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Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
Sulfide mining in Upper Great Lakes
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Sulfide mining in Upper Great Lakes

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Sulfide mine development will impact wetlands, surface water, groundwater, landscapes, aquatic and terrestrial biota, and human health in the Lake Superior basin. …

Sulfide mine development will impact wetlands, surface water, groundwater, landscapes, aquatic and terrestrial biota, and human health in the Lake Superior basin.

This presentation prepared for the National Wildlife Federation looks at the potential impacts of sulfide mining on the region's groundwater, waterways and health.

Prepared by:
-Ann Maest, PhD
-Richard Streeter, Stratus Consulting, Boulder, CO and
-Bob Prucha, PhD, PE
Integrated Hydro Systems, Boulder, CO

Published in: Technology
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  • 1. A New Environmental Threat in the Upper Great Lakes Region: Sulfide Mining Prepared for: National Wildlife Federation Prepared by: Ann Maest, PhD Richard Streeter Stratus Consulting Boulder, CO and Bob Prucha, PhD, PE Integrated Hydro Systems Boulder, COSTRATUS CONSULTING 19 March 2011
  • 2. Geographic Extent of Proposed Mining  Copper and other base metal deposits are wide- spread in the upper Great Lakes region – associated with midcontinental rift  Deposits are concentrated in Upper Peninsula of Michigan and Minnesota near Duluth (copper, nickel, platinum group metals, gold, uranium)  Prospects are located on and near National Forest and tribal lands  Some deposits and proposed processing plants are within a few kilometers of Lake Superior or Lake Michigan  Increase in exploration associated with increased worldwide demand (led by China and India) and increasing metal pricesSTRATUS CONSULTING
  • 3. Midcontinent Rift  Rocks in the midcontinent rift are an important source of copper and silver. Source:STRATUS CONSULTING http://www.geo.lsa.umich.edu/teaching/Bedrock%20v6.pdf
  • 4. Overview of Potential Mines and Associated FacilitiesSTRATUS CONSULTING See references for project locations and commodities.
  • 5. Potential Environmental Impacts  Mine development will impact wetlands, surface water, groundwater, landscapes, aquatic and terrestrial biota, and human health  Potential effects include – Destruction of wetlands and terrestrial habitat from mine facilities – Draining of wetlands and lowering of groundwater levels from dewatering – Metal and acid contamination of streams, wetlands, stream sediment, aquatic invertebrates, fish, groundwater, drinking water wells, and surface runoff – Mine subsidence (collapse affects land surface, waterways)  Regulatory agencies not adequately staffed to review proposals or manage new miningSTRATUS CONSULTING
  • 6. Screening methods used to identify potential environmental impacts from the proposed mines and projects  Used largely industry sources for location of mine projects; assigned confidence levels for locations  Estimated amount of groundwater, wetlands, streams, and disturbed areas potentially affected by proposed projects – see reference section for details  Measured amount of historically disturbed area at the Eagle and Northmet sites  Calculated amounts of potentially disturbed waters and lands are likely underestimates of actual mine- related disturbance and effects (e.g., does not include groundwater)STRATUS CONSULTING
  • 7. Minnesota Projects: Potentially Affected Surface Water ResourcesSTRATUS CONSULTING
  • 8. Eagle and Eagle East Projects: Potentially Affected Surface Water ResourcesSTRATUS CONSULTING
  • 9. Humboldt Mill: Historic Tailings Areas and Potentially Affected Waterways Potential Note: Former pit will be filled with tailings and impact streams to northSTRATUS CONSULTING
  • 10. Extent of Potential Wetland and Stream Impacts  Extent of potentially impacted wetlands at least 7,320 acres – Includes wetlands within ¼ mile of Eagle Haul Road and areas within 1-mile radius of project area (predicted size of cone of depression for Eagle Project)  Extent of potentially impacted streams at least 441 miles – From project areas downstream to dam or large lake  Likely underestimates impactsSTRATUS CONSULTING
  • 11. Potential Groundwater Impacts  Many communities rely on groundwater for drinking water  Mine dewatering operations could decrease availability of groundwater for many uses – Eagle will pump 113 million gallons/yr – NorthMet will pump up to 599 million gallons/yr  Development of mines could contaminate groundwater during and after mining and adversely affect human health  Following slides show alluvial aquifers (bedrock aquifers are also at risk of contamination) and known well locationsSTRATUS CONSULTING
  • 12. Known Wells and Alluvial Aquifers in UpperPeninsula of MI and Northeastern Wisconsin See references for sources of aquifer and well locations. USGS atlas doesSTRATUS CONSULTING not include smaller continuous aquifer systems.
  • 13. Known Wells and Alluvial Aquifers in Northern MinnesotaSTRATUS CONSULTING See slide 4 (overview map) for regional location.
  • 14. Potentially Impacted Wells and Groundwater Pumping  Wells in vicinity of projects in Michigan and Minnesota on previous maps: 429 to 652 wells – Lower number is for wells within 1-mile radius, higher for 2-mile radius – Only includes existing domestic wells in vicinity of projects with high confidence of location • For example, there are 29 domestic wells between NorthMet site and Embarrass River to the north – Does not include wells in Wisconsin – no state databaseSTRATUS CONSULTING
  • 15. Loss of Groundwater Use from Dewatering Operations  Groundwater pumping – Eagle Project estimates: • Estimated pumping ranges from 75 to 215 gallons/minute over nine years of operation – NorthMet Project estimates: • Dewatering will lower flows in Partridge River, drawdown levels in Whitewater Reservoir, and lower groundwater levels • Estimated pumping ranges from 200 to 1,150 gallons/minute over 20 years of operation Sources: Foth & Van Dyke and Associates.STRATUS CONSULTING 2006a; NorthMet DEIS, 2009.
  • 16. Loss of Groundwater Use from Dewatering Operations (cont.) – Water pumped at a subset of the projects in this study would supply between 76,000 to 407,000 people per year with domestic water • See methods file – used mine-estimated dewatering rates for Eagle and Northmet – Using 2009 census estimates, the projects would use more water annually than Kalamazoo, Michigan (73,000 people) on the low end and Minneapolis (385,000 people) on the high end – Estimates of water use are probably low because they do not include likely expansion of operations or inaccuracies on the upper bound of water useSTRATUS CONSULTING
  • 17. Contaminants of Concern  Most base metal sulfide mines have similar contaminants of concern – Metals: arsenic, cadmium, copper, lead, nickel, zinc – Non-metals: sulfate (from acid drainage), nitrate and ammonia (from blasting agents used to excavate mine), cyanide (from flotation operations) – Acid: acid drainage (from mined materials), low pH  Metals do not degrade to less toxic compounds and are toxic to aquatic life at low concentrations  Mineral deposits and surrounding rock in Upper Great Lakes area are predicted to create acid drainage and leach high concentrations of nickel and copper (see following slides for Eagle Project, MI)STRATUS CONSULTING
  • 18. Health Impacts from Mine-related Contaminants  Liver or kidney damage: copper, cadmium, lead  Learning impairment in children: lead  Blue baby syndrome: nitrate  Known or suspected carcinogen: arsenic  Nerve damage/thyroid problems: cyanide  Toxic to fish and aquatic biota at low concentrations: cadmium, copper, lead, zinc, ammonia  Impacts wild rice: sulfate Sources:US EPA, 2011.STRATUS CONSULTING
  • 19. Eagle Project, MI: Sulfate, pH, and nickel values in leachate from semi-massive ore unit 600 10.00 500 SO4 8.00 pH 400SO 4 (mg/l) 6.00 pH 300 acidic 4.00 200 2.00 100 0 0.00 0 10 20 30 40 50 60 70 0 10 20 30 40 50 60 70 Weeks Weeks 120 More acidic (lower pH) than acceptable range 100 Ni (6.5-8.5) for US Up to almost 2.5 80 drinking water Ni (mg/l) times higher than 60 MI water quality 40 Up to 1,200 times standard (250 mg/l) 20 higher than MI water quality standard 0 (0.1 mg/l) 0 10 20 30 40 50 60 70 Weeks STRATUS CONSULTING Data source: Geochimica, 2004, Phase I column 4 (12.85%S) .
  • 20. Eagle Project, MI: Sulfate, pH, and copper values in leachate from surrounding rock 500 10.00 SO4 pH 400 8.00SO4 (mg/l) 300 6.00 pH acidic 200 4.00 100 2.00 0 0.00 0 10 20 30 40 50 0 10 20 30 40 50 Weeks Weeks 14.0 12.0 Cu 10.0 Cu (mg/l) 8.0 6.0 4.0 Up to over nine 2.0 times higher than 0.0 MI water quality 0 10 20 30 40 50 standard (1.4 mg/l) Weeks STRATUS CONSULTING Data Source: Geochimica, 2004, Siltstone, Phase II column 4 (1.39%S).
  • 21. Movement of Contaminants  Contaminants move away from mine to groundwater and surface water  Groundwater feeds wetlands and streams – decreasing groundwater levels and quality can dry up surface waters  Metals remain in environment for millennia  Metals move from water to sediment to aquatic bugs to fish to piscivorous mammals and birdsSTRATUS CONSULTING
  • 22. Contaminants in the Environment  Contaminants move downstream with the water and sediment, exposing aquatic biota 979 Contaminants can be transferred back and forth between shallow groundwater and streamsSTRATUS CONSULTING 969
  • 23. Impacts from Similar Mines  Mines with high potential to generate acid and leach contaminants – and in close proximity to water resources – have the most adverse environmental effects of all hardrock mines (Kuipers and Maest, 2006) – 85% of these mines exceeded surface water quality standards due to mining releases  Proposed mines in the upper Great Lakes have these same inherent characteristics that lead to contamination regardless of commodity and mining method  Water quality standards are exceeded even though permit limits are in place and permit applications stated standards would not be exceededSTRATUS CONSULTING
  • 24. Impacts from Similar Mines (cont.)  Known water quality effects from modern sulfide mines near water resources are shown in the following table  Other effects include fish kills and reproductive and behavioral effects, draining and destruction of wetlands, lowering of shallow groundwater levels, depletion of stream and spring flowsSTRATUS CONSULTING
  • 25. Impacts from Modern Sulfide Mines in Wet Climates Mine Name, Ownership Commodity Operation Type Water Quality Impacts State Groundwater exceedences of manganese, pH, Flambeau sulfate, dissolved solids from pit backfill; (Ladysmith), WI Kennecott Copper, gold, silver Open pit, flotation exceedences of copper in stream on site. Hecla Mining Silver, lead, zinc, Surface water contaminated with acidity, sulfate,Greens Creek, AK Company gold Underground, flotation zinc from tailings/waste rock Springs contaminated with sulfate, copper, zinc, Black Pine, MT ASARCO Copper, gold, silver Underground, flotation cadmium, acid drainage from waste rock dump. Placer Dome, Inc. Groundwater contaminated with cyanide andGolden Sunlight, (now Barrick Underground and open copper from tailings; acid drainage in waste rock MT Gold) Gold pit, vat leach and open pit. Groundwater contaminated with nitrate, Stillwater Mining Platinum group chromium, sulfate, cadmium, zinc from adit Stillwater, MT Company metals Underground, flotation drainage; increased nitrate in surface water. Groundwater/surface water Beal Mountain, increases/exceedences of nitrate, cyanide, sulfate MT Pegasus Gold Co. Gold, silver Open pit, heap leach from heap leach and waste rock Open pit, heap and vat Groundwater and surface water contaminated withGrouse Creek, ID Hecla Mining Company Gold, silver leach cyanide from tailings leakage Surface water contaminated with cadmium,Thompson Creek, Cyprus/Thompson copper, lead, sulfate, zinc from tailings and waste ID Creek Mining Co. Molybdenum Open pit, flotation rock seepage; acid drainage in wastes and pit Zortman and Groundwater and surface water contaminated with Landusky, MT Pegasus Gold Co. Gold, silver Open pit, heap leach metals, acidity, nitrate, and cyanide
  • 26. Similar Mining Districts  Sudbury, Ontario, Canada – Rich copper, nickel, platinum group metal (PGM) sulfide deposits: 8th richest mining district in world – Formed by meteor impact, but also has massive sulfide deposits like the Eagle Project in Michigan (acid generators) – Extensive and severe soil and vegetation contamination from smelting; groundwater contamination from acid- generating mine wastes  Duluth, Minnesota, USA – Duluth deposit has produced low-pH drainage (as low as 4.5 to 6.4) and high metal concentrations (e.g., up to 22 mg/L copper  Following slides show many mines and prospects in Sudbury – there are similar geology, size, and commodities in Baraga and could be similar impacts  See attachment: Comparison to other base metal ultramafic depositsSTRATUS CONSULTING
  • 27. Sudbury District, Canada: >200 Nickel-Copper-PGE DepositsSTRATUS CONSULTING Source: Ames and Farrow, 2007
  • 28. Baraga Basin Geology – Similar Structure and Commodities to Sudbury Source: Prime Meridian Resources.STRATUS CONSULTING http://www.primemeridianres.com/i/maps/baraga/baraga-01.jpg
  • 29. Historical Mining Impacts in the Upper Great Lakes Have Not Been Cleaned Up  Historic iron mining destroyed landscapes – less impact to water quality because mines were generally not acid producers  Impacts to land have not been remediated  New mining will destroy landscapes and adversely affect groundwater and surface water quality and quantity  Need to clean up old contamination before new mining beginsSTRATUS CONSULTING
  • 30. Ongoing Mining Impacts: near Palmer, Upper Peninsula, MichiganSTRATUS CONSULTING
  • 31. Historic Mining Impacts: Duluth ComplexSTRATUS CONSULTING
  • 32. Historic Copper and Iron Mining Districts Sources: mining areas = http://www.mg.mtu.edu/shaft0.htm.STRATUS CONSULTING Surficial geology = USGS  http://tin.er.usgs.gov/geology/state/state.php?state=MI
  • 33. Specific Projects  Eagle Project in Michigan and NorthMet in Minnesota are in permitting stage or have already been permitted – Expected land disturbance = 144 acres at Eagle Project and 6,430 acres at NorthMet  Others range from initial to full-scale exploration  Specific information on mine plans and potential impacts for the Eagle Project and NorthMet Project are included in the following slidesSTRATUS CONSULTING
  • 34. Eagle Project, Michigan  Project has been approved by State of Michigan – Project is in native ceded territory – Main river (Salmon Trout) flows into Lake Superior  Copper, nickel in massive sulfide deposit with high acid drainage and contaminant leaching potential  Potential for contamination of groundwater and surface water, loss of water from wetlands, loss of water from Salmon Trout RiverSTRATUS CONSULTING
  • 35. Eagle Project, Michigan (cont.)  Underground mine; transport along haul road for flotation processing; discharge of treated water at ground surface – Existing water and soil contamination at Humboldt Mill site (tailings area) has not been addressed – Close to residential well, and groundwater is contaminated with arsenic, manganese, vanadium  Water and contaminant flow during and after mining are shown in the following slidesSTRATUS CONSULTING
  • 36. Eagle Project: Flows during Mining  Mine immediately beneath Salmon Trout River; flow in river could decrease from mine dewatering operations  Discharge from Treated Water Infiltration System (TWIS) will not meet surface water standards  Extensive groundwater impacts – contaminants will likely travel along extensive permeable faultsSTRATUS CONSULTING
  • 37. Eagle Project: Flows after Mining  Contaminated water from mine could flow to downgradient groundwater, Salmon Trout River, and Lake Superior  Contaminants would include metals and acid from mining and brine from deep groundwater encountered during miningSTRATUS CONSULTING
  • 38. NorthMet Project, Minnesota  First non-ferrous (sulfide) mine in Mesabi Range: Copper, nickel, platinum group metals  Three open pits, large disturbed area (>6,000 acres)  Located within Superior National Forest, land ceded by Indian tribes where they exercise their treaty rightsSTRATUS CONSULTING
  • 39. NorthMet Project, Minnesota: Impacts Predicted in EIS  All waste rock is acid generating  Water quality exceedences in Partridge River, Embarrass River, Colby Lake, St. Louis River  Tailings basin will leak contaminants to groundwater  Increased mercury loadings from waste rock to Lake Superior watershed  Direct impacts to > 1,000 acres of wetlands; inadequate mitigation plan  Assumes maintenance-free closure; no financial assurance information  EPA rated EIS an EU3 (environmentally unacceptable)STRATUS CONSULTING
  • 40. NorthMet ProjectSTRATUS CONSULTING Source: NorthMet DEIS, 2009.
  • 41. NorthMet Project: Impacted WetlandsSTRATUS CONSULTING Source: NorthMet DEIS, 2009.
  • 42. Summary  Upper Great Lakes region is at risk, with widely distributed base metal, precious metal, and uranium deposits  Deposits are sulfide-rich, and mining them can be more environmentally harmful than historic iron mining, especially to water quality  Estimates of potential adverse effects in this study are likely lower than actual effects  Mining of similar deposits has consistently caused water quality problems  Regulatory agencies are not adequately staffed to review proposals or manage new miningSTRATUS CONSULTING
  • 43. References  See files for report, data, and website references.STRATUS CONSULTING

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