kennecott eagle minerals 0 - deq · kennecott eagle minerals company (kemc) is in receipt of your...

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Kennecott Eagle Minerals Kristen Mariuzza Environmental and Permitting Manager 504 Spruce Street Ishpeming, Michigan 49849 (906) 486-1257

May 8, 2012

Mr. Andrew Drury, Senior Environmental Engineer MDEQ-Air Quality Division Constitution Hall, 525 West Allegan Street P.O. Box 30260 Lansing, Ml 48909

Re: Response to Initial Questions on Air Permit Application PTI 50-068 Kennecott Eagle Minerals Company- Eagle Project Site

Dear Mr. Drury:

Kennecott Eagle Minerals Company (KEMC) is in receipt of your email dated April 13, 2012 that asks initial questions from your preliminary review of the KEMC air permit application. KEMC has reviewed these questions and is providing the following responses. For clarity in preparing the responses, your question is presented followed by KEMC's response. Please note that some responses indicate that we have updated our emissions inventory. Once that process is complete, we will provide the updated inventory.

1. Please provide an explanation for the differences in the assumptions used in the emission calculations for application 50-06 compared to those used in application 50-068.

Response: As expected over the course of any industrial project, the Eagle Project mine design was initially engineered from a feasibility study to realized construction including optimization of space and individual facility design. Engineering for the Eagle Project mine has progressed as a result of additional exploration of the ore body and development rock. This has allowed Rio Tinto to refine the level of detail used to estimate emissions from the Eagle Project. Further, refinements to the overall project design have led to certain engineering and equipment changes that will result in a substantial emissions reduction. Differences in the emission estimation methodology resulting from the optimization of the mine design are discussed below.

Under the initial mine design, reflected in Permit to Install No. 50-06, ore was to have been stored and crushed above-ground in a partially enclosed structure, while aggregate was to have been stored in an outdoor pile. The optimized mine design now consists of fully enclosed buildings for ore and aggregate storage, as well as the elimination of ore crushing activities. This will result in improved control of fugitive emissions associated with storage activities, specifically at the Coarse Ore Storage Area (COSA) and the newly added aggregate storage building, which will be controlled with a baghouse. Rio Tinto (Eagle) chose to fully enclose the COSA to improve the logistics of storage and material handling between underground haul trucks and over the road trucks, and to isolate materials stored within the building from ambient weather conditions (snow, rain). The aggregate storage building is part of a planned relocation of the backfill facility from underground to the surface. Aggregate will not be dropped from the surface to the underground through a borehole, instead it will be directly supplied into a surface backfill facility from the enclosed aggregate storage building where emissions associated with dumping and loading operations will be controlled by the structure and a baghouse. The result is improved emissions control and a reduction in both above-ground and underground emissions. The emissions inventory submitted in support of the current Permit to Install application reflects improved control


efficiencies for the operations that will be performed within these structures, based on conservative engineering judgment and relevant guidance documents such as AP-42.

As stated above, Eagle has refined its mine design as the project has progressed. A refined mine design allows Eagle to better plan the logistical needs of its operation, such as the number and type of vehicles required to complete the operation. Based on future further exploration of the ore body and on metals commodity prices, ore reserves may grow. As a result, the ore production, development rock production, operating days, and emulsion rate of drilling and blasting figures have increased to add flexibility if reserves grow, and accordingly, the emissions inventory includes a conservative analysis of the predicted mine emissions. In August of 2010, Rio Tinto applied for an amendment to its Part 632 mining permit to relocate the temporary development rock storage area (TDRSA). That modification also included a reduction in the slope of the interior walls of the TDRSA. This slope change resulted in a surface area increase, which in turn increased the acreage exposed for fugitive emissions. The changes are reflected in the emissions inventory.

The underground ventilation design has progressed and has been tailored to meet stringent requirements of Rio Tinto's and the Mine Safety and Health Administration's (MSHA) worker health and safety standards, specifically those for radon, respirable silica and diesel particulate matter. As a result, volumetric air flow rates have changed from the previous application. It is important to note that particulate emissions associated with underground activities were conservatively estimated under the unrealistic assumption that the ventilation system would continually operate at its maximum air flow rate. To further develop a conservative estimate of air quality and depositional impacts, model simulations of the maximum emission associated with the high air flow rate were conducted using the lowest air flow rate expected to occur, a circumstance where air quality and depositional impacts would be considered 'worst case'.

Additional refinements to the emissions inventory in application 50-068 were added to increase the accuracy of estimating particulate emissions generated by vehicle travel, blasting, and road grading in the underground. For instance, settling factors based on particle size and density were combined with a detailed analysis of expected travel distances between sources and the ventilation point. All assumptions were conservatively-based to maximize the emissions estimate based on activities that could occur during periods of maximum ore production.

2. The final emission calculations for application 50-06 used a silt content of 3 percent for the vehicle travel and storage pile emissions, but the emission calculations for 50-068 used a silt content of 1 percent. Please explain this difference and provide corrected emission calculations if necessary.

Response: KEMC believes the use of 1 percent silt content represents a conservative modeling approach and that anything higher will result in a model that goes beyond reasonable worst case emissions. However, the use of 3 percent silt content at the Eagle mine site results in emissions that meet applicable standards. As noted above, KEMC has refined and is continuing to update its emissions inventory. A copy of the updated version and any modified calculations resulting from use of 3 percent silt content will be provided.


3. The application narrative and emission calculations make mention of using crushed development rock. However, there is no description or emission estimates for a crusher. Please clarify this.

Response: A final decision has not been made regarding the use of crushed development rock in underground operations. The emissions inventory has been conducted under a 'worst' case assumption for metals constituents in both rock types to build operational flexibility. If crushed development rock is used for backfill or as a paving surface for certain underground roads, a permitted crushing operation will be contracted. A Permit to Install for a crushing operation is not being sought at this time.

4. The "data" sheet in Appendix C lists a single mine heater with a capacity of 32 mmBtulhr but elsewhere the application states there will be two heaters with a total capacity of 48 mmBtulhr. Please explain or correct this discrepancy.

Response: The data sheet in Appendix C has been corrected to reflect the use of up to two heaters with a total heat input rating of 48 mmBtu/hr, and the "mine heaters" sheet now refers to the corrected information in the data sheet. Note that the potential to emit estimate was based on the 48 mmBtu/hr total heat input rating, which was also used in the modeling. Therefore, this clarification has no impact on estimated emissions. The total combined heat input will be no more than 48 mmBtu/hr, but the split between the two heaters has not yet been determined.

5. Please provide more information on the wetting that will be done in the mine to reduce emissions during ore and development rock transfers.

Response: Emissions will be generated during the muck (blast material that is generated following the blast) cycles, and manual wetting with hoses or dedicated spray bar equipment will be applied to muck after blasting occurs. The method will depend on the location of the blast and the feasibility of moving dust suppression equipment into that area. The dust suppression methodology that will be employed will be determined on a case-by-case basis, partially dependent on whether the blast face generates water in quantities sufficient to control dust to the stringent level necessary to meet the stringent worker health and safety standards promulgated by MSHA. Wetted muck will be transferred by a loader into haul vehicles to be taken to the TDRSA or COSA, to a secondary stope for backfill, or a portion of the muck may remain in place for temporary underground storage. Muck that is not immediately handled will be re-wetted as necessary before transfer. Whether the material is ore or development rock, the same basic principle for dust control will apply.

Other wetting techniques or surfactant additives may be used to help control fugitive emissions from vehicle traffic on the underground roadways. Dust from this source would be controlled by applying water to the roadway to keep it moist. Currently, the underground road tends to be more wet than dry without needing watering, but the road will continue to be maintained appropriately to ensure worker health and safety standards continue to be met.


6. In the emission estimates for vehicle travel, it appears that the incorrect value was used for the maximum daily development rock trucked into the mine for backfill (1,540 tonnes per day rather than 1, 698 tons per day). Please review this and provide revised calculations if necessary.

Response: The emissions inventory has been revised to reflect this inadvertent calculation error, which results in a small increase in maximum daily PM, PM 10, PM2.5 , and TAG emissions.

7. Also in the vehicle travel emission estimates (and on the "data" sheet}, it looks like more development rock is trucked into the mine for backfill than is removed from the mine. Please review this and provide revised calculations if necessary.

Response: Over the life of the mine, and therefore in an average year, the same amount of development rock will be trucked out of the mine as will be trucked in as backfill (for secondary stapes). In the anticipated 3 years of full ore production, much of the development rock will have already been trucked out of the mine, and secondary stopes will need backfilling. Thus, in these years, more development rock will indeed be trucked into the mine for backfilling than will be removed from the mine. Trucking development rock out of the mine will occur mainly in the early years, while trucking development rock back into the mine will occur mainly in the middle and later years of the mine operation. Because transport of development rock has already been accounted for in the emissions inventory, no change to the emissions inventory is necessary.

B. In the emission estimates for storage piles, please provide the basis for the "f' factor of 15.3 that was used in the calculations.

Response: The "f' factor of 15.3 is consistent with the factor used in the original Permit to Install application covering the Eagle Project. A review of five recent years (2005 through 201 0) of wind data measured at the Sawyer International Airport in Gwinn indicates that wind speeds in the region may exceed 12 miles per hour 24.8% of the period. This would result in an "f' factor of 24.8. To ensure that the emissions inventory continues to reflect a conservative assessment of emissions, storage pile emissions have been re-estimated using an "f' factor of 24.8. Note that the change in the "f' factor results in only a small increase in estimated emissions (e.g., 0.36 tons per year of PM10 from the TDRSA pile).

9. Also in the storage pile emission estimates, it appears that the incorrect "f' factor was used for the aggregate (15. 3 rather than 1 ). However, since this error results in a higher emission estimate, it does not need to be corrected.

Response: The emissions inventory has been revised to reflect this inadvertent calculation error. Note that this change results in a decrease in estimated emissions.

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10. Please provide a manufacturers specification sheet listing the emission rates for the emergency generator.

Response: The manufacturer's specification sheet for the emergency generator, previously submitted in support of the application that resulted in the issuance of Permit to Install No. 50-06A on July 14, 2011, is enclosed with this submittal.

11. It appears that the emission factor for propylene for the emergency generator is incorrect. Please review this and revise the emission estimates and TAG analysis accordingly.

Response: The emissions inventory has been revised to reflect this inadvertent calculation error. The correction results in a maximum 24-hour modeled concentration of 0.1 ~g/m3 , which is well under the AQD-published propylene initial threshold screening level of 1,500 ~g/m3 . Note that the factor was correctly listed in the inventory and dispersion modeling supporting the application that resulted in the issuance of Permit to Install No. 50-06A on July 14, 2011.

Sincerely,

~t::~-Environmental and Permitting Manager

cc: File

DIESEL GENERATOR SET

FEATURES

FUEL/EMISSIONS STRATEGY • EPA Certified for Stationary

Emergency Application (EPA Tier 2 emissions levels)

DESIGN CRITERIA

Image shown may not renect actual package.

• The generator set accepts 100% rated load In one step per NFPA 110 and meets ISO 8528-5 transient response.

UL2200 • UL 2200 listed packages available. Certain

restrictions may apply. Consult with your Cat® Dealer.

FULL RANGE OF ATTACHMENTS • Wide range of bolt-on system expansion

attachments, factory designed and tested • Flexible packaging options for easy and cost

effective installation

SINGLE-SOURCE SUPPLIER • Fully prototype tested with certified torsional

vibration analysis available

WORLDWIDE PRODUCT SUPPORT • Cot dealers provide extensive post sale support

Including maintenance and repair agreements • Cat dealers have over 1,800 dealer branch stores

operating In 200 countries • The Cot® S•O•S5

M program cost effectively detects Internal engine component condition, even the presence of unwanted fluids and combustion by-products

STANDBY 2000 ekW 2500 kV A 60Hz 1800 rpm 480 Volts Caterpillar Is leading the power generation marketplace with Power Solutions engineered to deliver unmatched flexibility, expandabllity, reliability, and cost-effectiveness.

CAT 3516C TA DIESEL ENGINE • Reliable, rugged, durable design • Field-proven In thousands of applications

worldwide • Four-stroke-cycle diesel engine combines

consistent performance and excellent fuel economy with minimum weight

CAT SR5 GENERATOR • Matched to the performance and output

characteristics of Cat engines • Industry leading mechanical and electrical design • Industry leading motor starting capabilities • High Efficiency

CAT EMCP 3 SERIES CONTROL PANELS • Simple user friendly Interface and navigation • Scalable system to meet a wide range of

customer needs •Integrated Control System and Communications

Gateway

SEISMIC CERTIFICATION • Seismic Certification available • Anchoring details are site specific, and are

dependent on many factors such as generator set size, weight, and concrete strength. IBC Certification requires that the anchoring system used is reviewed and approved by a Professional Engineer

• Seismic Certification per Applicable Building Codes: IBC 2000, IBC 2003, IBC 2006, IBC 2009, CBC 2007

• Pre-approved by OSHP and carries an OPA#(OSP-0084-01) for use In healthcare projects In California

STANDBY 2000 ekW 2500 kVA 60Hz 1800 rpm 480 Volts

C.I.TERPILLARe FACTORY INSTALLED STANDARD & OPTIONAL EQUIPMENT

Svstem _OJ!tion~l Air Inlet • Single element canister type air cleaner [ I Dual element & heavy duty air cleaners

• Service Indicator [ I Air inlet adapters & shutoff Cooling • Radiator with guard [ I Radiator duct flange

• Coolant drain line with valve [ I Jacket water heater • Fan and belt guards • Cat® Extended Life Coolant"

Exhaust • Dry exhaust manifold [ 1 Mufflers and Silencers • Flanged faced outlets [ 1 Stainless steel exhaust flex fittings

[ I Elbows, flanges, expanders & Y adapters Fuel • Secondary fuel filters 11 Water separator

• Fuel priming pump 11 Duplex fuel filter • Flexible fuel lines • Fuel cooler"

Generator • Class H Insulation [ 1 Oversize & premium generators • Cat digital voltage regulator (CDVRI with kVAR/PF [ 1 Bearing temperature detectors

control, 3-phase sensing • Winding temperature detectors • Anti-condensation heaters • Reactive Droop

Power Termination • Bus bar (NEMA or IEC mechanical lug holes)- right I I Circuit breakers, UL listed, 3 pole with shunt side standard trip, 100% rated, manual or electrically operated

• Top and bottom cable entry 11 Circuit breakers, IEC compliant, 3 or 4 pole with shunt trip, manual or electrically operated

( I Bottom cable entry I I Power terminations can be located on the right, left

and/or rear as an option . Governor • ADEMTM 3 [ 1 Load share module

Control Panels • EMCP 3.1 I I EMCP 3.2 ... I I EMCP 3.3 • User Interface paneiiUIP)- rear mount I I Option for right or left mount UIP • AC & DC customer wiring area (right side) I I Local & remote annunciator modules • Emergency stop pushbutton [ I Digital VO Module

[ I Generator temperature monitoring & protection ( I Remote monitoring software

Lube • Lubricating oil and filter [ 1 Oil level regulator • Oil drain line with valves [ I Deep sump oil pan • Fumes disposal [I Electric & air prelube pumps • Gear type lube oil pump II Manual prelube with sump pump

[ I Duplex oil filter Mounting • Ralls- engine I generator I radiator mounting [ ]Isolator removal

• Rubber anti-vibration mounts (shipped loose) [I Spring-type vibration Isolator [ ]IBC Isolators

Starting/Charging • 24 volt starting motor(s) [I Battery chargers (10 or 20 amp) • Batteries with rack and cables [I 45 amp charging alternator • Battery disconnect switch [ I Oversize batteries

[ 1 Ether starting aid [ I Heavy duty starting motors [ I Barring device (manual) [ l Air starting motor with control & silencer

General • Right-hand service II CSA certification • Paint- Caterpillar Yellow except ralls and radiators [ I CE Certificate of Conformance

are gloss black [I Seismic Certification per Applicable Building Codes: • SAE standard rotation IBC 2000, IBC 2003, IBC 2006, IBC 2009, CBC 2007 • Flywheel and flywheel housing - SAE No. 00 " Not Included with packages without radiators

Note Standard and optional equipment may vary for UL 2200 Listed Packages. UL 2200 Listed packages may have oversized generators with a different temperature rise and motor starting characteristics.

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SPECIFICATIONS

CAT GENERATOR

Frame ................................................................................. 825 Excitation ................................................ Permanent Magnet Pitch .............................................................................. 0.6667 Number of poles ................................................................... 4 Number of bearings ............................................................. 1 Number of leads ......................... ...................................... 006 Insulation ....................... UL 1446 Recognized Class H with tropicalization and antiabrasion Alignment .............................................................. Pilot Shaft Overspeed capability ...................... .............................. 125% Wave form ......................................................................... 2% Paralleling kit/Droop transformer .......................... Standard Voltage regulator.3 Phase sensing with selectible voltsiHz Voltage regulation ........... Less than +/- 112% (steady state)

Less than +1- 112% lwl3% speed change) Telephone influence factor ..... .... .. .... ...... .......... Less than 50

Harmonic distortion ................... ...................... Less than 5%

CAT DIESEL ENGINE

3516C ATAAC V-16, 4 Stroke, water-cooled diesel Bore ........................................................ 170.00 mm (6.69 in)

Stroke ..................................................... 190.00 mm (7.48 in) Displacement ......................................... 69.00 L (4210.64 in' ) Compression Ratio ....................................................... 14.7:1 Aspiration .................................. ......................................... TA Fuel System .................................... Electronic unit injection Governor Type ........................................................... ADEM3

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C.I.TERPILLARe

CAT EMCP CONTROL PANELS

• EMCP 3.1 (Standard) • EMCP 3.213.3 (Option) • Single location customer connector point • True RMS metering, 3-phase • Controls

- Run I Auto I Stop control -Speed Adjust

-Voltage Adjust - Emergency Stop Pushbutton - Engine cycle crank

• Digital indication for: - RPM

- Operating hours

- Oil pressure -Coolant temperature • System DC volts - L-L volts, L-N volts, phase amps, Hz - ekw, kVA, kVAR, kW-hr, %kW, PF (EMCP3.2/3.31

• Shutdowns with indicating lights for: - Low oil pressure - High coolant temperature - Low coolant level

- Overspeed - Emergency stop - Failure to start (over crank)

·Programmable protective relay functions: IEMCP 3.2 & 3.3)

- Under and over voltage - Under and over frequency - Overcurrent (time and inverse time) - Reverse power IEMCP 3.3)

• MODBUS isolated data link RS-485 half-duplex (EMCP 3.2 &3.3) • Options

-Vandal door - local annunciator module -Remote annunciator module - Input I Output module - RTD I Thermocouple modules

- Monitoring software

December 15 2010 10:48 AM


C.I.TERPILLARe TECHNICAL DATA

Open Generator Set· • 1800 rpm/60 Hz/480 Volts DM8263 EPA Certified for Stationary Emergency Application (EPA Tier 2 emissions levels)

Generator Set Package Performance Gensel Power rating@ 0.8 pf 2500 kVA Genset Power rating with fan 2000 ekW

Coolant to aftercooler Coolant to aftercooler temp max 50 ° c 122 • F

Fuel Consumption 100% load with fan 622.5lJhr 138.0 GaVhr 76% load with fan 406.8 Llhr 107.5 Gal/hr 50% load with fan 293.6lJhr 77.6 Gal/hr

Cooling System' Air flow restriction (system) 0.12 kPa 0.48 ln. water Air flow (max@ rated speed for radiator arrangement) 2480 m3/min 87580 cfm Engine Coolant capacity with radiator/exp. tank 476.0 L 125.5 gal Engine coolant capacity 233.0 L 61.6 gal Radiator coolant capacity 242.0 L 63.9 gal

Inlet Air Combustion air inlet flow rate 185.6 m3/min 6560.9 cfm

Exhaust System Exhaust stack gas temperature 400.1. c 752.2 oF Exhaust gas flow rate 433.1 m3/min 15294.8 cfm Exhaust flange size (internal diameter) 203.2 mm 8.0 in Exhaust system back pressure (maximum allowable) 6.7 kPa 26.9 ln. water

Heat Rejection Heat re)ectlon to coolant (total) 759kW 43164 Btu/min Heat rejection to exhaust (total) 1788 kW 101683 Btu/min Heat rejection to aftercooler 672kW 38217 Btu/min Heat rejection to atmosphere from engine 133kW 7664 Btu/min Heat rejection to atmosphere from generator 107.6 kW 6113.5 Btu/min

Alternator Motor starting capability@ 30% voltage dip 4647 skVA Frame 825 Tempera ture Rise 130 ° c 234 • F

LubaSystom Sump refill with filter 401.3 L 106.0 gal

Emissions (Nominal)' NOx g!hp·hr 5.45 g/hp-hr CO g/hp·hr .3 g/hp-hr HC g/hp-hr .11 g/hp-hr PM g/hp·hr .025 g/hp·hr . .

' For amb1ent and altitude capabilities consult your Cat dealer. A1r flow restnct10n (system) Is added to ex1stmg restnctlon from factory . 'UL 2200 Listed packages may have oversized generators with a different temperature rise and motor starting characteristics. Generator temperature rise Is based on a 40 degree C ambient per NEMA MG1-32. 'Emissions data measurement procedures are consistent with those described in EPA CFR 40 Part 89, Subpart D & E and IS08178-1 for measuring HC, CO, PM, NOx. Data shown is based on steady state operating conditions of 77"F, 28.42 in HG and number 2 diesel fuel with 35° API and LHV of 18,390 btu/lb. The nominal emissions data shown is subject to instrumentation, measurement, facility and engine to engine variations. Emissions data is based on 100% load and thus cannot be used to compare to EPA regulations which use values based on a weighted cycle.

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RATING DEFINITIONS AND CONDITIONS

Meets or Exceeds International Specifications: AS1359, CSA, IEC60034-1, 1503046,1508528, NEMA MG 1-22,

NEMA MG 1-33, UL508A, 72/23/EEC, 98/37/EC, 2004/1 08/EC Standby- Output available with varying load for the duration of the interruption of the normal source power. Average power output is 70% of the standby power rating. Typical operation is 200 hours per year, with maximum expected usage of 500 hours per year. Standby power in accordance with 1508528. Fuel stop power in accordance with 1503046. Standby ambients shown indicate ambient temperature at 100% load which results in a coolant top tank temperature just below the shutdown temperature.

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C.A.TERPILLAR~

Ratings are based on SAE J1349 standard conditions. These ratings also apply at 1503046 standard conditions. Fuel rates are based on fuel oil of 35° API [16° C (60" F)] gravity having an LHV of 42 780 kJ/kg (18,390 Btu/lb) when used at 29" C (85° F) and weighing 838.9 g/iiter (7.001 lbs/U.S. gal.). Additional ratings may be available for specific customer requirements, contact your Cat representative for details. For information regarding Low Sulfur fuel and Biodiesel capability, please consult your Cat dealer.

December 15 2010 1 0:48 AM

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