p. 1 of 2 April 10, 2015

Memorandum

Subject: Summary of Conference Call with Alcoa and Aluminum Association Representatives

From: David Green and Matt Hakos, RTI Internationa l

To: David Putney, EPA/OAQPS

I. Purpose

The purpose of the call was to clarify issues rais ed in public comments on the supplemental proposal for primary a luminum reduction plants, and to get information for improved cost estimates.

II. Date and Time

The call was held April 8, 2015 between 10:00 a.m. and 10:45 a.m.

III. Attendees David Putney, EPA/OAQPS David Green, RTI International Matt Hakos, RTI International Curt Wells, Aluminum Association Mike Palazzolo, Alcoa Henk van der Meyden, Alcoa

IV. Summary

A. Recalculation of Anode Bake Furnace Particulate Matter MACT Floor.

In their public comment, Alcoa provided corrections to bake oven emissions for their facilities and recommended that EPA colle ct data from previous years for all facilities to expand the database. Al coa representatives clarified that their analysis did not take into acc ount data from Century Aluminum that was not available to them and thus th e recalculation of the MACT floor that they provided did not reflect the a ctual 5 plants making up the MACT pool. With regard to additional emissions test data from non-Alcoa facilities, EPA stated that Century Aluminum may no t be subject to particulate matter (PM) limits and may not have PM emissions data available. Alcoa suggested that Century may have bake furnace PM data collected during EPA Method 315 testing for POM. EPA will contact Ce ntury Aluminum and request any additional PM emissions data they may h ave for the anode bake furnaces located at their facilities.

B. Variability on Intalco Emissions Test Data.

EPA asked if there was an explanation (e.g. control equipment or raw materials) for the unusually high variability in th e PM emissions from the Intalco anode bake furnace, citing a factor of 27 b etween the highest and lowest test runs. Alcoa representatives noted that all of the other facilities had emission test runs with about a ten- fold variation between the highest and lowest runs and suggested that the level of variability atp. 2 of 2

Intalco may not be unexpected. Alcoa representative s noted that they did not know the reason for the variability at Intalco but that it could be related to differences in production rate, or the age of th e bags in the fabric filter. Alcoa representatives will contact Intalco staff and request any information they may have that would account for th e higher variability in PM emissions from the anode bake furnace located at their facility.

C. Installation of Testing Equipment for Proposed Standards.

Alcoa representatives clarified that the Wenatchee plant had neither a manifold system nor a cassette system installed for measurement of secondary fluoride emissions in two of their potlines. Wenatc hee currently monitors HF (as a surrogate for TF) using a CEMS, as permitted by the current rule. In order to demonstrate compliance with POM and PM sta ndards for potlines, either a manifold or cassette system would be requi red. Alcoa representatives stated that there was no access to the roof. Rough cost estimates for installation of sampling systems were $600,000 to $800,000 however Alcoa agreed to provide more detailed estim ates based on previous installations in the 1990's and in 2010. EPA also a sked about the feasibility of basing PM and POM emissions estimate s for the potlines without manifolds on measurements of those pollutan ts from the potline that is currently equipped with a manifold, as is allowe d for HF measurements under current §63.848(d).

D. Discrepancy Between Test Report and Summary Emi ssions Data Provided in Public Comment.

Alcoa representatives confirmed that the results fo r Intalco bake furnace PM emissions given in the test report for testing cond ucted in June of 2011 were correct and that the data summary table in the public comment contained a transcription error.

E. Presence of Bag Leak Detection Systems (BLDS) a t Alcoa Rockdale and Lake Charles Carbon Facilities.

Alcoa representatives stated that the Rockdale bake furnaces had a total of 21 stacks, none of which have BLDS; the Rockdale pa ste plant has one stack with no BLDS; and the Lake Charles paste plant has one stack with no BLDS.