1

MEMORANDUM

To: David Putney, U.S. Environmental Protection Agency (EPA), OAQPS

From : David Green and Matt Hakos, RTI International

Date: November 13, 2014

Subject : Revised Draft MACT Floor Analysis for the Primary A luminum Production Source

Category

I. Introduction

Section 112 of the Clean Air Act (CAA) requires tha t the U.S. Environmental Protection Agency (EPA) establish National Emission Standards for Haz ardous Air Pollutants ( NESHAP) for the control of the hazardous air pollutants (HAP) emitted from bot h new and existing major sources in a source category. These standards must reflect the maximum degree of reduction in HAP emissions that is achievable. The minimum required level of control i s referred to as the “Maximum Achievable Control Technology (MACT) floor.” The method for determinin g the MACT floor for a NESHAP is defined for both new and existing sources in CAA section 112(d) (3). For new sources, the MACT floor cannot be less stringent than the emission control that is ac hieved in practice by the best-controlled similar s ource. For existing sources, the MACT floor cannot be less stringent than the average emission limitation achieved by the best-performing 12 percent of exist ing sources for source categories with 30 or more sources, or the best-performing five sources for so urce categories with fewer than 30 sources.

The purpose of this memorandum is to present the da ta, methodology, and results of the MACT floor analysis for the Primary Aluminum Production source category. This analysis was performed to establish the MACT floors for the previously unregu lated pollutants, listed below:

1. Polycyclic organic matter (POM) emissions from:

a. New and existing prebake potlines

2. Particulate matter (PM) (as a surrogate for HAP met als) emissions from:

a. New and existing potlines

b. New and existing anode bake furnaces

c. New and existing paste plants.

II. Data Set

On December 6, 2011, the EPA proposed revisions to the NESHAP for Primary Aluminum
Reduction Plants. This memorandum details the new e missions data obtained and the proposed MACT standards that were developed following the Decembe r 2011 proposal for the forthcoming supplemental proposal. MACT floor determinations supporting prop osed standards for carbonyl sulfide emissions from potlines and POM emissions from existing pitch storage tanks are unchanged from the December 2011 proposal (and not reopened for comment) and ar e detailed in docket item number EPA-HQ-OAR2011-0797-0145.

This MACT floor analysis used data gathered via an information request sent to the primary aluminum production industry in March of 2013. Data on process operations, emission controls, and air emissions data reported by respondents were compile d and serve as the data set used for this MACT2

floor analysis (referred to in this memorandum as t he “MACT floor data set”). PM and POM emissions test data was collected for the following:

Table 1. Summary of New Data Set

Facility
Identifier Facility Name Potline Category Potline

SubCategory PM Data POM
Data

Potline Paste

Plant Anode

Bake
Furnace Potline

SPPD_FAC_01 Alcoa - Massena West Prebake CWPB1    
SPPD_FAC_02 Alcoa - Warrick Prebake CWPB1    
SPPD_FAC_03 Alcoa - Wenatchee Prebake CWPB1    a
SPPD_FAC_04 Alumax - Mt. Holly Prebake CWPB1    
SPPD_FAC_05 Noranda Aluminum Prebake CWPB1  - - - SPPD_FAC_06 Rio Tinto Alcan - Sebree Works b Prebake CWPB1     SPPD_FAC_07 Ormet Primary Aluminum Prebake CWPB2  N/A N/A  SPPD_FAC_11 Century Aluminum Of WV Prebake CWPB2 -
- - - SPPD_FAC_12 Alcoa – Rockdale Prebake CWPB2 - - - -
SPPD_FAC_08 Century Aluminum Of KY Prebake CWPB3  -  
SPPD_FAC_09 Intalco Aluminum Prebake SWPB    c

SPPD_FAC_10 Alcoa - Massena East d Soderberg HSS  N/A N/A -
SPPD_FAC_13 Columbia Falls Aluminum Soderberg VSS2 - - N/A -

SPPD_FAC_14 Lake Charles Carbon N/A N/A N/A - - N/A

 New emissions test data were provided.

- No emissions data were provided.

N/A No affected sources are located at the plant.

a POM data were rejected due to damaged samples.

b Plant is presently owned by Century Aluminum and r eferred to as Century Aluminum - Sebree.

c PM data were rejected as testing was conducted und er non-representative conditions.

d Plant was permanently closed as a Soderberg facili ty in March of 2014.

It is important to note the current operational sta tus of several of the primary aluminum production facilities in the data set, as follows:

1. Ormet Primary Aluminum (SPPD_FAC_07) – this facilit y is currently shutdown and in bankruptcy proceedings;

2. Alcoa - Massena East (SPPD_FAC_10) – this facility is shutdown permanently as a Soderberg facility and is considering reopening as a prebake facility;

3. Century Aluminum Of WV (SPPD_FAC_11) – this facilit y is currently idle, but intends to reopen when market conditions improve;

4. Alcoa – Rockdale (SPPD_FAC_12) – this facility is c urrently idle, but intends to reopen when market conditions improve; and3

5. Columbia Falls Aluminum (SPPD_FAC_13) – this facili ty has been shut down for about five years and is not expected to reopen due to its less efficient aluminum production technology.

III. MACT Floor Analysis – Subcategories

Under CAA section 112(d)(1), the EPA has the discre tion to “...distinguish among classes, types, and sizes of sources within a category or subcatego ry in establishing...” standards. When separate subcategories are established, a MACT floor is determined separately for each subcategory. The following subcategories are defined for existing pr imary aluminum potlines, under 40 CFR part 63, Subpart LL:

1. Center-worked prebake one (CWPB1) means all existing center-worked prebake potlines not defined as center-worked prebake two (CWPB2) or cen ter-worked prebake three (CWPB3) potlines.

2. Center-worked prebake two (CWPB2) means all existing center-worked prebake potlines located at Alcoa in Rockdale, Texas; Kaiser Aluminum in Mea d, Washington; Ormet Corporation in Hannibal, Ohio; Ravenswood Aluminum in Ravenswood, West Virginia; Reynolds Metals in Troutdale, Oregon; and Vanalco Aluminum in Vancouve r, Washington.

3. Center-worked prebake three (CWPB3) means all existing center-worked prebake potlines that produce very high purity aluminum, have a wet scrub ber for the primary control system, and are located at the NSA primary aluminum plant in Hawesv ille, Kentucky.

4. Side-worked prebake (SWPB) process means a method of primary aluminum reduction using the prebake process, in which the alumina is added alon g the sides of the reduction cell.

5. Horizontal stud Soderberg (HSS) process means a method of primary aluminum reduction using the Soderberg process in which the electrical curre nt is introduced to the anode by steel rods (studs) inserted into the side of a monolithic anod e.

6. Vertical stud Soderberg two (VSS2) means all existing vertical stud Soderberg potline s located at Columbia Falls Aluminum in Columbia Falls, Montana.

There are no subcategories for new source potline e mission limits for POM or PM, as new sources would be expected to utilize the lowest emitting po tline configuration. By definition, there can be no new CWPB1, CWPB2, CWPB3, or VSS2 potlines. All new potlines of any type are required to meet the TF limits for new sources, and all new potlines wou ld be required to meet the proposed POM and PM limits for potlines. Further, all new Soderberg pot lines would be required to meet the risk based stan dard
for nickel and arsenic emissions.

Any new potline designed to produce very high purit y aluminum would be expected to comply with the new source POM emission standard either by using a suitably designed wet scrubber, or a dry alumina scrubber that is not integrated with their alumina feed system. In the latter case, the TF, POM and HA P metal laden alumina could be used in a non-high pur ity aluminum potline or discarded, as dictated by
financial considerations. A wet roof vent scrubber could be added, if necessary for additional control

.
There are no subcategories (existing or new) for an ode bake furnaces.4

IV. MACT Floor Analysis – Concepts

A. Upper Prediction Limit

The EPA determined the pool of best performers cons idering both the test results of each source and a determination of each source’s performance ov er time. Performers are then ranked from lowest emitters to highest and a pool of best performers ( referred to as the MACT floor pool) selected, based on the results of this analysis. For determining perfo rmance over time, the EPA used the upper prediction limit (UPL) statistical methodology. That is, the b est performers, and their level of performance, are determined after accounting for sources’ normal ope rating variability. The UPL represents the value which one can expect the mean of a specified number of future observations ( e.g. , 3-run average) to fall below for the specified level of confidence, based upon the results of an independent sample from the same population. A prediction interval for a single future observation (or an average of several test observations) is an interval that will, with a spec ified degree of confidence, contain the next (or th e average of some other pre-specified number of) rand omly selected observation(s) from a population. In other words, the UPL estimates what the upper bound of future values will be, based upon present or past background samples taken. The UPL approach enc ompasses all the data point-to-data point variability.

There are different equations for calculating a UPL based on the distribution of the data set. Data can be normally distributed, lognormally distribute d, or neither and thus have a skewed/unknown distribution. For this MACT floor analysis, the EPA implemented the statistical tests of skewness and
kurtosis to determine the distribution of each sour ce’s data.

The skewness statistic (S) characterizes the degree of asymmetry of a give n data distribution. Normally distributed data have an S value of zero. An S value that is greater than zero indicates that the data are asymmetrically distributed with a right ta il extending towards positive values; similarly, an S
value that is less than zero indicates that the dat a are asymmetrically distributed with a left tail e xtending towards negative values. The value of S can be appr oximated using the following equation (which is implemented in Microsoft Excel® using the “SKEW” fu nction):



## ( )( ) 3

1 2 1 

## ∑

= 

    

−

− − = n

i i stdev x x

n n n Skewness

Where:

n = sample size



### x = mean of MACT floor pool

x i = individual source mean

stdev = 

### ( )

( ) 

## ∑

− − 1 2

n x x i5

As part of determining whether a data distribution can be considered normal, the S value must be compared to the standard error of the skewness statistic (SES). The SES value can be approximated using the following equation:



## ( ) ( ) ( )( )( )

3 1 2 1 6

+ +

− − ×

=
n

n n n n SES

According to the skewness hypothesis test, if the a bsolute value of S is less than two times the absol ute value of SES, the skewness of the data can be consi dered normal.

The kurtosis statistic (K) characterizes the degree of peakedness or flat ness of a given data distribution in comparison to a normal distribution . Normally distributed data have a K value of three . A K value that is greater than three indicates a rela tively peaked distribution. A K value that is less than three indicates a relatively flat distribution. The estimate of K can be calculated one of two ways. F or data sets with more than three run values, kurtosis can be estimated using the following equation (whi ch is implemented in Microsoft Excel® using the “KURT” function):



## ( ) ( )( )( ) ( ) ( )( )

3 2 1 3

3 2 1 1 2 4



### − − −

−     
          

−

− − − +

= 

# ∑

n n n
stdev x x

n n n n n Kurtosis

This equation cannot be used for data sets with thr ee run values (n=3) because there will be a
zero in the denominator of the first and second ter m. Instead, for data sets with three run values, ku rtosis is estimated using the following equation:



## ( )

( )( ) 3 1 4 1 4

−

− +

= 

## ∑

= stdev n x x
Kurtosis n

i i

As part of determining whether a data distribution can be considered normal, the K value must be compared to the standard error of the kurtosis statistic (SEK). The SEK value, for n > 3, can be approximated using the following equation:

.

Where n = 3, the SEK value can be approximated as √ 8. According to the kurtosis hypothesis test, if th e absolute value of K is less than two times the abso lute value of SEK, the kurtosis of the data can be
considered normal.

For this MACT floor analysis, if the results from b oth the skewness and kurtosis hypothesis tests indicated the data set was normally distributed, th e data set was treated as normally distributed in subsequent UPL calculations. If either of these tes ts indicated the data set was not normally distribu ted, the data set was log-transformed, and the log-trans formed data set was evaluated for kurtosis and skewness. If both tests of the log-transformed data indicated the log-transformed data set was normall y distributed, the data set was treated as lognormall y distributed in subsequent UPL calculations. If ei ther 

# ( ) ( )( )

5 3 )3 )(2 ( )1

( 24 2



### +

− +

− −

=
n

n n n n n SEK6

of these tests indicated the log-transformed data s et was not normally distributed, the data set was treated as skewed/unknown distribution in subsequen t UPL calculations.

For data sets with only three run values, the resul t of both the skewness and kurtosis hypothesis tests always indicate the data set is normally dist ributed. Therefore, to determine the appropriate da ta distribution for those data sets, the skewness/SES values from raw data were compared to the skewness/SES values from log-transformed data. The smaller skewness/SES value was selected as an indication of a larger likelihood of the data to co me from the corresponding distribution.

After completing the determination of the type of d ata distribution for each source’s data set, the UPL was calculated using the corresponding equation for the distribution for that source. The UPL equations for normal, lognormal, and skewed/unknown distribution data sets are provided below.

Normally Distributed Data Set

     
+ + =
m

n s t x UPL df 1

1 2 99.0,

Where:

UPL = upper prediction limit



### x = mean of the data calculated as 

## ∑ ∑

= = = N

i n

j ij i x
n x 1 1 1

n = number of test runs = 

## ∑

= N

i i n 1

m = number of future test runs in the compliance a verage

N = number of sources

s 2 = pooled variance calculated as 

### ( ) 

## ∑

= − = n

i i x x
n s 1 2 2 1

t df,0.99 = quantile of t-distribution at the 99 percent lev el of confidence with degrees of

freedom (df); this value can be calculated with the Student’s t-test statistical method, using the “TINV” function in Microsoft Excel® softw are

df = degrees of freedom calculated as 

# ( ) 1
1 − = 

## ∑

= N

i i n df

Lognormally Distributed Data Set (Bhaumik and Gibbo ns, 2004)



# ( ) ( )        

− + +

− + = + + +


### 1 2 ˆ ˆ 1 4

2

ˆ ˆ 2 2 ˆ ˆ ˆ 2 99.0 2 ˆ

ˆ 2 2 2 2



### n n e m e me
m z e UPL σ σ σ μ σ σ μ σ μ7

Where:

μ

ˆ =
n y

log n

i i 

## ∑

= 1 ) ( = the average of the log transformed data from the data

2 ˆ σ = 

## ( ) ( )

1 ˆ

1 2

− − 

## ∑

=

n y log n

i i μ = variance estimate of the log transformed data

z 0.99 = the 99 th -percentile of the log-normal distribution estimate d using the trapezoidal rule

approach from the following equation: 

# ( ) ( ) 

# ( ) ( ) 99.0

24 6 3 3 3 6 1 99.0

0 4 2
2 3 1



### =         +

− − +

− − 

# ∫ z z z z z z z

z 

### φ

β β

Skewed/Unknown Distribution (Non-Normal/Non-Lognorm al) (Gayen, 1949)

     

+ + =
m

n s t x UPL
p

df 1 1 2

,

Where:

UPL = upper prediction limit



### x = mean of the data calculated as 

## ∑ ∑

= = = N

i n

j ij i x
n x 1 1 1

n = number of test runs = 

## ∑

= N

i i n 1

m = number of future test runs in the compliance a verage

N = number of sources

s 2 = pooled variance calculated as 

### ( ) 

## ∑

= − = n

i i x x
n s 1 2 2 1

t df,p = recalculated quantile of t-distribution based on specified level of confidence ( i.e.

,

99%)

df = degrees of freedom calculated as 

# ( ) 1
1 − = 

## ∑

= N

i i n df8

V. MACT Floor Analysis Methodology

Step 1.

The first step in the MACT floor analysis was to ca lculate the mean emission rate for each source. Table A-1 (Appendix A) details the dataset used for each individual source calculation.

Step 2.

Once the means were calculated for each source, sub category, and pollutant, they were ranked from lowest to highest value. Table A-1 (Appendix A ) details the rankings for each pollutant and subcategory.

Step 3.

From the rankings shown in Table A-1 (Appendix A), the best performing sources were
identified consistent with the criteria in CAA sect ion 112(d)(3) for determining MACT floors for new and existing sources. These sources are referred to as the “MACT floor pool”. For the new source MACT floors, the best controlled similar source was identified for each pollutant and emission source type, as detailed in Table A-1 (Appendix A). Note t hat the EPA is not proposing subcategories for the new source MACT standards. For the existing source subcategorized MACT floors, the best-performing five sources of a subcategory were identified when five or more sources for which we had emissions data existed in the subcategory. If a subcategory i ncluded fewer than five sources, or if emissions da ta was only available for fewer than five sources in a subcategory, then all of the sources for which we had emissions data were included in the MACT floor pool for that subcategory. All existing source subcategories had fewer than thirty sources.

Step 4.

Each existing MACT floor pool for each subcategory and pollutant was evaluated for kurtosis and skewness to determine the distribution, as desc ribed in Section IV of this memorandum. Note that each test run was treated as a separate data point in this MACT floor analysis. After determining the type of data distribution for the data set, the UPL was calculated using the corresponding equation fo r the distribution for that data set, as previously d escribed.

For more information regarding the general use of t he UPL and why it is appropriate for calculating MACT floors, see the memorandum titled Use of the Upper Prediction Limit for Calculating MACT Floors, which is available in the docket for t his action (Docket ID No. EPA-HQ-OAR-2011- 0797). Furthermore, with regard to calculation of M ACT floor limits based on limited datasets, we
considered additional factors as described in the m emorandum titled, Approach for Applying the Upper
Prediction Limit to Limited Datasets for the Primar y Aluminum Production Source Category, which is
available in the docket for this action.

VI. MACT Floor Analysis Results

Tables 2 and 3 present the existing source and new source MACT floor limit values determined for the Primary Aluminum Production source category . The data and algorithms used to calculate the MACT floor limits are presented in MACT Floor Calcu lation Details for Primary Aluminum Supplemental Proposal, available in the docket. Ref er to Appendix B for more detail.9Table 2. Proposed Existing and New Source MACT Floor Limits for Polycyclic Organic Matter (POM)Polycyclic Organic Matter (POM) StandardsCategory Source Type Subcategory Distribution N n Average MACT Limit (99% UPL)Existing Source StandardsPotline Prebake CWPB1 Normal 4 14 0.67 lb/ton Al 1.1 lb/ton AlPotline Prebake CWPB2 Normal 1 6 5.48 lb/ton Al 12lb/ton AlPotline Prebake CWPB3 Normal 1 6 1.31 lb/ton Al 2.7lb/ton AlPotline Prebake SWPB Normal 1 6 9.31 lb/ton Al 19 lb/ton AlNew Source StandardsPotline All types N/A Normal 1 4 0.54 lb/ton Al 0.77 lb/ton AlTable 3. Proposed Existing and New Source MACT Floor Limits for Particulate Matter (PM)Particulate Matter (surrogate for HAP metals) StandardsCategory Source Type Subcategory Distribution N n Average MACT Limit (99% UPL)Existing Source StandardsPotline Prebake CWPB1 Lognormal 5 22 3.84 lb/ton Al7.2 lb/ton AlPotline Prebake CWPB2 Normal 1 6 4.69 lb/ton Al 11lb/ton AlPotline Prebake CWPB3 Normal 1 6 12.43 lb/ton Al 20lb/ton AlPotline Prebake SWPB Normal 1 9 3.04 lb/ton Al 4.6lb/ton AlPotline Soderberg VSS2 Lognormal 1 3 12.24 lb/ton Al 26 lb/ton AlAnode Bake Furnace N/A N/A Normal 5 24 0.0331 lb/ton Anode 0.068 lb/ton AnodePaste Plant N/A N/A Lognormal 5 15 0.0143 lb/ton Anode 0.082 lb/ton AnodeNew Source StandardsPotline All types N/A Lognormal 1 9 3.04 lb/ton Al4.6 lb/ton AlAnode Bake Furnace N/A N/A Normal 1 6 0.0134 lb/tonAnode 0.036 lb/ton AnodePaste Plant N/A N/A Lognormal 1 3 0.0020 lb/ton Anode 0.0056 lb/ton Anode10

VII. References

Bhaumik, D.K. and Gibbons, R.D. 2004. “An Upper P rediction Limit for the Arithmetic Mean of a Lognormal Random Variable.” Technometrics , 46(2):239-248.

Gayen, A. K. 1949. “The Distribution of Student’s t in Random Samples of any Size Drawn from NonNormal Universes.” Biometrika , Vol. 36, No. 3/4 (Dec. 1949), pp. 353-369.11 Appendix A

MACT Floor Data Tables12Table A-1. MACT Floor Data TableRankFacility IDFacility NamenMeanUnit OfMeasureTest Run Data123456789POM (Potlines): CWPB11aSPPD_FAC_04Alumax - Mt. Holly 4 0.54 lb/ton Al 0.59 0.61 0.510.47 -- -- -- -- --2SPPD_FAC_06Rio Tinto Alcan - Sebree Works 3 0.55 lb/ton Al 0.24 0.73 0.68 -- -- -- -- -- --3SPPD_FAC_02Alcoa – Warrick 3 0.67 lb/ton Al 0.41 0.78 0.84 ---- -- -- -- --4SPPD_FAC_01Alcoa - Massena West 4 0.88 lb/ton Al 1.15 0.72 0.75 0.89 -- -- -- -- --POM (Potlines): CWPB21SPPD_FAC_07Ormet Primary Aluminum 6 5.48 lb/ton Al 4.67 1.87 4.99 4.49 8.59 8.29 -- -- --POM (Potlines): CWPB31SPPD_FAC_08Century Aluminum Of KY 6 1.31 lb/ton Al 1.64 1.93 1.12 1.79 0.57 0.83 -- -- --POM (Potlines): SWPB1SPPD_FAC_09Intalco Aluminum 6 9.31 lb/ton Al 6.07 4.31 13.42 13.52 6.80 11.75 -- -- --PM (Potlines): CWPB11SPPD_FAC_04Alumax - Mt. Holly 3 2.62 lb/ton Al 3.74 2.13 2.00-- -- -- -- -- --2SPPD_FAC_03Alcoa – Wenatchee 6 3.52 lb/ton Al 3.87 5.49 3.42 2.49 3.84 2.04 -- -- --3SPPD_FAC_01Alcoa - Massena West 4 3.86 lb/ton Al 4.36 3.12 3.73 4.24 -- -- -- -- --4SPPD_FAC_06Rio Tinto Alcan - Sebree Works 6 4.36 lb/ton Al 1.94 8.12 5.01 2.22 5.55 3.33 -- -- --5SPPD_FAC_02Alcoa – Warrick 3 4.63 lb/ton Al 3.55 6.30 4.04 ---- -- -- -- --6bSPPD_FAC_05Noranda Aluminum 4 5.25 lb/ton Al c c 3.40 7.18 4.05 6.36 -- -- --PM (Potlines): CWPB21SPPD_FAC_07Ormet Primary Aluminum 6 4.69 lb/ton Al 2.33 2.27 3.34 7.57 4.59 8.06 -- -- --PM (Potlines): CWPB31SPPD_FAC_08Century Aluminum Of KY 6 12.43 lb/ton Al 13.11 9.5513.49 9.22 12.30 16.91 -- -- --13RankFacility IDFacility NamenMeanUnit OfMeasureTest Run Data123456789PM (Potlines): SWPB1aSPPD_FAC_09Intalco Aluminum 9 3.04 lb/ton Al 2.87 1.92 2.88 4.03 3.92 4.01 2.94 2.60 2.21PM (Potlines): Soderberg1SPPD_FAC_10Alcoa – Massena East 3 12.24 lb/ton Al 8.70 10.60 17.43 -- -- -- -- -- --PM (Anode Bake Furnaces)1aSPPD_FAC_02Alcoa - Warrick 6 0.0134 lb/ton anode 0.0012 0.00260.0163 0.0261 0.0178 0.0163 -- -- --2SPPD_FAC_04Alumax - Mt. Holly 3 0.0217 lb/ton anode 0.0239 0.0236 0.0176 -- -- -- -- -- --3SPPD_FAC_06Rio Tinto Alcan - Sebree Works 3 0.0373 lb/ton anode 0.0330 0.0080 0.0710 -- -- -- -- -- --4SPPD_FAC_01Alcoa - Massena West 9 0.0439 lb/ton anode 0.0620 0.0170 0.0130 0.0740 0.0370 0.0400 0.0550 0.0410 0.05605SPPD_FAC_09Intalco Aluminum 3 0.0470 lb/ton anode 0.0340 0.0790 0.0280 -- -- -- -- -- --6bSPPD_FAC_03Alcoa - Wenatchee 3 0.0496 lb/ton anode 0.0477 0.0541 0.0469 -- -- -- -- -- --PM (Paste Plants)1aSPPD_FAC_04Alumax - Mt. Holly 3 0.0020 lb/ton anode 0.0016 0.0011 0.0032 -- -- -- -- -- --2SPPD_FAC_03Alcoa - Wenatchee 3 0.0023 lb/ton anode 0.0027 0.0017 0.0025 -- -- -- -- -- --3SPPD_FAC_01Alcoa - Massena West 3 0.0146 lb/ton anode 0.0160 0.0123 0.0156 -- -- -- -- -- --4SPPD_FAC_02Alcoa - Warrick 3 0.0160 lb/ton anode 0.0091 0.01710.0219 -- -- -- -- -- --5SPPD_FAC_06Rio Tinto Alcan - Sebree Works 3 0.0363 lb/ton anode 0.0730 0.0210 0.0150 -- -- -- -- -- --6dSPPD_FAC_09Intalco Aluminum -- -- lb/ton anode -- -- -- -- ---- -- -- --aIndicates facility that established the new sourceMACT floor for emissions of applicable pollutant from applicable source.bThe results of the testing at this facility were not part of the MACT floor pool in this instance since it was not one of the top 5 performers.cPM test results for runs 1 and 2 are statistical outliers and considered non-representative due to circumstances of the testing and were not used in theMACT floor determination.dThese tests were conducted under non-representativeconditions and were not used in the MACT floor determination.14 Appendix B

Summary of UPL Calculation Sheets in MACT Floor Cal culation Details for Primary Aluminum Supplemental Proposal (Available in Docket ID No. EPA-HQ-OAR-2011-0797)15Table B-1. Summary of UPL Calculation Sheets in MACT Floor Calculation Details for Primary Aluminum SupplementalProposal (Available in Docket ID No. EPA-HQ-OAR-2011-0797)Polycyclic Organic Matter (POM) StandardsCategorySourceTypeSubcategory DistributionMACT Limit(99% UPL)File Name in DocketExisting Source StandardsPotline Prebake CWPB1 Normal 1.1 lb/ton Al 01_UPL_POM_Existing_Potlines_CWPB1.xlsxPotline Prebake CWPB2 Normal 12 lb/ton Al 02_UPL_POM_Existing_Potlines_CWPB2.xlsxPotline Prebake CWPB3 Normal 2.7 lb/ton Al 03_UPL_POM_Existing_Potlines_CWPB3.xlsxPotline Prebake SWPB Normal 19 lb/ton Al 04_UPL_POM_Existing_Potlines_SWPB.xlsxNew Source StandardsPotline All types N/A Normal 0.77 lb/ton Al 05_UPL_POM_New_Potlines.xlsxParticulate Matter (surrogate for HAP metals) StandardsExisting Source StandardsPotline Prebake CWPB1 Lognormal 7.2 lb/ton Al 06_UPL_PM_Existing_Potlines_CWPB1.xlsxPotline Prebake CWPB2 Normal 11 lb/ton Al 07_UPL_PM_Existing_Potlines_CWPB2.xlsxPotline Prebake CWPB3 Normal 20 lb/ton Al 08_UPL_PM_Existing_Potlines_CWPB3.xlsxPotline Prebake SWPB Normal 4.6 lb/ton Al 09_UPL_PM_Existing_Potlines_SWPB.xlsxPotline Soderberg -- Lognormal 26 lb/ton Al 10_UPL_PM_Existing_Potlines_VSS2.xlsxAnode Bake Furnace N/A N/A Normal 0.068 lb/ton Anode 11_UPL_PM_Existing_Anode_Bake_Furnace.xlsxPaste Plant N/A N/A Lognormal 0.082 lb/ton Anode 12_UPL_PM_Existing_Paste_Plant.xlsxNew Source StandardsPotline All types N/A Normal 4.6 lb/ton Al 13_UPL_PM_New_Potlines.xlsxAnode Bake Furnace N/A N/A Normal 0.036 lb/ton Anode 14_UPL_PM_New_Anode_Bake_Furnace.xlsxPaste Plant N/A N/A Lognormal 0.0056 lb/ton Anode 15_UPL_PM_New_Paste_Plant.xlsx