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

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, CO
STRATUS 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 prices
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3. Midcontinent Rift
 Rocks in the midcontinent rift are an important
source of copper and silver.
Source:
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http://www.geo.lsa.umich.edu/teaching/Bedrock%20v6.pdf

4. Overview of Potential Mines and
Associated Facilities
STRATUS 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 mining
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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)
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7. Minnesota Projects: Potentially
Affected Surface Water Resources
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8. Eagle and Eagle East Projects: Potentially
Affected Surface Water Resources
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9. Humboldt Mill: Historic Tailings Areas
and Potentially Affected Waterways
Potential
Note: Former pit will be filled with
tailings and impact streams to north
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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 impacts
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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 locations
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12. Known Wells and Alluvial Aquifers in Upper
Peninsula of MI and Northeastern Wisconsin
See references for sources of aquifer and well locations. USGS atlas does
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not include smaller continuous aquifer systems.

13. Known Wells and Alluvial Aquifers in
Northern Minnesota
STRATUS 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
database
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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.
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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 use
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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)
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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.
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19. Eagle Project, MI: Sulfate, pH, and nickel
values in leachate from semi-massive ore unit
600 10.00
500 SO4 8.00 pH
400
SO 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
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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 8.00
SO4 (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
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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 birds
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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 streams
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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 exceeded
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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 flows
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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 and
Golden 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 with
Grouse 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 deposits
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27. Sudbury District, Canada: >200
Nickel-Copper-PGE Deposits
STRATUS CONSULTING Source: Ames and Farrow, 2007

28. Baraga Basin Geology – Similar
Structure and Commodities to Sudbury
Source: Prime Meridian Resources.
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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 begins
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30. Ongoing Mining Impacts: near
Palmer, Upper Peninsula, Michigan
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31. Historic Mining Impacts:
Duluth Complex
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32. Historic Copper and Iron Mining Districts
Sources: mining areas = http://www.mg.mtu.edu/shaft0.htm.
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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 slides
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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 River
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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 slides
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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 faults
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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 mining
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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 rights
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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)
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40. NorthMet Project
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41. NorthMet Project: Impacted Wetlands
STRATUS 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 mining
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43. References
 See files for report, data, and website
references.
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