The Millennium Plug Project at the Britannia Beach Research Field Station

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The Millennium Plug Projectat the Britannia
Beach Research Field Station
Brennan Lang, John Meech, and Rimas Pakalnis
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cerm
Centre for Environmental Research in Minerals,
Metals, and Materials
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Mine History
Britannia Mine operated between 1902-1963 by the
Britannia Mining and Smelting Co. and between
1963-1974 by the Anaconda Mining
Company - 47 million tonnes of ore mined - 150
km of underground development - 5 open pits
(glory holes)
Britannia Concentrator
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Site Ownership

• Britannia Mines and Reclamation Ltd.
• owns mine and mineral claims, as
  well as
• residential area north of
  Britannia Creek
• and North Fan Area
• Britannia Beach Historical Society
• owns most of South Fan Area
• Province of B.C.
• owns foreshore area between
  highway and
• Howe Sound

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Responsibility

• BMARC is the only organization to declare itself
  a Responsible
• Person under the Waste
  Management Act
• Other Potentially Responsible Persons that have
  been named
• as part of the
  Contaminated Sites process are
• Private PRPs Alcoa, Canzinco, Alumax Inc.,
  Anaconda/Arco,
• Howmet Holdings
  Corporation, Arrowhead/Ivaco,
• Intalco Aluminum
  Corporation
• Province of British Columbia
• Government of Canada

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Reclamation Issues

• Acid mine drainage from tunnels (500 m3/hr)

• Approximately ½ tonne of copper and ½ tonne of
  zinc discharged to Howe Sound each day
• Greater than 10,000 tonnes of heavy metals since
  closure
• Contamination of groundwater in the Britannia Fan
• Potential impacts on aquatic life
• Waste dumps and stockpiles
• Tailings
• Sealing of abandoned tunnels and shafts,
  demolition of derelict buildings (public safety
  issues)

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Groundwater discharge lt 5 of the flow 2-3 of
the copper 3-4 of the zinc
4100 Level effluent 50-80 of the flow 30-55 of
the copper 60-75 of the zinc
2200 Level effluent 20-50 of the flow 45-70 of
the copper 25-40 of the zinc
Plug the 2200 Portal
Build a Treatment Plant
Reclaim pits and waste dumps
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Open Pits and Glory Holes
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Jane Creek before it drains into Britannia
Creek(November 2001)
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A Synergistic Research Plan

• UBC had need for a research facility to conduct
  testwork into the design of bulkheads to seal
  tunnels
• by placing this laboratory at the 2200 level
  portal of Britannia Mine, two synergistic
  events occurred
• UBC installed its research lab at a full-scale
  field site
• Britannia Mines and Reclamation Inc. was able to
  comply with part of its Remediation Order
• The most harmful effects of the ARD discharging
  from Britannia are now mitigated.
• Britannia Mine closure plan moved nearer to
  fulfillment

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Cleaning up Britannia Creek

• In 2001, BMARC in cooperation with CERM3,
  constructed a concrete plug in the 2200 Level
  of Britannia Mine.
• This plug diverted water to the lower part of the
  mine from where it discharges into Howe Sound at
  23 m depth.
• The concrete plug facilitated construction of the
  experimental Millennium Plug
• Essentially all pollution to Britannia Creek and
  the surface waters of Howe Sound has been
  eliminated
• In 2004, the BC Ministry of Water, Land, and Air
  Protection will put a water treatment plant into
  operation

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UBC/CERM3 Britannia Research Station
CERM3 Britannia Beach Research Field Station
The Number 3 Mill Building now an historical
heritage site
The BC Museum of Mining from above Number 3 Mill
Building
The Number 3 Mill Building now an historical
heritage site
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Installation of Grout Tubes into the Rock Mass
around the Concrete Plug
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Installation of Grout Tubes into the Rock Mass
around the Concrete Plug
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Pumping Cement into the Plug Form Cavity Note
the seal around the formwork where it contacts
the rock face and the grout tubes used to deliver
grout into the rock mass after the concrete has
setup.
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The Concrete Plug was poured on December 17th in
a blinding snow storm over an 18 hour period. A
total of 16 cement trucks had to be pulled up to
the 2200 Level using front-end loaders and a
bulldozer. The effluent was turned off at 330
pm on December 31st, 2001.
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Results

• As of January 1, 2002, acid rock drainage from
  the 2200 Level tunnel into Jane and Britannia
  Creek has been halted.
• Britannia Creek before the 2200 Level Plug
• 0.5 mg/l copper,
• 0.5 mg/l zinc,
• 0.024 mg/l iron,
• pH 6.3
• Britannia Creek after the 2200 Level Plug
• 0.041 mg/l copper,
• 0.052 mg/l zinc,
• 0.009 mg/l iron,
• pH6.9
• Measurements taken at the Townsite Bridge

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Some people like to drink the Britannia Creek
water and it is now safe to do so, although like
all natural water streams in the wild, it is not
recommended without prior chemical treatment.
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The Millennium Plug

• Built in much the same way as an earth dam
• Impervious clay core
• Layers of sand, gravel, cobble, rip rap
• Resistant to acidic conditions
• Cheaper to build
• Uses locally available materials
• Generates a walk-away solution

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The Millennium Plug Research Station
Quartzite Rock/Sand
Contact Grouting
Concrete Plug
Pressurized Chamber
Coffer Dam
Bentonite/Sand Seal
Sand/Gravel Filters
Into the mine
Cobble/Rip Rap
Throttled Pipeline
Longitudinal Section
Pressurized Pipeline
The ARD effluent is diverted back into the mine
workings. The pressurized chamber allows CERM3
researchers to study the Millennium Plug under a
variety of pressure and seismic conditions up to
300 m of water head. The service pressure on the
concrete plug is only 9 m, but the plug was
designed for 300 m in order to conduct the
research. Upon completion of the research, the
Millennium Plug will be left in place to
essentially "back-up" the concrete plug which is
expected to fail in 60-70 years through chemical
attack by the acidic waters in the mine (pH
2.5-3.0)
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Conclusions

• Research can be applied to mitigate existing
  problems directly if one uses sustainable
  thinking.
• The Millennium Plug Research Station will allow
  CERM3 to design innovative, inexpensive,
  walk-away solutions to mine closure problems
  involving Acid-Rock-Drainage.
• Britannia Creek is now free of pollution thanks
  to the installation of the Millennium Plug
  Research Station.
• CERM3 will continue to search for other
  synergetic applications while conducting its
  research and setting up its laboratory
  infrastructure.