Michigan Air Use Permit –Permit to Install …...Aquila Resources Inc. Stephenson, Michigan March 26, 2019 REUSE OF DOCUMENTS Michigan Air Use Permit –Permit toInstall Application

Michigan Air Use Permit – Permit to

Install Application No. 205-15A

Response to Michigan Department of

Environmental Quality Comments

Project I.D.: 17A021.19

Aquila Resources Inc.

Stephenson, Michigan

March 26, 2019

https://17A021.19

Michigan Air Use Permit – Permit to Install Application

No. 205-15A Response to Michigan Department of Environmental Quality Comments

Project ID: 17A021.19

Prepared for

Aquila Resources Inc.

Stephenson, Michigan

Prepared by

Foth Infrastructure & Environment, LLC

March 26, 2019

REUSE OF DOCUMENTS This document has been developed for a specific application and not for general use; therefore, it may not be used without

the written approval of Foth. Unapproved use is at the sole responsibility of the unauthorized user.

Copyright©, Foth Infrastructure & Environment, LLC 2019 2121 Innovation Court, Ste. 300 • PO Box 5126 • De Pere, WI 54115-5126 • (920) 497-2500 • Fax: (920) 497-8516 • www.foth.com

www.foth.comhttps://17A021.19

Michigan Air Use Permit – Permit to Install Application

No. 205-15A

Response to Michigan Department of Environmental Quality

Comments

Table of Contents

Response to Comment # Page #

February 5, 2019 Email Message

1 1

2, 3, 4 2

5, 6, 7, 8 3

9, 10, 11 4

12, 13, 14, 15, 16 5

17, 18 6

19, 20, 21, 22 7

23, 24 8

25, 26, 27 9

28, 29, 30, 31 10

32, 33, 34, 35 11

36 12

February 22, 2019 Email Message

1, 2, 3 12

4, 5, 6 13

7, 8, 9, 10 14

References 15

Appendices

Appendix A Air Emissions Inventory

Appendix B Reagent Safety Data Sheets

Appendix C Guidelines for Selecting Dust Suppressants

Appendix D Air Pollution Control Technology Fact Sheets

Appendix E Vendor Information

PW_IE\Documents\Clients\Aquila Resources\0017A021\10000 Reports\Air Permit Amendment Response\R-Air Permit Response for Additional

Info March 2019.docx ii

Introduction

This document was prepared to respond to two requests for additional information from the Michigan Department of Environmental Quality (MDEQ) on the Permit to Install Application No. 205-15A. That application (Foth, 2018a) was sought to modify Permit to Install No. 205-15 issued to Aquila Resources Inc. (Aquila) for the Back Forty Project. The application and comment response were prepared by Foth Infrastructure & Environment, LLC (Foth). The first set of MDEQ comments was received in an e-mail dated February 5, 2019 (Drury, 2019a) while the second set of comments was received in an e-mail dated February 22, 2019 (Drury, 2019b). The original comment from each of the e-mail messages is re-stated below in italics, which is then followed by the response. To address comments requiring modifications to the emission calculations [included in Foth (2018a) as Appendix C], a complete set of revised emission calculations is included as Appendix A to this document. An Excel version of the revised emissions calculations will be provided to MDEQ separately.

In addition to MDEQ comments, Michigan Rule 227 (1) Allowable Emission Rate utilized in the emission calculations is undergoing an update that includes an Initial Risk Screening Level (IRSL) value for cobalt. This IRSL functions as a more stringent screening criteria for cobalt than the criteria used in Foth (2018a). Based on information from MDEQ, it is anticipated that this IRSL will be published prior to the close of public comment period for the permit associated with this permit application. Cobalt has been re-evaluated according to the anticipated IRSL and the screening shows the need for dispersion modeling for cobalt. Appendix A page 35 provides detail.

Air dispersion modeling has not been provided as part of this response document. As instructed by MDEQ, Foth will wait until MDEQ completes its review of the comment responses and revised emission calculations to determine whether additional air dispersion modeling will be required.

Response to MDEQ Questions and Comments in Email Message of

February 5, 2019 (Drury, 2019a):

Comment #1:

Table 3-2 and the SDS indicate SIPX is a solid, but page 9 of the application indicates it is a liquid. Please clarify if SIPX is a solid or liquid.

Response to Comment #1:

SIPX will be delivered to the facility as granular solid. Once it enters the reagent management facilities, it will be processed into an appropriate solution to be introduced into the beneficiation operations. The SDS of SIPX is provided in Appendix B.

Comment #2:

Please provide the CAS number for polyacrylamide, given in Table 3-2 as AN-926 VHM. The SDS does not provide any composition data; is AN-926 VHM 100% polyacrylamide?

PW_IE\Documents\Clients\Aquila Resources\0017A021\10000 Reports\Air Permit Amendment Response\R-Air Permit Response for Additional Info March 2019.docx Foth Infrastructure & Environment, LLC 1


The Safety Data Sheet (SDS) is provided in Appendix B and does not provide composition data. AN-926 VHM is a manufacturer name for a polyacrylamide flocculent. The CAS number for polyacrylamide is 9003-05-8. Without additional information, Aquila assumes AN-926 VHM is 100% polyacrylamide.

Comment #3:

The reagent handling PM emission calculations have emission estimates for both polyacrylamide and AN-926VHM Flocculent. However, in the reagent usage on page 3 of Appendix C, these appear to be the same material. Please address this potential discrepancy.


Polyacrylamide and AN-926 VHM are the same material. They should only be listed once in the emission calculations. This should not significantly change emissions from this source as emissions would be reduced by about 9 and 3 lbs. per year for PM10 and PM2.5, respectively. Revised emission calculations have been prepared to eliminate the listing for “polyacrylamide” on the “Reagents” page and added the qualifier “polyacrylamide” to the listing for AN-926 VHM. A yellow highlight has been placed in the line where polyacrylamide was removed. Revised emission calculations identified as Air Emissions Inventory REV 03-19 are included as Appendix A in this response document.

Comment #4:

There are several SDS in Appendix B that are not included in Table 3-2 and for which there do not appear to be emission calculations. Please provide emission calculations for these materials or explain why they will not be emitted. If emitted, these materials need to be evaluated for Rule 225 compliance, unless they meet the Rule 226(a) exemption from the Rule 225 screening level requirement. If Aquila believes any TACs meet the Rule 226(a) exemption, please provide an analysis showing that.


SDSs were provided for diatomaceous earth and borax but no emission calculations were provided in the application. The revised emission calculations in Appendix A have been updated to include these two reagents. The “Summary Criteria Pollutants” page has been updated to include emissions from these reagents in tons per year. Emission calculations were provided for silica but an SDS was not provided. An SDS for silica sand is provided with this response in Appendix B. SDSs were provided in the application for fluorspar (calcium fluoride), lead oxide, potassium nitrate, and sodium hydroxide. The current list of plant consumables does not include these reagents. They have been removed from the set of SDSs for reagents. An updated set of SDSs is provided in Appendix B. As part of this updated set of SDSs, Tables 1 and 2 that were at the beginning of the SDSs have been removed as they were from the previous application in 2015.

The emissions for diatomaceous earth and borax were each evaluated for Rule 225 compliance. While borax (disodium tetraborate, CAS No. 1330-43-4) does not have a health screening level, diatomaceous earth (CAS No. 61790-53-2) has a health screening level. However, emission calculations show that diatomaceous earth emissions should be no greater than 1.08 pounds per year based on total particulate matter. This should meet the Rule 226 (a) exemption in that PW_IE\Documents\Clients\Aquila Resources\0017A021\10000 Reports\Air Permit Amendment Response\R-Air Permit Response for Additional Info March 2019.docx Foth Infrastructure & Environment, LLC 2

emissions would be less than 10 pounds per month and the chemical does not appear in the Table 20 List of High Concern Toxic Air Contaminants.

Comment #5:

What is the Celatom LCS-3 used for? There is an SDS but it does not appear anywhere else in the application. If it will be used, please provide an emission estimate.


Celatom LCS-3 is diatomaceous earth. It will be used in the oxide plant as part of the precious metals recovery process. As noted in Response to Comment #4, estimated throughput and revised emission calculations are provided in the Air Emissions Inventory REV 03-19 attached as Appendix A.

Comment #6:

Carbon (bleached flour) is listed in Table 2 in Appendix B, but there does not appear to be an SDS for it. If it will be used, please provide an SDS and an emission estimate.


Foth (2018a) Appendix B includes a list of reagents to be used in the original (permitted) design of the oxide plant. For the current design, carbon is not listed as a reagent; therefore, emission calculations are not included. Appendix B of this document is an updated set of SDSs that provides a more accurate reagent list anticipated for the mill.

Comment #7:

SiO2 (silica) is listed in Table 2 in Appendix B, but there does not appear to be an SDS for it. If it will be used and is not already addressed, please provide an SDS and an emission estimate.


PM emission calculations for silica were provided in Appendix C of the application and it is listed in Table 3-2 of the application. However, no SDS was provided. An SDS is included with this response in Appendix B.

Comment #8:

Sodium sulfite is listed in the Reagents tab of Appendix C, but the emission rate is given as zero and there is no SDS for it in Appendix B. A note on the Reagents tab indicates this material will not be used. Please clarify this and, if it will be used and is not already addressed, please provide an SDS and an emission estimate.


Sodium sulfite will not be used in the revised process. The listing for sodium sulfite has been eliminated from the reagents spreadsheet. In the revised emission calculations in Appendix A, a yellow highlight is shown in the location where this listing was previously located.

Comment #9:

Will the waste rock be put back in the pit after mining is completed? If so, please provide emission calculations for this activity and address whether it should be included in the modeling, or if the modeling already represents the worst-case emissions from the facility. PW_IE\Documents\Clients\Aquila Resources\0017A021\10000 Reports\Air Permit Amendment Response\R-Air Permit Response for Additional Info March 2019.docx Foth Infrastructure & Environment, LLC 3


As part of reclamation, waste rock from the North and South Waste Rock Facilities will be moved into the pit as backfill. This part of reclamation will be accomplished after mining is complete. Figure 4-1 of the Mining Permit Amendment Application (Foth, 2018b) provides an illustration of the timeline.

The air emissions and modeling underlying the application to modify the air permit (Foth, 2018a) are the worst-case emissions: Year 4 of operations. Pit backfilling will take place several years later. To support the worst-case evaluation, pit backfill emissions have been prepared and are provided in separate tab as part of the revised emission calculations in Attachment A. Given they will not occur during operations, they have not been added to the facility-wide emissions estimate for the air permit application. The annual PM10 and PM2.5 emissions during pit backfill are estimated to be 30.7 and 1.7 tons/year, respectively during this step. Activities include removal and handling of waste from the two storage areas, transfer along surface haul roads, and transfer and placement into the pit.

Comment #10:

Is the building control efficiency assumed to be 98% or 95%? In 3.3.12, the application states the “building enclosure should be 98% efficient in controlling the release of PM, with the remaining 5% of the PM released outside the building.” In 4.1.4 and 5.1.5, the application gives the building control efficiency as 98%, but in 5.1.10 and 5.1.12, it is given as 95%. For copper and zinc concentrate packaging, a 98% control is applied for all process steps; however, for lead concentrate packaging, 98% and 95% are both used.


Building control efficiency should be 98% for all structures. The language in Sections 5.1.10 and 5.1.12 should have stated that the building control efficiency is assumed to be 98%. For the concentrate packaging area, all building control efficiencies should be 98%. The one 95% control in the emission calculations for one lead concentrate transfer point was corrected to be 98%. The revised emission calculation spreadsheet in Appendix A shows this change with the cell highlighted in yellow.

Comment #11:

Are the space heaters propane or diesel? The application primarily discusses propane, but 5.1.18 talks about diesel.


Diesel was considered for fuel in space heaters. As the application was being prepared, Aquila decided to use propane to fire all space heaters. Therefore, the reference to diesel in Section 5.1.18 is in error.

Comment #12:

Are the emergency generator engines exempt under Rule 285(2)(g), rather than Rule 235 as stated in 3.3.17?



The correct reference is to R 336.1285 (2) (g) or Rule 285.

Comment #13:

Does Aquila believe the fire pump engine is exempt from permitting, as well?


Given the heat input rating is less than 10 million British thermal unit (BTU) per hour, the fire engine should be exempt from permitting per Rule 285 (2) (g).

Comment #14:

Please identify potential dust suppressants that may be used on the facility haul roads.


As noted in the permit application, certain dust suppressants may be used on facility haul roads in addition to water. While a specific dust suppressant has not been selected, dust suppressants will be selected from the list provided in the MDEQ document Guidelines for Selecting Dust Suppressants to Control Dust and Prevent Soil Erosion, Revised February 2014. The guidance document indicates that dust suppressants such as calcium chloride, lignosulfate products, emulsified asphalt or resin stabilizers, or vegetable by-products may be used without triggering the need for a groundwater discharge permit under the Part 22 rules. If dust suppressants are used, they will be selected from this list. A copy of the dust suppressant guidance document is included as Appendix C.

Comment #15:

The application includes EUFLOTSTOCKPILE, which appears to be the stockpile for crushed floatation ore, but does not appear to have a similar emission unit for a crushed oxide ore stockpile, even though one is mentioned in 5.2.5. Please verify if there should be an emission unit for the crushed oxide ore stockpile.


The emission unit for the crushed oxide ore stockpile should be included in Section 5.1.10 of the application that describes fugitive emissions from the oxide mill feed system. To be complete, an emission unit designation EUOXIDESTOCKPILE could be added to represent the covered storage bin at this location. Emission calculations are provided on the “Ore Processing” tab for Crushing Fugitive Emissions, starting at Item 43, Line 195.

Comment #16:

Please provide the basis for the dust collector control efficiencies and the refining furnace scrubber control efficiency.


While specific control efficiency information has not been provided for dust collectors and the wet scrubber that will be used in the project, Foth has used control efficiencies that would be expected for this type of equipment for particulate removal. An Air Pollution Control Technology Fact Sheet prepared by EPA identified as EPA 452/F-03-024 indicates that typical


control efficiencies for new equipment should be in the range between 99 and 99.9%. Foth used 99.5% for all baghouse control efficiencies in this application. For the wet scrubber that will be used to control particulate matter at the refining furnace, an Air Pollution Control Technology Fact Sheet prepared by EPA identified as EPA 452/F-03-017 for venturi scrubbers indicates that control efficiencies can be expected between 70 and 99%, depending on the application. Collection efficiencies are generally higher for particulate matter with aerodynamic diameters of approximately 0.5 to 5 micrometer (µm). For this unit, Foth used a modest control efficiency of 95%. The two EPA technology sheets are attached to this response as Appendix D for reference.

Comment #17:

Why is there only one ore composition used in the particulate TAC calculations, while there appear to be two distinct types of ore (flotation and oxide). Please verify that the worst case ore composition is used in the emission calculations.


There are a number of different ore types that will be processed within the general categories of flotation and oxide ore. The metal concentrations in the emission calculations for ore represent the 95th percentile of highest metal values in all ore types providing a conservative representation of all ore types. This approach was used in the 2015 application (Foth, 2015). The only reason there is a distinction between flotation and oxide ore is that the two ore types will be processed differently in the mills.

Comment #18:

In the blasting particulate calculations, the ton per year values (row 71) appear to be incorrect. They appear to be the 24-hour average pound per hour emission rate multiplied 365 days per year.


The ton per year values in Row 71 have been corrected to reference the actual pound per hour rate in Row 69 rather the 24-hour average pound per hour rate in Row 70. The summary table beginning on cell Q92 of this worksheet was also revised to reflect revised tons per year. The new values are also shown on the Summary Criteria Pollutants worksheet. Revised emission calculations are provided as Appendix A with changes highlighted in yellow.

Comment #19:

The blasting emission calculation estimates an average pound per hour particulate emission rate, which is then used to calculate the metal emission rates used in the Rule 225 evaluation. This average rate is 4.2% of the maximum hourly emission rate. However, per Rule 227(2), an average emission rate that is less than 10% of the maximum hourly rate can only be used if the AQD also evaluates the maximum one hour impact. In addition, for the Rule 227(1)(a) Allowable Emission Rate analysis, the maximum hourly emission rate must be used; the emission rate for the averaging time can be the emissions expected during the time period (8 hour, 24 hour, or month). Please revise the Rule 225 evaluation to use the maximum hourly emission rate in the Rule 227(1)(a) analysis and an average emission rate that is not less than 10% of the maximum hourly emission rate in the dispersion modeling. Note, the drilling particulate pound per hour emission rate is also an average; the maximum hourly emission rate should also be addressed in the revised Rule 225 evaluation. PW_IE\Documents\Clients\Aquila Resources\0017A021\10000 Reports\Air Permit Amendment Response\R-Air Permit Response for Additional Info March 2019.docx Foth Infrastructure & Environment, LLC 6


The TACs hourly emission rates from intermittent blasting used for dispersion modeling have been increased from the average hourly rate to 10% of the maximum hourly rate, consistent with Rule 227(2) and Rule 227(1)(c). The previously submitted calculations used the maximum emission rate for intermittent drilling; we have reduced this emission rate to equal the average emission rate for TAC dispersion modeling purposes.

Rule 227(2) does not permit the use of average emissions in the Rule 227(1)(a) Allowable Emission Rate (AER) analysis. We have thus changed the TAC emission rate from an average hourly value to a maximum hourly value. The proposed emission rate has been calculated as relevant to each applicable AER time period for comparison to the AER value. Updated and revised emission calculations are shown in Appendix A.

Comment #20:

The haul truck weights used in the emission calculations do not match the specifications in Appendix A. Please clarify this and provide revised information as necessary.


The specification sheet in Appendix A is for a CAT 770G model. The correct specification sheet is for a larger CAT 777G model. All haul truck calculations were based on the larger CAT 777G specification. The correct CAT 777G specification sheet is attached to this message as Appendix E.

Comment #21:

While there have been changes to the mine plan, the road length for the mine pit used in the emission calculations is the same as the previous permit. Please confirm there is no change to the mine pit road length.


While the shape of the pit has changed slightly, the road length within the pit will remain the same.

Comment #22:

What is the basis for the 50% control efficiency applied to the ore storage pad material handling emission estimates? The application does not appear to include an explanation.


The 50% control efficiency factor was incorporated to account for additional work practice measures that will be utilized at the ore storage pads and ROM area and the relatively large particle size of the incoming ore material. As described in Section 4 of the Fugitive Dust Control Plan, these measures include use of concrete barriers around storage piles, situating ore storage areas in defined areas of the ore blending areas, and minimizing drop heights for both trucks and loaders that handle the material. In the revised emission calculations in Appendix A, this information has been added to the notes section below the material handling calculations for the ore storage pads and ROM.


Comment #23:

The mean vehicle weight of the haul trucks is slightly different in the Mine pit calculations (127.05 tons) compared to the ore storage calculations (127.3 tons). This appears to be due to the Mine pit calculations assuming a tonne to ton conversion of 1.1 and the other calculations assuming a conversion factor of 1.10231. There is a similar issue with the haul truck payload weight and concentrate truck payload weight in the haul truck travel calculations as well as the front end loader vehicle weight in the ore storage calculations. This discrepancy does not appear to affect the emission calculations in a material way; the difference is less than 0.1%. However, since it appears the calculations and modeling have to be revised for other reasons, please address this question, as well.


The conversion factor of 1.10231 is more accurate and is referenced in Data 2018b of the emission calculations at Cell R77. In the revised emission calculations, all truck weights in tabs for the Mine Pit, Ore Storage, Haul Truck, and TMF-WR emission calculations have been updated to reference 1.10231; therefore all converted truck weights to tons should now be the same. Changes are highlighted in yellow on the revised emission calculations, which are attached to this response as Appendix A.

Comment #24:

Please provide an estimate of the number of truck trips expected for delivering reagent to the facility. If this number is high enough relative to the other truck traffic such that the resulting emissions could influence the dispersion modeling results, vehicle travel emission estimates for these trucks will be required and the emissions will have to be included in the dispersion modeling.


Reagent delivery and concentrate haul will be accomplished using trucks suitable for public roads by approximately 250 truck deliveries per year. The ore and waste rock hauled within the facility use heavier off-road haul trucks and coupled with the larger quantity of material hauled, will generate more emissions than the reagent and concentrate trucks.

To provide a relative comparison of the various haul emissions, the following list summarizes annual PM emissions from each type of haul activity:

Activity

PM Emissions

(pounds/year)

Ore haul to storage piles 11,979 Waste rock haul to NWRF 53,480 Waste rock haul to SWRF 10,454 Waste rock haul to TMF 12,479 Concentrate transport off site 1,494 Reagent delivery 97

As shown, reagent delivery contributes very little (0.11%) to the overall PM emissions from hauling. PW_IE\Documents\Clients\Aquila Resources\0017A021\10000 Reports\Air Permit Amendment Response\R-Air Permit Response for Additional Info March 2019.docx Foth Infrastructure & Environment, LLC 8

Comment #25:

In the haul truck travel emission calculations, the vehicle miles travelled calculations refer to Note 1 and Note 2 for the distribution of waste rock between the waste rock facilities and the tailings management facility, but these notes do not appear to be included in the spreadsheet. Please provide these notes or point out where they are in the application.


The notes were inadvertently omitted from the emission calculations. The revised emission calculations now refer only to “Note 1,” which is placed just below Item 4 on TMF transfers. The note explains the proportions that will be transferred to each area based on information provided by Aquila. These proportions are the basis for the round trip miles per year traveled at each location. Note 1 is highlighted in yellow in the revised emission calculations, which are attached to this response as Appendix A.

Comment #26:

In the tailings and waste rock management facility calculations, the explanation for the trip length on the TMF refers to the NWRF. Please verify that the correct trip length for the truck travel on the TMF was used.


The reference to NWRF for the TMF trip length has been corrected. Revised emission calculations that are attached to this response as Appendix A show the change highlighted in yellow.

Comment #27:

In the previous application, emissions for ore handling and processing in the crusher plants were estimated using AP-42 Chapter 11.24; however, in this application, Chapter 11.19.2 is used. Please explain why this change was made.


The change was made because Chapter 11.19.2 emission factors were developed and updated more recently (August 2004) and appear to have better references for sources of information and supporting test data. A full background document is available for this AP-42 chapter explaining the source of the information and what test data were used to support the emission factors.

While the emission factors in Chapter 11.24 are specific to the metallic mineral processing industry, they were developed in 1982 and many of the sources of information for this set of emission factors are quite old (1970s and 1980s). It is unclear what test data were used to develop these emission factors in that a background document is not available. Importantly, Chapter 11.19.2 emission factors also have specific emission factors for PM2.5 whereas Chapter 11.24 does not have emission factors for PM2.5. When using Chapter 11.24, one has to interpolate emission factors for PM2.5.

Comment #28:

Which, if any, of the ore conveyors will be enclosed?



While many of the conveyor transfer points will be enclosed and/or ventilated, at the current time there are no plans to cover outdoor conveyor runs. Enclosures will be installed over conveyor discharge points. Conveyor runs located inside buildings will be enclosed by the structure itself but will not have covers over the actual conveyor run.

Comment #29:

Footnote 6 for item 29 in the Ore Processing calculations appears to be missing. Please provide the footnote or point out where it is in the application.


Footnote 6 was used in the original application (Foth, 2015) emissions calculations to explain how an emission factor for tertiary crushing was adjusted for the secondary crusher. It is not needed for this set of emission calculations and should have been deleted. The revised emission calculations in Appendix A have Lines 82 and 175 highlighted with the footnote reference deleted.

Comment #30:

Does the oxide tertiary crusher material throughput balance? Comparing Figure 3-6 and the emission calculations, there may be a discrepancy. 37 tons come from secondary crushing (point 31) and 37 tons are fed to the screen (point 32). However, it appears that 25 tons come from the tertiary crusher discharge conveyor (point 39) and is added to the 37 tons of point 31 to go to point 32. Of the 37 tons at point 32, 12 tons leave the crushing circuit (points 40 and 41) and 25 tons are returned to the screen feed (points 34 through 39). Point 42 has 12 tons and point 42 has 37 tons, but there does not appear to be any material added between points 41 and 42. Please review the material flow for the tertiary crusher.


Throughput values for emission point 32 were revised to include the additional 25 tons from point 39 for a total of 62 tons entering the double deck screen. Flow through the tertiary crusher still shows 25 tons while points 40 through 42 now show 37 tons discharge from the oxide circuit. This makes the flow balance. Revised emission calculations attached to this response as Appendix A show changes highlighted in yellow.

Comment #31:

Please clarify which emission points in the oxide plant secondary and tertiary crushing processes are controlled by water sprays. Points 31, 32, 33, and 38 in the calculations do not seem to match Figure 3-6.


From Figure 3-6, emission point 31 should be controlled by a water spray while emission points 32 and 33 should be controlled by a ventilation pick-up system. Emission point 38 should be controlled by a water spray. In addition, emission point 37 should be controlled by water spray rather than through a ventilation system. As a result of changing from ventilation to water sprays at emission points 31, 37, and 38, the capture efficiency factors have been removed since there is no longer a ventilation hood. Capture efficiencies were also removed from emission points 41 and 42 since these are both water spray controls. Adjustments for control efficiencies have been PW_IE\Documents\Clients\Aquila Resources\0017A021\10000 Reports\Air Permit Amendment Response\R-Air Permit Response for Additional Info March 2019.docx Foth Infrastructure & Environment, LLC 10

updated in the revised emission calculations which are attached to this response as Appendix A. Changes are highlighted in yellow.

Comment #32:

There appears to be a minor discrepancy in the oxide calculations between points 25 and 26. The throughputs, emission factors, and control efficiencies all appear to be the same, but the emission estimates are slightly different. Please investigate this apparent discrepancy.


There is a slight discrepancy in the Excel spreadsheet due to slight differences in the values where the throughput values were taken. These have been reviewed and updated such that the pound per hour values for points 25 and 26 should now be the same. Adjustments are reflected in the revised emission calculations in Appendix A with changes highlighted in yellow.

Comment #33:

Please explain why the flotation SAG mill feed fugitive emissions (point 15) assume a 98% control for occurring in a building, but the oxide ball mill feed fugitive emissions (points 46 and 47) do not.


The SAG mill feed drop point has a 98% control efficiency because it occurs inside the building. The oxide ball mill feed drop point goes first into a chute outside the building and then into the building where it discharges into the ball mill. A 98% control efficiency has been added to emission point 47 to account for emissions being released inside the building. Adjustments are reflected in the revised emission calculations in Appendix A with changes highlighted in yellow.

Comment #34:

In the MIBC reagent emission calculations, it looks like the cubic meters per year usage rate (264 cubic meters per year) shown in row 122 was not updated from the previous application; the calculation itself appears to be correct.


The equation shown on Line 122 has been updated to now show 672 m3 per year. The change is highlighted in yellow in the revised emission calculations in Appendix A.

Comment #35:

Based on comments received during the public comment period for the previous air permit, the mercury retort emission controls were modified to require two carbon beds in series rather than a single carbon bed. The new application does not state if the carbon will be one or two beds; please clarify if there will be two carbon beds. The AQD would expect to receive the same comment on this application and recommends the mercury retort be equipped with two carbon beds in series.


Aquila is not requesting a change to the current permit with respect to operation of the mercury retort and use of two carbon beds. The language in the air permit application amendment in Sections 3.3.14 and 5.1.14 should have specified a two-stage carbon bed system as part of the PW_IE\Documents\Clients\Aquila Resources\0017A021\10000 Reports\Air Permit Amendment Response\R-Air Permit Response for Additional Info March 2019.docx Foth Infrastructure & Environment, LLC 11

emission control system. In addition, the Malfunction Abatement Plan should have also specified use of a two-stage carbon adsorption system. The condition for a two-stage carbon bed system as reflected in the current permit should remain as stated.

Comment #36:

For the emergency generator engines, it appears the PM emissions for both engines has been presented as the emission rate for each engine in the criteria pollutants summary, double counting the engine emissions.


The PM emission rates in tons per year have been updated on the “Summary Criteria Pollutants” page such that emissions are not double-counted. The attached revised emission calculations in Appendix A show the changes highlighted in yellow.

Response to MDEQ Questions and Comments in Email Message of

February 22, 2019 (Drury, 2019b):

Comment #1:

Please confirm that SV-01B and SV-02C were modeled as horizontal, since that is indicated in the stack summary table.


Both SV-01B and SV-02C use source type "POINTHOR" in the AERMOD input files indicating that they were modeled as horizontal emission points, consistent with the stack summary table.

Comment #2:

Please verify the height of stack SV-05; the height in the modeling doesn’t match Table 3-4.


Stack SV-05 (lime silo) has a height of 20.7 meters in the AERMOD input files and 58 feet (20.7 meters) in Table 3-4. 58 feet (17.7 meters) is the correct value, as depicted in the updated tables and modeling files.

The correct value for the height of SV-05 is 17.7 m or 58 feet. The modeling files have been corrected.

Comment #3:

Please review the mine pit x-y dimensions, as the dimensions in the modeling (600 m x 510 m) don’t match Table 2-2 (570 m x 610 m). Is the pit area 306,000 square meters?


Mine surface area of 31.5 hectare (ha) was provided by Aquila from its pit design information. The model used 30.6ha to more closely match the shape of the mine in site drawings available when the modeling was performed. The surface area value of 31.5 ha is correct and the pit surface area has been revised in the model.


Criteria Pollutant Questions:

Comment #4:

None of the emission rates in the modeling files appear to exactly match the emission calculations, summarized in the “Air Dispersion Model Inputs” tab. These differences may be due to rounding; please confirm the correct emission rates are used in the modeling.


Much of the variation between the modeling files and the emission calculations results from differences in unit conversion. The modeling software does not always convert units consistently with the conversion calculated in spreadsheets. For example, we entered 0.007 lb/hr for PM10 from S01, which we convert to 0.000860 g/s in our spreadsheet, but the dispersion modeling software (Breeze ®) converts the value to 0.000882 g/s. We will update the emission rates entered into the model using the metric (SI) units as they are presented in our “Air Dispersion Model Inputs” tab, avoiding the discrepancy in conversion methods. As with many numerical models, some of the variation is likely due to inconsistent significant digits being used in the “inventory” value and the modeling files. Due to the limited number of significant digits available for many emission factors, the use of additional significant digits may not be appropriate in all cases.

Comment #5:

For REAG 1 to 4, HRSP, HRNWRF, HRSWRF, HRTMF, HRROM, FELROM, and HRCONC (as identified in the “Air Dispersion Model Inputs” tab), the PM10 emission rates in the modeling appear to be an order of magnitude lower than they should be. Please review the emissions rates used in the modeling for these sources to ensure the correct emission rates are modeled.

The modeling files have been corrected. The modeling inputs shown on the calculation sheets have changed slightly and are shown correctly.

Comment #6:

For OXIDESEC (as identified in the “Air Dispersion Model Inputs: tab), the PM2.5 emission rate in the modeling appears to be an order of magnitude lower than it should be. Please review the emission rate used in the modeling to ensure the correct emission rate is modeled.


This appears to be a data entry error where the g/s emission rate was entered incorrectly into the model as a lb/hr emission rate, which will be corrected in the modeling files. The modeling inputs shown on the calculation sheets are shown correctly.

TAC Modeling Questions:

Comment #7:

None of the emission rates in the modeling files appear to exactly match the emission calculations, summarized in the “TACs Dispersion” tab. These differences may be due to rounding; please confirm the correct emission rates are used in the modeling.



This comment is addressed in the Response to Comment #4 above.

Comment #8:

The West Ore Pad (WOP) cadmium emission rate in the modeling is quite different from the rate in the emission calculations, possibly due to transposition of two digits. Please investigate this to ensure the emission rate used in the modeling is correct.


It appears that two digits were transposed in the model input file, which will be corrected in the model input file.

Lead Modeling Question:

Comment #9:

It appears that the lead dispersion modeling was conducted in the same model run as the deposition modeling. Comparing the emission rates in the modeling files to the emission calculations, it appears that several volume sources that have emission estimates were not included in the dispersion and deposition modeling. Please review the modeling to ensure that all emission sources are included.


Two separate modeling input files for lead were provided to the MDEQ through our download links that were emailed to the MDEQ on November 26, 2018. We will also include two separate lead input files containing the updates referenced in this response.

The lead dispersion modeling files used for National Ambient Air Quality Standards and significant impact level evaluations include all volume sources that have lead emission values, consistent with other metal model input files. The lead deposition modeling files do not include the haul road volume sources. These sources were deemed to be insignificant due to the low metal concentration in surface soils, which is the source of haul road emissions. Additionally, this protocol is consistent with modeling performed for the PTI issued for this facility in 2015 and another recent mining air permit in Michigan developed by Foth.

Comment #10:

For the emergency generator engine TAC emission rates in the “Combustion 227(1)(a)” spreadsheet, the emission rates appear to include only a single engine. Please evaluate this and determine if the AER analysis needs to be revised to include both.


Correct, only a single emergency generator was included in the AER evaluation presented on the Combustion 227(1)(a) tab. The AER evaluation has been revised to include both generators and the outcome of the evaluation is unchanged.


References

Drury Andrew, 2019a. Aquila Resources PTI No. 205-15A Additional Information Request, email to Curt Dungey and David Anderson, February 5, 2019.

Drury Andrew, 2019b. Aquila Resources PTI No. 205-15A Additional Information Request #2, email to Curt Dungey and David Anderson, February 21, 2019.

Foth Infrastructure & Environment, LLC, 2015. Michigan Air Use Permit – Permit to Install. October 2015.

Foth Infrastructure & Environment, LLC, 2018a. Michigan Air Use Permit – Permit to Install Modification. November 2018.

Foth Infrastructure & Environment, LLC, 2018b. Mining Permit Amendment Application Back Forty Project. November 2018.


Appendix A

Air Emissions Inventory

PW_IE\Documents\Clients\Aquila Resources\0017A021\10000 Reports\Air Permit Amendment Response\R-Air Permit Response for Additional Info March 2019.docx Foth Infrastructure & Environment, LLC

TOC

Table of Contents

Sheet Page

Facility Data 1-3

Summary Criteria Pollutants 4

Summary PM and Toxic Air Contaminants 5-6

Operating Schedule 7

Summary of Composition of Materials 8

Mine Pit 9-11

Ore Storage 12-14

Haul Truck Travel 15-17

TMF-WR 18-21

Ore Handling and Processing 22-25

Reagents 26-27

Mercury Retort and Refining Furnace 28

Space Heaters 29

Emergency Generators 30

Fire Pump 31

Michigan PM and NSPS Limits Evaluation 32

Air Dispersion Model Inputs - Criteria Pollutants 33-34

Metals 227 (1)(a) 35

Combustion 227 (1)(a) 36

Air Dispersion Model Inputs - TACs 37

Air Deposition Model Inputs Data 38

Particle Size 39-42

Pit Backfill 43-47

Highlights indicate revisions March 2019 Comment Response

PW_IE\Documents\Clients\Aquila Resources\0017A021\10000 Reports\Air Permit Amendment Response\Appendix A - Air Emissions Inventory REV 03-19.xlsx i

Client: Aquila Resources, Inc. Project ID.: 17A021Project:

Prepared by: CED1 Date: 02/26/19Checked by: AKM Date: 03/19/19

Back 40 Project - Menominee County, Michigan

Facility Data

Overall Mine Production Oxide Plant Milling Production

Ore and waste rock production over life of mine -see Mine Plan 2018 Maximum Throughput in Year 4 292,000 tonne/yr 321,875 ton/year

Life of mine in years 7 years Daily Maximum Throughput 800 tonne/day 882 ton/day

average (actual) operating days 2555 days Hourly Maximum throughput 33.3 tonne/hr 37 ton/hr

Secondary breaking (5% by Rock Breaker) 1.7 tonne/hr 1.8 ton/hr

Average annual operations 365 d/y

Specific Data Description Flotation Plant Milling Production

Maximum Throughput in Year 4 1,460,000 tonne/yr 1,609,373 ton/year

Daily MaximumThroughput 4,000 tonne/day 4,409 ton/day

Waste rock Metric Units Comments English Units Hourly Maximum Throughput 167 tonne/hr 184 ton/hr

8 tonne/hr 9 ton/hr

maximum WR excavation in Year 4 13,750,000 tonne/year 15,156,763 ton/year Secondary Breaking (5% by Rock Breaker)

operating schedule 365 day/yr Crushing/Conveying operates 7 day/wk

24 hr/day 2 shifts/day

12 hr/shift

24 hr/day

90% Plant Availability

365 day/yr

Stockpile Closing Inventory - Year 4

maximum WR excavation rate Year 4 37,671 tonne/day 41,525 ton/day Stockpile 1 Flotation 2,636,000 tonnes

1569.6 tonne/hr 1,730 ton/hr Stockpile 5 Flotation 5,989,000 tonnes

Stockpile 6 Oxide 7,368,000 tonnes

emulsion factor 0.3 kg emulsion/tonne rock blast (National 0.6 lb emulsion/ton rock blast

Instrument 43-101 Technical Report)

Flotation Ore Mine Excavation

maximum flotation ore rate in year 4 1,896,000 tonne/year (Drilling, blasting, hauling) 2,089,980 ton/year Mine Plan 2018

operating schedule 365 day/yr

24 hr/day

maximum ore rate in year 4 5,195 tonne/day (Drilling, blasting, hauling) 5,726 ton/day Mine Plan 2018 Concentrate Production (Maximum year)

216.4 tonne/hr 239 ton/hr Copper Concentrate in Year 4 14,400 tonne/yr 39 tonne/day 1.6 tonne/hr

Oxide Ore Mine Excavation 15,873 ton/yr 43 ton/day 1.8 ton/hr

Lead Concentrate in Year 4 3,400 tonne/yr 9 tonne/day 0.4 tonne/hr maximum oxide ore rate in year 4 301,000 tonne/yr 331,795 ton/yr Mine Plan 2018 3,748 ton/yr 10 ton/day 0.4 ton/hr

825 tonne/day 909 ton/day Zinc Concentrate in Year 4 166,300 tonne/yr 456 tonne/day 19.0 tonne/hr 34.4 tonne/hr 37.9 ton/hr 183,314 ton/yr 502 ton/day 20.9 ton/hr

Dore (Au + Ag) 455,427 ounces Ore emulsion factor 0.30 kg emulsion/tonne rock blast 0.6 lb emulsion/ton rock blast

Equipment Specifications

Generators 2

Ore moisture content - oxide ore 5 % Lycopodium, 2015. Caterpillar CAT 3512C diesel generators (2) 1500 kW

Ore moisture content - flotation ore 5 % Lycopodium, 2015. Fire Pump 1

Waste rock moisture content 5 % Inferred from ore information Mercury Retort 1

Average wind speed: 2.7 m/s ERM, 2012 6.1 mph Refining Furnace 1

References:

Aquila Designed Pit Excavation Schedule, 2015. Mine pit road length - JOW 8/25/15 2842 m = 1.8 miles Note 3

ERM 2012. Quarterly Air Quality and Meteorological Monitoring program Data Report. Environmental Baseline Study Back Forty Joint Venture Menominee County, Michigan . 8 quarters from July 14, 2007 to July 31, 2009.

Lycopodium. Moisture content of oxide ore and sulfide ores provided in 5042 Back Forty - Water Balances for Permitting, Rev. A , June 29, 2015.

Notes:

1. Basis: experience from similar projects.

2. Storage Pile (SP) volume = 1/3*base x ht at bulk density of 1.6 tonne/m3 (PEA T 17.1, 17.2) h= 3 x Mass/(density x base area)

Mine Plan 2018

Mine Plan 2018

PW_IE\Documents\Clients\Aquila Resources\0017A021\10000 Reports\Air Permit Amendment Response\Appendix A - Air Emissions Inventory REV 03-19.xlsx 1




M - Avg tonnes base ore density

Year 4 SPs: present length - m base width - m tonne/m3 calculated height m

Type 1HG main 162000 110 145 1.6 19

Type 1LG main (assumed on West pad, assu 57000 60 100 1.6 18

Type 5 Tuff (LG) 499000 110 85 1.6 100

Type 6 HG oxide 3000 80 80 1.6 1

Type 6 LG oxide 611000 110 200 1.6 52

3. Mine pit road length calculated using CAD tools. The maximum distance of 2842 meters was estimated by tracking the centerline of the mine pit haul

road from the surface to the bottom of the pit.

Miscellaneous Notes

Online Conversion http://www.onlineconversion.com/

tonne (t)= 1000 kg

kg= 2.2 lb tonne= 1000 kg

m3= 35.315 ft3 tonne= 1.10231 ton

m3= 1.31 yd3 kg= 2.2 lb

megawatt= 3.412 mmBtu/hr m3= 35.315 ft3

kilowatt= 1.3405 hp m3= 1.31 yd3

mph= 0.44704 m/s

NOx 40 tpy

CO 100 tpy

SOx 40 tpy

PM 25 tpy

PM-10 15 tpy

VOC 40 tpy

Pb 0.6 tpy

Standard conditions: 70 deg F, 29.93 " Hg absolute

Facility Data

Production Schedule for Year 4 FS - Basecase Design

Ore Excavation units

Flotation ore

Oxide ore

Total Ore

Waste Rock Excavation

Total Expit

Milling

1896 000 tonnes

530 000 tonnes

2426 000 tonnes

13750 000 tonnes

units

Flotation ore 1460 000 tonnes

Oxide ore 290 000 tonnes

Total Ore 1750 000 tonnes

Tailings units

Flotation tails 1312 000 tonnes

Oxide tails 290 000 tonnes

Total Tailings 1602 000 tonnes

Stockpile Closing Inventory units

Stockpile 1 Flot 2636 000 tonnes Stockpile 5 flot 5989 000 tonnes

Stockpile 6 Oxide 7368 000 tonnes Total Stockpile 15993 000 tonnes

Concentrate Production Main Cu Conc 14.4 000 tonnes Total Pb Conc 3.4 000 tonnes Total Zn Conc 166.3 000 tonnes


http://www.onlineconversion.com

1

Facility Data




Reagent Usage 1

Maximum Use Actual use

Reagent Use (tonnes/yr) tonne/day tonne/hour tons/yr tonne/year tonne/hour 2

tons/yr

Xanthate (SIPX) 270 0.74 0.03 297 248 0.03 272

297 272

MIBC (frother)

594 545

540 1.48 0.06 594 495 0.06 545

Lime

hydrated lime 56,456 51,752

51,324 141 5.9 56,456 47,047 5.37 51,752

Sodium Cyanide

1,955 1,792

1,777 5 0.2 1,955 1,629 0.19 1,792

Aeroflot Promoter (AP 3418A)

587 538

534 1 0.1 587 490 0.06 538

Zinc Sulfate

1,557 1,427

1,415 4 0.2 1,557 1,297 0.15 1,427

Copper Sulfate

3,076 1,485

2,796 8 0.3 3,076 1,350 0.15 1,485

Polyacrimide

AN-926 VHM Polyacrylamide flocculant 948 869

862 2 0.1 948 790 0.09 869

Diatomaceous Earth 447 1.224 0.051 492 410 0.05 451

492

Borax 3.4 0.009 0.0004 3.7 3.1 0.0004 3.4

3.7

Lead Nitrate

73 67

Zinc Dust 266 0.7 0.03 293

293

244 0.03 268

75

Sodium Metabisulfate 3,504 9.6 0.40 3,854

3,854

3,212 0.37 3,533

3,533

silica 62 0.2 0.01 68

68

57 0.01 63

63

66 0.2 0.01 73 61 0.01 67

Miscellaneous Regents of negligible consumption,

0.36 0.13 0.04

Summary Criteria Pollutants




Estimated Actual Facility Emissions for Criteria Pollutants

Criteria Pollutant Emissions in ton/year Criteria Pollutant Emissions in ton/year

Stack Emission Source NOx SO2 CO VOC Lead PM PM10 PM2.5 NOx SO2 CO VOC Lead PM PM10 PM2.5

1Maximum Controlled Facility Emissions for Criteria Pollutants

SV-01A

SV-01B

SV-02A

SV-02B

SV-02C

SV-03

SV-04

SV-05

SV-06A

SV-06B

SV-07

SV-08

Stack Emissions

Flotation Ore Primary Crushing

Flotation Ore Mill Feed Transfer System

Oxide Ore Primary Crushing

Oxide Ore Secondary/Tertiary Crushing

Oxide Ore Mill Feed Transfer System

Mercury Retort

Refinery Furnace

Lime Silo (reagent)

Emergency Generator A

Emergency Generator B

Space Heaters LPG Boilers

Fire Pump Engine

2.13E-03 0.08 0.03 0.01

0.02 0.01 0.003

6.17E-04 0.013 0.005 0.002

0.24 0.09 0.026

0.005 0.002 0.0005

0.159 0.133 0.096

0.03 0.01 0.003

6.07 0.006 0.53 0.13 0.03 0.03 0.03

6.07 0.006 0.53 0.13 0.03 0.03 0.03

1.42 0.009 0.82 0.11 0.08 0.08 0.08

0.54 0.04 0.12 0.04 0.04 0.04 0.04

Total Stack Emissions 14.09 0.06 2.00 0.42 0.00 0.7 0.5 0.3

1.95E-03 0.07 0.03 0.01

0.02 0.01 0.00

5.66E-04 0.01 0.00 0.00

0.22 0.08 0.02

0.00 0.00 0.00

0.00 0.000 0.00 0.00 0.159 0.133 0.096

0.03 0.01 0.00

3.06 0.003 0.27 0.067 0.017 0.017 0.017

3.06 0.003 0.27 0.067 0.017 0.017 0.017

1.06 0.007 0.61 0.082 0.057 0.057 0.057

0.54

7.72

0.04

0.05

0.12

1.27

0.04

0.26 0.00

0.04

0.6

0.04

0.4

0.04

0.3

Fugitive Emissions

Mine Pit Fugitive Emissions

Drill

Blast

Material Handling

Vehicle Travel

Ore Storage Piles and Transfer

Wind Erosion - Storage Pile A

Wind Erosion - Storage Pile B Material Handling (at Store Piles & ROM)

Haul Truck & FE Loader Travel

Ore Handling and Processing

Flotation Ore Primary Crushing

Flotation Ore Mill Feed System

Mill Feed to SAG Mill

Oxide Ore Primary Crushing

Oxide Ore Secondary/Tertiary Crushing

Oxide Ore Mill Transfer System

Oxide Ore Ball Mill Transfer

Concentrate Packaging

Tailings and Waste Rock Management

Wind Erosion - TMF Material Transfer and WR Plcmnt

44.83 5.27 176.66 1.97E-02 44.88 13.93 1.32

1.38 0.70 0.21

44.83 5.27 176.66 12.81 6.66 0.38

2.97 1.40 0.21

27.73 5.16 0.52

2.87E-01 13.01 4.03 0.92

6.16 1.85 0.55

1.50 0.45 0.14

2.26 1.07 0.16

3.09 0.66 0.07

9.50E-03 0.36 0.13 0.04

0.15 0.06 0.02

0.05 0.02 0.01

0.00 0.00 0.00

0.03 0.01 0.00

0.05 0.02 0.01

0.01 0.00 0.00

0.05 0.02 0.01

0.018 0.007 0.002

6.42E-03 22.4 6.7 1.2

5.64 1.69 0.51

16.72 4.96 0.65

3On-Site Truck Travel 1.63E-04 44.94 9.61 0.96

Reagent - Material Handling 0.015 0.016 0.008 0.003

Total Fugitive Emissions 44.83 5.27 176.66 0.02 0.32 125.58 34.37 4.40

44.83 5.27 176.66 1.81E-02 42.33

1.38

13.38

0.70

1.26

0.21

44.83 5.27 176.66 12.81 6.66 0.38

2.72 1.29 0.20

25.42 4.73 0.47

2.63E-01 11.93

6.16

3.69

1.85

0.84

0.55

1.50 0.45 0.14

2.07 0.98 0.15

2.83 0.61 0.06

8.71E-03 0.33

0.14

0.12

0.05

0.04

0.02

0.05 0.02 0.01

0.00 0.00 0.00

0.03 0.01 0.00

0.04 0.02 0.00

0.01 0.00 0.00

0.05 0.02 0.00

0.02 0.01 0.00

5.89E-03 21.0

5.64

6.2

1.69

1.1

0.51

15.32 4.55 0.60

1.49E-04 37.76 8.08 0.81

44.83 5.27 176.66 0.00 0.30

0.014

113.33

0.007

31.53

0.002

4.05

Maximum Controlled Facility Emissions 1

58.92 5.33 178.66 0.43 0.33 126.30 34.83 4.72

Potential to Emit 2

14.09 0.06 2.00 0.42 0.003 0.73 0.46 0.32

Notes:

1. Maximum controlled facility emissions are all site emissions (including fugitive emissions) after applying collection and control efficiencies based on maximum operating schedule. Normal/actual emissions are based on the normal/actual operating schedule.

2. Potential to Emit (PTE) for this facility is the stack emissions with no fugitives. 40 CFR 60 Subpart LL (NSPS) for metallic minerals processing is applicable to this facility.

This NSPS (metallic mining) was developed after 1980 and since this facility is not subject to federal Maximum Achievable Control Technology (MACT) standards, fugitive dust is not part of PTE.

PTE is based on controlled emissions since operation of emission control equipment will be a legally enforceable requirement of the operation. PTE for hazardous air pollutants (HAPs)

is based on both stack and fugitive emissions per R 336.1116 (m).

3. On-Site Road emissions include fugitive emissions from surface roadway travel, no tailpipe emissions. It includes:

- Ore Trucks Unpaved Road to Storage Piles

- Waste Rock Truck transporting waste rock to North Waste Rock Facility

- Waste Rock Truck transporting waste rock to South Waste Rock Facility

- Waste Rock Truck transporting waste rock to Tailings Management Facility (for berm construction)

- Concentrate Truck transporting combined Concentrates on Unpaved Road from Concentrate Handling Facility to East Mine Entrance Gate


Summary PM and Toxic Air Contaminants



Back 40 Project - Menominee County, Michiganore

waste rock

tails

copper concentrate

zinc concentrate

lead concentrate

soil

Maximum Controlled Facility Emissions for PM and Toxic Air Contaminants (lb/hr)

Actual Emissions (lb/year & ton/year) Manganese 7

Aluminum Antimony Arsenic Barium Beryllium Cadmium Calcium Cerium Chromium Cobalt Copper Iron Lead Lithium Magnesium Mercury Molybdenum Nickel Phosphorus Selenium Silver Strontium Sulfur Thallium Tin Yttrium Zinc

Be Cd Ca Ce Cr Co Cu Fe Pb Li Mg Mn Hg Mo Ni P Se Ag Sr S Tl Sn Y Zn

7.66 0.0183 0.297 0.048 0.001 0.064 1.594 0 0.064 0.002 0.664 18.79 2.9 0.003 1.2 0.1 0.0153 0.012 0.003 3.81E-02 0.001 0.031 0.016 28.8 0.002 0.004 0.001 17.9

0 0.00067 0.02213 0.07315 0.00000 0.00033 0 0.006 0.002 0.0005 0.008 0 0.02 0.00 0.00 0.00 0.0001 0.0002 0.0004 0.00E+00 0.0001 0.0002 0.009 2.32 0.0003 0.0005 0.0022 0.13

0 0.0004 0.1470 0.0110 0.0000 0.0019 0 0.002 0.001 0.0003 0.785 0 0.06 0.00 0.00 0.00 0.000 0.003 0.003 0.00E+00 0.000 0.002 0.004 39.10 0.0002 0.0005 0.001 0.34

0.03 0.0752 0.0266 0.005 0.00005 0.0153 0.1 0.0005 0.0150 0.0003 30.2000 30 3.35 0.00 0.03 0.01 0.01 0.00 0.01 0.01 0.00 0.04 0.00 29.90 0.00 0.05 0.00 2.53

0.040 0.00259 0.02100 0.00500 0.00005 0.32800 0.190 0.0002 0.0050 0.0001 0.6170 10.8 0.27 0.0002 0.02 0.14 0.04 0.002 0.003 0.01 0.004 0.01 0.0003 24.60 0.0002 0.0019 0.0001 56.10

0.040 0.24000 0.08000 0.00500 0.00005 0.32800 0.190 0.0005 0.0150 0.0003 10.0000 30.0 38.70 0.0002 0.03 0.14 0.04 0.003 0.010 0.01 0.004 0.08 0.0003 29.90 0.0010 0.0535 0.0002 4.86

PM PM10 PM2.5 soil 0.573 0 0.00019 0.00331 0 0 0 0 0.00112 0.00029 0.00045 1.18 0.0004 0.0000 0.1030 0.0228 8.90E-07 0.0000 0.0008 0.0340 0.0000 0.0000 0.0000 0.0045 0.0000 0.0000 0.0000 0.0018

Mine Pit Fugitive Emissions (EUFUGITIVE)

(Maximum 1-hr)11

1 Drilling - ore (fugitive) 0.087 0.044 0.013 lb/hr ore 6.64E-03 1.59E-05 2.58E-04 4.14E-05 9.85E-07 5.54E-05 1.38E-03 0.00E+00 5.54E-05 1.75E-06 5.76E-04 1.63E-02 2.56E-03 2.63E-06 1.08E-03 3.70E-05 1.33E-05 1.06E-05 3.03E-06 3.30E-05 6.59E-07 2.69E-05 1.41E-05 2.49E-02 2.10E-06 3.63E-06 1.20E-06 1.56E-02

1 Drilling - waste rock (fugitive) 0.543 0.277 0.081 lb/hr wr 0.00E+00 3.65E-06 1.20E-04 3.97E-04 0.00E+00 1.81E-06 0.00E+00 3.35E-05 1.04E-05 2.71E-06 4.31E-05 0.00E+00 1.07E-04 0.00E+00 0.00E+00 0.00E+00 5.79E-07 9.04E-07 2.31E-06 0.00E+00 3.59E-07 9.23E-07 4.73E-05 1.26E-02 1.78E-06 2.69E-06 1.21E-05 6.87E-04

hr/yr 4380

(Average 1-hr) 1 Drilling - ore (fugitive) 0.043 0.022 0.007 lb/hr ore 3.32E-03 7.96E-06 1.29E-04 2.07E-05 4.93E-07 2.77E-05 6.91E-04 0.00E+00 2.77E-05 8.76E-07 2.88E-04 8.15E-03 1.28E-03 1.32E-06 5.41E-04 3.63E-05 6.64E-06 5.28E-06 1.51E-06 1.65E-05 3.29E-07 1.34E-05 7.04E-06 1.25E-02 1.05E-06 1.82E-06 5.98E-07 7.78E-03

1 Drilling - waste rock (fugitive) 0.271 0.138 0.041 lb/hr wr 0.00E+00 1.82E-06 6.01E-05 1.99E-04 0.00E+00 9.05E-07 0.00E+00 1.67E-05 5.18E-06 1.36E-06 2.15E-05 0.00E+00 5.34E-05 0.00E+00 0.00E+00 0.00E+00 2.89E-07 4.52E-07 1.16E-06 0.00E+00 1.79E-07 4.61E-07 2.37E-05 6.31E-03 8.88E-07 1.35E-06 6.07E-06 3.43E-04

(Average 1-hr) 2 Blasting - ore (fugitive) 0.4 0.2 0.012 lb/hr ore 3.09E-02 7.39E-05 1.20E-03 1.92E-04 4.58E-06 2.57E-04 6.42E-03 0.00E+00 2.57E-04 8.14E-06 2.68E-03 7.57E-02 1.19E-02 1.22E-05 5.03E-03 1.75E-04 6.17E-05 4.90E-05 1.41E-05 1.53E-04 3.06E-06 1.25E-04 6.54E-05 1.16E-01 9.77E-06 1.69E-05 5.56E-06 7.23E-02

2 Blasting waste rock (fugitive) 2.5 1.3 0.076 lb/hr wr 0.00E+00 1.69E-05 5.58E-04 1.84E-03 0.00E+00 8.41E-06 0.00E+00 1.56E-04 4.81E-05 1.26E-05 2.00E-04 0.00E+00 4.96E-04 0.00E+00 0.00E+00 0.00E+00 2.69E-06 4.20E-06 1.07E-05 0.00E+00 1.67E-06 4.29E-06 2.20E-04 5.86E-02 8.25E-06 1.25E-05 5.64E-05 3.19E-03

hr/yr 365 (1 r) g

(fugitive) 0.97 0.50 0.03 lb/hr ore 7.41E-02 1.77E-04 2.88E-03 4.61E-04 1.10E-05 6.18E-04 1.54E-02 0.00E+00 6.18E-04 1.95E-05 6.42E-03 1.82E-01 2.85E-02 2.93E-05 1.21E-02 8.09E-04 1.48E-04 1.18E-04 3.38E-05 3.68E-04 7.35E-06 3.00E-04 1.57E-04 2.78E-01 2.35E-05 4.05E-05 1.33E-05 1.73E-01

2 Blasting waste rock (fugitive) 6.05 3.15 0.18 lb/hr wr 0.00E+00 4.07E-05 1.34E-03 4.43E-03 0.00E+00 2.02E-05 0.00E+00 3.73E-04 1.15E-04 3.02E-05 4.80E-04 0.00E+00 1.19E-03 0.00E+00 0.00E+00 0.00E+00 6.45E-06 1.01E-05 2.58E-05 0.00E+00 4.00E-06 1.03E-05 5.28E-04 1.41E-01 1.98E-05 3.00E-05 1.35E-04 7.66E-03

(Maximum 1-hr)11

2 Blasting - ore (fugitive) 9.7 5.0 lb/hr ore 7.41E-01 1.77E-03 2.88E-02 4.61E-03 1.10E-04 6.18E-03 1.54E-01 0.00E+00 6.18E-03 1.95E-04 6.42E-02 1.82E+00 2.85E-01 2.93E-04 1.21E-01 8.09E-03 1.48E-03 1.18E-03 3.38E-04 3.68E-03 7.35E-05 3.00E-03 1.57E-03 2.78E+00 2.35E-04 4.05E-04 1.33E-04 1.73E+00

2 Blasting waste rock (fugitive) 60.5 31.5 lb/hr wr 0.00E+00 4.07E-04 1.34E-02 4.43E-02 0.00E+00 2.02E-04 0.00E+00 3.73E-03 1.15E-03 3.02E-04 4.80E-03 0.00E+00 1.19E-02 0.00E+00 0.00E+00 0.00E+00 6.45E-05 1.01E-04 2.58E-04 0.00E+00 4.00E-05 1.03E-04 5.28E-03 1.41E+00 1.98E-04 3.00E-04 1.35E-03 7.66E-02

3 Material Handling - ore (fugitive) 0.093 0.044 0.007 lb/hr ore 7.16E-03 1.71E-05 2.78E-04 4.46E-05 1.06E-06 5.97E-05 1.49E-03 0.00E+00 5.97E-05 1.89E-06 6.20E-04 1.76E-02 2.75E-03 2.83E-06 1.17E-03 3.70E-05 1.43E-05 1.14E-05 3.26E-06 3.56E-05 7.10E-07 2.89E-05 1.52E-05 2.69E-02 2.27E-06 3.91E-06 1.29E-06 1.68E-02

3 Mat'l Handling - waste rock (fugitive) 0.585 0.277 0.042 lb/hr wr 0.00E+00 3.93E-06 1.29E-04 4.28E-04 0.00E+00 1.95E-06 0.00E+00 3.61E-05 1.12E-05 2.92E-06 4.64E-05 0.00E+00 1.15E-04 0.00E+00 0.00E+00 0.00E+00 6.24E-07 9.74E-07 2.49E-06 0.00E+00 3.87E-07 9.94E-07 5.10E-05 1.36E-02 1.91E-06 2.90E-06 1.31E-05 7.40E-04

hr/yr 8030

4 Vehicle Travel - ore (fugitive) 0.9 0.2 0.02 lb/hr soil 5.00E-03 0.00E+00 1.66E-06 2.89E-05 0.00E+00 0.00E+00 0.00E+00 0.00E+00 9.77E-06 2.53E-06 3.92E-06 1.03E-02 3.23E-06 0.00E+00 8.98E-04 3.70E-05 7.76E-09 0.00E+00 6.63E-06 2.97E-04 0.00E+00 2.01E-08 0.00E+00 3.88E-05 0.00E+00 0.00E+00 0.00E+00 1.60E-05

4 Vehicle Travel - waste rock (fugitive) 5.5 1.0 0.1 lb/hr soil 3.13E-02 0.00E+00 1.04E-05 1.81E-04 0.00E+00 0.00E+00 0.00E+00 0.00E+00 6.11E-05 1.58E-05 2.46E-05 6.44E-02 2.02E-05 0.00E+00 5.62E-03 2.32E-04 4.86E-08 0.00E+00 4.15E-05 1.86E-03 0.00E+00 1.26E-07 0.00E+00 2.43E-04 0.00E+00 0.00E+00 0.00E+00 9.99E-05

hr/yr 8030

Total Mine Pit Emissions (fugitive) (include Average 1-hr drilling emissions and 10% of Max 1-hr

blasting) 14.3 5.3 0.42 lb/hr 1.21E-01 2.49E-04 4.82E-03 5.79E-03 1.25E-05 7.28E-04 1.76E-02 4.26E-04 9.08E-04 7.52E-05 7.91E-03 2.82E-01 3.39E-02 3.35E-05 2.03E-02 1.15E-03 1.76E-04 1.46E-04 1.16E-04 2.57E-03 1.30E-05 3.54E-04 7.81E-04 4.78E-01 4.94E-05 8.05E-05 1.70E-04 2.07E-01

(include Average 1-hr blasting and drilling emissions) 10.9 3.5 0.40 lb/hr 7.76E-02 1.22E-04 2.36E-03 2.94E-03 6.13E-06 3.56E-04 8.60E-03 2.08E-04 4.80E-04 4.61E-05 3.88E-03 1.76E-01 1.66E-02 1.64E-05 1.33E-02 5.17E-04 8.63E-05 7.13E-05 8.13E-05 2.36E-03 6.33E-06 1.73E-04 3.82E-04 2.34E-01 2.41E-05 3.93E-05 8.29E-05 1.01E-01

(include Average 1-hr blasting and drilling emissions) 30.05 7.0 0.89 1.95E-01 1.44E-04 2.83E-03 4.07E-03 7.26E-06 4.21E-04 1.02E-02 2.47E-04 7.69E-04 1.07E-04 4.67E-03 4.20E-01 1.97E-02 1.94E-05 3.41E-02 1.34E-03 1.02E-04 8.43E-05 2.32E-04 8.88E-03 7.49E-06 2.05E-04 4.52E-04 2.78E-01 2.86E-05 4.66E-05 9.81E-05 1.20E-01

lb per year toxics - actual 3.89E+02 0.3 5.7 8.1 0.0 0.8 20.4 0.5 1.5 0.2 9.3 839.8 39.4 0.0 68.3 2.7 0.2 0.2 0.5 17.8 0.0 0.4 0.9 555.4 0.1 0.1 0.2 240.1

Ore Storage Piles and Transfer (EUFUGITIVE)

1 wind erosion east ore storage pad 1.41 0.42 0.13 lb/hr ore 1.08E-01 2.58E-04 4.18E-03 6.71E-04 1.60E-05 8.98E-04 2.24E-02 0.00E+00 8.99E-04 2.84E-05 9.34E-03 2.64E-01 4.15E-02 4.27E-05 1.76E-02 3.53E-04 2.15E-04 1.71E-04 4.91E-05 5.36E-04 1.07E-05 4.36E-04 2.28E-04 4.05E-01 3.41E-05 5.89E-05 1.94E-05 2.52E-01

hr/yr 8760

1 wind erosion west ore storage pad 0.34 0.10 0.03 lb/hr ore 2.62E-02 6.28E-05 1.02E-03 1.63E-04 3.89E-06 2.19E-04 5.46E-03 0.00E+00 2.19E-04 6.92E-06 2.27E-03 6.44E-02 1.01E-02 1.04E-05 4.27E-03 8.60E-05 5.25E-05 4.17E-05 1.20E-05 1.30E-04 2.60E-06 1.06E-04 5.56E-05 9.85E-02 8.31E-06 1.43E-05 4.72E-06 6.14E-02

hr/yr 8760

2 material handling at east & west storage pads 0.33 0.16 0.024 lb/hr ore 2.52E-02 6.03E-05 9.78E-04 1.57E-04 3.74E-06 2.10E-04 5.24E-03 0.00E+00 2.10E-04 6.64E-06 2.18E-03 6.18E-02 9.69E-03 9.97E-06 4.10E-03 1.30E-04 5.04E-05 4.00E-05 1.15E-05 1.25E-04 2.50E-06 1.02E-04 5.34E-05 9.46E-02 7.98E-06 1.38E-05 4.54E-06 5.90E-02

hr/yr 8030

3 material handling at ROM 0.19 0.09 0.01 lb/hr ore 1.44E-02 3.44E-05 5.58E-04 8.94E-05 2.13E-06 1.20E-04 2.99E-03 0.00E+00 1.20E-04 3.79E-06 1.24E-03 3.52E-02 5.52E-03 5.69E-06 2.34E-03 7.42E-05 2.87E-05 2.28E-05 6.54E-06 7.14E-05 1.42E-06 5.81E-05 3.04E-05 5.39E-02 4.55E-06 7.85E-06 2.59E-06 3.36E-02

hr/yr 8030

Al Sb As Ba

ore

waste rock (wr)

tails

Cu conc.

Zn conc.

Pb conc.

4. Haul Truck & FE loader at Store Pads & ROM These two vehicle traffic emissions are inclued in Haul Truck Travel calcs below (rows 105, 107)

Total Ore Pile Emissions (fugitive) 2.27 0.77 0.19 lb/hr 1.73E-01 4.16E-04 6.74E-03 1.08E-03 2.57E-05 1.45E-03 3.61E-02 0.00E+00 1.45E-03 4.57E-05 1.50E-02 4.26E-01 6.68E-02 6.87E-05 2.83E-02 6.43E-04 3.47E-04 2.76E-04 7.91E-05 8.63E-04 1.72E-05 7.02E-04 3.68E-04 6.52E-01 5.50E-05 9.49E-05 3.13E-05 4.06E-01

9.73 3.28 0.84 ton/yr - actual 7.45E-01 1.79E-03 2.90E-02 4.64E-03 1.11E-04 6.22E-03 1.55E-01 0.00E+00 6.22E-03 1.97E-04 6.46E-02 1.83E+00 2.87E-01 2.95E-04 1.21E-01 2.74E-03 1.49E-03 1.18E-03 3.40E-04 3.71E-03 7.40E-05 3.02E-03 1.58E-03 2.80E+00 2.36E-04 4.08E-04 1.34E-04 1.75E+00

lb per year toxics - actual 1.49E+03 3.6 57.9 9.3 0.22 12.4 310.2 0.0 12.4 0.4 129.3 3657.9 573.7 0.6 243.0 5.5 3.0 2.4 0.7 7.4 0.1 6.0 3.2 5599.6 0.5 0.8 0.3 3491.5

Ore Handling and Processing

1 Flotation Ore Primary Crushing (SV-01A) 0.018 0.01 0.002 lb/hr ore 1.38E-03 3.30E-06 5.35E-05 8.58E-06 2.04E-07 1.15E-05 2.87E-04 0.00E+00 1.15E-05 3.63E-07 1.19E-04 3.38E-03 5.30E-04 5.46E-07 2.24E-04 5.72E-06 2.75E-06 2.19E-06 6.28E-07 6.85E-06 1.37E-07 5.57E-06 2.92E-06 5.17E-03 4.36E-07 7.53E-07 2.48E-07 3.23E-03

hr/yr 8030

01B) 0.005 0.002 0.0006 lb/hr ore 3.99E-04 9.57E-07 1.55E-05 2.49E-06 5.93E-08 3.33E-06 8.31E-05 0.00E+00 3.33E-06 1.05E-07 3.46E-05 9.80E-04 1.54E-04 1.58E-07 6.51E-05 1.60E-06 7.99E-07 6.34E-07 1.82E-07 1.99E-06 3.96E-08 1.62E-06 8.46E-07 1.50E-03 1.27E-07 2.18E-07 7.20E-08 9.35E-04

hr/yr 8030

3 Oxide Ore Primary Crushing (SV-02A) 0.003 0.001 0.0004 lb/hr ore 2.35E-04 5.64E-07 9.14E-06 1.47E-06 3.49E-08 1.96E-06 4.90E-05 0.00E+00 1.96E-06 6.21E-08 2.04E-05 5.78E-04 9.06E-05 9.33E-08 3.84E-05 9.84E-07 4.71E-07 3.74E-07 1.07E-07 1.17E-06 2.34E-08 9.52E-07 4.99E-07 8.84E-04 7.46E-08 1.29E-07 4.24E-08 5.51E-04

8030

4 Oxide Ore Secondary/Tertiary Crushing (SV-02B) 0.054 0.020 0.006 lb/hr ore 4.16E-03 9.95E-06 1.61E-04 2.59E-05 6.16E-07 3.47E-05 8.65E-04 0.00E+00 3.47E-05 1.10E-06 3.60E-04 1.02E-02 1.60E-03 1.65E-06 6.77E-04 1.67E-05 8.31E-06 6.60E-06 1.89E-06 2.07E-05 4.12E-07 1.68E-05 8.81E-06 1.56E-02 1.32E-06 2.27E-06 7.48E-07 9.73E-03

8030

5 Oxide Ore Mill Feed Transfer System (SV-02C) 0.001 0.0004 0.0001 lb/hr ore 8.08E-05 1.93E-07 3.14E-06 5.03E-07 1.20E-08 6.74E-07 1.68E-05 0.00E+00 6.74E-07 2.13E-08 7.00E-06 1.98E-04 3.11E-05 3.20E-08 1.32E-05 3.24E-07 1.62E-07 1.28E-07 3.68E-08 4.01E-07 8.01E-09 3.27E-07 1.71E-07 3.03E-04 2.56E-08 4.42E-08 1.45E-08 1.89E-04

8030

6 Crushing fugitive emission totals (fugitive) 0.0782 0.0291 0.0087 lb/hr ore 5.99E-03 1.43E-05 2.33E-04 3.73E-05 8.88E-07 4.99E-05 1.25E-03 0.00E+00 4.99E-05 1.58E-06 5.19E-04 1.47E-02 2.30E-03 2.37E-06 9.76E-04 2.43E-05 1.20E-05 9.51E-06 2.73E-06 2.98E-05 5.94E-07 2.42E-05 1.27E-05 2.25E-02 1.90E-06 3.27E-06 1.08E-06 1.40E-02

EUCPFUGITUVE hr/yr 8030

7 Flotation Plant Copper Concentrate Packaging

Operations (fugitive) 0.000 0.0001 0.0000 lb/hr Cu conc. 9.78E-08 2.45E-07 8.68E-08 1.63E-08 1.63E-10 4.99E-08 3.26E-07 1.66E-09 4.89E-08 9.78E-10 9.85E-05 9.78E-05 1.09E-05 6.52E-10 9.78E-08 8.37E-09 1.73E-08 9.98E-09 3.29E-08 3.26E-08 6.52E-09 1.16E-07 9.78E-10 9.75E-05 3.13E-09 1.74E-07 6.52E-10 8.25E-06

EUCONCPACKAGING hr/yr 8030

7 Flotation Plant Zn Concentrate Packaging

Operations (fugitive) 0.004 0.001 0.0004 lb/hr Zn conc. 1.51E-06 9.76E-08 7.91E-07 1.88E-07 1.88E-09 1.24E-05 7.16E-06 6.03E-09 1.88E-07 3.77E-09 2.32E-05 4.07E-04 1.02E-05 7.53E-09 7.53E-07 1.86E-06 1.39E-06 6.97E-08 1.28E-07 3.77E-07 1.51E-07 2.01E-07 1.13E-08 9.27E-04 9.04E-09 7.16E-08 3.77E-09 2.11E-03


7 Flotation Plant Pb Concentrate Packaging

Operations (fugitive) 0.0001 0.0000 0.0000 lb/hr Pb conc. 4.24E-08 2.54E-07 8.47E-08 5.29E-09 5.29E-11 3.47E-07 2.01E-07 5.40E-10 1.59E-08 3.18E-10 1.06E-05 3.18E-05 4.10E-05 2.12E-10 3.18E-08 5.24E-08 3.92E-08 3.24E-09 1.07E-08 1.06E-08 4.24E-09 8.31E-08 3.18E-10 3.17E-05 1.02E-09 5.67E-08 2.12E-10 5.15E-06


Total stack emissions associated 0.08 0.03 0.009 lb/hr 6.25E-03 1.50E-05 2.43E-04 3.89E-05 9.27E-07 5.21E-05 1.30E-03 0.00E+00 5.21E-05 1.65E-06 5.42E-04 1.53E-02 2.40E-03 2.48E-06 1.02E-03 2.54E-05 1.25E-05 9.92E-06 2.85E-06 3.11E-05 6.20E-07 2.53E-05 1.32E-05 2.35E-02 1.98E-06 3.42E-06 1.13E-06 1.46E-02

with Ore Handling and Processing 0.3 0.1 0.0 ton/yr - actual 2.51E-02 6.01E-05 9.74E-04 1.56E-04 3.72E-06 2.09E-04 5.22E-03 0.00E+00 2.09E-04 6.61E-06 2.18E-03 6.15E-02 9.65E-03 9.94E-06 4.09E-03 1.02E-04 5.02E-05 3.98E-05 1.14E-05 1.25E-04 2.49E-06 1.01E-04 5.32E-05 9.42E-02 7.95E-06 1.37E-05 4.52E-06 5.87E-02

Total fugitive emissions associated 0.08 0.03 0.01 lb/hr 5.99E-03 1.49E-05 2.33E-04 3.75E-05 8.90E-07 6.27E-05 1.25E-03 8.23E-09 5.02E-05 1.58E-06 6.51E-04 1.52E-02 2.37E-03 2.38E-06 9.76E-04 2.62E-05 1.34E-05 9.59E-06 2.90E-06 3.02E-05 7.55E-07 2.46E-05 1.27E-05 2.35E-02 1.91E-06 3.58E-06 1.08E-06 1.61E-02

with Ore Handling and Processing 0.3 0.1 0.0 ton/yr - actual 2.40E-02 6.00E-05 9.37E-04 1.51E-04 3.57E-06 2.52E-04 5.03E-03 3.30E-08 2.02E-04 6.36E-06 2.62E-03 6.11E-02 9.50E-03 9.56E-06 3.92E-03 1.05E-04 5.39E-05 3.85E-05 1.16E-05 1.21E-04 3.03E-06 9.88E-05 5.10E-05 9.45E-02 7.67E-06 1.44E-05 4.35E-06 6.48E-02

lb per year toxics - actual 4.91E-02 1.20E-04 1.91E-03 3.07E-04 7.30E-06 4.61E-04 1.03E-02 3.30E-08 4.11E-04 1.30E-05 4.79E-03 1.23E-01 1.92E-02 1.95E-05 8.01E-03 2.07E-04 1.04E-04 7.84E-05 2.31E-05 2.46E-04 5.52E-06 2.00E-04 1.04E-04 1.89E-01 1.56E-05 2.81E-05 8.87E-06 1.24E-01

Tailings and Waste Rock Management (EUTMFWR)

1 Wind Erosion TMF (fugitive) 1.29 0.39 0.12 lb/hr tails 0.00E+00 5.12E-06 1.89E-03 1.41E-04 0.00E+00 2.41E-05 0.00E+00 1.96E-05 1.29E-05 3.22E-06 1.01E-02 0.00E+00 7.78E-04 0.00E+00 0.00E+00 0.00E+00 1.49E-06 4.12E-05 3.22E-05 0.00E+00 1.29E-06 3.02E-05 4.96E-05 5.04E-01 3.09E-06 6.44E-06 8.89E-06 4.34E-03

hr/yr 8760

5.64 1.69 0.51 ton/yr - actual 0.00E+00 2.24E-05 8.30E-03 6.18E-04 0.00E+00 1.06E-04 0.00E+00 8.58E-05 5.64E-05 1.41E-05 4.43E-02 0.00E+00 3.41E-03 0.00E+00 0.00E+00 0.00E+00 6.52E-06 1.81E-04 1.41E-04 0.00E+00 5.64E-06 1.32E-04 2.17E-04 2.21E+00 1.35E-05 2.82E-05 3.89E-05 1.90E-02

lb per year toxics - actual 0.00E+00 4.48E-02 1.66E+01 1.24E+00 0.00E+00 2.11E-01 0.00E+00 1.72E-01 1.13E-01 2.82E-02 8.86E+01 0.00E+00 6.82E+00 0.00E+00 0.00E+00 0.00E+00 1.30E-02 3.61E-01 2.82E-01 0.00E+00 1.13E-02 2.64E-01 4.35E-01 4.41E+03 2.71E-02 5.64E-02 7.79E-02 3.80E+01

2 Material Transfer and Placement of Waste Rock 1.16 0.55 0.08 lb/hr wr 0.00E+00 7.77E-06 2.56E-04 8.46E-04 0.00E+00 3.86E-06 0.00E+00 7.14E-05 2.21E-05 5.78E-06 9.17E-05 0.00E+00 2.27E-04 0.00E+00 0.00E+00 0.00E+00 1.23E-06 1.93E-06 4.92E-06 0.00E+00 7.65E-07 1.97E-06 1.01E-04 2.69E-02 3.78E-06 5.73E-06 2.58E-05 1.46E-03

(fugitive) hr/yr 8030

3 Vehicle Travel on Waste Rock (fugitive) 1.84 0.34 0.03 lb/hr wr 0.00E+00 1.24E-05 4.08E-04 1.35E-03 0.00E+00 6.15E-06 0.00E+00 1.14E-04 3.52E-05 9.22E-06 1.46E-04 0.00E+00 3.63E-04 0.00E+00 0.00E+00 0.00E+00 1.97E-06 3.07E-06 7.85E-06 0.00E+00 1.22E-06 3.14E-06 1.61E-04 4.29E-02 6.03E-06 9.14E-06 4.12E-05 2.33E-03

hr/yr 8030

4. TMF Waste Rock Placement & Travel 0.82 0.24 0.03 lb/hr wr 0.00E+00 5.48E-06 1.81E-04 5.97E-04 0.00E+00 2.72E-06 0.00E+00 5.03E-05 1.56E-05 4.08E-06 6.47E-05 0.00E+00 1.61E-04 0.00E+00 0.00E+00 0.00E+00 8.70E-07 1.36E-06 3.47E-06 0.00E+00 5.40E-07 1.39E-06 7.11E-05 1.90E-02 2.67E-06 4.04E-06 1.82E-05 1.03E-03


Total Waste Rock Placement & Travel Emissions

(2-4) (fugitive) 3.8 1.1 0.1 lb/hr 0.00E+00 2.56E-05 8.44E-04 2.79E-03 0.00E+00 1.27E-05 0.00E+00 2.36E-04 7.28E-05 1.91E-05 3.03E-04 0.00E+00 7.51E-04 0.00E+00 0.00E+00 0.00E+00 4.07E-06 6.36E-06 1.63E-05 0.00E+00 2.52E-06 6.49E-06 3.33E-04 8.87E-02 1.25E-05 1.89E-05 8.53E-05 4.83E-03

15.3 4.5 0.6 ton/yr - actual 0.00E+00 1.03E-04 3.39E-03 1.12E-02 0.00E+00 5.11E-05 0.00E+00 9.46E-04 2.92E-04 7.66E-05 1.22E-03 0.00E+00 3.01E-03 0.00E+00 0.00E+00 0.00E+00 1.63E-05 2.55E-05 6.52E-05 0.00E+00 1.01E-05 2.61E-05 1.34E-03 3.56E-01 5.01E-05 7.60E-05 3.43E-04 1.94E-02

lb per year toxics - actual 0.00E+00 2.06E-01 6.78E+00 2.24E+01 0.00E+00 1.02E-01 0.00E+00 1.89E+00 5.85E-01 1.53E-01 2.43E+00 0.00E+00 6.03E+00 0.00E+00 0.00E+00 0.00E+00 3.27E-02 5.11E-02 1.30E-01 0.00E+00 2.03E-02 5.21E-02 2.67E+00 7.12E+02 1.00E-01 1.52E-01 6.85E-01 3.88E+01


Summary PM and Toxic Air Contaminants



Back 40 Project - Menominee County, Michiganore

waste rock

tails

copper concentrate

zinc concentrate

lead concentrate

soil

Maximum Controlled Facility Emissions for PM and Toxic Air Contaminants (lb/hr)

Aluminum Antimony Arsenic Barium Beryllium Cadmium Calcium Cerium Chromium Cobalt Copper Iron Lead Lithium Magnesium 7

Manganese Mercury Molybdenum Nickel Phosphorus Selenium Silver Strontium Sulfur Thallium Tin Yttrium Zinc

Al Sb As Ba Be Cd Ca Ce Cr Co Cu Fe Pb Li Mg Mn Hg Mo Ni P Se Ag Sr S Tl Sn Y Zn

Actual Emissions (lb/year & ton/year)

Haul Truck Travel (EUHAULROADS)

1 Haul Trucks (ore) to Storage Piles (fugitive) 1.37 0.29 0.029 lb/hr soil 7.84E-03 0.00E+00 2.60E-06 4.53E-05 0.00E+00 0.00E+00 0.00E+00 0.00E+00 1.53E-05 3.97E-06 6.15E-06 1.61E-02 5.06E-06 0.00E+00 1.41E-03 6.67E-05 1.22E-08 0.00E+00 1.04E-05 4.65E-04 0.00E+00 3.15E-08 0.00E+00 6.09E-05 0.00E+00 0.00E+00 0.00E+00 2.50E-05

hr/yr 8030

2 Haul Trucks (waste rock) to NWRF (fugitive) 6.11 1.31 0.13 lb/hr soil 3.50E-02 0.00E+00 1.16E-05 2.02E-04 0.00E+00 0.00E+00 0.00E+00 0.00E+00 6.84E-05 1.77E-05 2.75E-05 7.20E-02 2.26E-05 0.00E+00 6.29E-03 2.98E-04 5.43E-08 0.00E+00 4.64E-05 2.08E-03 0.00E+00 1.40E-07 0.00E+00 2.72E-04 0.00E+00 0.00E+00 0.00E+00 1.12E-04

hr/yr 8030

3 Haul Trucks (waste rock) to SWRF 1.19 0.26 0.03 lb/hr soil 6.84E-03 0.00E+00 2.27E-06 3.95E-05 0.00E+00 0.00E+00 0.00E+00 0.00E+00 1.34E-05 3.46E-06 5.37E-06 1.41E-02 4.42E-06 0.00E+00 1.23E-03 5.82E-05 1.06E-08 0.00E+00 9.07E-06 4.06E-04 0.00E+00 2.74E-08 0.00E+00 5.31E-05 0.00E+00 0.00E+00 0.00E+00 2.18E-05


4 Haul Trucks (wr) to TMF 1.42 0.30 0.03 lb/hr soil 8.16E-03 0.00E+00 2.71E-06 4.72E-05 0.00E+00 0.00E+00 0.00E+00 0.00E+00 1.60E-05 4.13E-06 6.41E-06 1.68E-02 5.27E-06 0.00E+00 1.47E-03 6.95E-05 1.27E-08 0.00E+00 1.08E-05 4.84E-04 0.00E+00 3.28E-08 0.00E+00 6.34E-05 0.00E+00 0.00E+00 0.00E+00 2.61E-05

(fugitive) 8030

5 Conc't Trucks Mill to Main Gate 0.17 0.04 0.004 lb/hr soil 9.77E-04 0.00E+00 3.24E-07 5.64E-06 0.00E+00 0.00E+00 0.00E+00 0.00E+00 1.91E-06 4.94E-07 7.67E-07 2.01E-03 6.31E-07 0.00E+00 1.76E-04 8.32E-06 1.52E-09 0.00E+00 1.30E-06 5.80E-05 0.00E+00 3.92E-09 0.00E+00 7.59E-06 0.00E+00 0.00E+00 0.00E+00 3.12E-06


Haul Truck Travel from Ore Storage Pads to ROM 0.61 0.13 0.01 lb/hr soil 3.48E-03 0.00E+00 1.15E-06 2.01E-05 0.00E+00 0.00E+00 0.00E+00 0.00E+00 6.80E-06 1.76E-06 2.73E-06 7.16E-03 2.25E-06 0.00E+00 6.25E-04 2.96E-05 5.40E-09 0.00E+00 4.61E-06 2.06E-04 0.00E+00 1.40E-08 0.00E+00 2.70E-05 0.00E+00 0.00E+00 0.00E+00 1.11E-05


End Loader from ROM to Ore Crusher Feed Hopper 0.10 0.02 0.00 lb/hr soil 5.66E-04 0.00E+00 1.88E-07 3.27E-06 0.00E+00 0.00E+00 0.00E+00 0.00E+00 1.11E-06 2.87E-07 4.45E-07 1.17E-03 3.66E-07 0.00E+00 1.02E-04 4.82E-06 8.79E-10 0.00E+00 7.51E-07 3.36E-05 0.00E+00 2.27E-09 0.00E+00 4.40E-06 0.00E+00 0.00E+00 0.00E+00 1.81E-06


Total Haul Truck Travel Emissions (fugitive) 11.0 2.3 0.2 lb/hr soil 6.28E-02 0.00E+00 2.08E-05 3.63E-04 0.00E+00 0.00E+00 0.00E+00 0.00E+00 1.23E-04 3.18E-05 4.94E-05 1.29E-01 4.06E-05 0.00E+00 1.13E-02 5.35E-04 9.76E-08 0.00E+00 8.33E-05 3.73E-03 0.00E+00 2.52E-07 0.00E+00 4.88E-04 0.00E+00 0.00E+00 0.00E+00 2.01E-04

44.0 9.4 0.9 ton/yr - actual 2.52E-01 0.00E+00 8.37E-05 1.46E-03 0.00E+00 0.00E+00 0.00E+00 0.00E+00 4.93E-04 1.28E-04 1.98E-04 5.20E-01 1.63E-04 0.00E+00 4.54E-02 2.15E-03 3.92E-07 0.00E+00 3.35E-04 1.50E-02 0.00E+00 1.01E-06 0.00E+00 1.96E-03 0.00E+00 0.00E+00 0.00E+00 8.06E-04

lb per year toxics - actual 5.05E+02 0.00E+00 1.67E-01 2.91E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 9.86E-01 2.55E-01 3.96E-01 1.04E+03 3.26E-01 0.00E+00 9.07E+01 4.30E+00 7.84E-04 0.00E+00 6.69E-01 2.99E+01 0.00E+00 2.03E-03 0.00E+00 3.92E+00 0.00E+00 0.00E+00 0.00E+00 1.61E+00

Mercury Retort (SV-03) 7.13E-05 7.13E-05 7.13E-05 lb/hr 7.13E-05

EUHGRETORT hr/yr 1200

lb per year toxics - actual 8.55E-02

Total TACs8

Aluminum Antimony Arsenic Barium Beryllium Cadmium Calcium Cerium Chromium Cobalt Copper Iron Lead Lithium Magnesium Manganese Mercury Molybdenum Nickel Phosphorus Selenium Silver Strontium Sulfur Thallium Tin Yttrium Zinc

2.13.E-01 lb/hr (Average 1-hr)9

total lb/hr 3.26E-01 5.98E-04 1.23E-02 7.39E-03 3.37E-05 1.95E-03 4.73E-02 4.64E-04 2.24E-03 1.49E-04 3.06E-02 7.62E-01 8.97E-02 9.00E-05 5.48E-02 1.75E-03 5.36E-04 4.14E-04 2.98E-04 7.01E-03 2.87E-05 9.62E-04 1.16E-03 1.53E+00 9.86E-05 1.67E-04 2.11E-04 5.48E-01

1520 lb/year decimal format lb/hr 0.326 0.00060 0.012 0.007 0.00003 0.002 0.047 0.000 0.002 0.0001 0.031 0.762 0.090 0.00009 0.055 0.002 5.36E-04 0.0004 0.0003 0.007 0.0000 0.0010 0.001 1.526 0.0001 0.0002 0.0002 0.548

0.8 ton/year (10% of Maximum 1-hr)10

total lb/hr 3.69E-01 7.25E-04 1.48E-02 1.02E-02 4.01E-05 2.33E-03 5.62E-02 6.81E-04 2.67E-03 1.78E-04 3.46E-02 8.68E-01 1.07E-01 1.07E-04 6.19E-02 2.38E-03 6.26E-04 4.88E-04 3.33E-04 7.22E-03 3.54E-05 1.14E-03 1.56E-03 1.77E+00 1.24E-04 2.08E-04 2.97E-04 6.53E-01

(Maximum 1-hr)11

total lb/hr 1.04E+00 2.69E-03 5.27E-02 5.42E-02 1.39E-04 8.07E-03 1.95E-01 4.04E-03 9.26E-03 6.26E-04 9.67E-02 2.50E+00 3.74E-01 3.71E-04 1.70E-01 9.66E-03 2.02E-03 1.64E-03 8.68E-04 1.05E-02 1.37E-04 3.93E-03 7.72E-03 5.54E+00 5.13E-04 8.42E-04 1.63E-03 2.28E+00

lb per year toxics - actual 2385 4 87 44 2.E-01 14 331 3 16 1 230 5537 626 1 402 12 3 3 2 55 0 7 7 11285 1 1 1 3810

Federal HAPS: marked as HAP

Criteria Pollutant marked as CRIT

TAC TAC TAC TAC TAC TAC TAC TAC TAC TAC TAC TAC TAC TAC TAC TAC TAC TAC TAC TAC TAC TAC TAC

HAP HAP HAP HAP HAP HAP HAP HAP HAP HAP HAP

CRIT

PM

Refining Furnace (SV-04) 0.27

EUREFINFURNACE 6

Fire Pump (SV-08) 0.15

EUFIREPUMP 6

Emergency Generators (SV-06a/b) 0.13

EUGENERATORS 6

Space Heaters - LPG Boilers (SV-07) 0.026

EUSPACEHEATERS

Reagents

Lime Silo (SV-05) 0.006

EULIMESILO

Reagent Material Handling (fugitive) 0.004

(exempt)

Stack Emissions - Total 0.80

0.7

PM10

0.221 0.161

0.15 0.15

0.13 0.13

0.026 0.026

0.002 0.001

0.002 0.0006

0.70

0.4

PM2.5

0.62

0.3

actual hrs

lb/hr

hr/yr 1200

lb/hr

hr/yr 500

lb/hr - each

hr/yr 500

lb/hr

5840

lb/hr

hr/yr 8760

lb/hr

hr/yr 8030

lb/hr

ton/yr

Notes:

1. Maximum facility emissions are all site emissions (including fugitive emissions) after applying collection and control efficiencies.

2. Mill operations, including activities at both the oxide and sulfide plants (between the loading of fine ore into the ball mill and the concentrate filter press) are performed in a wet state or slurry, and as such, no particulate matter is generated.

3. Roadway emissions only include fugitive emissions from surface roadway travel.

4. Potential to Emit (PTE) for this facility is the stack emissions with no fugitives. The New Source Performance Standards (NSPS) for metallic minerals processing is applicable to this facility

This NSPS (metallic mining) was developed after 1980 and since this facility is not subject to federal Maximum Achievable Control Technology (MACT) standards, fugitive dust is not part of PTE.

PTE is based on controlled emissions since operation of emission control equipment will be a legally enforceable requirement of the operation. PTE for hazardous air pollutants (HAPs)

is based on both stack and fugitive emissions per R 336.1116 (m).

6. Toxics from combustion appear on sheets for these emissions units.

7. Calculation of manganese TAC emissions is based on Note 29 in the MDEQ Table 2 List of Screening Levels. Note 29 states that the ITSL for manganese is most appropriately applied to PM10-Mn rather than TSP-Mn data. Therefore, all TAC calculations for Mn were based on PM-10 data.

8. The TACs totals do not include calcium, iron, sulfur or zinc.


Operating Schedule




Maximum & Average Operating Schedule of Emission Units Associated Stack Emissions

Stack Emission Unit hr/day day/yr hr/yr Fugitive Emissions hr/day day/yr hr/yr

Flotation Ore Processing Circuit

SV-01A EUFLOTCRUSH feed hopper, primary crusher 24 365 8760 Maximum EUFUGITIVES Mining and ore transfer Mine Pit Fugitive

Emis ions SV-01B EUFLOTFEEDCONVEYORS mill & reclaim feed conveyors Drill 12 365 4380 Max & Normal

22 365 28030 Normal Blast 1 365 365 Max & Normal

Material Handling 24 365 8760 Maximum

Oxide Ore Processing Circuit Vehicle Travel 24 365 8760 Maximum

SV-02A EUOXIDECRUSH feed hopper, primary crusher 24 365 8760 Maximum Material Handling &

Vehicle Travel 22 365 8030 Normal

SV-02B EUOXIDE2CRUSH secondary and tertirary

hers SV-02C EUOXIDEFEEDCONVEYOR mill & reclaim feed conveyors 22 365 28030 Normal Storage Piles

Material Handling 24 365 8760 Maximum

Miscellaneous Support Equipment 22 365 8030 Normal

SV-03 EUHGRETORT Mercury Retort 10 120 1200 Max & Normal Vehicle Travel 24 365 8760 Maximum

22 365 8030 Normal

SV-04 EUREFINFURNACE Refinery Furnace 10 120 1200 Max & Normal

SV-05 EULIMESILO Lime Silo (reagent) 24 365 8760 Max & Normal

EUCPFUGITIVES crushing plant building - fugitives Crushing Plant fugitive

emissions 24 365 8760 Maximum

22 365 8030 Normal