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From: "Palazzolo, Michael A." < Michael.Palazzolo@alcoa.com > To: David Putney/RTP/USEPA/US@EPA

Cc: Steffan Johnson/RTP/USEPA/US@EPA, Rachel Agnew/RTP/ USEPA/US@EPA, Jason Dewees/RTP/USEPA/US@EPA, Gerri Garwood/RTP/USEPA/US@EPA, "Bilskis, Patricia A." < Patricia.Bilskis@alcoa.com > Date: 12/21/2012 08:21 AM Subject: RE: Sampling at Intalco



### David,

Our environmental folks are out until after the New Year now, so we will have to wait until then to answer some of your questions. Howev er, in response to the earlier ICR, Intalco provided EPA test reports for all wet roof scrubber testing conducted during at least 2010. These data would include repeat testing on multiple scrubbers.

Please note however that each “test run” conducted on a roof scrubber lasts 20 hours and there will be run-to-run variability in em issions dependent solely on process activity (aluminum tapping, anode setting, or tr acking (quite time)). Three scrubbers sampled simultaneously over the 20-hour period make up one “test run” and the scrubbers are selected for testing to ensure that all three operating modes are represented during the test perio d.

We can discuss further in January.

Happy Holidays!

Mike

Michael Palazzolo

Alcoa Inc.

201 Isabella Street Pittsburgh, PA 15212-5858

Ph: 412-553-4832

From: Putney.David@epamail.epa.gov [ mailto:Putney.David@epamail.epa.gov ]

Sent: Thursday, December 20, 2012 4:00 PM

To: Palazzolo, Michael A.

Cc: Johnson.Steffan@epamail.epa.gov; Agnew.Rachel@epam ail.epa.gov; Dewees.Jason@epamail.epa.gov; Garwood.Gerri@epamail .epa.gov Subject: Sampling at Intalco

Mike,

I had a meeting with some of our test methods folks today to discuss sampling of secondary potline emissions at the Intalco facility. They looked at t he picture you sent me of a typical scrubber sampli ng

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location (i.e., the mist eliminator) and a copy of Alcoa Method B100 (B-54b). In order to develop an acceptable and defensible method of sampling of sec ondary potline emissions at the Intalco facility

these folks need to see:

• Historical emission test reports that include testi ng at a given scrubber outlet. Since the Title V permit for this facility allows for sampling of 3 w et scrubbers per operating potline, I presume that sequential testing of a given potline (e.g., t esting of potline A during January and February) would not necessarily occur at the same wet scrubbe rs. Please provide multiple test reports that involved sampling at a given scrubber outlet - the folks here want to see how much the emission rate, flow rate and velocity varies (both with time and across the cross sectional area of the mist eliminator) at the exhaust of a given wet scrubber.

• A schematic of a "typical" wet scrubber system. The y specifically want to know how much of a straight run exists after the scrubber but before t he mist eliminator shown in the pictures (e.g., is

the wet scrubber 10 feet or 10 inches below the roo f in the picture you provided?); the dimensions (length, width, and height) of the scrub ber exhaust (i.e., the yellow structure in the picture you provided); the dimensions of, and flow rate at, the wet scrubber inlet; whether any baffles are installed in the wet scrubbers; and any other information that would help them

determine the flow characteristics at the exhaust o f the wet scrubbers.

• If you have any pictures of a typical wet scrubber that also may be very helpful. Perhaps pictures looking up at the wet scrubber from within the potroom, looking at the inlet of the wet scrubber, and looking down through one of the assoc iated mist eliminators?

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