December 28 , 2010

Memorandum

Subject: Summary of Conference Call with Aluminum Association Representatives

From: David Green and Mark Bahner, RTI

To: Rochelle Boyd, EPA/OAQPS

I. Purpose

The purpose of the meeting was to discuss ke y issues that need to be addressed as part of the rule development process for the Residual Risk and Technology Review for Primary

Aluminum Reduction Plants.

II. Place and Date

The call was held December 1, 2010 between 11:00 a. m. and 1:00 p. m.

II I. Attendees

Rochelle Boyd, EPA/OAQPS David Putney, EPA/OAQPS Ann Pope, EPA/OAQPS Darcy Wilson, ERG David Green, RTI Mark Bahner, RTI Robert Strieter, Aluminum Association Mike Palazzolo, Alcoa Representatives from Noranda, Ormet and Rio Tinto Al can

IV. Meeting Summary

A meeting agenda is included a s Attachment 1

.

A

. Corrections to risk modeling files EPA has reviewed plant data in the updated National Emissions Inventory (NEI) [which is thought to incorporate data collected following the Advance Notice of Rulemaking (ANPR) ] and2 found that some of the latitudes and longitudes are of the emission points are incorrect. EPA requests that plant owners check these data and provide corrections.

B

. Modeling of actual emissions

EPA intends to evaluate resi dual risk based on actual emissions at full capacity. EPA requests updated capacity information and also confirmation of the sta t us of any plants that are permanently closed. EPA lacks speciated polynuclear organic matter (POM) emission data from prebake potlines and pitch storage tanks. Industry representatives pointed out that the limited data (two plants) on POM from prebake ovens was obtained prior to the development of Method 315 and may not be comparable to data that would be obtained with Method 3 15 , and that they were unaware of any prebake POM data obtained with Method 315

. Industry representatives also stated that they were unaware of any pitch storage tank emissions data

.

C

. Modeling of allowable emissions

EPA also intends to evaluate residual risk based on allowable emissions for emission points

with limits and a high estimate of actual emissions for emission points without HAP emission

limits. EPA referred to a document which could be used to estimate emissions from a dry

scrubber controlled paste plant. Industry representatives questioned the type of dry scrubber that

these estimates were based on.

D

. MACT determination for prebake potlines and existing pitch storage tanks

Industry representatives suggested, that in the absence of Method 31 5 data for prebake potlines, EPA could consider a standard based on PM as a surrogate for organic HAP. Industry representatives stated that they were unaware of any pitch storage tank emissions data and suggested that a work practice (such as venting disp laced gases through a cold tank to condense vapors) might be appropriate as a standard. EPA stated that it might be necessary to get some test data from these emission points at some time in the future. Industry representatives stated that those plants t hat use the Alcan cassette method to determine total fluoride emissions (TF) have no provisions to determine POM emissions (from roof vents). Capture efficiency for TF should be equal to capture efficiency for POM.

E

. MACT determination for emissions o f COS from potlines Industry representatives stated that they had COS emissions data from several potlines but

the data w e re not obtained with EPA Method 15. The COS emissions are a function of the

sulfur content of the anode. The sulfur in the anode is converted to SO 2 and COS. T he split between these compounds was approximately 5 to 10 % COS. At some locations, this has been

measured with FTIR.

F

. Surrogate pollutants Industry representatives suggested that PM might be a good surrogate for POM from potline primary control devices and that States have PM limits on these sources (primary exhaust only). Roof vents were thought to be a small fraction of the total PM emissions from prebake potlines.

G

. HAP metal emissions3 Alcoa determined HAP metal emissi ons from potlines and use these data for annual emissions reporting, however they only have one test and are not certain how representative the

data are.

H

. Startup and shutdown Industry representatives stated that they had no emissions data representativ e of startup and shutdown periods, that it would be difficult to set a numerical emissions limit, and it would be difficult to obtain a representative sample of emissions. They expected that the emissions profile would vary with anywhere between a few pot s and most of the pots undergoing startup. It addition, they expected that startup emissions would depend on the way in which the pots were shutdown, with different emissions for startup after a controlled shutdown than after an emergency shutdown. Since control devices must be operated during startup, approximately the same degree of control would be expected during startup as during routine operation.