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Condition and Hazard Evaluation of Crown Owned Inactive Mine Sites in Manitoba
Caius Priscu, Ph.D, P.EngAMEC Earth & Environmental, Winnipeg, MB
NOAMI Workshop, 26-27 October 2006 Winnipeg, Manitoba
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Outline of Presentation
IntroductionProject Scope and ObjectivesMethodology and ApproachSelected ExamplesProject StatusDiscussion
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Introduction
Manitoba: over 230 mine sites (estimated)– Orphan or abandoned– Approx. 180 – reverted to the Crown
Limited number of sites were inspected in the pastExact Location ?Size ? Condition? Liabilities?Project initiated by the Mines Branch (MB STEM) in 2005
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Objectives of the Project
Conduct full inspection of the mine sitesReview and asses their conditionEvaluate hazards and liabilities – screening level
– Public safety– Environmental impact
Evaluate approximate costs for rehabilitationPrepare databaseIntegrate with Provincial and Federal databases
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Background Information
Manitoba: 650,000 sq. kmThree major geological subdivisions:
– Precambrian Shield • Churchill Province and Superior Province
– Paleozoic Hudson Bay Basin– Paleozoic and Mezozoic Williston Basin
Precambrian Shield = 60% and is the only subdivision that hosts gold depositsTotal MB gold production (1996) : 6.2 M ozOther mines: Ni, Cu, Zn
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Geological Subdivisions and Domains
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Methodology
Manitoba map subdivided in mining areas (or sheets)Database managementConcentration of sites
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Methodology
Review of information available -Mines Branch
– Archive reports– Publications– Old inspection reports– Maps and pictures– Sketches and drawings– Discussions with mining and
exploration companies– Aerial photography– Anecdotal information
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Methodology (cont’d)
Logistical aspects and challenges– Site access
• Truck, ATV, Boat, Floatplane, Helicopter, and…hiking (lots!)
– Timing (season) for accessing the site– Equipment– Safety – Critical!
Preparation of a template / form for field inspection and data gathering (Excel)
– Uniformity in data input and presentation– Ease of manipulating data (import data to GIS, etc)
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Methodology (cont’d)
Hazard assessment criteria:– Fairly subjective in nature– Based on knowledge and experience– Specific to Manitoba sites and conditions – Best alternative: prepare a point-based assessment for
each mine site in each category (safety & environmental) that would allow ranking of the sites and prioritize sites that need immediate action
Hazard levels:Low Moderate High
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Methodology (cont’d) – Hazard Assessment
PUBLIC SAFETY– Accessibility– Closure status– Physical stability (waste
rock dumps, tailings)– Condition of buildings
and foundation– Presence of scrap
materials– Terrain morphology and
stability
ENVIRONMENTAL IMPACT
– Proximity to water bodies (lakes or streams)
– Water accumulations or discharges
– Scrap material and hazardous substances
– Hazard to wildlife– Ecological impact
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Methodology (cont’d) – Hazard Assessment
General criteria– Any mine openings left uncapped triggered a High
hazard rating– Only openings deeper than 1.5 m were considered– Proximity to public settings (towns, parks, leisure
activities, camp grounds, etc.) triggered increase in assigned points
– Water bodies present – on site analytical testing of water quality – screening level only
• pH, As, Cu, Cy, Fe, Ni, Pb, Zn
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Examples
A total of 155 sites were inspectedLimited to Crown owned sitesLiterature review & preparation: Nov. 2005 - May 2006Field work: May to November 2006Report preparation: December 2006 (final report)
Three examples presented here
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Example #1:Jowsey Island (Sheet 20)
Gods Lake
Jowsey Island Gold Mine
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Example #1:Jowsey Island (Sheet 20)
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Example #1:Jowsey Island (Sheet 20)
Field record
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Example #2:Cryderman Shaft (Sheet 25)
Air photo
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Example #2:Cryderman Shaft (Sheet 25)
Field record
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Example #3:Poundmaker Shaft (Sheet 24)
Air photo
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Gold Cup Shaft
Gold Field Shaft
Gold Standard Shaft
Big Four Shaft
Emperor Shaft
Poundmaker(Luleo) Shaft
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Example #3:Poundmaker Shaft (Sheet 24)
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Example #3:Poundmaker Shaft (Sheet 24)
Field record
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Example #3: Field Inspection Form
Used the identical form for all mine sitesSimplicityImport to GIS using subroutinesSame fields, comparison and hazard assessment based on same criteriaFairly comprehensive for a screening – level review
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Project Status
Finalizing field recordsHazard evaluation – ongoingPreliminary:
– 10 to 15 High hazard– 20 to 30 Moderate hazard– Over 100 Low hazard
Cost estimates for rehabilitation measures – ongoingReport to be completed by December 2006
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Acknowledgements
AMEC team members:– Wing Keat Wong– Jason Plohman– German Ciro– Larry Markwart– Lee Keong Tan
Mines Branch personnel– Ernie Armitt– Ben Edirmanasinghe– Mike Fedak– Ray Garvey– Dale Wride
Manitoba Labour – Mines Inspection Branch
– Ron Casson– Ted Hewitt– Jim Haines
Dana Johnson –Department of Geological Sciences, UofMAll our guides