From: Van Der Meyden, Henk [ mailto:Henk.VanDerMeyden@alcoa.com ]

Sent: Wednesday, April 22, 2015 10:04 PM

To: Putney, David;

Cc: Palazzolo, Michael A.; Hulse, David G. Subject: Installation of Method 14 or 14A sampling equipment at Alcoa Wenatchee

This e

- mail is to provide additional information regarding the installation of Method 14 or Method 14A sampling equipment at Alcoa’s Wenatchee facility. We had previously raised this

issue in our wri tten comments of February 05, 2015 and during our conference call on April 8,

2015. As detailed below, we believe that the cost for installing Method 14 or Method 14A sampling equipment is cost prohibitive. We recommend that EPA pursue an alternative

app roach for measuring the contribution of roof monitor emissions from existing potlines which currently do not have Method 14 or Method 14A sampling equipment installed for determining compliance with the proposed emission limits for PM and POM.

Background Alcoa’s Wenatchee facility has four potlines. Potlines 1, 2 and 3 have similar pot technology and primary control equipment. Potline 5 is different from Potlines 1

- 3. Potlines 1, 2 and 5 are operating while Potline 3 is currently curtailed. Potlines 1 and 5 use a Method 14 manifold for collecting samples to determine TF emissions from the roof monitors. Potline 2 uses the HF CEM approach for similar potlines as described in §63.848(d) of the current rule to determine
the roof monitor TF emissions. The proposed rule would require testing of roof monitor
emissions for PM and POM. To our knowledge, there are currently no CEMs for measuring PM or POM concentrations in long line sources like potline roof monitors. In order to comply with the proposed PM a nd POM limits, Alcoa Wenatchee would be required to install a Method 14 or Method 14A sampling equipment in Potlines 2 and 3.

Cost Estimate We contacted our facilities and obtained the following information on historic installations to
estimate the cost of future installation of Method 14 or Method 14A sampling equipment.

1. Method 14 Manifold
In 2004, the Massena East smelter had to move an existing manifold from one potroom
to another while the potline was shutdown. The actual cost just to move and rein stall the existing manifold in segments was $400K. This cost did not include moving the
testing trailer or the manifold's downcomer fan and motor. Massena personnel estimate that to install a M14 system where it does not exist today be in excess of $500K , when considering engineering, materials, and utilities. Furthermore, installation
of a Method 14 manifold in an operating potline brings logistical and safety challenges

that add costs.

2. Method 14A Cassette System
In 2010, one of our Canadian smelters i nstalled a radio

- controlled track and trolleysystem to get the cassette and anemometer to sampling point in the roof monitor. The

cost of this system was about $100K (CAN) per sampling point. We estimate that a
sampling system comprised of the required minimum 8 sampling points for Method 14A will cost in excess of $800K when considering inflation and currency adjustments. A system using pulleys to move the cassettes to the roof monitor would be less expensive
than the track and trolley system. While w e have no actual installation costs, we believe that a pulley system would still be in excess of $500K.

Based on the above, the cost impact to Alcoa Wenatchee for installing Method 14 or Method 14A sampling equipment is estimated at $600K for Potline 2 alone or $1,200K total for both

Potlines 2 and 3. We believe that this is excessive and that an alternative compliance approach is needed for existing potlines which currently do not have Method 14 or Method 14A sampling equipment installed.

Alternative Approach Potlines 1, 2 and 3 at Alcoa Wenatchee are of similar design, use the same CWPB1 pot technology (T51 pot design), have similar building and roof monitor dimensions, and are controlled by similar primary control systems (fluidized bed alumina scrub bers). We had previously established that Potlines 1, 2 and 3 were “similar potlines” as defined in §63.848(d) of the current rule for the purpose of monitoring TF emissions. We believe that this similarity
can extend to PM and POM emissions as well. Si nce Potline 3 is currently down, we focus the remainder of this discussion of an alternative approach on just Potline 2; however, it can be applied to Potline 3 as well.

The anodes used in the Potlines 1 and 2 are of the same size and formulation an d come from
the same anode bake furnace. The work practices of changing anode, tapping molten aluminum, and adding alumina are the same in the operating potlines. There should be little
difference in the evolution of PM and POM from Potline 1 and Potlin e 2. The use of an HF CEM and the emphasis on pot cover placement in proposed §63.854(a)(3) will ensure that the emissions capture efficiency in Potlines and 1 and 2 is similar.

We believe that an alternative approach for demonstrating compliance with th e POM emissions
limit for Alcoa Wenatchee’s Potline 2 should be based on the sum of the measured emissions of POM from the primary control device for Potline 2 plus the measured concentration of secondary emissions of POM from Potline 1 applied to the meas ured roof monitor air flow from
Potline 2. An example calculation for POM is shown below. The same approach can be used for demonstrating compliance with the PM emission limit.

POM Line2 Total (lbs/ton) = [POM Line2 Total (lbs/day) ] 

## / [Production Line 2 (tons Al/day) ]

POM Line2 Total (lbs/day) = [POM Line2 monitor (lbs/day) ] 

## + [POM Line2 control device (lbs/day) ]POM Line2 control device (lbs/day) = tested value from annual compliance test

POM Line2 roof monitor (lbs/day) = [(POM Line1 roof monitor (mg/dscf) ) x (Line 2 roof monitor flow (cf/min) ) x (1440

(min/day) )] / [453600 (mg/lb) ]

We appreciate the opportunity to provide this additional information. We are hopeful that these comments will help EPA develop and alternative app roach for measuring secondary emissions of PM and POM at existing primary aluminum smelter potlines that currently do not have Method 14 or Method 14A sampling equipment installed.

Should you require clarification or further discussion of our comments, p lease contact me or
Mike Palazzolo.

Sincerely,

Henk van der Meyden, PG Sr. Environmental Consultant Alcoa Inc. Cell: (843) 296

- 3359 henk.vandermeyden@alcoa.com