2 

## Table of Contents

1. Basic Facility and Site Visit Information

.................................................. ...................... 3

2. Introduction and Site Visit Objectives

.................................................. .......................... 4

3. “BART Eligible” Emission Units

.................................................. .................................... 4

3.1. Potline #5

.................................................. ................................................... ................. 5

3.2. Ingot Furnaces #1, #2, and #11

.................................................. ................................ 5

3.3. Anode Bake Furnace #62

.................................................. ........................................... 5

3.4. Green Mill Emission Units

.................................................. ......................................... 6

3.5. Alumina Handling Equipment (associated with Potline #5 construction) ............. 6

3.6. Alumina Railcar Unloading

.................................................. ........................................ 6

4. Opening Conference

.................................................. ................................................... .... 7

5. Facility Walk-Through (BART-Eligible Emission Units Only) ...................................... 7

6. Closing Conference

.................................................. ................................................... ..... 9



## Attachments

Attachment 1 ...................................... ............................................ EPA Re gion 10 Site Visit Photolog

Attachment 2 ......................................

................................................... ................. Facility Location Map

Attachment 3 ...................................... ..............................Plant Overview docume nt (from facility)

Attachment 4 ...................................... ....................... Table of BART emission unit s (from facility)

Attachment 5 .................................. Fac ility plan showing BART emission units (from facili ty)3

1. Basic Facility and Site Visit Information

Facility: Alcoa Wenatchee Works 6200 Malaga/Alcoa Highway, Malaga, WA 98828

Facility Contact: David Hulse, Environmental Manage r 509-663-9206 – office

509-669-0639 – cell
david.hulse@alcoa.com

Agency Staff: Zach Hedgpeth, EPA Region 10 Steve Body, EPA Region 10 Alan Newman, Washington State Department of Ecolog y

Date of Site Visit: June 24, 2013

Date of Report: July 12, 2013

Disclaimer
This report is a summary of observations and inform ation gathered from the facility at

the time of the site visit. The information is not meant to be a comprehensive summary of all activities and processes conducted at the fa cility.4

2. Introduction and Site Visit Objectives

The Alcoa Wenatchee Works primary aluminum smelter is located approximately 10 miles southeast of Wenatchee, Washington on the wes t side of the Columbia River. A map showing the location of the facility is include d as Attachment 2. A plant overview document was provided by the facility during the si te visit which includes a basic description of the industrial processes at the faci lity; this document is included as

Attachment 3.

Staff from the EPA Region 10 Office of Air, Waste, and Toxics and Office of

Environmental Assessment conducted the site visit f or the purpose of better understanding the Best Available Retrofit Technolog y (BART) eligible emission units at the facility, as well as associated air pollution c ontrol equipment. These emission units will be referred to as “BART eligible” for purposes of this field report in order to

differentiate them from other emission units at the facility.

3. “BART Eligible” Emission Units

Based on information provided by the facility and o bservations and discussions with facility and Alcoa Corporate staff (identified belo w) during the site visit, the sections below provide brief descriptions of each emission u nit at the facility which is BART eligible based on emissions as well as date of cons truction or modification 1 , as well as any associated air pollution control equipment. Th e BART eligible emission units are summarized in a table provided by the facility duri ng the site visit, which is included as Attachment 4. The general location of these emissi on units and/or their associated air pollution control devices is shown in an annotated site plan also provided by the facility during the site visit, which is included as Attachm ent 5.

As described below, during the site visit, EPA staf f were able to confirm that each of the BART eligible emission units or processes identifie d in this report are controlled by fabric filter air pollution control technologies fo r reducing emissions of particulate matter (PM). Fabric filter control devices general ly provide high efficiency control of particulate matter. Although several of the contro l devices discussed in this report provide control for other pollutants, these other p ollutants do not include pollutants considered significant for regional haze purposes, such as nitrogen oxides (NO X ) and sulfur dioxide (SO 2 ). Specifically, the potline #5 gas treatment cent er (dry alumina scrubber) and the A446 Anode Bake Scrubber provide control for fluoride and polycyclic organic matter (POM) in addition to PM, but do not control for NO X or SO 2

. Similarly, the Dry Coke Scrubber would be expected to provide control for organics and potentially other contaminants which may adsorb to the coke, but would not be expected to provide significant control for NO X or SO 2 . The remaining control devices described in this report are fabric filters which c ontrol for PM only.

1 To be BART eligible, an emission unit must have bee n constructed or modified during the “BART window” of August 7, 1962 to August 7, 1977.5

3.1. Potline #5

Potline #5 was constructed in 1967. The potline is configured in two parallel pot rooms, similar to the arrangement at the Alcoa Inta lco Works near Ferndale, WA. The two potline #5 pot rooms are located at the east en d of the facility, adjacent to the potline gas treatment centers (GTCs). Like Potline s #1 – #3, Potline #5 contains centerworked, pre-bake pots. Potline #4 was demolished i n 2004. Emissions from each pot

within Potline #5 are collected and routed to GTC # 5. GTC#5 was installed in order to achieve compliance with the Maximum Achievable Cont rol Technology (MACT) standards for primary aluminum smelters (40 CFR 63, subpart LL). The GTC’s consist of dry scrubbing with alumina followed by fabric fi ltration. This control system provides control of particulate matter, fluorides, and polycyclic organic matter (POM).

3.2. Ingot Furnaces #1, #2, and #11

The ingot furnaces are natural gas fired furnaces w hich heat molten aluminum after it has been siphoned out of the pots, prior to casting . The furnaces are used to remove

aluminum dross from the molten aluminum and in the past were used to create aluminum alloys with other metals being added and m ixed with the molten aluminum within the furnace. There are a total of five ingo t furnaces located in the casthouse, of which #1, #2, and #11 were constructed or modified within the BART window and are BART eligible units. All ingot furnaces operate un controlled, and the emissions are periodically tested by facility personnel.

3.3. Anode Bake Furnace #62

The facility operates two anode bake furnaces, #58 and #62. A third furnace (#60) has

been removed from service. Furnace #58 was constru cted in 1952 and so precedes the BART window, but furnace #62 was constructed in 196 7 (within the BART window). The furnaces consist of a series of pits lined with fire brick in which green (i.e. unbaked) anodes are baked using natural gas which is direct-injection-fired within granular coke packed around the anodes. Exhaust ga ses from both furnaces are collected in an underground duct, combined, and sen t to the A446 Anode Bake Scrubber for control. As described during the site visit, t his is one instance where exhaust gases from “BART-eligible” and “non-BART-eligible” emissi on units are combined and sent to

a common control device.

The A446 Anode Bake Scrubber is an Alcoa-designed c ontrol device that is essentially a dry alumina scrubber followed by fabric filtration. The alumina scrubbing is achieved

within a fluidized bed of alumina situated in the l ower portion of the control device through which the dirty exhaust gases pass. The ex haust gases then travel upward through a pleated cartridge bag fabric filter prior to being exhausted to the atmosphere.

The A446 consists of four identical units with thre e exhaust stacks each. A somewhat unique aspect of the control device is that a caref ully controlled quantity of water is injected with the dirty exhaust gases into the flui dized alumina bed as a quench. The6

quantity of water injected must be carefully contro lled in order to avoid the presence of liquid water formation within the fluidized bed. T he presence of liquid water can lead to cementing within the fluidized bed and blinding of the bags 2

.

3.4. Green Mill Emission Units

The green mill is the portion of the facility where “green” anodes (i.e. un-baked) are formed from coke and petroleum pitch. A mixture of coke and pitch is placed into a vibratory anode forming device that uses the elevat ed temperature of the raw materials, vibration, and pressure from an overhead weight to form the coke/pitch mixture into green anodes. The vibratory former wa s installed in 1972.

All emissions from the green mill, including the vi bratory forming unit, are collected and sent either to the Dry Coke Scrubber or Dust Co llector 2. Due to the abbreviated duration of the site visit and accessibility issues , we did not develop a detailed identification of all green mill emission units and their respective control device. The Dry Coke Scrubber is a dry scrubber using powdered coke, followed by fabric filtration. Dust Collector 2 is a fabric filter. Facility and Alcoa Corporate personnel stated that the emissions from both the Dry Coke Scrubber and Dust Collector 2 were identified as BART eligible based on the installation of the vibr atory former and associated material handling changes. Both of these control devices ma y also control emission units that are not BART eligible.

3.5. Alumina Handling Equipment (associated with Potline #5 construction)

There are two alumina handling emission points whic h involve equipment installed within the BART window related to construction of p otline #5. The first is a very small fabric filter dust collector on an alumina conveyan ce line which is identified as unit

21M. The second is another small fabric filter dus t collector controlling emissions from an alumina handling unit situated above an alumina storage silo. This second unit is

identified as unit 19C.

3.6. Alumina Railcar Unloading

The alumina railcar unloading facility is equipped with below ground hoppers controlled by a large fabric filter, identified as unit 43E. Facility staff stated that while no documentary information has established that the railcar unloading facility was constructed or modified within the BART window, the presence of significant site work in that area of the plant during the BART window le d Alcoa to conservatively determine that the railcar unloading process and associated f abric filter is BART eligible.

2 Blinding of the bags refers to a phenomenon caused by excess moisture or other factor where the parti culate matter adheres to or embeds in the bag material, in hibiting bag cleaning and negatively impacting the performance of the fabric filter device.7

4. Opening Conference

EPA Region 10 personnel arrived at the facility at approximately 11:20. Upon arrival, we entered the facility office building, and were e scorted to the former cafeteria where the opening conference for the site visit was held. At our arrival, the weather was cool and cloudy with light rain.

The following were present during the opening confe rence:

• Jimmy Jones, Alcoa Corporate Environmental

• David Hulse, Alcoa Wenatchee Works

• Garr Dorey, Alcoa Wenatchee Works

• Alan Newman, Washington Department of Ecology

• Steve Body, EPA Region 10

• Zach Hedgpeth, EPA Region 10

The opening conference began with brief introductio ns, during which the EPA staff explained the purpose of the site visit (as describ ed above). Some discussion of the context of the visit with respect to EPA Region 10 ongoing work related to the Washington State Regional Haze State Implementation Plan occurred. The facility’s safety video and orientation was completed at this time. During the opening conference, Alcoa staff provided the documents incl uded as Attachments 3-5 to this report, which include a plant overview document, a table of the BART eligible emission units, and a facility plan with the location of the BART eligible emission units and/or associated control devices highlighted.

The following items of discussion occurred during t he opening conference:

• Alcoa staff noted that at least two of the control devices identified in earlier BART-related documents provide emission control for units which are not BART eligible. Specifically, it was noted that the A446 Anode Bake Scrubber controls both anode bake furnaces, even though only one furn ace is BART eligible, and that the Dry Coke Scrubber and Dust Collector 2 at the green mill control emission units which are not BART eligible, includi ng the nine green anode

mixers.

• An extended discussion occurred regarding EPA’s req uest to take photographs of

the emission units and control devices which are BA RT eligible. This request was denied by Alcoa based on a very restrictive pho tograph policy. EPA staff did not raise significant objections to this policy, co nsidering the context of the site

visit.

The opening conference ended at approximately 13:45

.

5. Facility Walk-Through (BART-Eligible Emission Units Only)

Following the opening conference, a site walk-throu gh was held to allow EPA personnel

to examine the emission units and associated contro l devices (described above) which8

are BART eligible. The site walk examined these em ission units and control devices in the following order, with pertinent field notes inc luded below.

1. Dry Coke Scrubber – This device controls emissions from the vibratory anode former in the green mill and possibly additional gr een mill emission units. The vibratory anode former forms green anodes using a m ixture of petroleum pitch and coke via heat, pressure, and vibration. The gr een anodes are produced in batches of approximately 6. During the visit, EPA personnel observed production of two batches of anodes. The room hous ing the vibratory former is a respirator-required zone, and had visible dust/ha ze in the building headspace. Alcoa Wenatchee personnel did not know if the area is kept under negative pressure. No visible emissions were observed from this control device during

the visit.

2. Dust Collector 2 – This control unit functions as a general dust collector for the green mill operations. A differential pressure of 3 inches of water gauge was observed on collector section #1 (the easternmost s ection) during the visit. The baghouse is equipped with “sight glasses” on the ex haust stack which are intended to be an early warning indicator of poor p erformance. The “sight glasses” consist of an inverted funnel within the e xhaust stack which collects particulate matter and deposits it into a glass via l with a cone shaped end which is fastened outside the stack. The “sight glass” e xamined during the visit held 1- 2 centimeters of fine grained black particulate mat ter. When examining the glass, facility personnel commented this was more t han is typically observed. No

visible emissions were observed from this control d evice during the visit.

3. A446 Anode Bake Scrubber – This unit controls emiss ions from the two anode bake ovens. During examination of the unit, Alcoa Wenatchee personnel explained that required monitoring includes surroga te parametric monitoring for air flow rate through the control device. In t his case, the facility monitors fan amperage for compliance with an 8-hour average maxi mum limit. No visible

emissions were observed from this control device du ring the visit, although the unit was in operation.

4. Railcar Unloading Fabric Filter #43E – This unit is a large fabric filter that provides control of alumina dust during railcar del ivery. The railcar unloading station is partially enclosed and equipped with sub -grade receiving hoppers with ventilation pickups vented to the baghouse. D uring the visit, railcar unloading was not occurring and the fabric filter d id not appear to be in operation. The facility did not exhibit significan t alumina dust drift outside the unloading facility, indicating that the air polluti on control system appears to function reasonably well.

Based on their extremely small size and inaccessibi lity, the small alumina fabric filter

dust collectors identified as units 21M and 19C wer e not directly observed during the site visit. Photographs of these emission units we re viewed during the site visit. After a9

brief examination of the anode baking ovens and pot line #5, the site walk through concluded and the group returned to the former cafe teria for a brief closing conference.

6. Closing Conference

A closing conference was held to discuss the site v isit in general and any action items for follow-up work. The same staff attended the cl osing conference as listed above for the opening conference.

The closing conference was extremely brief and did not include significant discussion.

EPA staff stated that the site visit had been suffi cient to achieve their intended goals. The sole follow-up item is as follows.

During the site visit, Mr. Hedgpeth expressed an in terest in obtaining certain identifying information for the air pollution control devices d iscussed in this report, such as manufacturer, model number, and any design informat ion such as air flow rate. Brief examinations of the units during the site visit for the purpose of locating manufacturer name plates were unsuccessful. During discussion o f this issue, Mr. Dorey stated that he may be able to gather certain portions of this i nformation from files left in his care by a former employee. He committed to looking into th is possibility and communicating back to Mr. Hedgpeth with his findings.

EPA staff departed the facility at approximately 16 :30. Immediately following departure from the facility, EPA staff took photos to document the facility and its general geographic setting. These photos are inclu ded in the photolog (Attachment 1).DRAFT

1 EPA Region 10 Photolog -- DRAFT Clean Air Act (CAA) Site Visit Alcoa Corporation – Wenatchee Works Date: June 24, 2013

All photographs depicted in this photolog were take n June 24, 2013 at the times indicated below by Zach Hedgpeth of EPA Region 10 using a Nik on CoolPix L20 digital camera.

All photos have been resized for use in this photol og, and two sets of three photos have been combined to create panoramic views (included b elow).

Photo #DSCN0001.jpg

Taken 6/24/13 – 11:09

Description: Alcoa Wenatchee Works sign at entrance to facility.

Photo #DSCN0002.jpg

Taken 6/24/13 – 16:29

Description: Photo #1 of panorama looking east from facility entrance.DRAFT

2 Photo #DSCN0003.jpg

Taken 6/24/13 – 16:30

Description: Photo #2 of panorama looking east from facility entrance.

Photo #DSCN0004.jpg

Taken 6/24/13 – 16:30

Description: Photo #3 of panorama looking east from facility entrance.DRAFT

3 Photo #DSCN0005.jpg

Taken 6/24/13 – 16:33

Description: Photo #1 of panorama looking southeast from hillside adjacent to Malaga/Alcoa Highway northwest of facility. Alcoa Wenatchee Works is visible on the right in the photograph.

Photo #DSCN0006.jpg

Taken 6/24/13 – 16:33

Description: Photo #2 of panorama looking southeast from hillside adjacent to Malaga/Alcoa Highway northwest of facility. Alcoa Wenatchee Works is visible to the left in the photograph.

Photo #DSCN0007.jpg

Taken 6/24/13 – 16:33

Description: Photo #3 of panorama looking southeast from hillside adjacent to Malaga/Alcoa Highway northwest of facility.DRAFT

4 Photo #Panorama 1.jpg Taken 6/24/13 – 16:29-16:30 Description: Panorama looking east from facility e ntrance.

Photo #Panorama 2.jpg Taken 6/24/13 – 16:33 Description: Panorama looking southeast from hills ide adjacent to Malaga/Alcoa Highway northwest of facility. Alcoa Wenatchee Works is vi sible in the center of the photograph.© 2013 Google

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