By 2014, mine operators around the world will be investing more than US$13-billion in water-related infrastructure, according to Global Water Intelligence. AECOM’s Till Freihammer examines what this means for the industry in terms of emerging opportunities and challenges. The presentation was first delivered at the 2nd Annual Water Management for Mining Summit in Toronto, Canada, on May 10, 2013.

1. Till Freihammer

2. AECOM overview
– A global leader
• Professional Technical and Management Support Services
• Key end markets: Energy; Environment; Facilities; Government; and
Transportation
– Broad range of services, including:
• Architectural Planning/Consulting and Engineering Design
• Asset/Facilities Management
• Design-Construct/Public-Private Partnerships
• Environmental Health and Safety
• Government Support
• Management Support
• Program, Cost and Construction Management
• Specialist Consultancy
• Transportation Planning
– Approximately 45,000 employees operating in more than 140 countries
– US$8.2 billion of revenue during the 12 months ended March 31, 2013
– Currently No. 322 on the Fortune 500 list
– Ranked by Ethisphere as one of the world’s 110 most ethical companies
– Recognized by the U.S. Chamber of Commerce’s Business Civic Leadership
Center as honoree for Best Corporate Stewardship

3. Presentation Outline
Treating Mine Wastewater
– Global perspective
• Water infrastructure as a global business
• Water management
– Mine water and wastewater
• Minerals reserves and production
• Water use and water risks
• Water treatment regulations for the mine industry
• Treatment technologies
– Case studies
• Examples of mine wastewater projects

5. Mine Wastewater — Global Perspective
– Water is essential for mining operations
• Mining — dust suppression, cleaning equipment, etc.
• Processing — wet grinding, washing, flotation, leaching, etc.
• Transportation — pumping tailings and products
• Utilities — cooling water, pollution control, etc.
– Water is impacted by mining operations
• Acid rock drainage from mine waste
• Residual chemicals in mine waste
• Tailings management
• Diversion of streams
• Significant water use

6. Mine Wastewater — Global Perspective
Increasing importance of water infrastructure for the
mining industry
– New mines being developed in arid regions
– Lower grade ores mean increased water
demand for processing
– Higher standards for mining wastewater
effluent
– Increased environmental liability in mine
closures
– Recognition that water is a scarce resource
– Corporate Social Responsibility

7. Mine Wastewater — Global Perspective
Water Balance in a Typical Mine
Water
Chemicals and
Reagents
Raw Mineral Ores Refined Mineral
Product
Waste Mineral
Product
Effluent Water
Water Losses:
Evaporation
Drainage
Precipitation
The
Mining
Process
Global Water Intelligence . (2011) Water for mining: opportunities in scarcity
and environmental regulation.

8. Mine Wastewater — Global Perspective
– Water infrastructure for the mining industry is a
major global business
– Key mining locations: Australia, Canada, Peru,
Chile, Brazil, U.S.A., South Africa, Russia,
China and others
– Global mining-related water infrastructure
expenditure in 2011 estimated at US$7.74
billion
Global Water Intelligence . (2011) Water for mining: opportunities in scarcity
and environmental regulation.

9. Mining Sector
Key Locations in North America

10. Mine Wastewater — Global Perspective
– Generally, mining industry is cyclical, depending on commodity prices
– Currently, mining industry is growing rapidly but …

11. Mine Wastewater — Global Perspective
Water Management Challenges & Opportunities
– Alternative Water Supplies — Increasing potential due to decreasing water
resources. Desalination technology has strong potential
– Water Reuse — Increasing potential due to water scarcity and tougher
regulatory climate; mill internal recycling of process water
– Metal Recovery from Mine Waste — Increasing potential due to high
commodity prices and lower ore grades
– Effluent Treatment — Higher environmental standards mean greater
investment in effluent treatment and remediation projects
– Brine Management (RO plants) — Salt disposal is becoming a concern in
terms of stricter regulations and disposal cost
– Acid Mine Drainage — treatment

13. Selected Metals — Reserves and Production
Metallic
Mineral/
Metal
Top 3 Reserves – in Mt Top 3 Producers – in Mt
Iron Ore Brazil: 16000 (Fe-content)
Australia: 15000 (Fe content)
Russia: 14000 (Fe content)
China: 900
Australia: 420
Brazil : 370
Zinc Australia: 53
China:42
Peru: 23
China:3.5
Peru: 1.52
Australia: 1.45
Copper Chili:150
Peru: 90
Australia: 80
Chili:5.52
Peru: 1.285
China: 1.15
Nickel Australia: 24
Botswana:8.7
New Caledonia: 7.1
Russia: 0.265
Indonesia:0.232
Philippines: 0.156
Gold Australia: 7300 tons
South Africa :6000 tons
Russia: 5000 tons
China:345 tons
Australia: 255 tons
United States: 230 tons
Global Water Intelligence . (2011) Water for mining: opportunities in scarcity
and environmental regulation.

14. Key Water Supply Risks
– Security of water supply and management is an increasingly important
investment factor for the mining industry
– Estimated global water withdrawal for mining is 7 to 9 km3/a (GWI 2011)
• Compare to annual national freshwater withdrawal in Canada of 42 km3/a
or Germany of 47 km3/a
Risk Considerations
Water scarcity Mine requirements compete with other water users
Management of excess water Flooding and subsequent damage
Poor management of water quality Tailings, environmental degradation
Inefficient water use Increased withdrawal rates, cost impacts

15. Mine Wastewater
Regulations and Guidelines
– Regulations regarding the withdrawal and use of water
– Regulations regarding the discharge of wastewater and monitoring of water
quality
– Regional and National regulations
– International Frameworks
• International Mine Water Association — 1979 (www.imwa.info)
• International Network for Acid Prevention (www.inap.com.au)
• International Council on Mining and Metals — 2001 (www.icmm.com)
• Global Water Initiative — (www.globalreporting.org)

16. Mine Wastewater
Treatment Technologies
Category Examples Application
Neutralization lime or limestone addition acid rock drainage
Passive treatment wetland systems polishing
Metals removal sulfide precipitation, biological filters, fluidized
bed reactor
metal recovery - saleable
product
Metals removal hydroxide precipitation (HDS process),
coagulation-flocculation, clarification
metal removal; arsenic removal
Membranes microfiltration, ion exchange, reverse osmosis water reuse; metals removal
Biological treatment Fixed film or suspended Nitrogen removal, selenium
removal, bioleaching
Evaporators and
concentrators
brine concentrators, crystallizers zero liquid discharge
Dewatering clarifiers, dissolved air flotation volume reduction of tailings
Filtration and
thickening
pressure filters, paste thickeners volume reduction of tailings
Cyanide treatment alkaline chlorination,
hydrogen peroxide process
gold mine effluent

18. Treating Mine Wastewater
Case 1: Mine Dewatering System
Background
– Copper — nickel mine
operated from late 1960s to
early 1980s
– Mine shut down due to
market conditions
– Mine pits and mine shaft
flooded to surface
– Plan to re-open mine —
currently in the advanced
exploration phase

19. Treating Mine Wastewater
Case 1: Mine Dewatering System
Scope of Work
– Assess existing surface and groundwater
quality
– Develop a mine dewatering and treatment
strategy, including
• Design dewatering system — 30,000
m3/day
• Design water treatment system to remove
elevated metal concentrations to meet
discharge limits of receiving water
environment
• Develop preliminary cost estimates and
schedule
– Develop implementation plan

20. Wastewater Treatment Strategy
High rate clarification
Coagulation
Flocculation
Sedimentation
polymer
Metals precipitation
Raw water from
dewatering
system
Ferric
Sulfate
Lime
Treating Mine Wastewater
Case 1: Mine Dewatering System
pH adjustment
Sulfuric
acid
residuals
disposal
Sludge
recirculation

21. Treating Mine Wastewater
Case 1: Mine Dewatering System
Challenges
– Site works — there is little existing infrastructure at the site (electrical,
structural, etc.)
– Temporary design — all equipment and infrastructure designed to be easily
removable when they are no longer needed
– Unknown water quality — water quality at lower depths of mine pits and shaft
is unknown
– Flexible process concept required due to varying flows during dewatering and
future mine operations
– Remote location — limited availability of resources (chemicals, equipment
parts, etc.) and limited availability of trained operators

22. Treating Mine Wastewater
Case 2: Giant Mine Remediation — Yellowknife, NWT
Background
– Gold mine started operating in late 1940s, closed in
2004.
– In 2005, Government of NWT and Canada agreed
to remediate and maintain the mine
– Arsenic trioxide dust (mine by-product) is stored
underground. Permafrost was supposed to keep
storage areas dry. Permafrost is receding, resulting
in groundwater movement and seepage from
storage areas
– Current wastewater treatment system operates
seasonally to treat contaminated water. Effluent
currently meets MMER

23. Treating Mine Wastewater
Case 2: Giant Mine Remediation — Yellowknife, NWT
– Characterize the treated water
quantity and quality
– Analyze three treatment options and
recommend a concept for preliminary
design
– Develop/undertake a bench scale
testing program to optimize the
recommended treatment system
– Complete the preliminary design and
cost estimate for the selected
treatment system
Scope of Work — Water Treatment

24. Treating Mine Wastewater
Case 2: Giant Mine Remediation — Yellowknife, NWT
Wastewater Treatment Plant Design Criteria
Parameter
Akaitcho Water Quality
2009-10 data (mg/L)
General Northwest Pond
2009-10 data (mg/L)
Effluent Limits*
(monthly mean)
Arsenic 1.99 - 123 17.0 – 40.6 0.50
Copper 0.005 – 0.103 0.006 – 0.04 0.30
Cyanide <0.005 – 0.028 N/A 1.00
Lead <0.0001 – 0.150 0.004 – 0.017 0.20
Nickel 0.0006 – 0.198 0.064 – 0.106 0.50
Zinc 0.046 – 0.559 0.034 – 0.205 0.50
TSS <1.0 – 20.2 <1.0 – 39.2 15.0
Ammonia 0.02 – 5.3 0.06 – 0.49 12
pH 6.5 – 8.2 6.5 – 8.4 6.0 – 9.5
Oil & Grease <1.0 - 10 N/A 5
* Note: Effluent Limits are from water license N1L2-0043

25. Treating Mine Wastewater
Case 2: Giant Mine Remediation — Yellowknife, NWT
Wastewater Treatment Strategy Flow range 17 – 34 l/s
high rate clarification
Removal of arsenic
coagulation
flocculation
sedimentation
polymer
sludge disposal
sludge
sludge
thickener
KMnO4
Fe2(SO4)3
high rate clarification
Removal of metals
coagulation
flocculation
sedimentation
polymer
Ca(OH)2
Fe2(SO4)3
belt filter
press
to sump
to CO2 contact
tanks, filters,
effluent tanks

26. Diffusers – treated
water discharge
Water
treatment plant
Surface water
infiltration
Ground water input
Yellowknife Bay
Mine
Treating Mine Wastewater
Case 2: Giant Mine Remediation — Yellowknife, NWT
Challenges
– Northern climate
– Influent water toxicity
• Quality fluctuations
– Groundwater
management
– Mine water level
management
Mine Water – collection – treatment - discharge

27. Treating Mine Wastewater
Case 3: Low-level Radioactive Waste Management Facility
Port Granby, ON
Background
– 0.45 million m3 of low level radioactive waste and
soil will be excavated, transported to an approved
location, covered with an engineered cap.
Contaminated surface water and groundwater will
be treated at a new WWTP
– Waste material comprises residues from radium
and uranium refining , contaminated equipment
and other materials
– Waste contains radium-226, uranium and arsenic
– Legal agreement reached in 2001 between
municipalities and Federal Government for the
cleanup and long-term management of this waste

28. Treating Mine Wastewater
Case 3: Low-level Radioactive Waste Management Facility
Port Granby, ON
Atomic Energy of Canada Limited.
(2011). Presentation on the Port
Granby Waste Management Project
Presentation

29. Treating Mine Wastewater
Case 3: Low-level Radioactive Waste Management Facility
Port Granby, ON
Wastewater Treatment System Design
– Pilot scale testing for water treatment in 2010 to confirm the
performance of treatment systems and determine the design
requirements. Pilot scale tests included:
• Membrane bio-reactor (MBR)
• Reverse osmosis (RO) treatment
– Overall removal rates for arsenic, uranium, radium-226 and
nitrate were 98-99%

30. Treating Mine Wastewater
Case 3: Low-level Radioactive Waste Management Facility
Port Granby, ON
Wastewater Treatment System Design Criteria
– Average flow 10,000 to 14,000 m3/month (14 to 19 m3/hr)
– Peak flow 25,000 to 35,000 m3/month (35 to 48 m3/hr)
– Estimated maximum concentrations of primary contaminants:
Water Source
Arsenic
(mg/L)
Uranium
(mg/L)
Radium-226
(Bq/L)
Existing WMF 10 9 22
Long Term WMF 10 20 75
Atomic Energy of Canada Limited. (2011) . Licensing Package
4502-508760-LP-001, Rev.1.

31. Wastewater Treatment and Residuals Management Strategy
removal of metals & radionuclides
nitrification/de-nitrification
contaminated
water from all
sources
Treating Mine Wastewater
Case 3: Low-level Radioactive Waste Management Facility
Port Granby, ON
pH adjustment
removal of metals & radionuclides
removal of nitrate
equalization
aeration
tank
membrane
tank treated
effluent
contaminated
solids to long
term WMF
clarifier
brine
reaction
tank
brine evaporator
biological treatment (MBR)
reverse
osmosis
dryer
thickening/dewatering

32. Treating Mine Wastewater
Case 3: Low-level Radioactive Waste Management Facility
Port Granby, ON
Challenges
– Challenging residuals management process
– Varying inputs — concentrations and flows will vary significantly over the
life of the WWTP due to weather, construction
– Relatively unknown water matrix
– Flexible process concept required due to varying flows during construction
phase and post-construction
Source: Atomic Energy of Canada Ltd. Presentation on the Port Granby Waste Management Project
One Day Public Hearing. Sept. 2011

33. Treating Mine Wastewater
Project Requirements of Mine Industry — Examples:
– Accelerated timelines — fast track schedules
• Standardized process equipment packages
• Pre-fabricated buildings
– Bench scale testing programs and pilot testing programs
– Design/build
– Increased water use efficiency
– Minimize foot print
– Environmental baseline assessments
– Public and native populations consultations

34. Top Ten Issues for Mining Companies in 2013
– Rising energy and equipment costs
– Continuing commodity market volatility
– Capital project deceleration
– Upturn in mergers and acquisitions
– Expanding resource nationalism
– Raising business standards to combat corruption
– Increasing government and community requirements
– Addressing Labor issues
– Improving safety outcomes
– Increasing investments in technology
Deloitte. (2013) Tracking the trends 2013 : The top ten issues mining companies
may face in the coming year.

35. Till Freihammer
Till Freihammer is a senior process engineer with 15 years of experience in the
water and wastewater sector. He has worked in France, Germany, United
Kingdom and Canada from operations, process commissioning and
troubleshooting to design, tendering and project delivery. His responsibilities
include selection and validation of process design strategies, cost estimating,
and the coordination of multidisciplinary teams. His experience covers a wide
area of industrial and municipal water and wastewater processes including
membrane technology for water and wastewater treatment.
till.freihammer@aecom.com

36. till.freihammer@aecom.com