

stockpiled material will be supplied to the mill.

During this time 9,762,152 tonnes of

mineralized material will processed and;

143,501 ounces of gold will be milled.

Larger pit shell

4,380,000 tonnes per year (4.38 tpy)

12,000 tpd of mineralized material processed at the mill during

the first three years, and up to 30,000 tpd of mineralized material

processed at the mill starting the fourth year

During pre-production, 30,000,000 tonnes of waste, 12,500,000

tonnes of overburden and 6,500,000 tonnes of mineralized

material will be mined.

The estimated Life of Mine (LOM) for the Project is anticipated to

be 15 years (however this could range between 12-15 years

depending on the price of gold). In the last two year of

operation mining, drilling and blasting will cease and the

mineralized material stockpile will be the primary supply for the

mill and will account for most of the production.

This schedule will yield a total of 143,500,000 tonnes of

mineralized material at an average grade of 1.05 g Au/t diluted.

The total amount of mineralized material to be processed during

the first three years will be 13,140,000 tonnes, for a total of

460,000 ounces of gold. Year four represents the first year of full

production (up to 30,000 tpd). During years 4-15, 130,360,000

tonnes of mineralized material will be mined and 4,347,000

ounces of gold will be milled.

Waste Rock Storage

Areas

Disposal of PAG/ML rock will be separate

from the NAG rock is assumed at this time

due to leachate concerns.

Mine plan estimates approximately 388 Mt of

waste rock and overburden will be

generated over the life of mine.

NAG waste rock and overburden will be

stored separately to the south of the pit on

cleared ground that generally slopes toward

Kenogamisis Lake.

Co-disposal of PAG/ML rock with NAG rock is assumed at this

time.

Mine plan estimates approximately 505 kt of waste rock and 22

kt overburden will be generated over the life of mine

Waste rock will generally be stored around the perimeter of the

open pit. A phased waste rock deposition approach may be

considered as appropriate.

Waste rock pile height of 90 m


Waste rock pile height of 60 m at a 1.5:1 slope

with a bench every 10 m.

Ore Stockpile Three separate ore pads will be located east

of the mill and are capable of storing up to

one million tonnes of mineralized material.

One ore stockpile will be located west of the open pit capable

of storing up to 144 kt of mineralized material

Mill Feed Storage Area

and Crushing Plant

A truck dump and primary crusher will be

located east of the mill and adjacent to the

open pit road.

The dump will be capable of handling up to

250 tonne trucks.

The mill feed storage area is a fully enclosed

area and will accommodate 47,000 tonnes of

total ore capacity (27,000 tonnes live

capacity), providing 1.5 days of live storage

for the mill.

Ore will be transported to the mill by

conveyors (apron feeders).

No Key Changes

Ore Milling and

Processing Plant

Phase 1 will be capable of processing up to

10,000 tpd of ore and Phase 2 will bring the

plant capacity up to 18,000 tpd

Tailings will be pumped via a slurry pipeline to

the TMF located approximately 8 km from the

process plant.

Surface water taking likely from Mosher Lake

Phase 1 will be capable of processing up to 12,000 tpd of ore

and Phase 2 will bring the plant capacity up to 30,000 tpd

Tailings will be pumped via a slurry pipeline to the TMF located

approximately 5 km from the process plant.

Surface water taking likely from Kenogamisis Lake

Tailings Management

Facility

The TMF for the Project was conceptually

designed to satisfy the design criteria of 89 Mt

of tailings, dry density of 1.44 t/m3 and

volume of 62.3 Mm3

The TMF for the Project was conceptually designed to satisfy the

design criteria of 150 Mt of tailings, dry density of 1.44 t/m3 and

volume of 104.5 Mm3

Preliminary consultation on the location of the TMF presented in

the April 2014 Project Description indicated initial

comments/concerns, particularly from aboriginal communities,

regarding the proposed in-filling of Lake A-322. Premier

maintains their continued intent in ensuring the protection,

conservation and wise management of the environment.

Therefore, in response to comments and concerns raised, and

the evolution of the Project, Premier has identified an alternative

location for the TMF. The proposed TMF location is still considered

to be preliminary and will be subject to further evaluation

through the MMER alternatives assessment process that will be

undertaken in parallel with the Federal EA process.


Mine Water Treatment

Facility

Process water treatment is anticipated for

mine contact water on-site, ore pad runoff,

waste rock pile runoff, and any excess from

the TMF discharge.

Cyanide in tailings will be destroyed in the mill

using the Air/SO2 treatment method, the

parameters of concern will likely be arsenic,

metals, TSS, and potentially ammonia.

It has been assumed that water treatment will

be carried out using a high density sludge

clarifier / thickener system, with any excess

ammonia being treated by a typical

acidification/degassing system.

The effluent will at a minimum meet MMER

Schedule 4 limits.

No Key Changes

Internal Access Roads

and Pipelines

The main access to the Project will be via the

western leg of the existing Highway 11.

Upgrades to the road will not be required as it

is assumed to be currently rated for the loads

expected.

The road will be maintained by Premier

personnel year round.

Premier will also own and maintain internal

site roads which will link the main site facilities.

Large haul truck traffic and other site

vehicular traffic will be separated where

appropriate.

Pipelines will be needed to transport and

dispose of water/waste between various

facilities. The location and dimensions of

pipelines will be confirmed as the Project

progresses.

No Key Changes

Parking Areas Four parking areas have been proposed. Two parking areas have been proposed.

Mine Dry, Office Building

and Assay Lab

Two-storey mine dry and office building

capable of accommodating 300 personnel.

An assay lab will be constructed.

No Key Changes

Mine Maintenance,

Shop and Warehouse

A combination shop and warehouse building

will be constructed to service open pit trucks

and other service equipment.

No Key Changes


The warehouse will be located at the rear of

the building.

Explosives Storage and

Manufacturing

Explosives will be prepared in a dedicated

explosives manufacturing facility.

The facility will be located a safe distance

from the open pit and site buildings.

The facility will be licensed under the

Explosives Act.

No Key Changes

Water Distribution

System

The plant site will be connected to the

Geraldton municipal potable water supply.

Upgrades to the existing system will be

required.

No Key Changes

Sewage Treatment

Facility

Anticipated average sanitary wastewater

flow rates would be 75,000 L/person-day.

A Large Subsurface Disposal system would be

required and will consist of an outfall pipe

and diffuser to the selected surface water

receiver (likely Kenogamisis Lake).

The effluent will be treated to meet regulatory

requirements.

No Key Changes

Fuel Supply, Conversion,

Storage and Distribution

Tanker trucks will deliver diesel fuel and

gasoline to the site on an as-needed basis.

LNG is being considered as a potential fuel

source.

Tanker trucks will deliver diesel fuel and gasoline to the site on an

as-needed basis.

It is anticipated that LNG will be trucked to site during the first

few years of mining, however in the longer term a small scale

LNG facility may be required. If it is determined that a LNG

facility is required it is anticipated that trucking will occur for

approximately the first 3 years of operation or until the LNG

facility is constructed. If an LNG facility is not required trucking

will occur of the Life of Mine. The LNG facility will be located in

relatively close proximity to the power plant. The anticipated

processing capacity of the LNG facility is 20 metric tons per day

with a storage capacity of 450 tons (14 days of storage on site)

at full operation (assuming a density of 550 kg/m3 for LNG).

Power Generation and

Distribution

Power for the Project will supplied by HONI.

Upgrades to the existing substation and a

new Project substation will be required.

Power for the Project will be generated on-site; up to 56 MW of

installed power generation capacity is anticipated to be

required for the Project at full operation. 20 to 25 MW are

anticipated to be required for Phase 1 and 35 to 40 MW are

anticipated to be required for Phase 2 (assuming 40 MW of

running capacity and 16MW of standby capacity). The power


plant will be fueled by natural gas (refer to key activities table

below).

Domestic and Solid

Waste Handling Facility

Solid waste will be collected in steel bins and

recycled and reused to the extent practical.

Paper and cardboard will be recycled; waste

steel will be sold as scrap; wood and plastic

will be salvaged and recycled where

possible.

Non-hazardous domestic solid waste may be

deposited in an on-site landfill, unless a

suitable off-site landfill with sufficient capacity

can be found.

No Key Changes

Temporary Construction

Camp

A small temporary mining camp will include a

mine dry, office and cafeteria facilities.

Portable trailers will be installed to

accommodate the construction and

development personnel required to

complete the construction of the garage,

administration and mill buildings.

Anticipated to be no longer required, however the need will be

confirmed as the Project progresses.

Key Project Activities Project Description (April 2014) Addendum Submission – Key Changes (July 2014)

Existing Property

Acquisitions

Premier intends to acquire 37 houses and 5

vacant lots in the MacLeod Townsite, a public

park in the MacLeod Townsite, 12 houses and

11 vacant lots in the Hardrock Townsite, a

police station, a discovery centre, a

headframe and a gas station/general store.

Site remediation associated with the gas

station and the historic MacLeod tailings will

be evaluated by Premier.

No Key Changes

Realignment of Highway

11 and Potential

Relocation of MTO

Patrol Yard

As the ore deposit is partially located

underneath Highway 11, realignment of a

portion of the existing Highway 11 is required

to accommodate the proposed open pit.

Relocation of approximately 4.2 kilometres of

length of highway is anticipated.

Mining feasibility studies have identified a 500m safety setback

from the open pit. A corridor has been identified for evaluating

re-alignment options

Re-location of the MTO Patrol Yard may also be required

depending on selection of the preferred highway alignment

Watercourse

Realignments

As part of the proposed development of the

TMF, Lake A-322 and the associated first order

watercourse draining the lake will be in-filled.

A Goldfield Creek Tributary will also be

realigned (between Lake A-323 and

Goldfield Creek).

The SW Arm Tributary located within the

footprint of the proposed waste rock storage

area will also likely be re-aligned.

In-filling and realignments will require further

investigation and review as engineering

studies are advanced.

As part of the proposed development of the TMF Goldfield

Creek will be diverted/re-aligned. The SW Arm Tributary located

within the footprint of the proposed waste rock storage area

may also be re-aligned along with a number of smaller

watercourses generally located within the golf course area.

Were re-alignments are not possible in-filing may be considered.

Realignments will require further investigation and review as

engineering studies are advanced.

Historic McLeod Tailings A portion of the historic MacLeod tailings will

likely require to be relocated as a result of the

Project.

It is anticipated that the tailings will be

stripped and placed into the TMF.

No Key Changes

HONI Substation and

Associated Overhead

Transmission Lines

Premier will work with HONI should a potential

relocation of the substation be required..

A potential relocation of the HONI substation and associated

overhead power lines is anticipated to be required as a result of

the proximity of the open pit, discussions with HONI are ongoing.

Key Project Activities Project Description (April 2014) Addendum Submission – Key Changes (July 2014)

Natural Gas Pipeline

(Union Gas)

N/A Discussions are ongoing with TCPL and Union Gas to confirm the

need for a new gas distribution pipeline. If the need for this

pipeline is confirmed it is assumed that the existing distribution

line, located to the west of Geraldton, would be twinned. It is

anticipated that the line would be approximately 10 km in

length. At this time is has been assumed that the

owner/operator for this pipeline would be Union Gas. This will be

confirmed as the Project progresses. The pipeline will supply the

Power Plant

premier gold mines hardrock inc. project description ... · 2014 by premier gold mines hardrock...

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