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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. However, 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 emissions dependent solely on 

process activity (aluminum tapping, anode setting, or tracking (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 period. 

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@epamail.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 the picture you sent me of a typical scrubber sampling 
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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 secondary potline emissions at the Intalco facility 

these folks need to see: 

• Historical emission test reports that include testing at a given scrubber outlet. Since the Title V 

permit for this facility allows for sampling of 3 wet scrubbers per operating potline, I presume 

that sequential testing of a given potline (e.g., testing of potline A during January and February) 

would not necessarily occur at the same wet scrubbers. 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. They specifically want to know how much of a 

straight run exists after the scrubber but before the mist eliminator shown in the pictures (e.g., is 

the wet scrubber 10 feet or 10 inches below the roof in the picture you provided?); the 

dimensions (length, width, and height) of the scrubber 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 of 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 associated 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