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Britannia BC:Past, Present & Future
Al ColodeyEnvironment CanadaPacific and Yukon Region
Location
x Britannia
Pre-mining conditions
• Exposed ore-bodies (sulphides)occur at summit
• Lower BritanniaCreek fish habitat
• No adverseeffect on HoweSound
Post-mining conditions
• Mining exposedsulphide minerals tooxidation (‘acid rockdrainage’)
• Acidic, metals-richflows from two aditsdrain mine workings
• 2200 adit drains toBritannia Creek
• Larger, 4100 portalflow discharges toHowe Sound
Mining:1902-1974
Plan view of Britannia features and contamination
Sources of PollutionUPLAND SOURCES� Mine drainage
� Contaminated lands
� Oxidized ore in mill area
� Contaminated ground water
AQUATIC SOURCES� Howe Sound sediments
contaminated by tailings andprecipitates
Mine Drainage Sources
4100 Level4100 Level pH 3.7 Flows: 37 to 900+ L/sec Av Cu: 15 mg/L Av Zn: 22 mg/L
2200 Level2200 Level pH 3.2 Flows: 1 to 70+ L/sec Av Cu: 21 mg/L Av Zn: 17 mg/Liron sludge from 4100iron sludge from 4100
Onshore Contamination• Spilled reagents
concentrate, oilsand fuels
• Foreshore areahas oxidizedtailings
• Stabilize/removemill building
Aquatic Effects of Mine Drainage
Loss of Britannia Creek habitat
Lack of Algae & Invertebrates
Toxic conditions to Juvenile Salmon & Bivalves (DFO Research)
Howe Sound Sediments
• 40 M tonnes of high-sulphide tailings to fjord200 m deep
• Chemical stability oftailings not studied
• Covering by plume ofSquamish River glacialsediments (2 cm/y)
Treatment of mine drainage• Lime in the high-density sludgeprocess causesheavy metals toprecipitate
• Plant over-flow isnon-toxic to aquaticlife
• Sludge to on-sitelandfill but Cu, Znrecovery may bepossible
Treatment Plant Costs
1998 conceptual plant costs by AMEC/ H.A. Simons
Total plant costs including pipeline and $4.2 M
contingency, excluding engineering:
Annual operating cost including $0.80 M/yr
on-site sludge disposal:
Federal & Provincial Expenditures
1990-2001
$ K
Mine inspections 30Treatment tests, design, monitoring 402Marine effects research 421Repair discharge pipeline 144
Total 997
Funding by Former Owners
• BC Contaminated Sites Regulations apply strict,joint/several, and retrospective liability forcontamination to former owners
• Apr 2001, BC indemnified all former owners ofBritannia for $30 M cash
• Ultimate remediation costs unknown
Remediation: Key parties• BC Environment (regulator & responsibleparty)
• BC Mines regulates all work at mines
• Owners of surface and mineral rights
• Environment Canada, Fisheries & Oceansadvise on effects & remediation
• Infrastructure Grant application submitted
Other parties with direct interests
• 200 + Britannia Residents• Regional District: planning
and services• Squamish First Nation• BC Mining Museum• Adjacent land owners• BC Mining Industry
Next Steps� Formation of an ‘Operational Entity’� Undertake Workplan Items
� Treatment Plant Design & Infrastructure� Site Remediation: DSI� Treatment Laboratory� Public Displays
Marine Sediment Assessment
Coresparticle sizemetal scanorg Cavs
Grabsas per coresbioassaysinfaunal communty
Sediment Imaging Mappingtowed vehiclesubstrate classificationbiota mapping
Intertidal Sampling/Mapping
- special thanks to Rob McCandless & Mike Hagen
