# lBISON .t:ERING. INC.

June 19, 2008

Callie Videtich Air Quality Planning and Management Unit US EPA
- Region 8 1595Wynkoop Street Denver, CO 80202-1129 

# REDACTED

Dear Ms. Videtich: RE: CFAC BART Analysis
- Response to EPA Comments
- REVISED Columbia Falls Aluminum Company (CFAC) is re-submitting the response to comments 

### from your letterdated February 12, 2008. As explained to Laurel Dygowski verbally and bye-mail, an error was found in CFAC's BART analysis modeling that supported CFAC's April 14, 2008, BART submittal to EPA. CFAC inadvertently provided Bison Engineering, Inc. (Bison), CFAC's consultant, with an incorrect stack diameter and an 

### incorrect stack heightforthe A398 dry alumina scrubbers. The following table shows the revised model inputs:

SpecIficvelocIty depends on mdlVldual scrubber 

### Stack Height Stack Exit Velocity* Version Diameter (feet) (inchesl (feeUsec) 

### Previous 92 24 56-63 Corrected 111 38 66
- 75



# . CFAC has provided a drawing of an alumina scrubber stack as documentation of the properstack parameters (Attachment K). Bison has corrected the error and fe-run the visibility models. As a result 

### ofthe revised 

### models, Bison has revised the April 14, 2008, submittal package. The enclosed package includes newly updated CALPUFF model results for all of the various scenarios analyzed for BART. This revision dated June 18, 2008, only changes the CALPUFF model results, deciview impacts and costs in dollars per deciview. This 

### revision does not change any other information or data used in the BART analysis. Because the overall deciview impacts for the existing plant and most of the control 

### options were reduced, the costs of control per deciview generally are higher in this revised submittal. CFAC believes this only further emphasizes the conclusion of CFAC'sBART analysis, that all of the examined control strategies are cost-prohibitive, and none 

### was selected as BART. The remainder of this submittal is a revised response by CFAC to your letter dated February 

### 12, 2008, requesting more information. On behalf of GFAG, Bison is pleased to submit responses to your questions. We have copied EPA's comments from your letter (numbered and in small type), and furnished CFAG's responses in larger type_ The responses are contained in Attachment A to this letter. Detailed information referenced in our responses is contained in other attachments, as follows: 

### Attachment A - Responses to EPA Comments Attachment B - Single Alkali Scrubber CostAnalysis
- CONFIDENTIAL Attachment C - Dual Alkali Scrubber CostAnalysis
- CONFIDENTIAL Attachment 0 - Spray Dry Absorber (SDA) CostAnalysis
- CONFIDENTIAL Attachment E - Spray Room Scrubber CostAnalysis
- CONFIDENTIAL Attachment F - Fabric Filter Baghouse Cost Analysis
- CONFIDENTIAL Attachment G - Emissions Calculation Spreadsheets Attachment H - Summary of S02 Control Investigation Attachment I - Sumitomo Process Conversion Letter 

### Attachment J - RoofVent Flowrate Data Attachment K - Drawing ofA398 Scrubber and Stack Please note that the revisions solely affect the contents of the tables presented in Appendix A, and the addition of Attachment K. The contents of the other attachments are unchanged. CFAC requests that the cost information in the analyses contained in Attachments B through F be treated as CONFIDENTIAL business information and 

### not be distributed to the public or published on the Region VIII website. Please let us know if you have any questions on our responses. I can be reached at 

### 406-442-5768, or Steve Wright (CFAC) can be reached at406-892-8211. Sincerely, BISON ENGINEERING, INC



# 1kJ**/)~** Harold W. Robbins President


### cc: Steve Wright
- CFAC John Parker
- PICO Attachments

## Attachment A

EI'A COllllllent #1 

### General Comments 1. The CFAC BARTanalysis uses the 5thedition ofthe<'EPA AirPollution Corurol COS1 M<:nuaJ" instead ofthe 6th edition. CF

### Aeneeds 

### [0 redo lhe BA.R.T**ancly~is** using the

### 6.h edition of"EPA's 

### Air Pollution CooLroI CostManual" ("EPA AirPollution Control Cost Manual", SiXthedition, EPA-452-Q2-QO]. January 200.2). 

### CFAC Response In response to the EPA request that CFAC "redo the BART analysis using the 6'h 

### edition of the EPA's "Air Pollution Control Cost Manual," we have studied the sections related to this BART study and conclude that there are some minor version-to-version differences attributed to "the necessary revisions, updates, and expansions of each of 

### these chap/ers,"alluded to on page 1.5 of Version 6 of the manual. I 

### (Incorporation of these changes does not change the conclusions previously reached.) These changes are oftwo types:

• Adjustments to the coefficients or "factors" applied to base costs to account for "foundations, piping, etc."; and



### • Changes to some ofthe cost algorithms for estimating pumps, blowers, etc. We have re-estimated the capital costs and annual costs of the various controls and, where appropriate, substituted the Version 6 values. in the process of reviewing the cost tables, a small number of other corrections, additions, or deletions have also been made which effected minor changes (plus and minus) to the overall costs. The effects ofthese changes are generally categorized in Table 1 below. 

### Table 1: 2008 Update Effeets on Detailed CostAnalyses Changes to Detailed Cost Estimates Cost 1m act (+1-) Chemical and freiQht cost increases: lime u 80%, NaOH up 66% Laroe Plus Calcium Chloride was removed from both orimarv S02 scrubber svstems Neqliqible Cost coefficients increased per EPA Cost Manual version chanQe from 5 to 6 Plus Decreased operator/maintenance cost oer EPAcomments Minus Site oreelbuildina costs inadvertently omitted in 11/5/07 report Small Plus Removed 3% sales tax coefficient inadvertently aeelied in 11/5/07 Lar e MinUS More detailed electrical powercost analYSIS NetZero More detailed water cost analysis Small Plus Applied a 15 year 'IS 10 yearcapital recovery factor Minus

1 EPA Air Pollution Control Cost Manual, Version 6, Section 1-3, page 1-5. Attachment A Page 1In no case did we determine that any of these changes altered the conclusions of the 

### study. The revised cost tables and associated detail are attached to this response as follows 

### (note that the Spray Dry Absorber was newly added in this response, and did not appear in the November 11, 2007 BART report): Attachment B
- Single Alkali Scrubber CostAnalysis Attachment C
- Dual Alkali Scrubber Cost Analysis Attachment D
- Spray Dry Absorber (SDA) Cost Analysis Attachment E
- 

### Spray Room Scrubber Cost Analysis Attachment F
- Fabric Filter Baghouse CostAnalysis EPA Comment#2


### 2. Onpage4-33 ofthe 

### analysis it stat::s "Any requirementto implemeot any ofthe 

### pollution control strategies described in

### this documentwill 

### greatly increase CFAC's operatingcost and

### probably result in tbe shutdown

### ofthe 

### facility." The B.4R.T 

### Guidelines provide that "There may be unusual circumStances thatjustify taking 

### into considerationthe

### conditions oftheplantand the economic 

### effectsorrequiTing theuseofagivencontroltcdmo!ogy. These 

### effects wouid include effectson**pToduc~** 

### prices, the**marlce~** 

### share, and profitability ofthe

### source. 

### Wberetiereare suchunusual circumstances Ll-tat

### arcjudged to affect plant 

### operations, you maytakeinto consideration the 

### conditions ofthepla.'11andtheeconomic effects**ofr~quiring** 

# meuse ofacontrol technology. Where theseefte..."'1.S**ar~** 

### judged to ha....e asevere impeact onplantoperations you may

### considerthem intheselectionprocess, butyoumay \\'ishtoprovide aneconomlcanalysis that

### demonstrates, 

### insu..:.t'ficient detail for public review,t'f1e specificcconomic effects, parameters, 

### and reasoning. (\Ve recognize that this review 

### process mustpreservetbe 

### confidentiality ofsensitive business information)" (see

### 70 FR 39171, July 

### 6, 2005). CFAC Deeds (0include 

### adetailed 

### economic and fimmcial analysis for**th~i.r** 

### facility thGt

### provides information on how additional controls wouldresult intheshutdown ofthe 

### facility. The a!'.alysis !leedsto encompass all BART

### contra] measures and theirassociated costs that

### arepartofthe revised BART

### analysis. CFAC Response Although CFAC still believes the original statement to be true, CFAC would like to withdraw this comment at this time. CFAC believes the original BART submittal, and the 

### supplemental information in this submittal, show that there is no add-on technology available to CFAC that meets the definition of BART. Therefore, no further analysis of CFAC's financial ability to afford any of these technologies has been provided.

Attachment A Page 2EPA Comment #3
3. CPAC needs to provide the following information as partofibc revised B.A.RTa.'1alysis: Tbe source oftbe emissions data usedin the analysis (e.g., source testing, em!ssions**monitorir~g** equipment, emission factors, other). Information on what operational datathe emLssionsprovided 

### in Tables 3-4 and 3- 5**~e** basedupon. It appears that there are basedon 24hours/day, 365 days a year operation ofthe facility. Operational 

### data. iDcludLl.g:burnot

### limitedto, 

### actual emissions aTld 

### typical operating parameters in hom'S/day a!ld days/year. The t}'pice.l annual outputin Ions/yearofaluminum. Additional documentation onho\.',' the estimaicd capital 

### equipmentcost

### forthe dual andsingle alkali 5crubbcrs was calculated (e.g., costmodel and inputs

### used to dctcrminecosts, or Cl.uotes from vendors, ctc.). Addiriona[ documentation onhow the value forannualized costs for coke sulfur 

### contentreductionwas calculated. Docmnentadon ofthe operating mmerials coscs (e.g., NaOH, Ca(OH)2, and CaCl/floculant). CFAC Response Source of Emissions Data
- Emissions estimates have been used for the preparation of the BART analysis. CFAC is not required to perform stack testing for the pollutants analyzed for BART. CFAC does not have actual emissions data available for the sources. A spreadsheet containing the emissions data used in the BART analysis is provided in the tables in Attachment G. The tables included are: Table 3a: Sulfur Dioxide Emission Factor Calculation Table 3b: Sulfur Dioxide Emission Inventory Table 3c: PM 10 Emission Inventory Table 3d: NOx Emission Inventory Background information regarding these spreadsheets is prOVided below: In 2005, the Montana Department of Environmental Quality (MDEQ) requested emission rates based on the highest daily aluminum production rate. At the time of MDEQ's request, CFAC was only operating one potline of production. For the purposes of the BART analysis, it was agreed that CFAC should provide emission data based on 1999 production, which was the most recent year when all three BART-eligible potlines were operating. CFAC reviewed production data for 1999 and found the highest daily production rate occurred on February 3, 1999. The production value for this day was 323 tons of aluminum/day.

Attachment A Page 3As seen in Table 3a, Sulfur Dioxide Emission Factor Calculation, an S02 emission factor 

### was calculated by CFAC based on the percent sulfur in the petroleum coke and coal tar pitch raw materials, and assuming all of the sulfur was emitted from the facility in the form of SO,. As can be seen in Table 3b, PM 10 emissions are calculated based on emission factors from the MDEQ AIRS / annual emission inventory and the aluminum production value 

### for February 3,1999. The NOx emission calculations in Table 3d are based on the estimated natural gas use 

### on February 3, 1999 and the MDEQ AIRS /annual emission inventory emission factor. Operational Data: The emission estimates are based on CFAC's operations and the nature of the aluminum electro-reduction process. The emissions estimates are based 

### on operation of potlines 3, 4 and 5, 24 hours a day, 365 days/year. Typical Annual Aluminum Output - The annual output of aluminum in tons/year from 

### the three BART-eligible potlines (3, 4 and 5) varies somewhat year to year. Below are the production numbers for the years 1997, 1998 and 1999 for these three potlines. CFAC considers these production rates as typical for these potJines. 

### Year 1997 1998 1999 Tons ofAluminum Produced 114,041 113,098 112,584 Documentation of Estimated Capital Costs - Detailed analyses and cost estimates 

### for the dual and single alkali scrubbers have been provided in Attachments Band C. In addition, updated cost estimates have been provided for a Spray Dry Absorber, Spray Room Scrubber and Fabric Filter Baghouses in Attachments D, E and F, respectively. Coke Annualized Costs
- In CFAC's original BART analysis (page 4-12), the cost of switching from a 1 5% sulfur coke to a 0.75% sulfur coke was estimated to be 

### $7,079,680/year based on 1999 usage of petroleum coke for potlines 3, 4 and 5 (the BART-eligible potlines). The incremental increased cost of the 0.75% sulfur coke over 

### CFAC's current coke cost was estimated at $160/ton 

### of coke consumed. Potlines 3, 4 and 5 combined used 44,248 tons of coke in 1999. The $160/ton of coke cost increase was based on verbal discussions with coke vendors in October, 2007. Documentation of Operating Materials Costs - 

### On March 28, 2008, CFAC obtained fresh quotes for the SO, scrubber operating materials from Hawkins, Inc., an industrial chemical supplier based in Minneapolis. 50% Caustic Soda (NaOH): $584/ton (dry basis) (rail tank cars, FOB Minneapolis) Hydrated (slaked) Lime [Ca(OHh]: $231/ton (40 ton truckloads, FOB Columbia Falls) Calcium Chloride (CaCI,): $652/ton (truckload FOB Columbia Falls)

Attachment A Page 4

### The price quotes for the original November 2007 BART report were from ICIS Pricing and Index Mondi, international chemical pricing services. They were increasing daily 

### but were in the range: 

### 50% Caustic Soda (NaOH): $360/ton (FOB Gulf/Houston) Hydrated (slaked) Lime [Ca(OH),): $150/ton (FOB Columbia Falls) EPA Comment #4 

### 4. Onpage4-2oft.i:lca."1alvsis, CFACst<l.testhat :uneunitsere not included in the**:~.llalvsis** 

### becausethey h:J.\'every"lowemissionrates. These nine unilS, 

### blcludingthealumina" elevator, unloader, conveyor storage, oU heating S)'ste!Il, transfer pointS, c2Sting furnace 

### andpit

### and.sheetingotsaw, ha,'e

### combinedPMIO emissionsof4.81 Ibs/houror21 tons/year. Accordingto the BA.RTGuidelines, 

### lOInorderrosimplify BART determinations, Statesmay choose 10

### identify deminimislevelsofpollutants atBARTeligiblesour<::es (bet

### arenotrequired 1.0

### doso).De

### minimis valuesshould be identified 

### ""iththepurposeofexcluding only thoseemissions sornini..m:zJthatLhey aretmlikelyto contributeto regional haze. An)' 

### deminimis valuest.l)aryouadopt must not be

### higher 

### than the 

### PSD applicability 

### levels: 40 tons/yrfor

### 802 and NOXand 15 tonsJyr for

### PMIO. 

### Thesedeminirt"jslevelsmayonly be applied onaplant-\vicie basis1l 

### (sec 70FR

### 39161. July S. 

### 2006). CFAC

### exceeds the suggested deminimis lcvcl 

### for PMJO in 

### theBART Guidelines 

### and l.f}US 

### all BA.T{Teligibleunitsat the facility need to

### be included in the BART

### analysis. CFAC Response CFAC understands that the total annual emissions from nine sources of 

### PM,o emissions 

### are greater than the 

### de minimis threshold of 15 tons peryear. In the original submittal, CFAC stated that, "The other nine units have very low emission rates and were not 

### analyzed for BART by CFAC." To expand upon this statement, CFAC has followed the guidance in 40 CFR 51 Appendix Y, Section III, as quoted below. Please note the underlined section. 

### III. How To IdentifySources "Subject to BARr' Once you have 

### compiled your list ofBART-eligible sources, you need to determine whether (1) 

### to make BARTdeterminations for all ofthem or(2) 

### to considerexempting some ofthem from BARTbecause theymay 

### not reasonably be anticipatedto cause or contribute to any visibility impairment in a 

### Class I 

### area. If

### you 

### decide to make BART determinations forall the BART-eligible sources on yourlist, you should work with your 

### regionalplanning organization (RPO) to showthat, collective/y, theycause 

### orcontribu/e to visibility impairment in at least one Class I area. You should then make indIVidual 

### BART determinations by applying the five statutory factors discussed in Section IV below. On the otherhand, you also may choose to perform an initial examination to determine 

### whethera 

### particularBART-eligible source 

### orgroup ofsources causes 

### orcon/ributes to visibility impairment in nearby Class I areas. If

### youranalysis, orinformation submitted AttachmentA Page 5

### bythe source, shows 

### thatan individualsource orgroup ofsources 

### (orcertain pollutants from those sources) is not reasonably anticipated to cause orcontribute to any visibility impairment in 

### a Class I area, then you do not need to make BARTdeterminations for that source orgroup ofsources (orforcertain pollutants from those sources). In such 

### a case. the source 

### is not "subject to BART" andyou do notneedto applythe five statutory factors to make 

### a BARTdetermination. This section ofthe Guideline discusses severat approaches thatyou can use to exemptsources from the BARTdetermination process. 

### Bison modeled the group of nine PM" sources mentioned above, both at the EPA supplied emission rates and at a zero pound per hour emission rate. The average change in deciviews modeled for Glacier National Park was 0.193 deciviews. This delta deciview result shows the effect of removing these emissions completely; i.e., a 

### 100% control efficiency. Since any realistic overall control efficiency would be less, this delta deciview represents the highest possible deciview improvement resulting from the control of these nine sources. A realistic deciview improvement would also be less. The deciview improvement result is significantly less than the recommended 

### 0.5 deciview threshold, where the source or group of sources would be considered to contribute to visibility impairment. Therefore, Bison concluded that this group of sources "is not reasonably anticipated to cause or contribute to any visibility impairment in a Class 

### I 

### area." Following along above, "the source (or group of sources in this case) is not 'subject to BART' and you do not need to apply the five statutory factors to make a 

### BART determination." Bison can provide the modeling showing these results upon request.

EPA Comment #5 5. Thecost analysis forthe coutrol technologies included in the analysisdoesnot cootain the properdocumentation to supportthe COSts contained in the appendices. The BART Guidelines state that "Once (he control technology al1ematives and achievable emissions pedorroance ievels have beenidentified, you then develop estimates ofcapital and annual costs. The basis for eqUipment cost estimates also shouJd be documented, eitherwith duta supplied by an cquipmem vendor (i.e., budget**cst~mates** orbids) or by,E referenced source 

### (suchastbe OAQPS COn/rol COSIManual, Fifth 

### Edition, February 1996, 

### EPA 453/B.96. 001). In order to 

### rnaintairl and improve consistency, costestimates should be based onthe 

### OAQPS Control COSIManual, 

### whe.cpossible." 

### (scc 70 

### FR 39166, 

### July 6,2005), 

### CFAC needs to provide theproper documentation to 

### support al! ofthe costs used in the ana!vsis. Pleasenote that"the "OAQPS Control COSt Manual", Fifth Edition, referenced**above~** has 

### been replaced by**th~** "EPA Air Pollution Control Cost Menua!", Sixth Edition,

### January 2002.


### CFAC Response CFAC has attempted to document all cost analyses used but not provided in the original 

### submittal. Please see the other sections of this attachment for details.

Attachment A Page 6**I~I)** A Comment#6 6. CFAC needs 10 include an analysis ofthe controllechJ10Iogies using 

### the most stringent 

### conrrol efficiency iliat

### they are capable ofachieving. 

### TneBART Guidelines 

### statethat "It is not ourintentto require 2Dalysis ofeachpossiblelevel ofefficiency for acontrol 

### techoiqu::. assuch an analysis 

### wouldresult in .a.

### largenumberofoptions. 1t 

### is important, however, thatin analyzing 

### the technology you take intoaccountthe most stringeni: emission control level that the technology is capable 

### orac}-ojeving. You should consider recent regulatory decisions and perfoanance

### d2.t2. (e.g., manufacturer's data, engineering estimates andthe experience ofothersources) when identifying anemissions performance lev:::,] orlevels 

### 10 evaluate." (see 70 FR 

### 39166, July 

### 6, 2005). Control technologies notevaluated "withthe most stringentemission control levels resuJts 

### in 

### inflated ealculatedcosteil'cctiven""svelues. CFAC needs 10 

### redothe analysis 

### forcontroJ technologies usingthe maS! st:riI:!gentcnllssioncontrol level thatthetechnology is capableofachieving. One e.xampleis the analysisfor**S~.** CFAC only estimates a 90% 

### removal efficiency\

...**~th** 

### additional controltechnology, butin the EPA 

### COOlrol Cost Manual, 

### E?A Slates that most absorbers haveremoval efficiencies in excess of90%, and packed towerabsorbers haveremoval efficiencies as high as 99.9% ("EPA 

### AirPollution Control Cost**~1anUe.1",** Sixth ed., EPA-452-o2-Q01. January 2002. Section 52, Chapter], pg 

### J-3). 

### CFAC Response Theoretical analysis supported by actual reference plant data validates our 90% 802 wet scrubber efficiency assumption as appropriate. We do not believe our S02 control level of 90% is underestimated. 

### The scrubbers listed in the EPA Cost Manual (i.e., packed column absorbers) can remove up to 99% of the 

### SO, from a sufficiently concentrated stream. The absorption mechanism is driven by a concentration gradient of the absorbed gas between the 

### scrubbed vapor and the liquid solute. A large majority ofthe data on 

### SO, scrubbers has been collected on flue gas streams from coal-fired power plants or sulfide ore reductions where the SOz concentrations are typically 3-6% or more. A 6% S02 concentration is equivalent to 

### 60,000 ppmv. Removing 99% of this stream still leaves 

### 600 ppm, or approximately 

### double the 300 ppm inlet 

### SO, concentration of an aluminum primary stream 

### (and 300x Iypicalroofemissions.) Even with high liquid/gas ratios (20- 40 gal/1 000 acfm), absorption from these dilute streams will be very slow. The European Union Document, "Reference Document on Best Available Techniques in the Non-Ferrous Metallndustries,"z comments on the treatment of dilute streams: UThe combustion gases add to the overall gas volume and result in a very low 

### sulfur dioxide content, which is very

### difficult to remove effectively."

2 European Union "Reference Document on Best Available Techniques In the Non Ferrous Metals Industries," December 2001, Section 3.1 1 1 1 Attachment A Page 7

### Even the hypothetically 95% efficient packed column scrubber example in the EPA Cost Control Manual' describes an inlet concentration of 

### 1871 ppmv of HCI (a gas with very high solubility in water). 

### Both technologies studied most extensively by CFAC, single and dual alkali scrubbers, use the same primary stage reactor, a fe-circulating NaOH tower. We studied both the packed column and spray column configurations. The dual alkali stage simply accepts the outlet stream of the primary stage and precipitates the sulfates as insolubJes. This secondary reaction has its own efficiency which, although high, is something less than 100%. It is apparent that the efficiency of either system can be no better than that of 

### the first stage, which, due to the inlet concentrations of only 

### -300 ppmv, we estimate at 90%. 

### The European Union Document, "Reference Document on Best Available Techniques in the Non-Ferrous Metal Industries" specifically describes potrine emissions having a 

### concentration of 50-400 mg/Nm3 

### prior to wet scrubbing and 5-40 mg/Nm3 

### after' - a 90% reduction. In another section, the E.U. Document lists in Table 4.6, Section 4.2.4.2.11, that for VSS smelters, uncontrolled S02 emissions;; 10-30 kg/metric ton and "wet scrubbed" ;; 1-3.5 kg/metric ton. This corresponds to efficiencies ranging from 88-90%. VSS operator, Northwest Aluminum (the Dalles, Oregon), collected data from an NaOH 

### spray column scrubber over a period from 

### 1996-2000 and recorded an average 

### SO, removal rate of 91%.5

I':PA Comment #7 Modeling 

### 7. TheBARTanalysis contains modeling performedby

### BisonEngineering. Theres.t.lt5 provided in the BART analysis sho'-\' the impact aE GlacierNational Park. CFACneeds 

### to p'ovidetheresult; ofthemodeling for other Class I areas 

### in theStateand reportall maximum impDCCS greaterthan 0.5 dv for each year. 

### CFAC Response Bison had previously completed the modeling for all of the required Class I areas, but only reported the impacts on Glacier National Park because it is the closest and most 

### directly impacted. The impacts at all other modeled Class I areas also show maximum visibility impacts of less than 0.5 deciviews. To be complete, Bison has attached the results of the modeling on all of the Class I areas. All modeling files can be supplied to EPA upon request.

3 EPA Cost Manual, 611\ Edition, Section 5 p,1-32,
4 European Union -Reference Document on Best Available Techniques in the Non Ferrous Metals Industries," December 2001, Section 4.2.1.2.5. 5 NWA S02 analysis data: attached. Attachment A Page 8The results listed in Table 2 below are the 8th high, which is considered equal to the 98th percentile receptor in that Class I area. 

### Table 2: CFAC Visibility Impacts for All Modeled Class I Areas
Modeled Year 2001 2002 2003 Average of (Delta Dv) 8th High (Delta 0'1) 8th (Delta Dv) 8th High 3 Years Class I Areas Modeled Hich Bob Marshall Wilderness Area 0.462 0.428 0.603 0.498 Mission Mountain Wilderness Area 0.425 0.448 0.348 0.407 Cabinet Mountain Wilderness Area 0.199 0.266 0.316 0.260 ScapegoatWilderness Area 0.276 0.211 0.306 0.264

EPA Comment #8 

### S02 .Emissions 

### and Control 

### 8. TheBARTanalysis onlyexamines fiveadciitiooai technologies as possibleBARTfor 302 control. The BARTGuiddincsslate**~'A** 

### vailablcretrofit control options are those air pollutioncontrol tecr..nologies v.-itb :::l practical potcnriaJ for epplic::!tion to t.1-tc: emissions 

### unitandthe regulmcdpollutant under evaluation. Air

### .pollutioncontrel Icchnologies Carl 

### include awide variety ofavailable methods, s)'stems1 

### andtechniques forcontrol ofthe affected pollutant. Technolog,ie.s required as BACTor L.A.ER are available for BART

Attachment A Page 9

### purposes andmus, 1>eincluded. as control alternatives. The control alternatives can includenot only existing controls for the source category in questionbutalso takeinto account technology

### transrerofcontrols**~hal** 

### havebeenapplied La similar

### source categories cmdga.s .streams." (sce

### 70 FR 39164). In addition. 

### the BARTGuidelines state "Yeu

### a:.-c expected Lo identifypotentiallyapplicableretrofit

### control technologies thatrepresent the full renge

### oidemonstrated alternatives. Exunples of

### general 

### infonnauon sources 

### to considerinclude: •The

### EPA**~s** 

### CleanAirTechnologyCenter,which inciudes the 

### RACTIBACTILAERClearinghouse(RELC);' Stateand Local BestAvailableControl Technology 

### Guidelines--many agencies haveonlineinfonnation--rorexample SOt.rth CoastAir Quality

### lvfanagcmentDistrict, Bay**Are~** 

### Air Quality !'vjanagementDistrict, and TexllS 

### Naru..ral Resources Conservation Commission; •Control technology vendors; • Federal/Stare/LoadNSR 

### permilS 2nd

### associatedinspection!performancelestreports; • Environmental 

### consultants; •Technicaljournals, 

### reports 2nd 

### newsletters, air

### pollution control 

### seminars; and" The EPA'sNSR bulletin board-hnp://v..-"\

....w.epa.govlttnlnsr:

.. 

### DepartmentofEnergy's Cle,m CoalProgrem-tcchnical reports; •TheNOX Control Technology :'CostTool"-CleanAir Ma.rkets Division Web 

### pagebttpJIVNv"W.epa.govJainnarkets/arp/noxicontroltech.btm.l;· 

### PerfonnGnreofselecri;:e catal)l::icreduction oncoal-firedsteam generatingWlits-final 

### repon. OARJARD: June j

### 997 

### (also available at

### hnp:IIVoww.epa:govlalnnarketslarp/noxicoDtroltech.hlmJ);· Cost estimates for 

### selected applications 

### ofNOX control technologies 

### on stationarycombustion boilers. 

### OARJARDJune 1997. 

### (DOCketforNOX 

### SIP Call, A-9&-56; 

### item 11- A--03);' Investigationofperfo:-oance and costofNOX controls as applied 10 group 2 boilers. 

### OAR/ARD, 

### August 1996. 

### (Docketfor Phase IINOX 

### rule, 

### A-95-28, item

### rv-A-4); • Comroiling S02 Emissi.ons: A ReviewofTechnologies. EP.A.-600IR-OO-Q93, USEPAf 

### ORDINIl'-1RL, October

### 2000; and •

### TI,e OAQPS Control CostManual," (see

### 70FR 39164). \Ve have identified

### otherpoteotial controls for 802 thatCFAC**n~ds** 

### to include

### in the BARTanalysis. The EuropeanUnionbas sponsored an analysis ofpotential controls for various industries nnd based ontheiranalyses, the**follo,~iDg** 

### improvements are available forconventional vertical studSederberg 

### electrodes

## wreduce

### particulateand sulfur dioxide 

### emissions (European Commission. 2001. "l{efe::rence**Doeurn~nt** 

### on Best AvailableTech.rtiques in theNon Ferrous Metals lndustries." Ir.(egrafedPoilu/ion 

### PrevenlionalldControl(IPCC) scrics, hnp;llc;PDcb.;rc.esJoagcslf

....ctivities.htm 

### page 286) (see attached disk). Automatic alu.rnina pointfeeding a.'ld control ofelectrolysis (provides bener control andmore 

### accuraw feeding ofalumina to the 

### bath)**~ompJete** 

### skirt

### coverage ofbath crust (gas 

### collection skin is connected to 

### a 

### simple gas burnerleading to 

### agas exhaust**tube~** 

### the burncr

### burns emitted CO and hydrocarbons) The use of"ciry paste" 

### V"jth a 

### towerpitch contentImproved burnerfor :':,cineration 

### ofPAHs arid 

### other hydrocarbons in 

### potexhaUSl gas Completehood coverage oftne: anode top, which !s cO£mccted 

### to a separate 

### gas exhaust a'1d 

### drJ 

### alumina scrubberordry anode :op in combination with stud hold paste and increased anode height depending on**effectiver~ess**

Attachment A Page 10

### CFAC Response As a result of this EPA comment, CFAC again surveyed likely sources of information concerning 

### 502 controls on aluminum reduction facilities. A brief compilation of comments appears in Attachment H. CFAC has also reviewed the additional S02 

### controls listed by EPA, and offers the following comments: During the years 1976 to 1980. the Columbia Falls aluminum reduction facility was converted to Sumitomo aluminum reduction technology. Please refer to the attached 

### July 7, 2003, letter from CFAC to MDEQ that summarizes the Sumitomo conversion project (Attachment I). Most of the items referred to in the European Commission 

### document were a part of the CFAC facility's conversion to Sumitomo technology. In addition, as part of the Sumitomo conversion, the primary air pollution control system was changed from a wet scrubbing system to a more effective 

### dry scrubbing system. Below is a summary of the Sumitomo conversion as documented 

### by MDEQ on page 4 

### of CFAC's Operating Permit Technical Review Document: "The facility underwent significant improvements between 1976 and 1980, when all aluminum reduction cells and polline operation were converted to Sumitomo 

### Technology. Sumitomo Technology was adopted by the Anaconda Aluminum Company (AAC) in an effort to reduce particulate and fluoride emissions from the facility, and to show compliance with Montana's stringent Fluoride Standard. The 

### Sumitomo Technology, purchased by AAC from the Sumitomo Chemical Company LTD, is a combination of engineering (structural) changes to the aluminum reduction cells, operational, and process changes, and raw material changes, for Soderberg aluminum reduction cells and potlines. Other benefits, besides reduced power consumption and reduced emissions (power consumption, as claimed 

### by the Sumitomo Company, could easily be 

### reduced by 15-20% and emissions of hydrocarbon smoke and fluoride could be reduced by 50%

...), realized by AAC when adopting the Sumitomo Technol09Y 

### were a dramatic increase in cell operating lifespan and a reduction in man-hours required to operate and maintain the facility. 

### During that same time period (1976-1980), AAC also converted the Columbia Falls facility from multiclones and wet scrubbers to Alcoa A398 Dry Alumina Scrubbers as its primary emission control device, and installed ten dry scrubbers operating in two groups; four dry scrubbers for the West Plant and six dry 

### scrubbers for the East Plant. Dry Alumina Scrubbers are designated as appropriate primary pollution control devices for the purposes of the Aluminum MACT." Large fluoride emissions reductions were achieved after the conversion of CFAC pots to 

### Sumitomo technology. The attached Chart 1 illustrates historical fluoride emissions from 1957 to 2007. The Sumitomo technology conversion at CFAC was completed in 1980 and the impact of this conversion is evident in the fluoride emissions reduction 

### illustrated in Figure 1.

Attachment A Page 11

### Figure I: CFAC Historical Fluoride Emissions 

# 1' 0 Ib

# F/~ Operating

# 1
Potlines



# "



# - '--- 

# , 

# - <Il • 

### o o , o 

# . - CFAC HISTORICAL FLUORIDE EMISSIONS



# ,.. , 

# : J

# .lu,u,u,u,u,u,ll,U,U.~.~.~ll,IlJJJlJl.ll.Iln.n.OillUUtn._.n..".......JI**~=~o-N~i~=~=~O-N~~~=~==O-N~~~=~==O-N~.~!~=~g-N~~~=~ ~~;~~~~_~~~~~~;;~;~~;~;~;~~~~~~e;;~e;;e_;~;~~~~~~~~**  

### Year
Below are point-by-point responses to questions raised in EPA's letter. -Automatic alumina point feeding and control of electrolysis (provides better 

### controlandmore accurate feeding ofalumina to the bath) In the past, CFAC has investigated and experimented with point feeders on the 

### pots in the facility. Between 1982 and 1986, GFAG experimented with different point feeder designs, but abandoned the project due to the feeder plugging up with alumina are and cryolite bath behind the gas collection skirt. In 1992, another attempt at point feeding began, with a modification to the previous 

### design used in the 1980s. Point feeding experiments continued until June 2002, when the effort was abandoned. At the time of project curtailment, point feeders were operating on 15 pots. CFAC's point feeder project was ended because of 

### are feeding difficulties, high iron in the aluminum metal and muck forming in the bottom ofthe pots, reducing pot efficiency. The aluminum reduction process at CFAC is controlled 

### by PLCs (programmable 

### logic controllers) and computers using voltage input signals from the pots to determine feed cycles and duration. The software for this system was customized for CFAC 

### by outside consultants, who continue to work on process 

### optimization. -Complete skirt coverage ofbath crust (gas collection skirt is connected to 

### a simple gas burnerleading to the gas exhaust tube; the burnerbums emitted

### GO andhydrocarbons)

Attachment A Page 12

### CFAC currently uses this technology. One aspect of the Sumitomo conversion was the installation of gas collection skirts to improve primary air pollution control system collection efficiency. Slotted burners were installed on each end of each 

### pot to allow the induction of combustion air into the pot gas stream to combust carbon monoxide and hydrocarbons. This system is still in use today.

.The use of 

### "drypaste" with lowerpitch content. Improvedburnerforincineration 

### of

### PAHs andotherhydrocarbonsin the potexhaustgas CFAC currently uses this technology. As part of the Sumitomo conversion, 

### anode operation was converted to use "dry paste" to reduce hydrocarbon emissions. As mentioned above, slotted burners were installed on each end of 

### each pot to allow induction of combustion air into the pot gas stream to combust carbon monoxide and hydrocarbons. 

### -Complete hood coverage of the anode top, which is 

### connected to a 

### separate gas exhaustand

### dryalumina scrubber, or

### dryanode top in combination with stud 

### holepaste andincreasedanode heightdepending on effectiveness CFAC has already implemented this measure at the Columbia Falls facility. The Sumitomo conversion at CFAC specified 

### dry anode tops in combination with stud 

### hole paste and increased anode height. At CFAC, the effective anode height was increased by using "dry paste- briquettes and filling the anode shell 

### completely to the top (rather than partially filling the anode shell with "wet paste" as had been done prior to the Sumitomo conversion). As a result of the investigations with the references in Attachment H, CFAC has revised 

### its opinion of the Spray Dry Absorber (SDA) for primary SO, control. The SDA was preViously rejected as technically infeasible control technology (in the original BART 

### analysis dated November 5, 2007). CFAC, after several positive references, now believes that an SDA would be a technically feasible method of controlling SO, from the primary gas streams. As such, CFAC has prepared a cost estimate for this control methodology (found in Attachment D), and has carried that forward to a cost per ton of 

### S02 removed, and a cost per deciview improvement.

EPA Comment #9



### 9. On Page4·9 ofthe 

### reportyou state "Significam 

### process improvements ovcrthe currem 

### efficiency. whilehighJy

### desirable, are verydifficultto achieve: and mustbecategorized as technically e>:perimental atthis point.': 

### CFACneeds to include ananalysis Ortechnical justitication in 

### the**B.A...~T** 

### analysis forthis s!ate!TIcnt.

Attachment A Page 13

### CFAC Response CFAC's statement from the November 5,2007, report was intended to point out that the aluminum reduction process is one in which carbon anodes are consumed 

### by electrolytic reduction reactions, which are less than 100% stoichiometrically efficient. Consequently, there is a theoretical limit to how much reduction in carbon usage could be achieved. The following reactions account for most ofthe carbon consumption: 

### 1. 2AI203 + 

### 3C 4AI + 

### 3C02 1 2. 2AI203 + 

### 6C 4AI + 

### 6CO 1 An absolute minimum theoretical lower limit of 0.33 Ibs carbon per Ib aluminum was 

### described in the November 5, 2007, submission. The following is offered to provide a more detailed explanation: 

### The 0.33 Ibs carbon per Ib aluminum theoretical limit could only be achieved if 100% of the reduction reaction took place via reaction (1). In practice, from 10% - 20% of the reduction takes place via reaction (2), and because the secondary reaction consumes exactly twice the carbon to reduce the same amount of aluminum, a more realistic lower 

### limit is about 0.39. Some pre-baked anode facilities operate at ratios as low as 0.45 but, worldwide, Soderberg-anode plants operate at about 0.55. 

### Whether the theoretical limit is 0.33 or 0.39 is not particularly important, because actual plants in operation do not approach these theoretical limits. Aluminum producers in the 

### United States and elsewhere have worked hard to improve process efficiency. A 1956 reference text6 states, "The carbon for the reaction comes from the anode, for which is 

### required from 0.6 to 0.7 Ib of carbon per pound of metal." Improvements to anode and cell design have improved these ratios significantly since 1956. A 1994 draft report, "S02 Emissions from Primary Aluminum Production,,,7 prepared for EPA, described the 

### 23 (US) primary aluminum plants in operation at that time. It states: "The coke and pitch are consumed at a ratio of roughly 0.45 to 0.55 Ib (carbon) per Ib of aluminum." Even though it would be a boon to aluminum producers worldwide, that ratio has not 

### been significantly improved since 1994. The CFAC 1999 data referenced in this BART analysis describes a carbon/aluminum ratio: Pot Lines 3, 4, 5 - 61659 tons carbon / 

### 112582 tons aluminum 

### = 0.547. At CFAC (a vertical Soderberg smelter) only a comprehensive conversion to a prebaked anode facility could significantly improve the ratio. A conversion such as this was 

### accomplished by Reynolds Aluminum at their Messina, N.Y. facility (now owned by ALCOA) for a cost of
- $200M.'

6 The Chemical Process Industries, Shreve, McGraw Hill, 1956, p.317 7 "502 Emissions for Primary Aluminum Production," unpublished review draft, April 1994, Marvin Branscome, Research Triangle Institute. S Phone conversation: J. Parker/M. Palazzolo, Alcoa, 3/12108 Attachment A Page 14EPA Comment #10 

### to. CfAC 

### needs to document El.I1Q e:-:plairilhe u.s:e ofa 1,5 

### retrofit factor that is included in the cost analyses. CFAC 

### Response CFAC, Bison and Performance Industrial Company (PICO) collaborated on the cost estimate methodology used for the various 

### 502 

### scrubber estimates. All three entities have experience in applying retrofit cost factors to pollution control systems. The universal consensus was to use a 

### 1.5 retrofit factor due to the enormous complexity and size of the proposed systems, and the fact that these types of control systems were not envisioned to exist or planned forwhen the plantwas originally constructed. The EPA Air Pollution Control Cost Manual- Sixth Edition (EPA 452/B-02-001), Section 2.5.4.2
- states the following: "The proper application of a retrofit factor is as much an art as it is a science, in that it requires a good deal of insight, experience, and intuition on the partof the analyst. "The magnitude of the retrofit factor varies across the kinds of estimates made as well as across the spectrum of control devices. At the stUdy level, analysts do not have sufficient information to fully assess the potential hidden costs of an installation. At this level, a retrofit factor of as much as 50 percent can be justified. Even at detailed cost level (± 

### 5 percent accuracy), vendors will not be able to fully assess the uncertainty associated with a retrofit situation and will include a retrofit factor in their assessments." Given the experience of the three entities performing the cost estimates and the quasiguidance from the EPA 

### manual, a retrofit factor of 1.5 

### was chosen for this installation.

EPA Comment #1 t



### II. Forall analyzed tc:cb_Tlologiesin the**analysis~** 

### operating laborfigures arebased on three full 8-hourshiftswith wee to six operators at atime. significantly increasing the laber 

### costs. In 

### the EPA Control Cost!\,[anual, the number

# orhours for 

### an operator

### is ahalf hour per8-hour shift (EPA 

### 2002, Section S, Chapter I, pg. j 

### -26). CFAC needs 10 

### reevaluateoperating laborfigures based 

### onLl,e EPA 

### Control Cost Manual 

### uslog 1,642.5 hours (0.5 hOlliS far each ofthree 8-hour shifts vtith one (1) operator).

CFAC 

### Response EPA Comment #11 references the EPA Cost Manual's sample calculation for the operator costs associated with a single packed column device operating at 22,288

AttachmentA Page 15

### acfm.' At 204,000 acfm, the process equipment we estimate for CFAC would be approximately 10 times the size of that referenced in the EPA example. All flows of process chemicals, water, and waste are proportionally higher as well. For this 10X larger scale operation, process excursions, whatever the cause, have 10X the potential for financial and environmental impact. As such, CFAC feels 24/7 operator attention is required. In addition and more importantly, the reaction described in the Cost Manual reference example is a simple Hel > NaOH reaction in which the waste product, table 

### salt, is simply discharged to a municipal sewer

### w The waste products at CFAC, whether sodium sulfate (in a single alkali process) or the mixed salts, calcium/sodium sulfite/sulfate (in the dual alkali or spray 

### dry processes), are waste streams which must 

### be monitored, handled, and disposed of in a controlled manner. All this requires 24/7 operator attention. 

### After considering EPA Comment #11, CFAC has lowered the Single Alkali operator load to 1 operator, 3 shifts/day, but argues that the Dual Alkali process with its associated slurry make·up, reaction vessel monitoring and solids filtration/disposal would require no less than 

### 2 operators per shift, 

### 3 shifts per day. Appropriate reductions to operating labor have been made to the affected cost analysis 

### tables in Attachments B, C, D, E and F. The operator costs for the Spray 

### Dry Control analysis, which was added in response to EPA comment #8, are estimated to be the same as the Dual Alkali process.

EPA Comment#12 

### 12. Theanalysis used 10yearsforthe remaininguseful life 

### forall ofthe control technologies. However, the**ty~ical** useful life ofthese control technologies is expected to be 15 years based on 

### infonnation from theEPA Control Cost 

### Manual (EPA 2002, Section 5.2, Chapter 1,pg. 1-2&). CFAC needsto reuncl.yze the anIlUclized 

### costs forthe contrOL technologiesusing fifteen years as provided in the EPA Control Cosr Manual.


### CFAC Response CFAC understands that the useful life expectancy of a wet scrubber is up to 15 years; however, CFAC still believes a 1O-year basis for BACT and BART analysis is standard and typical. This is based on financial concerns (i.e., duration of financing rather than 

### equipment life expectancy). To be complete, CFAC has analyzed the annualized cost for 15 years. As you can see in Tables 3 and 4 below, the annualized costs for the dual 

### and single wet SO, scrubbers and spray dryer do decrease; however, the changes are not large enough to substantially affect the results of CFAC's BART analysis as to whether the control devices are economically feasible on a $/ton or a $/deciview basis.

II EPA Cost Manual Sixth Edition, Section 5, page t.32. 10 Ibid, page 1.42. Attachment A Page 16As a result of the revised cost analyses contained in this attachment, CFAC has prepared a table (Table 6) containing a matrix of combinations of PM,o and S02 controls 

### similar to the previous Table 4-8 (Summary of SO,/PM" Emissions Cost Analysis and Visibility Impacts) contained on page 4-26 of the original BART analysis report. This table shows a range of combinations of control strategies for 502 and PM,o, with associated costs, declview improvements, and 

### $ per deciview amounts. 

### Please note that, although CFAC did add a Spray Dry Absorber (SDA) to the list of technically feasible SO, control technologies, CFAC has not included the SDA in the matrix table (Table 6) because it has the same control performance (90% control) as the single and dual alkali wet scrubbers. The single alkali is the lowest cost option of the three wet scrubbers, so it represents the wet scrubber primary 502 control category in 

### the table.

Attachment A Page 17

### Table 3: Revised Primary 802 

### Emission Controls Cost Analysis and Visibility Impacts 

# I Glacier Nat'l Park SO, SO, 

# I Decivlews Capilal Annualized Efficiency Emitted Removed Cosl S02 Impact Removed {24 Cost Control Option COSI Cost (%) (Ipy) (Ipy) (S/ton) (deciviewl hr-ll)

. 'Slde1 Spray Dry**~bsorbe~)lLime**

10yrlife $34204,364 $12,519,712 90% 153 1377 $9091 2.560 0.693 $16065962 Spray Dry Absorber ILime

, (15 vr life) $34 204 364 $12179653 90% 153 1 377 S6645 2.560 0.693 $17,575545

Dual Alkali Wet S02 ScrUbber Controi'(-10 vr life) $43637616 $11476097 90% 153 1 377 $8333 2.560 0.693 $16560025 Dual Alkali Wet 802 Scrubber Control (15 vr lile) $43,637,616 $10047,430 90% 153 1377 $7296 2.560 0.693 $14498456 Single Alkali WeI 802 Scrubber Control I (10 vr life) $37027,896 $10902,195 90% 153 1377 $7917 2.560 0.693 $15731683

Single Alkali Wet S02 Scrubber Control li,5vetilo) $37027,896 $9 709 526 90% 153 1377 $7051 2.560 0.693 $14010860

Coke Sulfur Contenl Reduction SO $7,079,680 42% 887 843 510,245 2.743 0.510 $13,881725 Baseline (Total) SO SO 0% 1,530 0 

### -- 3.253 0.00 

## --

Attachment A Page 18

### Table 4: Revised Secondary SO, Emission Controls CostAnalysis and Visibility Impacts

Glacier Nat'l Park SO, S0, Deciviews Capital Annualized Efficiency Emilled Removed Costb S02 Impact Removed (24 Cost Control Option Cost Cost (%) (Ipy) (Ipy) (S/lon) (deciviewl hr

- Dl (Sfd,' RoofVent S02 Control (Spray Room)- 10 vr life $42,350.409 $13,121,647 50% 58 58 $227,865 2.435 0.818 $16,041,133 RoofVent S02 Control (Spray Room)
- 15vr life} $42,350,409 $11741447 50% 58 58 $203,897 2.435 0.818 $14,353,847 Coke Sulfur Content Reduction SO 57,079,680 42% 67 48 $10,245 2.743 0.510 $13,881,725 Baseline /Total} SO $0 0% 115 0 

### -- 3.253 0.00


### --

Attachment A Page 19EPA Comment#13 Particulate MatterEmi!o>sions and ContToIs 13. InsectiOIl 3.8 you stateth::n 

### "la)lthough the six dry alumina scrubbers are eligible for BARTanEllysis, CFAC believes tOa! the currentPM10 control isalready the bestpossible <:.t 99+% cOnlrQlandfmther improvement could notbe practicru]yaccomplished." CFAC**n~ds** 10 provide the design para.'1letcrs for**th~** dry aluminascrubbers and an analysis of how the clli,cnl PMJ

## acontrol is at99+%. CFAC Response The six scrubbers are Alcoa A398 Dry Alumina scrubbers with associated baghouses. CFAC does not have an air quality permit requirement to perform PM" tests on the scrubbers, and has not performed these particulate tests. For purposes of this BART analysis, CFAC has relied on manufacturer's information and generally available information regarding the particulate capture efficiency ofthe baghouses. The baghouses were manufactured by Wheelabrator (now Siemens), and are a modern design pulse jet baghouse. Each alumina scrubber baghouse contains 5406.25" x 107" polyester felt bags. The bags used by CFAC are GE Energy PEO-72 fabric, a material typically used in this type of installation in the aluminum industry. GE Energy stated that, although a complicated test designed to simulate CFAC's specific operating conditions would have to be performed to quote an outlet grain loading specification, they nominally rate that type of bag at 99.997% capture efficiency." Another source of information on baghouse performance, EPA literature (fabric filter fact sheet: http://www.epa.gov/ttn/catc/dir1/ff-pulse.pdf) shows a modern baghouse with a 99+% removal efficiency for PM 10. CFAC believes that the existing alumina scrubber is a particulate control device that has one ofthe highest available capture efficiencies, performing equal to or better than other types of particulate control devices. Therefore, CFAC has not analyzed the six alumina scrubbers for additional BART control for PM".
1':1)1\ Comment #14 14. In section 4.3.2 (it) 

### it is staled that "'CFACbelieves thatadded exhausthood capture efficiency would b::: expenmen1a] in nature and could only corne atthe expense ofaccess to the pol'; for nomal operations and interference wi'!.b thtexistingprocess." Please provideevidence and supporting docmnentalicn to show**L~at** further reduction is not possible Or is cKpeiimental.

11 Conversation between Chris Hiltunen of Bison and Eric Huggins at GE Energy, 4/8/08. Attachment A Page 20

### CFAC Response To operate Vertical Stud Soderberg anodes, access must be maintained to the anode 

### tops for stud (pin) pulling tasks. Stud pulling and re-setting the studs is an integral operation of a Soderberg anode and is usually done by overhead cranes. Hooding of anode tops interferes with the existing overhead crane operation. CFAC is not aware of any commercially available hood retrofits. Any retrofit would have to be custom engineered, designed, fabricated and prototyped on a trial basis. Experimentation, 

### testing and optimization would have to be performed to detenmine if hooding that was actually effective in reducing pot emissions would interfere with required operational access. 

### Rather than try to design a system to maintain Soderberg stud pulling activities while hooding the Soderberg anode, some aluminum companies have chosen to convert the Soderberg potlines to pre-bake potlines. This option was discussed in the European Union BAT document. Using estimating techniques from the European Union SAT 

### document (pg 722), the cost to convert CFAC's facility from a Soderberg facility to a pre-bake facility is estimated to be: Vertical Stud Soderberg (VSS) conversion to 2500 - 4000 Euros per Metric ton annual production Point Feeder Pre-Baked Anode Operation $3400 - $5400 per short ton Using this approximation, CFAC cost to convert: 5382,000,000 - 5734,000,000 (at 112584 tonslyr I oroductionl

EPA Comment #15 

### 15. Theestimatedcapital equipment COst for

### thebaghouseincludes

## meuse ofagasflow rate inorderto calculatethe required

## fr' offilterbag cloth. The flaw rete used in Appendix C, which is 3,000.000 acfm perpo! :,oorn, 

### is not consistent

### with the value reported on page 

### 4-6, wlrich is 6,080,000 acfin perpotline. Thcvalues in Appendix C and on page 4-6 ore also inconsistent 

### viiilithe flow rate 

### n::pon<:d [or fugitive sources in the 

### 2005 MOnlana 

### Deparum:ntofAirQuaHly ernissions inventory for CFAC (330,000 acfm). CFAC needs 

### to pfO'vide additicnal**dQcumen~tion** 

### or. theresults ofany measurements of

### the: 

### flow rate, on the flow rate usedtocal::ulale lherequired

## ft?offl.lter 

### bag**clOI.~** 

### in the tOSt 

### analysis, andan analysis ofwhy the nwnberuseri in AppendixC differs from boththenumber used on page 4-6 and

### the: flov.! mtcreported for fugitive sources in 

### the2005 Montzna 

### Dcpa.tT.mentofAirQuality emission inventory.
CFAC Response The CFAC facility has five potlines, each poUine consisting of two potrooms, for a total 

### of ten potrooms. CFAC has years of fluoride stack testing data which measured potroom airflow rates out the roofvenls, and believes Ihis is quite accurate. CFAC used long tenm averages of this data to calculate the flows used in the BART analysis. An example of this data is included in Attachment 

### J, which is the f10wrate data from the 

### 1999-2000 MACT testing. The airflow rates shown in the one year in the example provided are approximately 6,000,000 acfm per potline. There are two potrooms per Attachment A Page 21potline, so approximately 3,000,000 acfm per potroom multiplied by two equals the longterm average of 6,080,000 acfm per potline. CFAC is still unsure where the 330,000 acfm came from, but no such flowrate is 

### reported on the annual MDEQ emissions inventory, and this value is clearly incorrect.

EPA Comment #16 

### 16. CFAC needs todocumentand explainthe useofa 1.S retrofitiactor

### that is

### i..:.'1cJudcd in 

### thecosta.:.ialyses.
CFAC Response CFAC, Bison and Pica collaborated on the cost estimale methodology used for the various PM 10 control technology estimates. All three entities have experience in 

### applying retrofit cost factors to pollution control systems. The universal consensus was to use a 1.5 retrofit factor due to the enormous complexity and size of the proposed systems, and that these types of systems were not envisioned to exist when the plant 

### was originally constructed. The EPA Air Pollution Control Cost Manual
- Sixth Edition (EPA 452/B-02-001), Section 2.5.4.2
- states the following: "The proper application of a retrofit factor is as much an art as 

### it is a science, in that 

### it requires a good deal of insight, experience, and intuition on the part ofthe analyst. 

### "The magnitude of the retrofit factor varies across the kinds of estimates made as well as across the spectrum of control devices. At the study level, analysts do not have 

### sufficient information to fully assess the potential hidden costs of an installation. At this level, a retroflt factor of as much as 50 percent can be justified. Even at detailed cost level (± 5 percent accuracy), vendors will not be able to fully assess the uncertainty 

### associated with a retrofit situation and will include a retrofit factor in their assessments." Given the experience of the three entities performing the cost estimates and the quasiguidance from the EPA manual, a retrofit factor of 1.5 was chosen for this installation.

Attachment A Page 22EPA Commcnl #17 

### 17. For the 

### analyzed tccp..nologics, operating 

### laborfigures are based on 24 hours oflabor to 

### operate the equipment, signifiC3..'1tly increasingthe laborcosts. 

### b. the EPA Control Cost Manual, thenumber

### ofhours for an oper.2toT is

### 2-4hours per 8-hourshift (EPA 2002, Section 6, Chapter I, pg. 1-44). CFAC needs to 

### revise 

### Loeoperating laborfigures 

### baseo ontheEPA Cont!ul CostManual using 2-4 hours per 8 hourshift. 

### CFAC Response The secondary ("roof top") processes described here are very large in scale. In the roof-top Spray Chamber for example, there are 96 secondary spray rooftop chambers each approximately the size of a railroad boxcar. Each chamber is fitted with 4 spray bars holding 12 nozzles each (48 individual spray nozzles per chamber) and a 6' 

### x 10' 

### chevron mist eliminator. These 96 de-mister pads and over 4600 nozzles gradually plug and foul with precipitated salts and particulates and must be cleaned, replaced and repaired. The piping which feeds the spray bars is PVC and susceptible to freeze 

### breakage if flow is impaired during cold weather. An EPA report on the development of proposed standards for the primary aluminum industry" states that the daily average low temperature in Columbia Falls is below 27°F 40% of the year, making it mandatory to keep any water-based system such as the spray chamber flowing 24 hours a day to avoid freeze-up. Maintenance and operation of this corrosive system of 

### 4600 nozzles, 

### 48 ten-foot 

### diameter rooftop fans, each operated by 60 HP motors, and 15,000 feet of associated piping, along with the monitoring and pH control of the recycle tanks and evaporation ponds is a 24-hour/day job for at least two operators. These operators could concurrently keep track of a less demanding, lower maintenance control system such as 

### a primary scrubber for potline exhaust, but would in fact need to be available strictly to support rooftop systems when the situation demanded it. 

### Particularly in the case of the rooftop baghouse concept, one could totally ignore operating labor and maintenance costs and the annual operating costs would still be prohibitive.**~:PA** Comment #18 

### t8. The analysis used 10yearsfor the remaining

### useful lift: 

### for all

# orthe

### control technologies. However,the

### ty,ical useful life

### ofthese control 

### teehnojogiesisexpecledto be20years based on information from r."'e**EP.A~** 

### Control Cost Manual 

### (EPA 2002. Section 5.2, 

### Chapter 1, pg. J

### -28). CFACneeds to reanalyzethean.!lUaJized costs ror

### Li-}e control !ec.hnologiC,5 usiog20

### year.:; as provided l!llhe EPA Control CostMGnual.

12 Basis and Purpose Document for the Development of Proposed Standards for the Primary Alummum Industry, US Environmental Protection Agency, OAQPS, July 19, 1996. page 22. Attachment A Page 23

### CFAC Response CFAC understands that the useful life expectancy of a fabric filter baghouse is up to 20 years; however, CFAC still believes a la-year basis for BACT and BART analysis is standard and typical. This is based on financial concems (i.e., duration of financing rather than equipment life expectancy). CFAC believes the financing and depreciation of this equipment over 20 years is excessive and could not be accomplished at CFAC. To 

### be complete, CFAC has analyzed the annualized cost for 15 years, to at least be consistent 

### with the revised 502 calculations provided in response to EPA Comment #12. The analysis included updating the cost analysis using EPA's Control Cost Manual, 

### 6th 

### Edition, as discussed in EPA Comment#12. As you can see from Table 5 below, the annualized cost for the fabric filter baghouses does decrease with the change to 15 years; however, the changes are not large enough to substantially affect the results of CFAC's BART analysis as to whether the control devices are economically feasible on a 

### $/ton or a $/deciview basis. As a result of the revised cost analyses contained in this attachment, CFAC has 

### prepared a table (Table 6) containing a matrix of combinations of PM,. and SO, controls similar to the previous Table 4-8 (Summary of S02/PM lO Emissions Cost Analysis and 

### Visibility Impacts) contained on page 4-26 of the original BART analysis report. This table shows a range of combinations of control strategies for S02 and PM1o, with associated costs, deciview improvements, and 

### $ per deciview amounts. 

### Please note that although CFAC did add a Spray Dry Absorber (SDA) to the list of technically feasible SO, control technologies, CFAC has not included the SDA in the matrix table (Table 6) because it has the same control performance (90% control) as the single and dual alkali wet scrubbers. The single alkali is the lowest cost option of the three wet scrubbers, so it represents the wet scrubber primary SO, control category in the matrix table.

Attachment A Page 24

### Table 5: Revised Secondary PiVIIO 

### Emission Controls Cost Analysis alld Visibility Impacts

Glacier Nal'l Park' PM,o PM,o PMIO Declvlews Capital Efficiency Emilled Removed Cosl Impact Removed Cost Control Option COSI Annualized Cost (%) Ilpy) Ilpy) (S/lon) fdeciviewl (24 hr -6\ (Side} RoofVent Control; I fBanhollse· 10 rlifel $569149375 $107637826 99% 2.18 216 $498739 1.621 1.632 $65954550

Roof Vent Conlrol: 

### I fBaahovse
- 15 Vf mall $569,149375 $89089,248 99% 2.18 216 $412794 1.621 1.632 554589000

RoofVent PM'Q 

# I Control: (Spray Room
- 10 yr life)) $42 350,409 $13,121,647 50% 109 109 $120.382 2.435 0.818 $16.041,133 Roof Venl PM'Q Control: (Spray Room
- 15 yr life) $42350409 $11,741,447 50% 109 109 $107720 2.435 0.818 $14,353,847 Baseline SO 0% 218 

### a .. 3.253 0.00 

### ..

Allachment A Page 25

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## Columbia FallsAlumillum Company 20110 Aluminum Drht Culumhi:t F;llb

.**.\lT:''}91~** 1400)**K'):!~:!1l** 1·H}6)**~n·~2u;** f;u

Julie Ylerkel, Air Quzlity Specialist 

### Pcrmiuing &. ComplianceDi·,.'!s!on**~1omana** Depanmen: ofEnvironmemc.! Quality POBox 200901 Helena.**~1T** 59620-090I**R~** You:,**R~quest** torkforrr.atiol1 Concerning Sumiro:TIo Ccnversicr: De.:!.f .\15 MerkeL A:; requested in your lener of**~!arch** 28. 2003. below is information regarding :he construction projects completed bet\',:eer, !976 and 1980 Zt CFAC"s aluninum ,edl.:ctior. 

### f:lciiit\'**Th~~** conSlnlction activity conductt:C**be:w~cn** !976 ami 1980 did not occuron a pmiint.: by**p,1tlin~** basis. so information C3nnOl be supplied on thot basis Belo\v is a summary of t:ach major task. '.vit!"! Stan and enc dales, and co!>",:, 1. Cell Rebuild and _-\UlOnlation

ThlS uClivily consisted**ofr~building** each ofthe 600 

### pOlS according to Sumitomo de:-;ign This**includ~d** changing the anode and cathode 

### contiguratio!ls to match Sumiwmo 

### Spt.:Cilicntions Key elemems ofthe pOi 

### convt::lsion to Sumitomo ol:sign included

.

• cathode cons"lnJoion 

### changt.:s Ie improve energy 

### cflicicncy and ca;hode life

- anode construction and**Oil::'C!.!~On** ch::nges 

### to char:t::.e lrcm a wet to a 

### ct,
.... anode

..
. 

# - - which impro

....ed energy efficiency and reduced atlodc hydrocarbon er.1issions

- inst.allation of gas collec[!on skirts to Improve p,lrr:ary 3,r po]Jmion cornroi :;,v::,!cm collection efticienC"v

• Installatior: of al..:Hmll!.tic crust b:'t;akt;:'"s <::I1C 

### e compu:er:zed con:;ol SyS,t;r:l (1:1**t:~ch** pot 10 impron: the 2.lumir:a fccdi:1g 

### cyc:c.\ll.'r;;:l.'ll<.'!il'·**j;.:,~** -**:~Il"**

Ccnwr:.ton 0:' !i'1l' pOl:- to SUmiWr.10 design beg,::) in October :97()**\\,jl~':** a test ;::ot section W;l.;:. Ii,s: com::=rtcd Af1.er successful op::=r<.llion :.){ C:ll' re$1 pOt !-t'ctio:-., the**n:n1:linin~** pots wer\.' convened rzndo:nly througnou: tne pl:":lil a,;cQr;;::lng tc po: age The fil":al pcl! cor.vc;"'Iec to Sumitomo desigOl s:o.l.r:ed up**CI~** :'.larch : i

.. 19800

Thc :·1Il::.1 COS! tOI lhi:> purtiun C! the 

### proJeci**\~a;)** 

### f:su:na:ec In June ICSf,1 tr. he S:2t,,-100.nl1O

Description The SumiIOmo anode design specified a dry anode comprised 

### oipe:roieum coke and coal tar pitch Previous 10 Sumitomo. the facility opera:.ed 

### w::h we:. mort:: f.uid anodes. To manufaciUrt: dry anode briquettes, numerous modificalions were madt: to the exisling paste plam including,

• installation

## or<l hOI oil 5)'!>tt'Jn

• redt:sign and construction ofextrude:-s to hendle [he dry P<!.SIC Stan :lr:C Er.d Datt's ?bnning for**th~** cOTl\.ersion ofthe !laste plant to Sumi:omo tecr.nology began 1:1**Augus~** 19i6 The pastepi::mt was 

### fully convened and operetional i:1 June 197Q

COSt ofthi:,;**phas~** oflhe project W;lS estimated in Junl.' 1980 al SQ6S,OOO 3. Of')' Scrubbtr

A dry scrubbing system for POl gases was designed and installed to improve the air pollution control ofthe facility, The dry scrubbing system, srill in use today, is bascd on Alcoa :'\398 dry scrubbing technology, Key elements ofthis. p:"ojeci were'

- design.**co~struc:ion** and instalJetion ofd:-v**scnl~b~r re2.c:or~** **u~cd** !a

## n:.t:d:zcc inco:ni:'l§ alull:Jn.J ere with pot**g.a5~S** in**ord~r** to**r~cU\.el LJcn~t:**  <Inc**hy::i:-aC<:.~I')l~r:** t:lilis,:;:on:-; and rerun: tne':n to**i~~** proces!'

## Attachment GTable 3a: Sulfur Dioxide Emission FactorCalculation 

## I

- 

# r Columbia Falls Aluminum Company 

## I Regional Haze Emission Inventory Sulfur Dioxide Emission Factor Calculation Assume all ofthe sulfur in the c:oke and pitch is released to the**environm~n!!~** sulfur dioxide



### - Assume none of the sulfurdioxide is captured in Ihe drv alumina scrubbers.



### - Petroleum Coke % SulfurSpecification 1.5 2007 Pitch % Sulfur 0.7



## - . East Plant Tolal East Plant Plant Potline 3 Polline 4 Potline 5 1999Aluminum Production tons 186,178 37,466 37,517 37,601 112,584 Fraction ofannual production 0.201 0.202 0.202



# -- . 1999 Coke Use
- tons 73,171 14,725 14,745 14,778 1999 Pitch Use· tons 28,792 5,794 5,802 5,815 1999 Sulfur in Coke tons 1,098 22' 22' 222 1999 Sulfurin Pitch Ions 202 4' 41 41 Total Sulfurtons 1,299 25' 262 262 Total SulfurDioxide tons 2,598 5231 524 525 Tolal Sulfur Dioxide nds 5196433 1,045,728 1 1,047,150 1049,485

..

## - Sulfurdioxide lbslton aluminum 27.9 27.9 27.9 27.9 

### I 

## ._- Assume 93%**hoodi~ ~!!icie**  ofthe ols; ie; 93% of 502 DeS to prima d scrubbers, 7% oes Ihrou h roofs 

### I Primary Dry Scrubber S02 Iblton aluminum 25.96 25.96 25.96 25.961



# -- Potroom Roof502 Iblton aluminum 1.95 1.95 1.95 1.951

4/14/2008 Allachment G - Emissions Spreadsheel.xls**';I~;;ll'** Hi: -!t --.



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## Attachmcnt HSpecific List of**EPA-Su~mestod** Sourcess Relevant Coulon!; 1 EPA Cloarlng Uouse RBLcl....:..'

_ hltpJ/cfpub.epa.gov/rblclhlmlbI02.cfm
RBle: A search orlhe RBLe database using paramelers Alumlnlm and S02 yields only two references since 10BBdescribing Aluminum processes trealing S02. Requested edvlce from EPA in locatlng more relevanl aluminum Industry docs, (see noles below.) 1) (Sept·199B,) involved permiUng for a NEW polline inslallllUon, (SWA ·Southwire. Kentucky) whore on 502 wet scrubber II prescribed to havea design efficiency of93% or greater. This is for a PREBAKE anode plant (higher concenlralions and mudllarger flow rates,) plus the requlremenls were lora NEW installation. 2) (Aug·1995) Involved expansion or an anode bake plant (AlumalC In South CMollna.) NO nevI conlrols were required. BACT p!!lcllco Was described as ·,lmplY lirolling the suUur cootont 01 tho raw materials," 

# I Texas Nalural Rcsourcoss Conservation comml ,I

### hltp:II~'AVI,v.lceq.stale.lx.us/permitling/air/rulesilederal**--'---'Ac,CeCa""OhC,CI"'~h''"''T"e<c.c,"c",CmmJ=",","~",",7.;17e7r,C,"A"r==""c"cmc,C'"I,C,,7,O,CeC,c.c."id"'"h"eO,ec.c.c,",CaC,7IyC5~,e7reC,".c,7r** pC,C,"",c.".-- occurrences In the stale ond thoy would nol be covered In tho database.

QUeeN ElIglnnorln!!, Farmingdale, NY
- DanIel Uhr Ducon was askod 10 recommend and give budgelary estlmatos fora Singlo Alkali, a Dual Alkali, and a Spray Dry process to coouollowconcentrations ofS02 in a -220,000 IIcfm 01 nUB gas. Even though their CEO, has been a developerofthe Dual Alkali system, DUCON was In favor ofa Spray Dry system over lhe other two. They believed a SingleAlhli system (such as lhe one at NWAI would pose WOller disposal problems. DUeON submittod budgotcslinlillcs of$28M lorIhe Spray Dry process and $J5M for lhe Dual Alkali, bolh orwhich camo within +f- 30% of the delail estimates PICO madefor lhe 18rne processes. 

## I Control Tochnology Vondorsl-",-'**_~_~~~-~_-** __- ----------------

Clvde BowrllDn Engjneorjno. Hanover, MD
- Rod KImball Contacted Bergman fe "Lurgl Process· (mentioned in Vatavuk) Bergman Initially boughllhe process Irom FMC but no longer uses or recommends il. ·uses far more lime· 2.5 .4.0 times stoichiometric reaction, Said Spray Dry would be a belter choice (or ease of operallon bul 90".4 efficiency may be difficlullo obaln \\;th anything less Ihao a weI systom. TurhoS9/lIC Eonlnoorluu. Parsippany, NJ
- Marguerite Svldunovlch Recommended lh81 Singlo Alkali using a packed column would be most successful due\0 low502 concentrations. Besl resclant 50% NaOH with 10% bleed rolo. 316 type SS reoulred for column. Adding Caldum sail preclpllaUon (leo Dual AIIaU) would MmOre than doubleM the cost orthe process.

Daln!t Rluflonsa 10 EPA· recommended SOllrce LISI. Shaoll 313012008: 11 13 AM1 Environmental Engineering Consultantsl ..J Barr EngineerIng BART an.lVII" Northshore Mining Co; A BART analysis for 502 emission!! "om Mldwesl region COIlI·fired gonCHaHon plonls used II retrofit factor of 1.6 due 10 crowded work areas,

MACTEC Fodoflll Progr:lms, Ellulnoorlng & Consultlng; CFAC reviewed eXlensive Midwest RegIonal Planning BART analyses conducted by MACTEC for the Lake i't.lchlgan Ar Directors Consortium. The**anal~is** included 502 cootlol and selected the same three controls as tochnlctllly (easlble: 'Advanced FGO· (a type of dual alkaJl system,) aWet Scrubbar, and a Spray Dry scrubber. Siotamant from the repor! "COllllol costs for boilerS with 101'llnlel concentrations of S02, (eg boilers Ihol firo primarily nalural gilS,) are very high." Allhough baUer processes are Inherently vory different from aluminum pot lines In torms of nUl gas temperature (>1000F VI .:300F) and S02 concentrallons. Iheir estimated caplllli costs for slmbr Inlloftallons feU within the aome range as CFAC's for olllhree opllons, ie.- $40M, However, because S02 INLETconcentralions are 100 -1000 limes higher, tolal ton5lyr removed by these installations Is roughly <lx higher(4500lpyvs 15001py,) Consequently the "cosl elfoctlvenosn" Ihoy calculate ($/ton removed) Is lower (- $2·3KJton) because Ihelrdenominator (tans) Is much higher. 

## I Industry**ASSOCIatlonsl~'** Aluminum Assoclatlol1: Director for Environmonlal Affairs· Roberl Streller MrStroller had been recommended 10 me by David MeisenheImerat EPA. Streiter slated that In genersl, 502 emmlsions hod not been a NSPS issue for the aluminum Industry. A BACTsludy roferenced In Ihe RBLC described suflurconlent control 01100 coke as ftBACT,ft and lhol BACTstandards whould be sufrlCient 10 sallslfy regional haze requiremenls. He reforred me to Mike Polaz;zolo ofALCOA. 

## I Direct communlcallons Other Industry Contactsl--"

_ Golen May· Superintendent NWA, Tho Oollos; This Vertical Soderberg plant Is a very closo anologuo ofthe CFAC Inslallation. 502 ond parliculate controls were installed and are referenced throughout our report.

Mike Pnlnuolo· Ofreelorof Environmental Health and Safely, ALCOA Aluminum: Mr. Palazzolo roferenced ALCOA'a Messina plant (folmerly owned by Reynolds Aluminum) which has been relrofilled with II '.5M acfm wei scrubberas pari ala complete conversion ollhe facmty to a SWBP plant. The Reynolds cost was "SlBO·200M and costs have gone up dramatlcaMy since then." The Messina scrubber Is single alkaR using Na2COJ (lor Max RX efficiency) bul Ihe s!ngle pass emuenl from Ihls mega·scrubberdischarflCs dircclly into the St. Lawrence without posltreatmont A separate 200,000 acfm IImestone·based wet sCfubber fortheir prebake furnaces cosl-$30M (Tolollns!alled Cost.)

Delail RelpOn.e to EPA. rec.omlllendl'ld Source U5" Sheen 3130120011: 11'13 At.1

## I EPAOPQASI '

## --'-!O~,",~',I'**MMi.Ei,~,;;,,~"i.';;m;;.;;,=, ~EfP~A=,** **~O~A~9~P~'~I~Ii~E~'D~I~A~BijC~G~';M;;;;:','M.e;;i;,e;;"'he;;;'m~e;;,",;;e~'Oo;mMm~.;;"dd';;d"'I,,;;,"A;~'"'C"O;;";;""'.'N"E<Tr:-.-** Documentallon report which yielded lIttle on Aluminum. He asked his fellowworker, larry Sorlcls 10 look but he also found lillJa. SOffels recommended Steve FfUh as a source closer to the Aluminum Industry. Fruh had been Instrumental In devolopment of the MACT guldllnos and specialized in lhe Aluminum Industry. Meisenheimer llSl(cd Frllh to contact mo, which he diet
Sieve Fruh, EPA, Soctor Polls:lo§ and Programs Division, Motllis and Mlnorals Grollp: Mr. Fruh Illid lhat the EPA hod focussed on Flourides end Particulates in generating !he MACTlulos Dnd (hnt 502 references were Iimiled. Fruh focommonded I contact Marvin Branscome.

Marvin Branscome, Rese"rch TriallCiIo Instill/te, contractor for lha EPA: Mr Branscomo said Ihal he had partic'pated In 8 short alOOy on 502 tonlrolln the aluminum indusl/)' In 1994 and would sond me II copy of the draft repor\. II was nevor publlshod. low concentrations of 502 in prima/)' aluminum slroams made II "doubly hald to deal with." He sloted thallho doslgnallon VSS2 was specincally cronted to descrIbe the Columbia Falls Sodoruorg facility because the weather conditons in the ragion of the plenl prohlblled the use of rooftop scrubbers such liS woro used nt lhe other Iwo V5S1 plants, NWAlumlnum and Goldllndnlo. bolh near Porlland on the Columbia river. He said thai the four plants total with wet roof serubuels for secondary exhausls wero 40·60-/. offlclent nnd were considered a "prohibilively expensive" option for the MACT standard. He rocalled they were casted al "aboul $5Of.1 15-20 years ago." The control method which had been accepted was 10 control the lIulfurconlent of the anode coke which, 15 years ago, cost about $7/10n for each 1% of reduction. 

## I NOX Control Technology "Cost Tool"l " \w

...v.epa.gov/alrmarkelsfarp/noxleonlroltech.hlml

### L.;'-,W::;:"'~=O"d",~"C.""~"kC.lc"",;:."It,,,C."~""d"bOV'"'--P"A""C,o.C,"',"to"'b.=,,,,,,,=.c'","b"'.', 

### ""cow'.c,'.",Cmc.",",co',

### ~.,",

### o',",",..=,,"'o',=m'.",,=o,,-- following lhall1nk, referred to In the Roglon 0 comment, was related to NOX: I.e. "The NOX Conlrol Technology "Cost Tool", www.opD.gov/nirmarkelsfarpJnoxlcontroltech,Cost estimatos for teleeled appllcalions of NQX control technologios on stal10nary combustion bollars, OAR/ARO June 1997. (Dockot 101 NOX SIP call), Investigation of performnnclI and cost of NOX controls as applied 10 group 2 bailors, etc. etc. Because lhls study was not focussed on NOX. bUI on 502 and pantculatas. it Is notciear why Region 0 chose to lequesl we investigate these NOX specific sources. 

## I Use of the EPA Control Cost Manual- Version

## 61'-"

_ The EPA Cost Control Manull Version 6 was used extensively and relerences cited throughoutlhe analysis

CFAC made 1II1dcxtensive Revlow ofIhe European document and responded to the SPIICInC comments by Reg'on a. A serHlrale altachmnnt describes this review in detail. 1 European Union: BATII,Noll Ferrous**Meta'sl_,,'~==-~- -_~_--_--**  __--

__-_-

__------

OctaD ReSllOll$O Ie EPA. lecommcndcd Source lIst Sheell 313012008 11 13 AM

## Attachment I**\kn~l'!** kllC' JLlh -.2th,I'

- desIgn Clms::ucl.lO[; 3:1d inst<!.H3HOI; .,fbaghousl.:**~YSlt:Jl!~** on :op oft:H:: dn ;:,;';!"'Jb!Jt': lcaClor::.

• dt.'siull. cnnSUl.lClIon aGd mSlailaiion 0: dUC:WOfi\: for**coll~ctiO!~** 

# "rthe :)0: :.:.a:.l.:.5 

# - . -

- :--.:mova: Oflhc exi$t:ng wcr scrubomg 5\'S1<:0:**~,:Ht** and! I1C Dalt:s Deslg.n of,he**w~s: plan~**  dry**sca~bbing** S}Stl:m,

....hich WllIrol!> ciJlissiol:s froill pOll:ncs : and 2, beg.an in**AU~L1si.** 1976. Stanup ofthe west plam Ot;> s;;rubbmg systcn: was Ja:lUary 0. lQ7S**D~.!olgn** ofthe: t'3St plar.t dry sc:ubb:ng**s~'s':c:T'.,** whict':**c~tJtrol!'** e:r.:s:;;ons from iJO::ines 3. -L and 5 b:.:gar. ir. September 19i7 S:3!"mp ofthe caSt pia:li. 

## c::; scrubo!ng**~Y!'te::1** W:l!' De:cember .: 1. !978

The tm",1 COst ofthe west and**t:~st** pl:.!.nl dry s;;rubb:ng l>yStcm wa:- esti:na:...:: lil Ju:w :';;80 ;:0 bC' $5.134,000, -L Potlinc Suppon Equipment, Techrwlog)' Licensing :H1d olher activities**De~cription** Tn suppon the r...:dmology 2nd made. $uch as changt:s made to the facility tiS ::l fCSllh of the**adopt:ol~** of Sun:itomo Alcoa or\'**sca:bbiJl~** tt:dlllO]Og\. Ollt"':l**'!iJ~ra<h.:~** 31ld c,pcndi:urcs \\crl':

. 

## - 

# _. .-

• specify<!ond puchase SilUnt l11achtncs

- spl-cify 

### and puchase pin service machines

- spccify and ?urcha..o.;e stud**pul1in~** ow.cbino:

- upg!<!dc air compress-or sys'lem**~.J!.l1.d-'·.nd** Dates T!IC'5e aCli\itie$ "ere**cor:~** tk:::wccTl Aug.usi: 1976 anc bnt.: :980.**Th~'** co:-1 ufpodinc support**~l!ipmcnl.** !cdmoiog.y li:::::n.sing fees a:ld**C;U1:tl:lgl;nCll:~** \l';!.S l::stm131l:d 

### ir: jUll,,;**jCl~i:J** tobl: S9.900.:)()(i,

## ..i , , L 

# !
- .f**\k~kL:1** kitcl Ju.\' '7 :U().i**T!l~'** ovcr:l.!!**C~l~1** of**!h~' \\Ol~,**  cl:mplclc:! bl..'I\\'l:l..'ll :\Ugl!SI aiumimijJ\ produc,iQr: facili:\" \.';a:-; estimated in June: 

### S·CAOO,OOO P1CJ.Si' call ifyou ha\'e fiJrthe:- questions on this**ma:!t:~ Sincerel~,** 



### ,.- 

# ..

'">,_L f I I ./ }LtL:.-:-t

# v**SI~eW:igh: Etlv:;ol!m~mal**  &: Labormory \'lan\!.gc:

cc Caltn Laughner. Esq Sie\e Knigh: 1(:'7(, ;:nd l:mr.: l.,)Srl Ui ::ll 1%:1 10 bl' <:lp?IOXli:Ul'..:iy

## Attachment

## JColumbia Falls Aluminum Company Pothne Roof Exit Velocities, Temperatures & Flows As measured via EPA Method 14 for nuoride and POM emission compliance testing as required by the primary aluminum MACT regulations

Roof Cross Single Roof Velocity Temperature**S~tional** Area Flow Polline Roof Flow I Date**R~f** ftlmin F ft2 actual ftJ/min actual ftJ/min Potline J 10/111999 

# , 3437**77.~** 9.125 3,136.263 6.272,525 11'111999 5 '" 5 

# " 9.125 3,116.188 6,232,375 12/211999 5 3239 

# "., 9,125 2.955.566 5,911,175 113/2000 

# , 3004 52 9,125 2,741.150 5,462.300 2/812000 5 307.3 69.2 9,125 2,e04,113 5,508,225 31112000 5 317 1 72.3 9.125 2,893.535 5,787,075 4/15/2000 

# , 358.4 77.2 9,125 3,270.400 6.540,800 ""'000 5 350.6 82,'\ 9.125 3,H}9,225 6,398,450 6112/2000 5 351.6 

# " 1l.125 3,263,100 6,526,200 7/512000 5 360.6 87.2 9.125 3.290.475 6.580.950 'MOOO 5 

# '''' 10lL3 9.125 3.253.975 6,507.950 """000 

# , '"

# , 83,1 9.125 3.117.100 6,23<4.200 "1/212000 5 349,5 79,9 9,125 3.189.188 6,378.375 l1t112lll10 5 367.7 66.' 9,125 3.355.253 6.710.525 AlIl!fage 341.2 77.6 9,125 3,113,254 6.226.509 Potlino 4 101111999 7 360.6 64.9 9,125 3,290,475 6.580,950 111211999 7 331.5 63,9 9,125 3,024,938 6,049,875 1212/1999 7 334.2 69,4 9,125 3,049,575 6.099.150 1/4/2000 7 310,4 65.1 9,125**2.832,~00** 5.66<:.800 """"0 7 271.5 60.8 1l,125 2,477.438 4,954,875**~1nooo** 7 339.7 ".7 9,125 3,099.763 6,199,525 414/2000 7 333.7 60 9,125 3,045,013 6,090.025 

# """'10 7 363.4 72.3 1l,125 3,316,025 6.632.050 ,,",,000 7 

# '" 

# '" 9.125 3,513,125 7,026.250 7/5/2000 7 36a.• 85.' 9.125 3,366,213 6,732.425 81112000 7 3SO,4 103.7 9.125**3,562,~OO** 7,124,800 91512000 7 399,1 607 9,125 3,641,788 7.283.575 10'2J2000 7 378.8 

# " 9,125 3.456,550 6,913.100 11/112000 7 365,4 55.7 9,125 3,334,275 6,658.550 Avel:lDe 352.3 74.2 9,125 3,214,998 5,429.996 Potline 5 101JJ1999 

# • 279.5 81' 9,125 2,550,438 5.100.875 111211999 

# • "" 

# '" 9.125 2.3111.575 4.639.150 12/1'1999 

# • 262.9 73.1 9,125 2.398.953 4,797.925 lft2J2ooo 

# • 235.3 62.9 9,125 2,156,238 <.312.<75 

### mnooo 

# • 211 4 

# 71' 9,125 1,929.025 J.B58.G50 311/2000 

# • 237,4 7t 9,125 2.166,275 4,332,550 4/</2000 

# • 2<:1.2 73,4 9,125 2.200.950 4.401.900 ""'000 

# • 301.7 77.7 9,125 2,753,013 5,506,025 15112/2000 

# • 298,6 79.7 9,125 2,724.725 5,449,<:50 71512000 

# • 325.9 8<:.8 9,125 2,973,838 5.947,675 8/1/2000 

# • 327.8 

# '" 9,125 2,991.175 5,982,350 91512000 

# • 316.0 50.' 9,125 2.888.975 5,777.950 101212000 

# • 298.6 78.5 9,125 2,724.725 5.449.450 11/112000 

# • 270.3 66.' 9,125 2,466.488 4.932.975 A\/Crage 275.9 76,8 9,125 2.517,457 5,034.914

, eao;h pOWne is o;ompr;l'ed oftwo (2) potrooms AVERAGE 2,948.570 5,897.140

## Attachment K