Britannia Mine, ARD, and the Millennium Plug Project

1. Brennan Lang, John Meech, and Rimas Pakalnis Britannia Mine, ARD, and the Millennium Plug Project Centre for Environmental Research in Minerals, Metals, and Materials

2. 40 km from Vancouver Britannia Mine

3. Beautiful Howe Sound

4. Sea to Sky Highway

5. Britannia Beach Harbour

6. Britannia Beach - from the mill building

7. Britannia Valley

8. 300 Tonne Truck at the Museum

9. Inside the mine at Britannia

10. 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

11. Britannia Flood and Landslide - October 1921

12. Old Time Miners – circa 1950s

13. Customs Shed at Britannia – 1940s

14. 1992 Flash Flood Debris

15. Cementation Launders – 4100 Level

16. Mill Building in 2002

17. Mill Building in 2010

18. View inside the Mill Building

19. Beaty Lundin Centre – Britannia Mining Museum

20. Site Ownership (2001) • Britannia Mines and Reclamation Ltd. – owned mine and mineral claims, as well as residential area north of Britannia Creek and “North Fan Area” • Britannia Beach Historical Society – owned most of “South Fan Area” • Province of B.C. – owned foreshore area between highway & Howe Sound

21. Housing Development Britannia Mines and Reclamation Corporation Britannia Beach Historical Society - BC Museum of Mining British Columbia Assets and Land - a Crown Corporation Britannia Mines and Reclamation Corporation Howe Sound Map of the Fan Area

22. Responsibility • BMARC was the only organization to declare itself a Responsible Person under the Waste Management Act • Other Potentially Responsible Persons named as part of the Contaminated Sites process in 1999 were: • Private PRPs: Alcoa, Canzinco, Alumax Inc., Anaconda/Arco, Howmet Holdings Corporation, Arrowhead/Ivaco, Intalco Aluminum Corporation • Province of British Columbia • Government of Canada • Government indemnified companies in exchange for $30M

23. Site Ownership (2003) • Macdonald Development Corporation bought the mortgage and foreclosed on BMARC – Macdonald retained ownership of the residential area north of Britannia Creek and “North Fan Area” – Macdonald sold remaining ~9,500 acres to the Provincial Government

24. Reclamation Issues in 2001 • Acid mine drainage from tunnels (620 m3/hr) • About 800 kg of Cu & Zn discharged per day • Over 13,000 tonnes of metal since closure • Groundwater contamination on the Fan • Potential impacts on aquatic life • Waste dumps and stockpiles • Tailings at bottom of Howe Sound • Sealing abandoned adits, demolition of derelict buildings (public safety issues)

25. Reclamation Issues in 2001 • Acid mine drainage from tunnels (620 m3/hr) • About 800 kg of Cu & Zn discharged per day • Over 13,000 tonnes of metal since closure • Groundwater contamination on the Fan • Potential impacts on aquatic life • Waste dumps and stockpiles • Tailings at bottom of Howe Sound • Sealing abandoned adits, demolition of derelict buildings (public safety issues) ________________________________________________________ Concentration Annual 1975-2001 Metal ppm Tonnes tonnes Aluminum 37 200 5,000 Zinc 23 141 3,525 Copper 26 109 2,725 Iron 10 54 1,350 Manganese 4.5 23 570 Cadmium 0.11 0.6 15 Cobalt 0.066 0.36 9 Total = 528.96 13,194

26. Groundwater discharge < 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 Plugthe 2200 Adit Build a Treatment Plant Reclaim pits and waste dumps

27. Glory holes/pits at Britannia Mine

28. Open Pits and Glory Holes

29. Cutaway View of the Mine Workings

30. Water Quality in 1995

31. Water Quality Change in 2001 Discharge 2000 2001 2200 Level (m3/hr) 125 0 4100 Level (m3/hr) 495 620 Cu in 2200 Level (ppm) 59- Cu in 4100 Level (ppm) 18 (26) 20 Zn in 2200 Level (ppm) 29- Zn in 4100 Level (ppm) 21 (23) 20 Copper Reduction (%) - 30 Zinc Reduction (%) - 15

32. Discharge from 2200 Level prior to 2001

33. At the adit

34. A Synergistic Research Plan • UBC had need for a research facility to conduct test work into the design of bulkheads to seal tunnels • By placing this Lab at the 2200 level portal, two synergistic events occurred: • UBC installed its research lab at a full-scale site • Britannia Mines and Reclamation Corp. was able to comply with part of its Remediation Order • The most harmful ARD from Britannia could be mitigated • Britannia Mine closure plan would move closer to fulfillment

35. Jane Creek showing a “Yellow-Boy”

36. Sampling and Monitoring

37. In the 2200 Level Adit

38. Installing Grout Tubes

39. 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

40. The Millennium Plug Research Station Quartzite Rock/Sand Concrete Plug Contact Grouting Pressurized Chamber Coffer Dam Bentonite/Sand Seal Sand/Gravel Filters Into the mine Cobble/Rip Rap Throttled Pipeline Pressurized Pipeline Longitudinal Section Not to scale 4 m 25 m ARD effluent is diverted back into the mine workings. Pressurized chamber allows the Millennium Plug to be studied under pressure/seismic conditions up to 300 m of water head Service pressure = 9 m, but concrete plug designed for 300 m The Millennium Plug was to be left in place to "back-up" the concrete plug that will fail in 60-70 years from attack by acidic water (pH = 2.5-3.0)

42. 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 3:30 pm on December 31st, 2001.

43. Results at Britannia Creek Bridge • Copper and Zinc down by 2 orders of magnitude • pH up by 2 units to virtually neutral

44. 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.

45. EPCOR Water Treatment Plant HDS = High-Density Sludge Started up December 2005 Capital Cost = ~ $12.0M Operating Costs = ~ $ 1.5M

46. HDS Plant – Process Flow Diagram Recycle Water Flocculants LimePaste Flocculants Tanks Acidic Feed Water Lime Tank Lime Reactor Sludge/Lime Mix Tank Clarifier Effluent Overflow Air Sludge Recycle Sludge disposal

47. Permit Requirements Element Required Typical mg/L mg/L Dissolved Cu ≤ 0.1 0.05 Dissolved Zn ≤ 0.2 0.03 Dissolved Cd ≤ 0.01 0.002 Dissolved Fe ≤ 0.1 0.01 Dissolved Al ≤ 1.0 0.5 Dissolved Mn ≤ 0.4 0.5 Total Suspended Solids ≤ 30 20 pH 6.5 to 9.5 9.2 95HR LC50 fish bioassay 100% (non-acutely toxic)

48. Sludge Disposal Sludge Disposal involves filtration Pressure plate filters Final water content = 60%solids (like toothpaste) Material consists of colloidal particles (sub-micron) All metals are present as hydroxides or hydrated sulfates Cu and Zn contents are about 4-5% each Crystalline Ettringite, Ca6Al2(SO4)3(OH)12·26 H2O ~ 35% Calcite, CaCO3 (minor quantities of aragonite) ~ 15% Gypsum, CaSO4·2H2O ~ 5% Quartz, SiO2 ~ 5% Amorphous Phases ~ 40%

49. Sludge Disposal Sludge Disposal involves filtration Pressure plate filters Final water content = 60%solids (like toothpaste) Material consists of colloidal particles (sub-micron) All metals are present as hydroxides or hydrated sulfates Cu and Zn contents are about 4-5% each Crystalline Ettringite, Ca6Al2(SO4)3(OH)12·26 H2O ~ 35% Calcite, CaCO3 (minor quantities of aragonite) ~ 15% Gypsum, CaSO4 .2H2O ~ 5% Quartz, SiO2 ~ 5% Amorphous Phases ~ 40% Ettringite Calcium sulfoaluminate is found in all Portland cement concretes and is commonly referenced in petrographic reports. Calcium sulfate sources i.e., gypsum, are added to Portland cement to prevent rapid setting and improve strength development. Sulfate is also present in supplementary cementitious materials and admixtures. All sulfate compounds react with calcium aluminate to form Ettringite within the first few hours after mixing with water. All sulfur is consumed to form Ettringite within 24 hours.

50. Crystalline etteringite Ca6Al2(SO4)3(OH)12·26 H2O (Ca(OH)2)6(Al2O3)(SO3)3·26 H2O In Portland Cement: Plates of calcium hydroxide and Needles of etteringite (CaO)6(Al2O3)(SO3)3·32H2O