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JP858259:kah/1999300 438823-605002 VIA OVERNIGHT MAIL Conrad K. Chin Environmental Protection Agency July 2, 2012

Sector Policies and Programs Division, OAQPS Mail Code D243-02 1

09 TWAlexander Drive Research Triangle Park, NC 27711 ChuckFrench Environmental Protection Agency Metals & Inorganic Chemicals Group Mail Code D243-02 1

09 TWAlexander Drive Research Triangle Park, NC 27711 Re: ProposedNational Emissions Standards for Hazardous Air Pollutants: Ferroalloys Production 76 Fed. Reg. 72508 (Nov. 23, 2011) Dear Messrs French and Chin: Direct Number: (216) 586-7542 jrego@JonesDay.com

I am writing onbehalfofEramet Marietta Inc. ("EMI") to provide detailed follow-up on the matters EMI and FelmanProduction Inc. ("Felman") discussed with you at our meeting on May 1, 2012 and in subsequenttelephone conversations. Specifically, this correspondence includes (i) an evaluation ofone potential fugitive particulate source control strategy that satisfies the residual riskrequirements ofSection 112(t) ofthe Clean Air Act, and (ii) a proposal to address the current data deficiencies with respect to EPA'sproposal to establish first-ever MACT standards for four pollutants (mercury, polycyclic aromatic hydrocarbons ("PAH"), hydrochloric acid and formaldehyde).
I. 

### Evaluation of Enhanced Source Control of Process Fugitive Particulate Emissions atEMI For the reasons set forth inEMI's and Felman's comments onthe proposed NESHAP, EPA'sproposed "total building enclosure" approach to address residual risks related to manganese particulate emissions is neither feasible nor cost-effective as proposedby EPA. Similarly, while the proposed NESHAP theoretically provides an opportunity to propose an alternative to total building enclosure, the option does not, inreality, provide any flexibility, because EPA expressly designed the "fenceline" alternative to require equivalent overall emissions reductions to total building enclosure (i.e., a 98% reduction intotal particulate emissions). Not only is such a ALKHOBAR • ATLANTA • BEIJING • BOSTON • BRUSSELS • CHICAGO • CLEVELAND • COLUMBUS • DALLAS • DUBAI FRANKFURT • HONG KONG • HOUSTON • IRVINE • JEDDAH • LONDON • LOS ANGELES • MADRID • MEXICO CITY MILAN MOSCOW MUNICH NEW DELHI NEW YORK PARIS PITTSBURGH RIYADH SAN DIEGO • SAN FRANCISCO • SHANGHAI • SILICON VALLEY • SINGAPORE • SYDNEY • TAIPEI • TOKYO • WASHINGTONConrad K. Chin Chuck French July 2, 2012 Page 2 

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reduction impossible to achieve without sealing the facility, but the proposedrule would also impose an impossible duty on EMI to ensure that ambient manganese never exceeds 0.1 J.lg/m3 at EMI'sproperty boundary over any six-monthperiod. EPA's own school toxics monitoring data demonstrate that ambient concentrations inMarietta, Ohio have exceeded the proposed fenceline standard irrespective ofemissions from the EMI facility. EMI believes that the best that can be reasonably achieved is 95% capture ofprocess fugitive emissions at the individual source, with 98% control ofsuch captured emissions via a baghouse. EMI is evaluating a number ofpotential fugitive source control strategies based on 95% capture and has fully evaluated, as detailed below, one conceptual source control strategy againstthe residual risk requirements ofSection 112(f) ofthe Act. While EMI has not developed detailed cost estimates for any such conceptual strategy, it is nevertheless clear that construction of the particulate control enhancements assessed below would cost significantly more than EPA's estimate ofthe cost ofimplementing total building enclosure, butbelow the true cost of implementing the proposed rule (as detailed in EMI's comments on theproposedNESHAP). If EPA concludes

-- as EMI has

-- that the 95% fugitive capture approach can satisfy the residual risk requirements ofSection 112(f), EMI will proceed to develop such an estimate. 

### A. Process Fugitive Emissions Sources Subjectto Enhanced Source Control EMI has evaluated the following processes for enhanced capture offugitive particulate emissions: tapping, casting (including slag raking/skimming), and crushing/screening. Based on that evaluation, EMI has developed conceptual plans to address the following operations, with the expected capture efficiency improvements (i.e., net ofcapture provided by existing systems) indicated in Table 1below. More detailed descriptions ofthe assumed control systems are provided in Appendix A. Table 1: Proposed Fugitive Particulate Source Controls Capture Efficiency Source Process Description ofControl lmprovemem Furnace Tapping Enhanced hood system extending over charge ladle (70,000 85

.7 I CFM), captured emissions to existing baghouse Casting, including New hood for casting at midpoint ofcasting station and new slag raking/skimming retractable hood for slag raking/skimming (70,000 CFM 95 each), captured emissions to existing baghouse Furnace Tapping Enhanced hood system extending over charge ladle (70,000 87.5 12 CFM), captured emissions to new 100,000 CFM baghouse Casting, including New hood for casting at midpoint ofcasting station and new slag raking/skimming retractable hood for slag raking/skimming, with captured 95 emissions to a new 100,000 CFM baghouse MOR Tapping (pouring) Modify pour /casting station by extending hood, increasing hood height in rear, and sealing ofintakes to duct (120,000 90 CFM), captured emissions to existing baghouse Casting Newhood for casting at midpoint ofcasting station (120,000 91.7 CFM), captured emissions to existing baghouseConrad K. Chin ChuckFrench July 2, 2012 Page 3


### B. Corrected Emission Source Model Parameters 

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EMI has identified several errors in the physical parameters associated with the area sources inthe AERMOD air dispersion model used to estimate residual risks associated with the EMI facility's manganese emissions: 1. The release height for fugitive emissions from tapping and casting at Furnaces 1 and 12, casting at MOR, and crushing/screening shouldbe set at the height ofthe facility's roofmonitors (100 ft), which is generally consistent with the NATA 2005 dataset. 2. The dimensions ofthe facility roofmonitors through which the fugitive emissions described in #1 are emitted are generally understated and should be revised to lengths corresponding to 1/3 ofthe building roofmonitor length in the end ofthe building where the relevant process is located, which is also generally consistent with the NATA 2005 dataset. 3. The physical parameters for the Furnace 1baghouse outlet used in the modeling supporting the Proposed Rule were based on data for the wet scrubber that was replaced by the baghouse in 2011. Those data have beenupdated to reflect current conditions. EMI has also identified several necessary corrections and updates to the emissions estimates included by EPA in the AERMOD dataset: 1. Furnace 1process baghouse emissions: Rather than modeling emissions from Furnace 1'sprocess baghouse, whichhas been operational since April 2011, it appears that EPA based actual and allowable emissions for Furnace 1on data from the former Furnace 1 scrubber, which has not been operational since April 2011. Based on stacktests conducted in May and November 2011, baseline emissions from the Furnace 1process baghouse should be 1.08 tons/year ("tpy") manganese. 2. Furnace 1tapping baghouse emissions: Furnace 1includes a separate baghouse to capture tapping emissions at that furnace. Based on stacktests conducted in May and November 2011, baseline emissions from the Furnace 1tapping baghouse should be modeled as 0.169 tpy manganese. Emissions from this point source should be added to the model. 3. Furnace 1tapping fugitive emissions: Uncontrolled particulate matter (PM) emissions of0.29 lb/ton were assumed based on AP-42, Table 12.5-1 for "Basic Oxygen Furnace (BOF) Tapping, Atbuilding monitor" with a maximumprocess rate of 13 tons/hour. The manganese content ofthese emissions was estimated to be 41% ofPM, based on speciation inthe mostrecent stack test ofproduct fugitives from the C2P crusher. These emissions are partially captured by an existing hood. The tapping hood's current

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65% efficiency in capturing these emissions yields a baseline manganese emission rate from Furnace 1

### tapping of2.37 tpy. 4. Furnace 1

### casting (including slag raking/skimming) fugitive emissions: Uncontrolled PMemissions of0.056lb/tonwere assumed based on AP-42, Table 12.5-1 for "Hot metal transfer, At building monitor" with a maximum process rate of 13 tons/hour. The manganese content ofthese emissions was estimated to be 41% ofPM. This yields a baseline manganese emission rate from Furnace 1 casting of 1.31 tpy. 5. Furnace 12 process exhaust scrubber emissions: Based upon the results ofthe most recent stack tests conducted on this source in August 2010, May 2011, and November 2011, the baseline manganese emission rate from this point source should be 13.88 tpy. This is an increase above the emissionrate used by EPA for this source. 6. Furnace 12 tapping fugitive emissions: Uncontrolled PM emissions of0.29lb/tonwere assumed based on AP-42, Table 12.5-1 for "BOF Tapping, Atbuilding monitor" with a maximum process rate of 12.5 tons/hour. The manganese content ofthese emissions was estimated to be 41% ofPM. These emissions are partially captured by an existing hood. The existing hood's 60% efficiency in capturing these emissions yields a baseline manganese emission rate from Furnace 12 tapping of2.6 tpy. 7. Furnace 12 casting (including slag raking/skimming) fugitive emissions: Uncontrolled PM emissions of0.056lb/tonwere assumed based onAP-42, Table 12.5-1 for "Hot metal transfer, Atbuilding monitor" with a maximum process rate of 12.5 tons/hour. The manganese content ofthese emissions was estimated to be 41% ofPM. This yields a baseline manganese emission rate from Furnace 12 casting of 1.26 tpy. 8. MORinitial pouring fugitives: Removal ofmaterial from the MORis viathe pouring ofa vessel rather than by tapping an active furnace. Accordingly, uncontrolled PM emissions of0.056lb/tonwere assumed based on AP-42, Table 12.5-1 for "Hotmetal transfer, Atbuilding monitor" with a maximum process rate of25.5 tons/hour. The manganese content ofthese emissions was estimated to be 41% ofPM. These emissions are partially captured by an existing hood. The existing hood's 50% efficiency in capturingthese emissions yields a baseline manganese emission rate from MORpouring of 1.28 tpy. 9. MOR casting fugitives: Uncontrolled PM emissions of0.056 lb/ton were assumed based on AP-42, Table 12.5-1 for "Hot metal transfer, At building monitor" with a maximum process rate of25.5 tons/hour. The manganese content ofthese emissions was estimated to be 41% ofPM. These emissions are partially captured by an existing hood. The existing hood's 40% efficiency in capturing these emissions yields a baseline manganese emissionrate from MOR casting of 1.54 tpy.Conrad K. Chin Chuck French July 2, 2012 Page 5 

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10. C2P crushing/sizing baghouses 1, 2 and 3: Baseline manganese emissions from each ofthese three stacks is 1.48 tpy based on the results ofthe most recent stacktest, conducted in August 2010. 11. C2P crushing/sizing fugitive emissions: Estimates ofuncontrolled emissions from this operation are based on emission factors for metallic minerals processing, as presented in AP-42, Table 11.24-2. Emission factors for PM10 were utilized, as those most likely represent the size fractions having the potential to be carried up from these groundlevel mechanical processes to the release point 100 feet above. PM10 emission factors were appliedto the various crushers, screens, belts, and transferpoints, with a maximumprocess rate of 140 tons/hour for up to the permit-limited maximum of5,840 hours annually. Each ofthese crushers, screens, and transferpoints is fitted with closecapture ventilation hoods ducted to the crushing and sizing baghouses. The hoods are consideredto be 95% effective in capturing PMbased upon their design, consistent with American Conference ofGovernmental Industrial Hygienists guidelines. Based on a manganese content of41% ofthe PM1 

### o, from the most recent stack test ofthe C2P baghouse, the baseline manganese emission rate is 6.355 tpy. Documentation for the updated emissions estimates described above is presented inAppendix B.


### C. Revised Emissions After Additional Fugitive Emission Source Control Taking into account the effects ofthe enhanced fugitive source controls described above in Section I andthe data corrections described above in Section II, Table 2 sets forth the baseline (i.e., current) manganese emissions for each fugitive source along with estimates offugitive emissions after additional source control. Table 3 sets forth updated point source manganese emissions reflecting the impact ofenhanced capture offugitive emissions, including newpoint sources associated withthe proposed fugitive controls. Table 2: Estimated Fugitive Manganese Emissions After Additional Source Control Capture Source Baseline Fugitive Mn Efficiency Source Process JD Emissions (tpy) Improvement Furnace 1 Tapping F901 2

.37. 85.7 Casting, including slag F007 1.31 95 raking/skimming Furnace 12 Tapping F908 2.60° 87.5 Casting, including slag F008 l.26 95 raking/skimming MOR Tapping (pouring) F012 1.28c 90 Casting F009 1.5411 9l.7

•Reflects existing 65% capture ofcalculated uncontrolled fugitive emissions of6.80 tpy. b Reflects existing 60% capture ofcalculated uncontrolled fugitive emissions of6.50 tpy. cReflects existing 50% capture ofcalculated uncontrolled fugitive emissions of2.57 tpy. d Reflects existing 40% capture ofcalculated uncontrolled fugitive emissions of2.57 tpy. Controlled Mn Emissions (tpy) 0.339 0.065 0.325 0.063 0.128 0.128Conrad K. Chin Chuck French July 2, 2012 Page 6 

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Table 3: Estimated Point Source Manganese Emissions After Additional Source Control BaselineMn Revised Mn Source Emissions Emissions Source ID (tpy) (tpy) Explanation Furnace 1Baghouse Outlet P901 1.08 1.59 Additional 70,000 CFM ofair flow at existing exit velocity Furnace I Tap Baghouse Outlet P901 0.169 0.246 Air flow increases from current 48,000 CFM to 70,000 CFM Furnace 12 Scrubber Outlet P908 13.88 13.88 Newly captured emissions will go to new baghouse New Furnace 12 Fugitive Post-control emissions from NA 0 0.352 enhanced tapping, casting and slag Baghouse Outlet raking/skimming MOR/Fumace 18 Baghouse P909/F 0.981 0

.981 Outlet No additional controls C2P Crushing/Sizing Baghouse 1 P917 1.48 1.48 No additional controls C2P Crushing/Sizing Baghouse 2 P917 1.48 1.48 No additional controls C2P Crushing/Sizing Baghouse 3 P917 1.48 1.48 No additional controls Based on establishedperformance criteria for the types ofclose-capture hooding described in Table 1, the additional source controls proposed by EMI should collectively reduce emissions from the affected sources by 95% and reduce overall process fugitive emissions ofmanganese by over 50%. 

### D. Residual RiskAfter Enhanced Fugitive Emission Source Control EMI has revised the area source andpoint source parameters in the AERMOD model to reflect (i) the fugitive source controls described in Table 1, (ii) the corrected physical parameters described in SectionII, and (iii) the baseline and controlled emissions estimates set forth in Section III. Consistentwith Section 2.3.4 ofthe Gradient Corp.'s "Technical Review ofAir Modeling and Risk Assessments" (Jan. 30, 2012), maximum off-site exposure concentrations and associated non-cancer risks (HQ) for the hypothetical Maximum Individual Risk (MIR) receptor were then recalculated. Table 4 summarizes the resulting HQ for a range ofpotential manganese reference concentrations (RfCs) under several modeled scenarios: (1) corrected meteorological data, (2) corrected meteorological data and adjustment ofexposure concentrations to reflect a 41% respirable manganese fraction, and (3) corrected meteorological data, adjustment for respirable manganese, and use ofa more reasonable MIR exposureperiod to reflect time indoors and time away from home.

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Table 4: Residual Risks After Additional Source Control
Exposure Scenario (EPA model with various Maximum Off

-Site Manganese HQ at Various Reference Concentration (RfC) revisions) Values Highest Exposure Use of Use of Calculated Adjusted for Parkersburg Respirable Time Indoors Off-Site 0.05 0.1 0.5 1 2 Meteorological Fraction and Away Mangane e Jlg/m3 Jlg/mJ Jlg/m3 Jlg/m3 Jlg/mJ Data (PMl.s) From Home Cooc

. entration (1Jg/m3 ) 

# • 0.145 3 1 0

.3 0.1 0

.07 

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.1 0

.06 0

.03 

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.033 0

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### As summarized in Table 4, the additional fugitive emission source controls described above will reduce estimated residual risks to an HQ of 1 or less under a conservative range of manganese reference concentrations. The modeling files upon whichthis table is based are included on the CD labeled Appendix C.
E. Ventilation and WorkPractice Standards For Enhanced Fugitives Control Consistent with EPA'sNESHAP(s) and New Source Performance Standards for other metallurgical industries employing electric arc furnaces and related processes, such as those for iron and steel foundries, and steel minimill electric arc furnaces, EMI has identified the following standards that would be appropriate to ensure proper operation ofthe fugitive emission source controls upon which this evaluation is based: 1. All EAF furnace tapping operations shall be fitted with ventilation hooding whose design is consistent with accepted engineering standards, such as those published by the American Conference ofGovernmental Industrial Hygienists, and with a design hood face capture velocity ofat least 300 feet/minute. 2. All ferroalloy slag raking and casting operations shall be fitted with ventilation hooding whose design is consistent with accepted engineering standards, such as those publishedby the American Conference ofGovernmental Industrial Hygienists, and with a design hood face capture velocity ofat least 300 feet/minute. 3

. Visible emissions from any building housing a ferroalloy EAF,MOR, or casting operation may not exceed 20 percent opacity, measured as a six-minute average, except for one six-minute period per hour.Conrad K. Chin Chuck French July 2, 2012 Page 8 

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II. Proposal for Supplemental Information Collection Request To Address NonRTRPollutants From Manganese Ferroallovs Production at EMI In conducting its Risk and Technology Review ("RTR") ofthe existing NESHAP for Ferroalloys Productionpursuantto Sections 112(d)(6) and 112(f) ofthe Clean Air Act, EPA elected also to develop and propose emissions standards for four pollutants (mercury, PAH, hydrochloric acid and formaldehyde) that are not currently subject to technology-based MACT standards. Accordingly, the four newly identified pollutants are not subject to either the Act's RTRprocess or thejudicial deadlines established in Sierra Club v. Jackson, Case No. 09-cv00152 SBA (N.D. Cal.). Since emissions ofthe four newpollutants are not currently regulated under the Ferroalloys ProductionNESHAP, emissions data for those pollutants have not been collected by the companies pursuant to the existingNESHAP. Additionally, EPA obtained limited data pursuant to the information collection request ("ICR") issued during the RTRprocess. As a result, EPA does not yethave a dataset that accurately reflects the existing emissions ofthose pollutants across differentproducts and expected operating conditions, which is essential to the development ofa defensible MACT "floor." The adverse consequences ofestablishing first-ever MACT standards inthe absence of representative data is exacerbated by EPA's decision to propose "beyond the MACT floor" standards for mercury and PAH. The proposed NESHAP would require a continuous 90% reduction in emissions ofeach pollutant below the levels measured in a single stack test, based on EPA assumptions regarding the effectiveness ofa technology (activated carbon injection or "ACI") that has never been applied to ferroalloys production. The docket for the proposed NESHAP does not contain any performance data demonstrating the feasibility or costeffectiveness ofachieving 90% removal efficiencies based on use ofACI on ferroalloys emissions. Thus, EPA'sproposed standards for the four newpollutants suffer from two serious data deficiencies: a lack ofdata onthe actual emissions necessary to set MACT floors, and a lack of ACI performance data upon which to reliably assess the feasibility and cost-effectiveness of "beyond the floor" standards

. In light ofthe fact that these issues are legally independent ofthe RTRprocess that is subject to ajudicial deadline, EMI proposes that EPA separate those four pollutants from the manganese RTRrulemaking for a period of 10 months (to July 15, 2013) during whichtime EMI would collect and report datapursuantto a newICRwith the following components: 1. Stack Testing for the Four Newly Regulated Pollutants. EMI would collect two rounds ofdata for the four newly regulated HAPs, a summerround in July 2012 and a winter round during the first quarter of2013, based on the stacktesting protocol developed by EMI in consultation with EPA, which is attached as Appendix D

. In addition, prior to second round ofsampling, EMI will separately evaluate mercury emissions via Hg-CEM and, ifsuch testing provides moreConrad K. Chin Chuck French July 2, 2012 Page 9 

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reliable results, EMI will substitute Hg-CEMtesting for the mercury method set forth inthe attached stacktesting protocol. 

### 2. ACI Performance Testing in Ferroalloy Production. EMI will contract with one ormore vendors to conducttrial use ofACI oneach ofits two ferroalloy electric arc furnaces, one ofwhich is equipped with a wet scrubber for particulate control and the other ofwhich is equipped with a baghouse. Thetrials, which would last a minimum offour days oneach furnace, would evaluate ACI using a minimum oftwo activated carbonproducts and at a range of injection rates. Duringthetrials, EMI would collect (i) real time Hg-CEM data to evaluate howmercury concentrations and levels ofmercury oxidation in the flue gas relate to EMI's smelting process and operational variables, (ii) Method 30B carbontrap mercurymeasurements, both as a means to corroborate the Hg-CEM data, and to assess the feasibility ofusing carbontraps to report mercury emissions, and (iii) FT-IR analysis ofthe flue gas to ascertain levels ofHCl and formaldehyde. The trials would be completed intime to provide EPA with a complete performance testreport no later than March 25, 2013. EMI looks forward to discussing the approached described herein onour July 6, 2012 Web Ex meeting. Ifyou have any questions in advance ofthat meeting, please do nothesitate to contact me.

cc (w/encl.): JohnA. Willoughby JeffMcKinney Gregory D. Timmons, Esq. John S. Konrady Amy M. Lincoln, Esq. A. Rego ounsel for ErametMariettaInc.