EMI agrees that the second test result is very different from the first test result. In addition to the fact that

different test methods were used in the 2010 and 1012 stack tests, the results could simply reflect the

inherent variability in measurements of emissions that are, in absolute terms, very small to begin with.

We have no basis for knowing where these results fall along the range of potential emissions -- hence the

need for additional tests to provide sufficient data points to construct a meaningful estimate of the MACT

floor.

As we have discussed in the past, since mercury is very volatile, EMI believes it is predominately emitted

shortly after the ore is charged to the furnace, It’s possible that the measurement periods of the later test

were more heavily weighted toward this higher-emitting portion of the smelting process. This is why EMI

proposed to include CEM of pre-treatment emissions in the proposed ACI performance test. EMI still

believes that would make sense.

I understand from EMI that they do not have data that would allow a comparison of ore content to

emissions during a particular test, because such data were collected on the barge, well before the testedshipment of ore was commingled in stockpiles and well before the specific ore used in a particular run was

removed from those stockpiles for processing.

Let me know if you would like to discuss these issues further.

John

John Rego• Environmental, Health & Safety901 LAKESIDE AVENUE CLEVELAND, OHIO 44114

DIRECT 216.586.7542 • FAX 216.579.0212.

JREGO@JONESDAY.COM

Fro Conrad Chin <Chin.ConradepamaiI.epa.gov>

m:

To: John Rego <jregoJonesDay.com>

Cc: Chuck French <French.Chuck@epamail.epa.gov>, Jeff.McKinneyerametgroup.com, Jonathan

Averback <Averback.Jonathanepamail.epa.gov>, chin.conradepa.gov

Date 09/18/2012 03:13 PMSubj Recent mercury emissions test data

ect:
In past discussions with Jeff McKinney, Eramet probably analyzed the mercury ore content of the Comilog

ore. Would you be able to provide the mercury content in the ore for the 2010 ICR test and the July 2012

test?Thanks and best regards,

Conrad K. Chin

Mail Code D243-02Metals and Minerals GroupSector Policies and Programs Division

Office of Air Quality Planning and Standards

U.S. Environmental Protection Agency

919-541-1512 (voice)

919-541-3207 (fax)

‘John Rego ---09/04/2012 02:33:04 PM---Chuck: Attached are the data tables from EMI July stack tests.

At this point EMI

From: John Rego <jregoJonesDay.com>

To: Chuck French/RTP/USEPA/US@EPA

Cc: Conrad Chin/RTP/USEPAIUS@EPA, Jeff. McKinneyerametgroup.com, lmcafee@bdlaw.com,

jskonradyfpiwv.com

Date: 09/04/2012 02:33 PMSubject: Re: Ferroalloy - recent emissions test data

Chuck:

Attached are the data tables from EMI July stack tests. At this point EMI has only received a full reportwith respect to the compliance portion of the test (i.e., the PM testing) and I will be forwarding a hard copy

of that report. EMI is awaiting the full report regarding the four non-RTR compounds, which I will also

forward when available. I had the sense that you would, however, like to see the data tables as soon as

they were available. My understanding is that there were no unusual occurrences during the testing at EMI

and that the full reports should be routine.

Please let me know if you have any questions.

John

John Rego• Environmental, Health & Safety

D&. 901 LAKESIDE AVENUE CLEVELAND, OHIO 44114

DIRECT 216.586.7542 • FAX 216.579.0212’

JREGO@JONESDAY.COM