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 Region 10 Site Visit Photolog 

Attachment 2 .......................................................................................................... Facility Location Map 

Attachment 3 ....................................................................Plant Overview document (from facility) 

Attachment 4 ............................................................. Table of BART emission units (from facility) 

Attachment 5 .................................. Facility plan showing BART emission units (from facility) 
3 

1. Basic Facility and Site Visit Information 

Facility: Alcoa Wenatchee Works 

 6200 Malaga/Alcoa Highway, Malaga, WA 98828 

Facility Contact: David Hulse, Environmental Manager 

 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 Ecology 

 

Date of Site Visit: June 24, 2013 

Date of Report: July 12, 2013 

Disclaimer

This report is a summary of observations and information 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 facility. 
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 west side of the Columbia River. A 

map showing the location of the facility is included as Attachment 2. A plant overview 

document was provided by the facility during the site visit which includes a basic 

description of the industrial processes at the facility; 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 for the purpose of better 

understanding the Best Available Retrofit Technology (BART) eligible emission units at 

the facility, as well as associated air pollution control 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 observations and discussions with 

facility and Alcoa Corporate staff (identified below) during the site visit, the sections 

below provide brief descriptions of each emission unit at the facility which is BART 

eligible based on emissions as well as date of construction or modification1, as well as 

any associated air pollution control equipment. The BART eligible emission units are 

summarized in a table provided by the facility during the site visit, which is included as 

Attachment 4. The general location of these emission 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 Attachment 5. 

As described below, during the site visit, EPA staff were able to confirm that each of the 

BART eligible emission units or processes identified in this report are controlled by 

fabric filter air pollution control technologies for reducing emissions of particulate 

matter (PM). Fabric filter control devices generally provide high efficiency control of 

particulate matter. Although several of the control devices discussed in this report 

provide control for other pollutants, these other pollutants do not include pollutants 

considered significant for regional haze purposes, such as nitrogen oxides (NOX) and 

sulfur dioxide (SO2). Specifically, the potline #5 gas treatment center (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 NOX or SO2. 

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 NOX or SO2. The remaining control devices 

described in this report are fabric filters which control for PM only. 

 

1

To be BART eligible, an emission unit must have been 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 Intalco Works near Ferndale, WA. The 

two potline #5 pot rooms are located at the east end of the facility, adjacent to the 

potline gas treatment centers (GTCs). Like Potlines #1 – #3, Potline #5 contains centerworked, pre-bake pots. Potline #4 was demolished in 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 Control Technology (MACT) 

standards for primary aluminum smelters (40 CFR 63, subpart LL). The GTC’s consist 

of dry scrubbing with alumina followed by fabric filtration. 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 which 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 mixed with the molten aluminum 

within the furnace. There are a total of five ingot 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 uncontrolled, 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 constructed in 1952 and so precedes the 

BART window, but furnace #62 was constructed in 1967 (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 gases from both furnaces are 

collected in an underground duct, combined, and sent to the A446 Anode Bake Scrubber 

for control. As described during the site visit, this is one instance where exhaust gases 

from “BART-eligible” and “non-BART-eligible” emission units are combined and sent to 

a common control device. 

The A446 Anode Bake Scrubber is an Alcoa-designed control 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 lower portion of the control device 

through which the dirty exhaust gases pass. The exhaust 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 three exhaust stacks each. A somewhat 

unique aspect of the control device is that a carefully controlled quantity of water is 

injected with the dirty exhaust gases into the fluidized alumina bed as a quench. The 
6 

quantity of water injected must be carefully controlled in order to avoid the presence of 

liquid water formation within the fluidized bed. The presence of liquid water can lead 

to cementing within the fluidized bed and blinding of the bags2. 

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 elevated temperature of the raw 

materials, vibration, and pressure from an overhead weight to form the coke/pitch 

mixture into green anodes. The vibratory former was installed in 1972. 

All emissions from the green mill, including the vibratory forming unit, are collected 

and sent either to the Dry Coke Scrubber or Dust Collector 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 vibratory former and associated material 

handling changes. Both of these control devices may 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 which involve equipment installed 

within the BART window related to construction of potline #5. The first is a very small 

fabric filter dust collector on an alumina conveyance line which is identified as unit 

21M. The second is another small fabric filter dust 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 led Alcoa to conservatively determine 

that the railcar unloading process and associated fabric filter is BART eligible. 

 

2

 Blinding of the bags refers to a phenomenon caused by excess moisture or other factor where the particulate 

matter adheres to or embeds in the bag material, inhibiting 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 escorted 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 conference: 

• 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 introductions, during which the EPA staff 

explained the purpose of the site visit (as described 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 included 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 the 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 furnace 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, including the nine green anode 

mixers. 

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

the emission units and control devices which are BART eligible. This request 

was denied by Alcoa based on a very restrictive photograph policy. EPA staff did 

not raise significant objections to this policy, considering 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-through was held to allow EPA personnel 

to examine the emission units and associated control devices (described above) which 
8 

are BART eligible. The site walk examined these emission units and control devices in 

the following order, with pertinent field notes included below. 

1. Dry Coke Scrubber – This device controls emissions from the vibratory anode 

former in the green mill and possibly additional green mill emission units. The 

vibratory anode former forms green anodes using a mixture of petroleum pitch 

and coke via heat, pressure, and vibration. The green anodes are produced in 

batches of approximately 6. During the visit, EPA personnel observed 

production of two batches of anodes. The room housing the vibratory former is 

a respirator-required zone, and had visible dust/haze 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 section) during the visit. The 

baghouse is equipped with “sight glasses” on the exhaust stack which are 

intended to be an early warning indicator of poor performance. The “sight 

glasses” consist of an inverted funnel within the exhaust stack which collects 

particulate matter and deposits it into a glass vial with a cone shaped end which 

is fastened outside the stack. The “sight glass” examined during the visit held 1-

2 centimeters of fine grained black particulate matter. When examining the 

glass, facility personnel commented this was more than is typically observed. No 

visible emissions were observed from this control device during the visit. 

3. A446 Anode Bake Scrubber – This unit controls emissions from the two anode 

bake ovens. During examination of the unit, Alcoa Wenatchee personnel 

explained that required monitoring includes surrogate parametric monitoring 

for air flow rate through the control device. In this case, the facility monitors fan 

amperage for compliance with an 8-hour average maximum limit. No visible 

emissions were observed from this control device during 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 delivery. The railcar unloading 

station is partially enclosed and equipped with sub-grade receiving hoppers 

with ventilation pickups vented to the baghouse. During the visit, railcar 

unloading was not occurring and the fabric filter did not appear to be in 

operation. The facility did not exhibit significant alumina dust drift outside the 

unloading facility, indicating that the air pollution control system appears to 

function reasonably well. 

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

dust collectors identified as units 21M and 19C were not directly observed during the 

site visit. Photographs of these emission units were viewed during the site visit. After a 
9 

brief examination of the anode baking ovens and potline #5, the site walk through 

concluded and the group returned to the former cafeteria for a brief closing conference. 

6. Closing Conference 

A closing conference was held to discuss the site visit in general and any action items 

for follow-up work. The same staff attended the closing 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 sufficient to achieve their intended goals. 

The sole follow-up item is as follows. 

During the site visit, Mr. Hedgpeth expressed an interest in obtaining certain identifying 

information for the air pollution control devices discussed in this report, such as 

manufacturer, model number, and any design information 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 of this issue, Mr. Dorey stated that 

he may be able to gather certain portions of this information from files left in his care by 

a former employee. He committed to looking into this 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 included 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 taken June 24, 2013 at the times indicated 

below by Zach Hedgpeth of EPA Region 10 using a Nikon CoolPix L20 digital camera. 

All photos have been resized for use in this photolog, and two sets of three photos have 

been combined to create panoramic views (included below). 

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 entrance. 

Photo #Panorama 2.jpg 

Taken 6/24/13 – 16:33 

Description: Panorama looking southeast from hillside adjacent to Malaga/Alcoa Highway 

northwest of facility. Alcoa Wenatchee Works is visible in the center of the photograph. 
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