p. 1 of 5 

From: Putney, David 

Sent: Monday, December 30, 2013 3:32 PM 

To: 'Coomes, Jamie'; Coomes, Brandon; Lane, Sean 

Subject: RE: Draft emissions file for the Century Aluminum facilities 

Jamie, 

The possible cell entries for the column with the header 

“Emission Calc Method” include Engineering Judgement, EPA 

Emission Factor (WebFire or AP-42), Stack Test, and

(Blanks). First, let me try to clarify those choices. 

• Engineering Judgement: This is used for emissions from those sources for which emissions test data is 

not available and for which testing is not viable (e.g., speciated POM from pitch storage tanks). 

• EPA Emission Factor (WebFire or AP-42): This is used for pollutants that were not stack tested at a 

given facility but that were stack tested at other primary aluminum facilities and for which we 

developed an emission factor (e.g., lb pollutant per ton of aluminum produced) based on the stack 

tests that were conducted. For example, only the Noranda and Alcoa-Massena East facilities tested for

speciated POM (e.g., anthracene, pyrene, etc.) and Cr+6 emissions. Emissions of those pollutants from 

the other primary aluminum facilities were subsequently estimated based on emissions factors 

generated from the testing conducted the Noranda and Alcoa-Massena East facilities. (The “WebFire 

or AP-42” portion of this standard choice label is misleading.) 

• Stack Test: This is used for those pollutants for which a given facility conducted stack testing in 2013 

(e.g., metal HAP, except for Cr+6, from the potlines at the Century Aluminum of Kentucky facility and 

from the potlines, anode bake furnace, and paste plant at the Century Aluminum – Sebree facility). 

• (Blanks): This is for those pollutants for which stack testing was not viable (e.g., carbonyl sulfide – due 

to very low concentrations in the secondary potline exhaust) but for which we believe a mass balance 

approach provides reasonable emissions estimates. 

Also, keep in mind that for the risk modeling POM (as 

methylene chloride extractable matter - MCEM), and 

particulate matter emissions data are not included. These 

data may be used in the decisions on MACT standards (e.g., 

in the case of POM from prebake potlines or PM as a

surrogate for HAP metals from potlines, bake furnaces 

and/or paste plants), but are not used as inputs to the 

risk model. Speciated POM and individual metal HAP 

emissions estimates are used as inputs in the risk model. 

So, the direct answer to your question would be that 

emissions of speciated POM from the Century Aluminum of KY 

facility were based on emission factors for those POM 

species developed based on testing at the Noranda facility. 
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Note that estimates of emissions of POM (as MCEM) from the 

potlines at the Century Aluminum of KY facility (when we 

look at possible MACT standards for prebake potlines) will 

be based on the testing done at that facility. At this time 

we are not looking at emissions of POM as MCEM from anode 

bake furnaces or paste plants as those sources already have 

numerical MACT standards for POM as MCEM. 

Clear as mud? 

Thanks, and please let me know if you have any more

questions. 

David Putney, Environmental Engineer 

U.S. Environmental Protection Agency 

Office of Air Quality Planning and Standards 

Sector Policies and Programs Division 

109 T.W. Alexander Drive, RTP, NC 27711 

Mail Drop D243-02 

Ph: (919) 541-2016 Fax: (919) 541-3207 

Email: putney.david@epa.gov

From: Coomes, Jamie [mailto:JCoomes@centuryky.com] 

Sent: Friday, December 27, 2013 10:47 AM 

To: Putney, David; Coomes, Brandon; Lane, Sean 

Subject: RE: Draft emissions file for the Century Aluminum facilities 

David, 

I am having my testing consultant review our facilities ICR 

test data to verify it matches what is on your 

spreadsheet. Actual stack test data (metal compounds and 

mercury) was conducted on Potline stack and roof vents. 

I have a question as to what EF were used for POM from the 

anode paste plant? Your spreadsheet says EPA emission 

factors. We have historically used the POM emission factor 

based on the Example calcs from refractory products
p. 3 of 5 

NESHAP. I have attached that document. It is on page 2 

Table 1 Pitch bonded Heated Mixer POM (3.9 lbs /ton). 

Is this different than what you have used in your 

spreadsheet? 

Jamie 

From: Putney, David [mailto:putney.david@epa.gov] 

Sent: Wednesday, December 18, 2013 8:39 AM 

To: Coomes, Brandon; Coomes, Jamie; Lane, Sean 

Subject: Draft emissions file for the Century Aluminum facilities 

Hello Jamie/Brandon/Sean, 

Please find attached to this message a draft emissions file 

(Excel spreadsheet) for the Century Aluminum primary 

aluminum production facilities. Columns highlighted in 

yellow are available for revisions or to indicate if 

records should be deleted. Please do not overwrite the 

data in columns that are not highlighted in yellow as this 

would complicate the development of the final emissions 

file for use in risk modeling. 

The tab titled “primary Al category” includes emissions 

from the primary aluminum production operations (e.g., 

potlines, paste plants, pitch storage tanks, and anode bake 

furnaces) at the Century Aluminum facilities as estimated 

via emission factors developed from test results obtained 

in response to the testing ICR sent out in April of 2013. I 

expect that the stack parameters are correct as-is since 

industry previously had opportunity to review those items 

in CY2010 before the initial residual risk and technology 

review (RTR) proposal for the primary aluminum production 

source category. There are, however, some emissions (e.g., 

metal HAP, dioxins, PCB, etc.) that are new to the RTR 

analysis for the primary aluminum production source

category and, although these have been QA/QC’d by 

contractor and EPA staff, we do welcome 

feedback/corrections you might have on these emissions. A 

revision column highlighted in yellow is provided for you 
p. 4 of 5 

to revise emissions (in units of tons per year, tpy) if 

needed. 

The tab titled “noncategory” includes 2005 NATA NEI, 2008 

NEI and 2010 state HAP data for the Century Aluminum 

primary aluminum production facilities. These records are 

intended to include emissions from operations at your 

facility which are not directly associated with primary 

aluminum production (primary aluminum emissions are

addressed under the first tab, discussed above) or 

secondary aluminum production (secondary aluminum emissions 

will be addressed via the RTR associated with the secondary 

aluminum source category). Revision columns highlighted in 

yellow are included for emissions, pollutants, stack 

parameters, fugitive parameters and latitude/longitude. If 

any of these parameters needs modification, please put the 

corrected value in the associated revision column (again, 

please do not overwrite the data in columns that are not 

highlighted in yellow). Note that fields were also added 

to identify if a record should be deleted, and a reviewer 

comment field where you can add a comment if appropriate. 

Please review these data with the following in mind: 

1. Should the operation be included in the spreadsheet? 

a. Does the operation still exist at the facility? If not, or if it exists but is not legally allowed to 

operate (e.g., you do not have a valid operating permit for this operation) then the operation 

and associated emissions need not be included. 

b. If the operation does exist at the facility, is it part of any secondary aluminum operations that 

may exist at your facility? If so, then the operation and associated emissions need not be 

included (so as to avoid double counting those emissions). 

c. If the operation does exist at the facility, would the emissions from this operation be 

considered part of the monitored primary aluminum emissions? For example, if the emissions 

associated with the operation in question are routed through the control device associated 

with the paste plant and would be monitored as part of the paste plant emissions then the 

operation and associated emissions need not be included (so as to avoid double counting 

those emissions). 

2. If the operation should be included, are the cited emissions representative of that operation? 
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3. If the operation should be included but the cited emissions are not representative of that operation,

then please provide representative annual actual emissions in units of tons emitted per year (tpy). 

4. Verify or modify the stack parameters and location as appropriate and necessary. 

If I might make a suggestion – you can use the filter 

function in Excel to narrow down the file to review a 

single facility at a time. 

I do not have any information for a contact at the Century 

Aluminum facility in West Virginia. Would you please pass 

this email and attachment along to someone at that facility 

that could review this information? Also, would you please 

forward me that person’s contact information? 

Please provide any comments, changes, corrections, etc. to 

this file to me by close of business on Friday, 01/03/14. I 

understand that more time might be preferable with the 

holidays upon us, but please give me what you can by 

01/03/14 and remember that you will have another 

opportunity to make comments and corrections during the 

upcoming public notice and comment period associated with 

the primary aluminum production RTR supplemental proposal. 

If you have any questions concerning these issues, please 

feel free to contact me by email or telephone. 

Thanks, 

David Putney, Environmental Engineer 

U.S. Environmental Protection Agency 

Office of Air Quality Planning and Standards 

Sector Policies and Programs Division 

109 T.W. Alexander Drive, RTP, NC 27711 

Mail Drop D243-02 

Ph: (919) 541-2016 Fax: (919) 541-3207 

Email: putney.david@epa.gov