## Date: November 6 , 2014

To: Jeff Telander

, EPA/OAQPS/SPPD

From: Gabrielle Raymond and Kristin Sroka (RTI International)

Subject : Maximum Achievable Control Technology (MACT) Floor Analysis for Brick and Structural Clay Products

I. Introduction

In accordance with section 112 of the Clean Air Act (CAA), the U.S. Environmental Protection Agency (EPA) established national emission standards for hazardous air pollutants (NESHAP) on May 16, 2003

, for the brick and structural clay products (BSCP) manufacturing industry. The NESHAP regulated emissions of hydrogen fluoride (HF)

, hydrogen chloride (HCl), and particulate matter (PM)

— a surrogate for hazardous air pollutant (HAP) metals

— from

t unnel kilns located at BSCP facilities

. On March 13, 2007, the D.C. Circuit Court vacated the emission standards for BSCP manufacturing due to issues associated with the methodology used to determine the minimum regulatory “floors” for new and existing units

. 1 

## Therefore , the EPA is proposing new standards for BSCP manufacturing, including standards for HF, HCl, chlorine (Cl 2 

## ), mercury (Hg), and non

- Hg HAP metals (or PM surrogate)

.

Section 112 of the CAA requires that the EPA establish NESHAP for the con trol of the HAP emitted from both new and existing sources in a source category

. These standards must reflect the maximum degree of reduction in the HAP emissions that is achievable

. The minimum

level of control is referred to as the “ maximum achievable control technology (MACT) floor. ” The method for determining the MACT floor is defined for both new and existing sources by CAA section 112(d)(3)

. For new sources, the MACT floor cannot be less stringent than the emission control that is achieved in prac tice by the best controlled similar source

. For existing sources, the MACT floor cannot be less stringent than the average emission limitation achieved by the best performing 12 percent of existing sources for source categories with 30 or more

sources, or the best performing 5 sources for source categories with fewer than 30 sources.

The purpose of this memorandum is to present the methodology and the results of the MACT floor analysis for the BSCP source category

. This MACT floor analysis uses data

colle cted in a survey of BSCP owner s and operators conducted by the EPA in 2008 and 2010

under s ection 114 of the C AA. The emissions data supplied by BSCP owners and operators in

1 

### Sierra Club v. EPA , 479 F.3d 875 (D.C. Cir. 2007).

## 2 response to the survey were compiled into a Microsoft Excel ® data base that serves as the dataset used for this MACT floor analysis (referred to in this memorandum as the “ survey dataset”). For more details about the survey dataset, see Test Data Used in BSCP Proposed Rule ( Raymond

, 2014)

.

II. Hazardous Air Pollutants

The specific chemicals, compounds, or groups of compounds designated to be HAP are listed in CAA section 112(b)

. Included on the list are metals, organic compounds, and inorganic

chemicals

. From this HAP list, the following HAP were identified to be emitted from BSCP facilities: the acid gases HF, HCl, and Cl 2 

## ; the metals antimony (Sb), arsenic (As), beryllium (Be), cadmium (Cd), chromium (Cr), cobalt (Co), lead (Pb), manganese (Mn), Hg, nickel (Ni), and selenium (Se) ; and d ioxin s and f urans (D/F)

. MACT floo r levels for HAP metals other than Hg were analyzed using filterable PM emissions as a surrogate for total non

- Hg HAP metals

from BSCP facilities (see the preamble to the BSCP proposed rule for more information about filterable PM as a surrogate for total non

- Hg HAP metals)

.

MACT floors were not developed for acid gases or D/F. A health

- based emission limit was developed for acid gases under CAA section 112(d)(4), and work practice standards were developed for D/F under CAA section 112(h)

. The rationale behind these standards is discussed in the preamble to the BSCP proposed rule.

III. MACT Floor Analysis Subcategories

Under CAA section 112(d)(1), the EPA has the discretion to “...distinguish among classes, types, and sizes of sources withi n a category or subcategory in establishing...” standards. When separate subcategories are established, a MACT floor is determined separately for each subcategory

. To determine whether the BSCP source category warrants subcategorization for

the MACT floo r analysis, the EPA reviewed BSCP tunnel kiln design, operating information, and emissions data compiled in the survey dataset and other information collected by the Agency for development of the NESHAP for this source category ( Raymond et. al, 2014 )

. Bas ed on this review, the EPA concluded that there are significant design and operational differences in BSCP

tunnel kiln s that affect the levels of emissions of certain HAP to justify subcategorizing BSCP

tunnel kilns for the purpose of establishing MACT flo ors. For the BSCP source category , the following two subcategories were identified :

• Large tunnel kilns : New and existing BSCP tunnel kilns with a design capacity equal to or greater than 10 tons per hour (tph) of fired product.

• Small tunnel kilns : New a nd existing BSCP tunnel kilns with a design capacity less than 10 tph of fired product

.

For the proposed standards, these subcategories were only used for the MACT floors for Hg. In the subcategory analysis (Raymond et. al, 2014 )

, the data showed that for PM, sources

controlled with a fabric filter

- based control device ( i.e. , a dry injection fabric filter (DIFF), dry lime scrubber and fabric filter (DLS/FF), or a stand

- alone fabric filter (FF)) are better performers

as a group than kilns without fabric filter

- based controls

. Therefore, the proposed MACT floor

## 3 for PM (as a surrogate for non

- Hg HAP metals) was developed without size subcategories and

was based on emissions data for the sources with fabric filter

- based controls.

As discussed in Section VI of this memorandum

, the EPA is also considering the alternate approach of subcategorizing the PM data by kiln size. Therefore, this memorandum also presents the MACT floors for that alternate approach.

IV. MACT Floor Analysis Concepts

A. Upper Prediction Limit

T he MACT floor analysis for BSCP manufacturing uses an upper prediction limit (UPL) approach to identify the average emission limitation achieved by those best performing sources

. The EPA us es a UPL approach in its MACT floor analyses because it in corporates the average performance of the best performing source s and the variability of the performance during testing

conditions

. The UPL represents the value which one can expect the mean of a specified number of future observations ( e.g. , 3

- run averag e) to fall below for the specified level of confidence, based upon the results of an independent sample from the same population. The level of confidence represents the level of protection afforded to facilities whose emissions are in line

with the best performers. For example, a 99 percent level of confidence means that a facility

whose emissions are in line with the best performers has one chance in 100 of exceeding the

floor limit. A prediction interval for a single future observation (or an average of several test observations) is an interval that will, with a specified degree of confidence, contain the next (or the average of some other pre

- specified number of ) randomly selected observation(s) from a population

. In other words, the UPL estimates wh at the upper bound of future values will be, based upon present or past background samples taken

. The UPL approach encompasses all the data point

- to

- data point variability

. The predictions derive from the dataset to which it is applied, and, thus, can be applied to any type of data.

The re are different equations for calculating a UPL based on the distribution of the

dataset . Data can be normally distributed, lognormally distributed, or neither and thus have a

skewed/unknown distribution. The EPA impleme nted the statistical tests of skewness and

kurtosis to determine the distribution of the best performing sources’ data.

The skewness statistic (S) characterizes the degree of asymmetry of a given data

distribution

. Normally distributed data have an S valu e of zero

. An S value that is greater than zero indicates that the data are asymmetrically distributed with a right tail extending towards positive values; similarly, an S value that is less than zero indicates that the data are asymmetrically distributed with a left tail extending towards negative values

. The value of S can be approximated using the following equation (which is implemented in Microsoft Excel® using

the “ SKEW ” function ) :

## 4 

# ( ) ( ) 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 i



## As part of determin ing whether a data distribution can be considered normal, the S value must be compared to t he 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 absolute value of S is less than two times the

absolute value of SES, the skewness of the data can be considered normal

.

The kurtosis statistic (K) characterizes the degree of peakedness or flatness of a given data distribution in comparison to a normal distribution

. Normally distributed data have a K

value of zero

. A K value that is greater than zero indicates a relativel y peaked distribution

. A K

value that is less than zero indicates a relatively flat distribution. The estimate of K can be

calculated one of two ways. For dataset s with more than three run values, kurtosis can be

estimated using the following equation (which 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

T his equation cannot be used for dataset s with three run values ( n=3 ) because there will

be a zero in the denominator of the first and second term. Instead, f or dataset s with three run values, kurtosis is estimated using the following equation:



# ( )

( ) ( ) 3 1 4 1 4



## −

− +

= 

# ∑

= 

## stdev n x x

Kurtosis n

i i

## 5 As part of determining whether a data distribution can be considered normal , the K value must be compared to t he standard error of the kurtosis statistic (SEK)

. The SEK value can be approximated using the following equation : 

# ( ) ( ) ( ) ( ) ( ) ( ) 5 3 3 2 1 24 2



## +

− +

− −

=

n n n n n n SEK 

## (for datasets with more than three runs (n>3))

n SEK 24

= 

## (for datasets with three runs (n=3))

According to the kurtosis hypothesis test, if the absolute value of K is less than two times

the absolute value of SEK, the kurtosis of the data can be considered normal

.

For this MACT floor analysis, i f the results from both the skewness and kurtosis hypothesis tests indicated the dataset was normally distributed, the dataset was treated as normally distributed in subsequent UPL calculations

. If either of these tests indicated the dataset was not normally distributed, the dataset was log

- transformed , and the log

- transformed dataset

was ev aluated for k urtosis and skewness

. If both tests of the log

- transformed data indicated the log

- transformed dataset was normally distributed, the dataset was treated as lognormally distributed in subsequent UPL calculations

. If either of these tests indic ated the log

- transformed

dataset was not normally distributed, the dataset was treated as skewed/unknown distribution in subsequent UPL calculations.

For dataset s with only three run values, the result of both the skewness and kurtosis hypothesis tests alw ays indicate the dataset is normally distributed. Therefore, to determine the

approp riate data distribution for those dataset s, the s kewness/SES values from raw data were compared to the skewness/SES values from log

- transformed data. T he smaller skewness/SES

value was selected as an indication of a larger likelihood of the data to come from the corresponding distribut ion.

After completing the determination of the type of data distribution for each data set, the UPL was calculated using the correspo nding equation for the distribution for that dataset

. The

UPL equations for normal, lognormal, and skewed/unknown distribution dataset s are provided

below.

Normally Distributed Data s et



##      

+ + =

m n s t x UPL df 

## 1 1 2

99

. 0

,



## where:

UPL = upper prediction limit

## 6 x 

## = mean of the data calculated as 

# ∑ ∑

= = 

## = N

i n

j ij i 

## x

n x 1 1 

## 1



## n = n umber of test runs = 

# ∑

= N

i i 

## n 1



## m = n umber of future test runs in the compliance average

N = n umber 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 level of confidence with degrees of freedom (df) ; this value can be calculated with the Student’s t

- test statistical method, using the “TINV” functi on in Microsoft Excel® software

df = degrees of freedom calculated as 

# ( ) 1

1 

## − = 

# ∑

= N

i i 

## n df

Lognormally Distributed Data s et (Bhaumik and Gibbons

, 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 m σ σ m σ m



## 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 estimated 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

- Lognormal) (Gayen

, 1949)



##      

+ + =

m n s t x UPL

p df 

## 1 1 2

,



## where:

UPL = upper prediction limit

## 7 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 average

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 df

B. Representative Detection Limit

The imprecision of t est method measurement s is another component of data variability

. At very low emissions levels, as encountered in some of the data in the BSCP da taset , the inherent imprecision in the pollutant measurement method has a large influence on the reliability of the data underlying a MACT floor emission limit. Of particular concern are those data that are reported near or below a test method’s pollutant detection capability. Because of matrix effects, la boratory techniques, sample volume , and other factors, method detection limits normally vary from test to test. The guidelines for the 2010 section 114 BSCP survey requested

that sources identify ( i.e. , flag) data which were measured below the method detection limit and to report those values as equal to the test

- specific method detection limit

.

Variability of data due to measurement imprecision is inherently and reasonably addressed in calculating a MA CT floor emission limit when most of the data are significantly

above the method detection limit

. For dataset s with a large number of test results below the

method detection limit ( reported as method detection limit values ) , other techniques need to be

us ed to account for data variability. Indeed, under such a shift, the data distribution becomes truncated on the lower end, leading to an artificial overabundance of values occurring at the

method detection limit

. There is a concern that a MACT floor emiss ion limit based on a

truncated data base ( i.e.

, calculated using values at or near the method detection limit ) may not account adequately for data measurement variability, because the measurement error associated with those values provides a large degree o f uncertainty.

The expected measurement imprecision for an emissions value occurring at or near the detection limit is about 40 to 50 percent. Relative p ollutant measurement imprecision decreases

to a consistent 10 to 15 percent for values measured at a level about three times the method detection limit (ASME

, 2001)

.

The approach taken to account for measurement variability includes defining a detection limit that is representative of the data used in establishing a MACT floor emission limitation and

also minimizes the influence of an outlier test

- specific method detection limit value. The EPA

## 8 has developed a list of representative detection levels (RDL) from available pollutant

- specific method detection levels (Westlin and Merrill

, 2011). These RDL values are then multiplied by three to decrease measurement imprecision to around 10 to 15 percent (as noted in the previous paragraph) , resulting in values referred to as “3xRDL” values.

The appropriate 3xRDL value is compared to the calculated UPL value for each pollutant and subcategory. The larger of the 3xRDL value and the calculated UPL value is used for the

MACT floor emission lim it to ensure that measurement variability is adequately addressed

. This check was part of the variability analysis for all existing MACT floors that had below detection

level (BDL) or detection level limited (DLL) run data present in the best performing d ataset s

.

For more information regarding the general use of the UPL and why it is appropriate for calculating MACT floors, see the memorandum Use of the Upper Prediction Limit for Calculating MACT Floors (Telander, 2014a)

.

V. MACT Floor Analysis Methodology

A. MACT Floor Calculation Steps

Step 1.

The first step in the MACT floor analysis was to calculate an average emission value for each source per pollutant based on the available test data.

For any run fractions per test run marked a s “< method detection limit (or other reporting limit)” the fraction was considered BDL

. 2 

## For this analysis, the method detection limit for that

fraction was used as the mass to calculate a run value ( i.e. , lb/ton, μg/ dscm, and lb/hr)

. For PM runs, if the ma ss was below the 1 milligram ( mg ) RDL value, 1 mg was used as the mass to

calculate a run value ( Raymond, 2014 )

. Step 6 was added to the MACT Floor Calculation Steps

to account for dataset s with BDL values.

Step 2.

Once an average emission value was calcu lated for each source, in each s ubcategory and pollutant, all of the individual average emission values were ranked from lowest to highest value

. See Appendix A for the rankings for each pollutant and subcategory

.

Step 3.

From th e ranking s shown in Appendix A , the best performing sources were identified

consistent with the criteria in CAA section 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 from the sources that had

individual source test run data in the survey dataset

. For the existing source MACT floors, the

2 

### For the EPA Method 29 multi

- metals test, each metal lab analysis typically has two separate fractions: front

- half (filter) and back

- half (impinger catch); mercury can have three additional back

- half fractions.

## 9 number of sources in the MACT floor pool was determined on an individual subcateg ory basis

, as described in Table 1

.

Table 1

. Number of Sources in Existing Source MACT Floor Pool

Pollutant Subcategory No.
Sources

Nationwide No.
Sources

with Data No. Sources
in MACT

Floor Pool Based on

PM None; used data from kilns
with fabric filter

- based controls 225 31 27 12% of sources

nationwide

Hg Large Kilns 122 19 3 12% of sources

with data

Hg Small Kilns 103 2 1 12% of sources

with data



## Step 4.

Each MACT floor dataset (for each subcategory and pollutant) was evaluated for kurtosis

and skewness to determine the distribution, as described in Section IV .A of this memorandum

.

Step 5.

After determinin g the type of data distribution for the dataset

, the UPL was calculated using the corresponding equation for the distribution for that data set , as described in Section

IV.A of this memorandum

. See Appendix B for UPL summary tables for new and existing

sources

.

Step 6.

For source dataset s that contained BDL or DLL data , there was an additional step taken

after the subcategory UPL was calculat ed. The results of the UPL calculation were compared to

the 3xRDL value of the relevant performance test method(s) (Westlin and Merrill

, 2011)

. As described in Section IV, this step ensures that data measurement variability is addressed.

The 3xRDL values in the guidance document (Westlin and Merrill , 2011) were given in units of concentration ( micrograms per dry standard cubic meter [ μg/dscm ] with no oxygen correction) . The PM emission limits for th e proposed BSCP NESHAP are in units of p ound per ton ( lb/ton ) of brick and grains per dry standard cubic f oo t at 7 percent oxygen ( gr/dscf @ 7%

O 2 

## )

. The proposed Hg emission limits are in units of lb/ton of brick

, micrograms per dry

standard cubic meter at 7 percent oxygen ( μg/ dscm @ 7% O 2 

## ) , an d pounds per hour ( lb/hr ) . In order to compare the calculated UPL to the 3xRDL, the 3xRDL value was converted to the units

of the emission limits using a ratio of the emission data in the units of interest ( e.g. , lb/ton brick)

to the emission data in μg/dscm (uncorrected)

. See A ppendix C for more details about the

conversion of the 3xRDL values to the units of measure used in UPL calculations

.

## 10 T he converted 3xRDL value was then compared to the calculated UPL in the same units

of measure

. If the c alculated UPL value was less than the 3xRDL value, the 3xRDL value was

used as the basis for the standard because the 3xRDL value provides the lowest emission rate that can be measured using the performance test method while maintaining a relative method

p recision on the order of 10 to 20 percent of the measured value

. If the UPL value was equal to or greater than the 3xRDL value, then the UPL value was used as the basis for the standard.

Step 7.

For limited datasets with less than seven data points, the steps outlined in the

memorandum Approach for Applying the Upper Prediction Limit to Limited Datasets (Telander, 2014b) were followed. See Appendix D for more details about limited datasets.

B. Calculation of Equivalent Limits

As previously noted, i n addition to the lb/ton emission limits for PM and Hg, equivalent limits in other units of measure were developed for those pollutants. The MACT floors were calculated in units of lb/ton first. For the equivalent concentration

- based l imits for PM and Hg and the equivalent lb/hr limit for Hg, the concentration or lb/hr data were used from the best performing sources as determined from the lb/ton UPL ranking.

The survey dataset did not include much total non

- Hg HAP metals data, particula rly for

the kilns in the MACT floor pool for PM. Therefore, the total non

- Hg HAP metals equivalent

lb/hr limit was calculated from the PM MACT floor lb/ton limit using an average production rate (tph) and the average total non

- Hg HAP metals content of the PM (as a percentage of PM ) for sources in the MACT floor pool . See Appendix E for more details about the development of the

conversion factors and calculation.

V I

. M ACT Floor Analysis Results

Table s 2 and 3 present the existing source and new source MACT floor values

determined for the BSCP source category. In addition to these MACT floors, the equivalent total

non

- Hg HAP metals limits were calculated as described in Appendix E to be 0.022 lb/hr for existing sources and 0.0018 lb/hr for new sources.

## 11 Tabl e 2

. Proposed Existing Source MACT Floors

Subcategory Pollutant Avg. 99% UPL 3xRDL MACT

Floor Unit of Measure

All Kilns PM 0.04 1 0.1 6 0.022 0.1 6 lb/ton

Equivalent PM 0.011 0.04 0 0.006 6 0.04 0 gr/dscf @ 7% O 2 Large Kilns Mercury 1.6 E

- 05 2.2 E

- 05 8.0 E

- 0 6 2.2 E

- 05 lb/ton

Equivalent Mercury 1 4 29 6.4 29 μg/dscm @ 7% O 2 Equivalent Mercury 1.7 E

- 04 2.7 E

- 04 8.0 E

- 0 5 2.7 E

- 04 lb/hr

Small Kilns Mercury 1.8E

- 04 2.0E

- 04 1.7E

- 05 2.0E

- 04 lb/ton

Equivalent Mercury 62 70 6.1 70 μg/dscm @ 7% O 2 Equivalent Mercury 0.0010 0.0011 2.4E

- 04 0.0011 lb/hr



### Table 3

. Proposed New Source MACT Floors

Subc ategory Pollutant Avg

. 99% UPL 3xRDL MACT

Floor Unit of Measure

All Kilns PM 0.00 60 0.01 8 0.022 0.0 22 lb/ton

Equivalent PM 0.002 0 0.00 59 0.0066 0.00 66 gr/dscf @ 7% O 2 Large Kilns Mercury 1.5E

- 05 2.0E

- 05 8.0 E

- 0 6 2.0E

- 05 lb/ton

Equivalent Mercury 10 13 6.4 13 μg/dscm @ 7% O 2 Equivalent Mercury 0.00018 0.00024 8.0E

- 05 0.00024 lb/hr

Small Kilns Mercury 1.8E

- 04 2.0E

- 04 1.7E

- 05 2.0E

- 04 lb/ton

Equivalent Mercury 62 70 6.1 70 μg/dscm @ 7% O 2 Equivalent Mercury 0.0010 0.0011 0.00020 0.0011 lb/hr

NA: Not Applicable



## VI I

. Alternate Standards Under Consideration

As noted in Section III of this memorandum , the EPA used its discretion not to subcategorize by kiln size to develop the proposed standards for non

- Hg HAP metals (with PM as a surrogate). However, alternate MACT floors were developed for PM to assess the potential cost and emission reduction impacts if the EPA did choose to use its discretion to subcategorize by kiln size

.

Tables 4, 5, and 6 present the number of sources included in the analysis of the alternat e MACT floor options and the alternat e existing and new source MACT floor values determined for the BSCP source category. The rankings for these subcategories are shown in Appendix A, the calculation of the subcategory UPL values is shown in Appendix B, the 3xRDL values are shown in Appendix C, and the results of the evaluations conducted for limited datasets are shown in Appendix D. In addition to these PM MACT floors, the equivalent total non

- Hg HAP metals limits were calculated as described in Appendix E to be 0.012 lb/hr for existing large and small

kilns and 0.0018 lb/hr for new large and small kilns. (Note that the total non

- Hg HAP metals limits are the same for both size subcategories because none of the kilns in the PM MACT floor

## 12 pool for small kilns have metals data. Therefore, the total non

- Hg HAP m etals limit for small

kilns was set equal to the limit for large kilns.)

Table 4

. Number of Source s in the MACT Floor for Alternat e Options

Pollutant Subcategory No. Sources

Nationwide No.
Sources

with Data No. Sources
in MACT Floor

Pool Based on

PM Large Kilns 122 71 9 12% of sources

with data

PM Small Kilns 103 21 3 12% of sources

with data



### Table 5

. Alternat e Existing Source MACT Floors

Subcategory Pollutant Avg. 99% UPL 3xRDL MACT

Floor Unit of Measure

Large Kilns PM 0.012 0.02 8 0.016 0.02 8 lb/ton

Equivalent PM 0.00 45 0.016 0.007 7 0.016 gr/dscf @ 7% O 2 Small Kilns PM 0.026 0.063 NA 0.063 lb/ton

Equivalent PM 0.0029 0.0050 NA 0.0050 gr/dscf @ 7% O 2 NA: Not Applicable



### Table 6

. Alternat e New Source MACT Floors

Subc ategory Pollutant Avg

. 99% UPL 3xRDL MACT

Floor Unit of Measure

Large Kilns PM 0.00 60 0.01 8 0.016 0.01 8 lb/ton

Equivalent PM 0.002 0 0.00 59 0.0077 0.00 77 gr/dscf @ 7% O 2 Small Kilns PM 0.0093 0.029 NA 0.029 lb/ton

Equivalent PM 0.0023 0.0072 NA 0.0040 a gr/dscf @ 7% O 2

NA: Not Applicable

a Limited dataset , see Appendix D

.



## V II I

. Referenc es

ASME (founded as the American Society of Mechanical Engineers). 2001. Referenc e Method Accuracy and Precision (ReMAP): Phase 1, Precision of Manual Stack Emission

Measurements . CRTD Vol. 60, February 2001.

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

- 248.

## 13 Gayen, A. K. 1949. “ The Distribution of Student’s t in Random Samples of an y Size Drawn

from Non

- Normal Universes

. ” Biometrika , Vol. 36, No. 3/4 (Dec. 1949), pp. 353

- 369

.

Raymond, G. 2014. Test Data Used in BSCP Proposed Rule . Memorandum from Gabrielle Raymond, RTI International, to J eff Telander, EPA/OAQPS/SPPD

. November 6, 2014

.

Raymond, G., Sroka, K., and Munoz, B. 2014. Analysis of Potential Subcategories in the BSCP

Tunnel Kilns

. Memorandum from RTI International, to Jeff Telander, EPA/OAQPS/SPPD. November 6, 2014

.

Telander, J. 2014 a

. Use of the Upper Prediction Limit for Calcula ting MACT Floors

. Memorandum from Jeff Telander, EPA/OAQPS/SPPD, to Docket ID No. EPA

- HQ

- OAR

2013

- 0291. September 9, 2014

.

Telander, J. 2014b. Approach for Applying the Upper Prediction Limit to Limited Datasets

. Memorandum from Jeff Telander, EPA/OA QPS/SPPD, to Docket ID No. EPA

- HQ

- OAR

2013

- 0291. September 17, 2014

.

Westlin, P. and Merrill, R. 2011. Data and procedure for handling below detection level data in analyzing various pollutant emissions databases for MACT and RTR emissions limits

. Memo randum from Peter Westlin, SPPD/MPG and Raymond Merrill, AQAD/MTG, to SPPD management and MACT rule writers. December 13, 2011.

## Appendix A

MACT Floor Ranking Tables

## A

- 1 MACT Floor Ranking Tables

For each source per pollutant and subcategory

, an average emission value was calculated.

The average emission values for each source per pollutant and subcategory were than ranked by the average emission values to determine the best performing sources. The corresponding Appendix A

Microsoft Excel ® files provide the calculations for each source average emission value per pollutant and sub category. They also provid e the rankings of the average emission values per pollutant and subcategory. The following tables are summary excerpts of the rankings from those

Microsoft Excel ® files. The MACT floor pool in each table includes those kilns listed above the

bolded line.

## A

- 2 Table A

- 1

. Proposed Standards

– P M lb/ton R anking

Kiln ID APCD Type Size Class Average (lb/ton) Variance Below 1 mg

RDL Value n Rank by Average

514 DIFF Large Area Source (synthetic) 0.00604 1.08E

- 05 yes 3 1

686 DIFF Large Area Source (synthetic) 0.00821 3.67E

- 06 3 2

687 DIFF Large Area Source (synthetic) 0.00821 3.67E

- 06 3 3

538 DIFF Large Major Source 0.00868 1.09E

- 05 yes 5 4

599 DIFF Small Major Source 0.00930 2.99E

- 05 3 5

508 DIFF Large Major Source 0.01000 1.36E

- 05 6 6

503 DIFF Large Area Source (synthetic) 0.01399 3.67E

- 07 3 7

600 DIFF Large Area Source (synthetic) 0.01799 2.98E

- 04 yes 6 8

604 DLS Large Area Source (synthetic) 0.01843 3.98E

- 05 3 9

568 DIFF Large Area Source (synthetic) 0.02021 4.79E

- 05 5 10

688 DIFF Large Area Source (synthetic) 0.03157 1.53E

- 04 6 11

603 DLS Large Area Source (synthetic) 0.03278 2.23E

- 04 3 12

558 DIFF Large Major Source 0.03471 1.05E

- 03 yes 6 13

610 DIFF Large Area Source (synthetic) 0.03732 7.38E

- 05 6 14

543 DIFF Large Area Source (synthetic) 0.03790 1.10E

- 03 yes 5 15

606 DIFF Large Major Source 0.03901 1.80E

- 03 yes 3 16

502 DLS Large Major Source 0.04255 1.48E

- 03 yes 6 17

544 DIFF Large Area Source (synthetic) 0.04487 1.09E

- 03 yes 14 18

654 DIFF Large Area Source (synthetic) 0.04500 3.28E

- 05 3 19

653 DIFF Large Major Source 0.05159 3.21E

- 05 6 20

547 DIFF Large Major Source 0.05283 1.06E

- 03 yes 6 21

548 DIFF Large Major Source 0.05283 1.06E

- 03 yes 6 22

506 DLS Large Area Source (synthetic) 0.05578 4.25E

- 04 9 23

566 DIFF Large Major Source 0.06024 3.28E

- 03 yes 8 24

526 DIFF Large Major Source 0.06969 1.05E

- 03 9 25

527 DIFF Large Major Source 0.07699 6.23E

- 03 yes 9 26

567 DIFF Large Major Source 0.09304 5.67E

- 04 3 27

738 DIFF Large Area Source (synthetic) 0.11217 8.58E

- 03 6 28

675 DIFF Large Area Source (synthetic) 0.14825 1.72E

- 03 3 29

676 DIFF Large Area Source (synthetic) 0.18995 3.55E

- 02 6 30

655 DIFF Large Area Source (synthetic) 0.23971 5.23E

- 02 5 31

## A

- 3 Table A

- 2. Proposed Standards for Large Kilns

– Hg lb/ton Ranking a



### Kiln No APCD Type Size Class Average (lb/ton) Variance Run
Status n Rank by Average

568 DIFF Large Area Source (synthetic) 1.48E

- 05 8.83E

- 13 BDL 3 1

558 DIFF Large Major Source 1.70E

- 05 1.43E

- 12 DLL 3 2

655 DIFF Large Area Source (synthetic) 1.72E

- 05 3.10E

- 11 ADL 3 3

547 DIFF Large Major Source 2.31E

- 05 2.33E

- 11 DLL 3 4

548 DIFF Large Major Source 2.31E

- 05 2.33E

- 11 DLL 3 5

676 DIFF Large Area Source (synthetic) 2.70E

- 05 8.99E

- 12 DLL 3 6

503 DIFF Large Area Source (synthetic) 2.91E

- 05 7.63E

- 12 DLL 3 7

566 DIFF Large Major Source 3.27E

- 05 2.37E

- 12 BDL 3 8

606 DIFF Large Major Source 3.85E

- 05 3.30E

- 11 DLL 3 9

721 WS Large Area Source (synthetic) 3.93E

- 05 4.84E

- 10 DLL 2 10

720 WS Large Area Source (synthetic) 6.22E

- 05 2.92E

- 10 DLL 2 11

543 DIFF Large Area Source (synthetic) 7.66E

- 05 7.09E

- 12 DLL 3 12

775 None Large Major Source 7.79E

- 05 1.60E

- 09 DLL 3 13

526 DIFF Large Major Source 8.50E

- 05 7.47E

- 10 ADL 3 14

600 DIFF Large Area Source (synthetic) 8.94E

- 05 1.08E

- 10 ADL 3 15

508 DIFF Large Major Source 9.08E

- 05 1.21E

- 10 DLL 3 16

527 DIFF Large Major Source 9.08E

- 05 5.98E

- 11 ADL 3 17

544 DIFF Large Area Source (synthetic) 9.78E

- 05 1.02E

- 10 DLL 3 18

653 DIFF Large Major Source 1.02E

- 04 9.35E

- 12 DLL 3 19

a ADL = above detection level ; WS = wet scrubber; NA = not applicable.

## A

- 4 Table A

- 3. Proposed Standards for Small Kilns

– Hg lb/ton Ranking a



### Kiln No APCD Type Size Class Average (lb/ton) Variance Run
Status n Rank by Average

531 SD/ESP Small Major Source 1.76E

- 04 5.51E

- 11 DLL 3 1

532 SD/ESP Small Major Source 1.76E

- 04 5.51E

- 11 DLL 3 2

a SD/ESP = spray dryer/electrostatic precipitator.

## A

- 5 Table A

- 4

. Alternate Standards for Large Kilns

– PM lb/ton R anking a



### Kiln ID APCD Type Size Class Average (lb/ton) Variance Below 1 mg RDL

Value n Rank by Average

514 DIFF Large Area Source (synthetic) 0.00604 1.08E

- 05 yes 3 1

686 DIFF Large Area Source (synthetic) 0.00821 3.67E

- 06 3 2

687 DIFF Large Area Source (synthetic) 0.00821 3.67E

- 06 3 3

538 DIFF Large Major Source 0.00868 1.09E

- 05 yes 5 4

508 DIFF Large Major Source 0.01000 1.36E

- 05 6 5

695 None Large Major Source 0.01163 4.65E

- 06 yes 3 6

503 DIFF Large Area Source (synthetic) 0.01399 3.67E

- 07 3 7

696 DLA Large Major Source 0.01761 1.38E

- 04 3 8

600 DIFF Large Area Source (synthetic) 0.01799 2.98E

- 04 yes 6 9

604 DLS Large Area Source (synthetic) 0.01843 3.98E

- 05 3 10

568 DIFF Large Area Source (synthetic) 0.02021 4.79E

- 05 5 11

688 DIFF Large Area Source (synthetic) 0.03157 1.53E

- 04 6 12

603 DLS Large Area Source (synthetic) 0.03278 2.23E

- 04 3 13

558 DIFF Large Major Source 0.03471 1.05E

- 03 yes 6 14

673 DLA Large Major Source 0.03627 1.23E

- 04 6 15

674 DLA Large Major Source 0.03627 1.23E

- 04 6 16

610 DIFF Large Area Source (synthetic) 0.03732 7.38E

- 05 6 17

647 DLA Large Area Source (synthetic) 0.03758 1.37E

- 04 3 18

662 DLA Large Major Source 0.03784 6.66E

- 04 3 19

543 DIFF Large Area Source (synthetic) 0.03790 1.10E

- 03 yes 5 20

606 DIFF Large Major Source 0.03901 1.80E

- 03 yes 3 21

502 DLS Large Major Source 0.04255 1.48E

- 03 yes 6 22

544 DIFF Large Area Source (synthetic) 0.04487 1.09E

- 03 yes 14 23

654 DIFF Large Area Source (synthetic) 0.04500 3.28E

- 05 3 24

583 DLA Large Major Source 0.04765 3.08E

- 04 3 25

680 DLA Large Major Source 0.04959 6.83E

- 05 3 26

653 DIFF Large Major Source 0.05159 3.21E

- 05 6 27

547 DIFF Large Major Source 0.05283 1.06E

- 03 yes 6 28

548 DIFF Large Major Source 0.05283 1.06E

- 03 yes 6 29

506 DLS Large Area Source (synthetic) 0.05578 4.25E

- 04 9 30

649 DLA Large Major Source 0.05658 1.29E

- 04 3 31

## A

- 6 Kiln ID APCD Type Size Class Average (lb/ton) Variance Below 1 mg RDL

Value n Rank by Average

566 DIFF Large Major Source 0.06024 3.28E

- 03 yes 8 32

646 DLA Large Area Source (synthetic) 0.06031 1.08E

- 04 3 33

770 DLA Large Major Source 0.06884 1.92E

- 04 3 34

526 DIFF Large Major Source 0.06969 1.05E

- 03 9 35

527 DIFF Large Major Source 0.07699 6.23E

- 03 yes 9 36

725 DLA Large Area Source (synthetic) 0.07840 1.93E

- 03 3 37

691 DLA Large Area Source (synthetic) 0.08227 4.29E

- 04 3 38

769 DLA Large Major Source 0.08635 4.66E

- 04 3 39

625 DLA Large Major Source 0.09099 5.79E

- 04 3 40

567 DIFF Large Major Source 0.09304 5.67E

- 04 3 41

721 WS Large Area Source (synthetic) 0.09565 1.82E

- 03 5 42

724 DLA Large Area Source (synthetic) 0.09599 7.78E

- 04 3 43

641 DLA Large Area Source (synthetic) 0.09977 1.64E

- 03 3 44

518 DLA Large Major Source 0.10624 5.28E

- 04 3 45

679 DLA Large Major Source 0.10847 3.80E

- 03 3 46

738 DIFF Large Area Source (synthetic) 0.11217 8.58E

- 03 6 47

573 DLA Large Area Source (synthetic) 0.13228 2.02E

- 04 3 48

730 DLA Large Major Source 0.13851 2.63E

- 03 6 49

675 DIFF Large Area Source (synthetic) 0.14825 1.72E

- 03 3 50

740 DLA Large Area Source (synthetic) 0.15802 2.68E

- 03 3 51

517 DLA Large Area Source (synthetic) 0.16373 5.57E

- 03 6 52

729 DLA Large Major Source 0.17786 1.91E

- 03 3 53

644 DLA Large Major Source 0.17806 9.79E

- 04 3 54

676 DIFF Large Area Source (synthetic) 0.18995 3.55E

- 02 6 55

736 DLA Large Area source (synthetic) 0.20060 7.15E

- 03 3 56

655 DIFF Large Area Source (synthetic) 0.23971 5.23E

- 02 5 57

577 DLA Large Major Source 0.24112 1.86E

- 01 15 58

578 DLA Large Major Source 0.24112 1.86E

- 01 15 59

645 DLA Large Major Source 0.26210 6.74E

- 03 6 60

539 None Large Major Source 0.28166 5.73E

- 03 2 61

720 WS Large Area Source (synthetic) 0.32413 1.33E

- 01 5 62

768 DLA Large Major Source 0.37699 1.40E

- 02 3 63

## A

- 7 Kiln ID APCD Type Size Class Average (lb/ton) Variance Below 1 mg RDL

Value n Rank by Average

643 WS Large Area Source (synthetic) 0.37757 5.25E

- 02 7 64

612 DLA Large Major Source 0.41284 1.27E

- 02 3 65

613 DLA Large Major Source 0.41284 1.27E

- 02 3 66

551 DLA Large Major Source 0.55342 5.04E

- 02 18 67

552 DLA Large Major Source 0.55342 5.04E

- 02 18 68

775 None Large Major Source 0.64068 4.38E

- 02 6 69

766 DLA Large Major Source 0.82067 7.89E

- 01 6 70

767 DLA Large Major Source 0.82067 7.89E

- 01 6 71

a WS = wet scrubber; NA = not applicable.

## A

- 8 Table A

- 5

. Alternate Standards for Small Kilns

– PM lb/ton R anking

Kiln ID APCD Type Size Class Average (lb/ton) Variance Below 1 mg RDL

Value n Rank by Average

599 DIFF Small Major Source 0.00930 2.99E

- 05 3 1

549 None Small Major Source 0.01960 1.36E

- 05 3 2

665 None Small Major Source 0.05004 7.63E

- 05 3 3

663 None Small Major Source 0.05628 3.14E

- 04 3 4

571 None Small Area Source (synthetic) 0.06847 1.92E

- 04 3 5

531 SD/ESP Small Major Source 0.11149 6.80E

- 03 6 6

532 SD/ESP Small Major Source 0.11149 6.80E

- 03 6 7

533 SD/ESP Small Major Source 0.18153 1.96E

- 03 3 8

180 None Small Major Source 0.18290 1.06E

- 03 3 9

521 None Small Major Source 0.23121 1.31E

- 03 3 10

178 None Small Major Source 0.24311 5.22E

- 03 3 11

650 None Small Major Source 0.25022 4.06E

- 03 3 12

516 None Small Major Source 0.29156 7.25E

- 03 6 13

179 None Small Major Source 0.31288 1.06E

- 04 3 14

669 None Small Major Source 0.37566 2.73E

- 04 3 15

529 None Small Major Source 0.38192 1.95E

- 02 3 16

530 None Small Major Source 0.39455 1.49E

- 02 9 17

535 None Small Major Source 0.66397 1.98E

- 02 3 18

706 None Small Major Source 0.74622 2.61E

- 01 6 19

704 None Small Major Source 1.18767 6.79E

- 02 3 20

705 None Small Major Source 1.18767 6.79E

- 02 3 21

## Appendix B

UPL Tables

## B

- 1 UPL Tables

Once the best performing sources were identified per pollutant and sub category, the existing and new source UPL value s were calculated. The corresponding Appendix B M icrosoft

Excel ® file s provide the calculations for each existing and new source UPL per pollutant and

sub category. They also provide a summary of the UPL values per pollutant and subcategory. The following tables are summary excerpts of the UPL values from those Microsoft Ex cel ®

files.

## B

- 2 Table B

- 1. Proposed Standards Existing Source UPL Summary

Sub

c ategory Pollutant No. of
Sources Industrywide No. of
Sources

with Data Determination
of No. of
Sources in
MACT Floor No. of
Sources
in MACT Floor (N) No. Data
Points in

MACT

Floor (n) Average of Top
Sources UPL Unit of

Measure Data
Distribution

All Kilns PM 225 31 12% Sources Industrywide 27 148 0.041 0.16 lb/ton lognormal

Equivalent PM 225 31 12% Sources Industrywide 27 148 0.011 0.040 gr/dscf @
7% O 2 lognormal

Large Kilns Mercury 122 19 12% Sources

with Data 3 9 1.6E

- 05 2.2E

- 05 lb/ton normal

Equivalent Mercury 122 19 12% Sources

with Data 3 9 14 29 μg/dscm @
7% O 2 normal

Equivalent Mercury 122 19 12% Sources

with Data 3 9 1.7E

- 04 2.7E

- 04 lb/hr skewed/

unknown

Small Kilns Mercury 103 2 12% Sources

with Data 1 3 1.8E

- 04 2.0E

- 04 lb/ton lognormal

Equivalent Mercury 103 2 12% Sources

with Data 1 3 62 70 μg/ dscm @
7% O 2 normal

Equivalent Mercury 103 2 12% Sources

with Data 1 3 0.0010 0.0011 lb/hr lognormal

## B

- 3 Table B

- 2. Proposed Standards New Source UPL Summary

Sub

category Pollutant No. of
Sources Industrywide No. of
Sources

with Data Determination
of No. of
Sources in
MACT Floor No. of
Sources
in MACT Floor (N) No. Data
Points in

MACT Floor (n) Average
of To p Sources UPL Unit of

Measure Data
Distribution

All Kilns PM 225 31 12% Sources Industrywide 1 3 0.0060 0.018 lb/ton lognormal

Equivalent PM 225 31 12% Sources Industrywide 1 3 0.0020 0.0059 gr/dscf @
7% O 2 lognormal

Large Kilns Mercury 122 19 12% Sources

with Data 1 3 1.5E

- 05 2.0E

- 05 lb/ton normal

Equivalent Mercury 122 19 12% Sources

with Data 1 3 10 13 μg/dscm @
7% O 2 lognormal

Equivalent Mercury 122 19 12% Sources

with Data 1 3 0.00018 0.00024 lb/hr normal

Small Kilns Mercury 103 2 12% Sources

with Data 1 3 1.8E

- 04 2.0E

- 04 lb/ton lognormal

Equivalent Mercury 103 2 12% Sources

with Data 1 3 62 70 μg/dscm @
7% O 2 normal

Equivalent Mercury 103 2 12% Sources

with Data 1 3 0.0010 0.0011 lb/hr lognormal

## B

- 4 Table B

- 3

. Alternate Standards Existing Source UPL Summary

Sub

category Pollutant No. of
Sources Industrywide No. of
Sources

with Data Determination
of No. of
Sources in
MACT Floor No. of
Sources
in MACT Floor (N) No. Data
Points in

MACT Floor (n) Average of Top
Sources UPL U nit of

Measure Data
Distribution

Large Kilns PM 122 71 12% Sources

with Data 9 34 0.012 0.028 lb/ton lognormal

Equivalent PM 122 71 12% Sources

with Data 9 34 0.0045 0.016 gr/dscf @
7% O 2 skewed/

unknown

Small Kilns PM 103 21 12% Sources

with Data 3 9 0.026 0.063 lb/ton normal

Equivalent PM 103 21 12% Sources

with Data 3 9 0.0029 0.0050 gr/dscf @
7% O 2 normal



### Table B

- 4

. Alternate Standards New Source UPL Summary

Sub

category Pollutant No. of
Sources Industrywide No. of
Sources

with Data Determination

of No. of
Sources in
MACT Floor No. of
Sources
in MACT Floor (N) No. Data

Points in

MACT Floor (n) Average of Top
Sources UPL Unit of

Measure Data
Distribution

Large Kilns PM 122 71 12% Sources

with Data 1 3 0.0060 0.018 lb/ton lognormal

Equivalent PM 122 71 12% Sources

with Data 1 3 0.0020 0.0059 gr/dscf @
7% O 2 lognormal

Small Kilns PM 103 21 12% Sources

with Data 1 3 0.0093 0.029 lb/ton lognormal

Equivalent PM 103 21 12% Sources

with Data 1 3 0.0023 0.0072 gr/dscf @
7% O 2 lognormal

## Appendix C

Conversion of 3xRDL Values to Units Other Than Concentration to Facilitate Comparison

with UPL Values

## C

- 1 Conversion of 3xRDL Values to Units Other Than Concentration to Facilitate Comparison

with UPL Values

The s tandard 3xRDL values developed for specific pollutants at certain sample volumes are presented in a guidance document developed by the EPA ( Westlin and Merrill

, 2011 ).

For the BSCP MACT floors

, the units of measure used to develop the UPL value s were lb /ton brick

, lb /hr

, gr/dscf @ 7% O 2 

## , and μg/ dscm @ 7% O 2



## . However, t he 3xRDL value s from the guidance document are given in units of concentration, specifically μg/ dscm for metals and

PM

. In orde r to compare the calculated UPL with the 3xRDL for a particular pollutant, we needed to convert the 3xRDL value to the units of measure used in the UPL calculation. This appendix describes the procedure used for that conversion.

The Appendix C Microsoft E xcel® file provides the run

- by

- run test data and the

calculations used to convert the 3xRDL values for each pollutant and subcategory. The tables in this appendix are summary excerpts of the information from that Microsoft Excel® file.

1. For all of the sour ces in the MACT floor pool , we look ed at each test run that was flag ged by respondents to the BSCP survey as below detection level (BDL) or detection level limited (DLL) . If any test runs we re BDL or DLL, we proceed ed with the following

steps to convert the 3xRDL value to the units of measure used in UPL. For PM, if any run was below the 1 mg RDL value, we also proceeded with the following steps. If all

runs we re above detection level (ADL) and all PM runs were above 1 mg

, it was not
necessary to compar e a 3xRDL value to the UPL; instead, we use d the UPL value for

MACT floor. For the BSCP source category, there were values below the 1 mg RDL for PM, and values BDL/DLL for Hg.

2. For all of the sources in the PM and Hg MACT existing source floor pool s
, we c ompile d

the available concentration

, oxygen

- corrected concentration

, lb/ton , and lb/hr values for

those sources and note d the sample volume (dscm) for all runs used in the dataset

.

3. We c alculate d the ratio of the run

- by

- run data for PM lb/ton / μg/dscm; PM gr/dscf @ 7%

O 2 

## / μg/dscm; Hg lb/ton / μg/dscm; Hg μg/dscm @ 7% O 2 

## / μg/dscm ; and Hg lb/hr / μg/dscm

.

4. We c alculate d the average of all the ratio values. Table C

- 1 provides the calculated average of all of the ratio values for each pollutant and sub categor y.

## C

- 2 Table C

- 1. Average of All the Run

- by

- Run Ratios

Option Subc ategory Pollutant Average
Ratio Units Of Measure

Proposed All Kilns PM 7.37E

- 06 lb/ton / μg/dscm

PM (equivalent) 2.19E

- 06 gr/dscf @ 7% O 2 / μg/dscm

Large Kilns Hg 4.70E

- 06 lb/ton / μg/dscm

Hg (equivalent) 3.74E+00 μg/dscm @ 7% O 2 / μg/dscm

Hg (equivalent) 4.72E

- 05 lb/hr / μg/dscm

Small Kilns Hg 1.02E

- 05 lb/ton / μg/dscm

Hg (equivalent) 3.60E+00 μg/dscm @ 7% O 2 / μg/dscm

Hg (equivalent) 1.16E

- 04 lb/hr / μg/dscm

Alternate Large Kilns PM 5.21E

- 06 lb/ton / μg/dscm

PM (equivalent) 2.55E

- 06 gr/dscf @ 7% O 2 / μg/dscm

Small Kilns PM NA lb/ton / μg/dscm

PM (equivalent) NA gr/dscf @ 7% O 2 / μg/dscm



## 5. We id entif ied the typica l sample volume (in units of dscm) for each dataset

. F or PM and Hg

, the typical sample volume was equal to 1 dscm for most BSCP tests.

6. We i dentif ied the appropriate 3xRDL concentration value s for the typical sample volume

of the test runs in this dataset (1 dscm) to use from the memorandum Data and procedure for handling below detection level data in analyzing various pollutant emissions databases for MACT and RTR emissions limits ( Westlin and Merrill, 2011 ). Table C

- 2 displays the appropriate 3xRDL concentration v alues for PM and Hg at the typical sample volume of 1 dscm and other various dscm tests

.

Table C

- 2. 3xRDL Values from Guidance Document (Westlin and Merrill, 2011)

Pollutant RDL (μg) 3xRDL (μg) 3xRDL Concentrations (μg/dscm)

1 dscm test 2 dscm test 3 dscm test 4 dscm test

PM filterable (Method 5) 1.0 E +03 3.0 E +03 3.0 E +03 1.5 E +03 1.0 E +03 7.5 E +02

Mercury (Method 29) analyzed by Cold Vapor AA 5.6E

- 01 1.7E+00 1.7E+00 8.4E

- 01 5.6E

- 01 4.2E

- 01

## C

- 3 7. We multiplied the appropriate 3xRDL concentration value for the typical sample volume by the average ratio in Table C

- 1 to
convert the 3xRDL value into the units of measure used in the UPL calculation ( e.g. , lb/ton ; lb/hr; gr/dscf @7% O 2 

## ; or μg/dscm @7% O 2 

## ). Table C

- 3 displays a summary of the converted 3xRDL values.

Table C

- 3

. Converted 3xRDL Values

Option Subc ategory Pollutant Average

Ratio Average Ratio Units Of

Measure 3xRDL at Typical Sample

Volume ( μg/ dscm) Converted

3xRDL

Value Converted

3xRDL Valu e Units Of

Measure

Proposed All Kilns PM 7.37E

- 06 lb/ton / μg/dscm 3.0E+03 0.022 lb/ton

PM (equivalent) 2.19E

- 06 gr/dscf @ 7% O 2 / μg/dscm 3.0E+03 0.0066 gr/dscf @ 7% O 2 Large Kilns Hg 4.70E

- 06 lb/ton / μg/dscm 1.7E+00 7.99E

- 06 lb/ton

Hg (equivalent) 3.74E+00 μg/dscm @ 7% O 2 / μg/dscm 1.7E+00 6.4 μg/dscm @ 7% O 2 Hg (equivalent) 4.72E

- 05 lb/hr / μg/dscm 1.7E+00 8.0E

- 05 lb/hr

Small Kilns Hg 1.02E

- 05 lb/ton / μg/dscm 1.7E+00 1.7E

- 05 lb/ton

Hg (equivalent) 3.60E+00 μg/dscm @ 7% O 2 / μg/dscm 1.7E+00 6.1 μg/dscm @ 7% O 2 Hg (equivalent) 1.16E

- 04 lb/hr / μg/dscm 1.7E+00 2.0E

- 04 lb/hr

Alternate Large Kilns PM 5.21E

- 06 lb/ton / μg/dscm 3.0E+03 0.016 lb/ton

PM (equivalent) 2.55E

- 06 gr/dscf @ 7% O 2 / μg/dscm 3.0E+03 0.0077 gr/dscf @ 7% O 2 Small Kilns PM NA lb/ton / μg/dscm NA NA lb/ton

PM (equivalent) NA gr/dscf @ 7% O 2 / μg/dscm NA NA gr/dscf @ 7% O 2

## C

- 4 8. We compared the 3xRDL value to the calculated UPL

.

a. If the 3xRDL value was less than or equal to the calculated UPL value, we used the UPL value as the MACT floor

emission limit.

b. If the 3xRDL value was greater than the calculated UPL value, we used the 3xRDL value as the MACT floor emission

limit.

c. Table C

- 4 and C

- 5 summarize the results of the calculated UPL and 3xRDL comparison for existing and new source

floors.

Table C

- 4

. Existing Source Floors

Option Subc ategory Pollutant Converted

3xRDL Value a 

### UPL Floor Floor Based

On Units Of Measure

Proposed All Kilns PM 0.022 0.16 0.16 UPL lb/ton

PM (equivalent) 0.0066 0.040 0.040 UPL gr/dscf @ 7% O 2 Large Kilns Hg 7.99E

- 06 2.2E

- 05 2.2E

- 05 UPL lb/ton

Hg (equivalent) 6.4 29 29 UPL μg/dscm @ 7% O 2 Hg (equivalent) 8.0E

- 05 2.7E

- 04 2.7E

- 04 UPL lb/hr

Small Kilns Hg 1.7E

- 05 2.0E

- 04 2.0E

- 04 UPL lb/ton

Hg (equivalent) 6.1 70 70 UPL μg/dscm @ 7% O 2 Hg (equivalent) 2.0E

- 04 0.0011 0.0011 UPL lb/hr

Alternate Large Kilns PM 0.016 0.028 0.028 UPL lb/ton

PM (equivalent) 0.0077 0.016 0.016 UPL gr/dscf @ 7% O 2
Small Kilns PM NA 0.063 0.063 UPL lb/ton

PM (equivalent) NA 0.0050 0.0050 UPL gr/dscf @ 7% O 2

a NA: Not Applicable if all runs in the MACT floor pool were ADL for Hg and above the 1 mg RDL value for PM.

## C

- 5 Table C

- 5

. New Source Floors

Option Subc ategory Pollutant Converted

3xRDL Value a 

### UPL Floor Floor Based

On Units Of Measure

Proposed All Kilns PM 0.022 0.018 0.022 3xRDL lb/ton

PM (equivalent) 0.0066 0.0059 0.0066 3xRDL gr/dscf @ 7% O 2 Large Kilns Hg 7.99E

- 06 2.0E

- 05 2.0E

- 05 UPL lb/ton

Hg (equivalent) 6.4 13 13 UPL μg/dscm @ 7% O 2 Hg (equivalent) 8.0E

- 05 2.4E

- 04 2.4E

- 04 UPL lb/hr

Small Kilns Hg 1.7E

- 05 2.0E

- 04 2.0E

- 04 UPL lb/ton

Hg (equivalent) 6.1 70 70 UPL μg/dscm @ 7% O 2 Hg (equivalent) 2.0E

- 04 0.0011 0.0011 UPL lb/hr

Alternate Large Kilns PM 0.016 0.018 0.018 UPL lb/ton

PM (equivalent) 0.0077 0.0059 0.0077 3xRDL gr/dscf @ 7% O 2 Small Kilns PM NA 0.029 0.029 UPL lb/ton

PM (equivalent) NA 0.0072 0.0072 UPL gr/dscf @ 7% O 2

a NA: Not Applicable if all runs in the MACT floor pool were ADL for Hg and above the 1 mg RDL value for PM.

## Appendix D

Limited Data s ets

## D

- 1 For the BSCP source category, we have limited datasets for the following pollutants and subcategories: Hg for existing and new small tunnel kilns; PM for new all tunnel kilns; and Hg for new large tunnel kilns. For the BSCP alternate options

, we have limited datasets for the following pollutants and subcategories: PM for new large tunnel kilns and PM for new small

tunnel kilns. We evaluated these specific datasets to determine whether it is appropriate to make any modifications to the approach used to calculate MACT floors for each of these datasets.

For each dataset, we performed the following steps : ensuring that we selected the data distribution that best represents each dataset; ensuring that the correct equation for the distribution was then applied to the data; and comparing individual components of each limited

dataset to determine if the standards based on limited datase ts reasonably represent the performance of the units included in the dataset (Telander, 2014b)

.

We determined that no changes to our standard floor calculation procedure were warranted and are proposing the MACT floor limits as calculated

. We did determi ne that further evaluation of the best performing unit for the alternate option limit for PM for new small tunnel

kilns was needed (Telander, 2014b)

. We reevaluated the best performing unit for that option and found that another unit better represents the best performing unit. As such, the MACT floor is 0.0040 gr/dscf @ 7% O 2 

## for PM from alternate new small tunnel kilns (Telander, 2014b). The Appendix D Microsoft Excel® file provides additional information about the reevaluation of the best performing un it.

## Appendix E

Development of Conversion Factors Used to Determine Total Non

- Hg HAP Metals Limit

## E

- 1 Development of Conversion Factors Used to Determine Total Non

- Hg HAP Metals Limit

The BSCP dataset included limited data for non

- Hg HAP metals. Of the 27 sources in the top 12 percent of the pro posed PM MACT floor pool, only nine sources had viable metals

data

. ( F our other sources had metals data that ha d to be removed due to two or more manganese

contaminated runs

. ) Of the nine sources in the top 12 percent of the alternat e PM MACT floor pool for large kilns , only one source has viable metals data

. ( T wo other sources had metals data

that had to be removed due to two or more manganese

- contaminated runs

. ) Of the three sources in the top 12 percent of the alternat e PM MACT floor pool for small kilns , there were no sources

with metals data. For more information on the identification and treatment of m anganese

contaminat ed runs , see Test Data Used in BSCP Proposed Rule (Raymond, 2014).

Therefore, i n order t o develop a t otal n on

- Hg HAP m etals limit equivalent to the MACT floors developed for PM

, we needed to develop conversion factors to convert the PM M ACT

floor limits to total non

- Hg HAP metals limits

. The following steps were used to develop the

conversion factors and the total non

- Hg HAP metals limits equivalent to the existing source PM

MACT floors. The Appendix E Microsoft Excel® file includes the compiled data for sources in the MACT floor pool and the results of the calculations in the steps below. Tables E

- 1 and E

- 2 are summary excerpts of the information from that Microsoft Excel® file.

Step 1 . Compiled the production rate (tph), PM emission rate (lb/hr), and t otal n on

- Hg

HAP m etals emission rate (lb/hr) from kilns in the MACT floor pool for the PM limit.

Step 2. Calculated the percent total non

- Hg HAP metals in the PM by dividing the total

non

- Hg HAP m etals lb/hr value by the PM lb/hr value for each simultaneous run with data

.

Step 3

. Calculated the average percent age of PM that is non

- Hg HAP metals

.

Step 4

. Calculated the average production rate.

Step 5. Multiplied the PM MACT floor value (lb/ton) b y the average production rate (t ph ) to convert from PM in lb/ton to PM in lb/hr.

Step 6

. Multiplied the PM lb/hr by the average percent total non

- Hg HAP metals in the

PM to convert from PM in lb/hr to total non

- Hg HAP metals in lb/hr.

## E

- 2 Table E

- 1

. Existing Source Total Non

- Hg HAP Metals lb/hr Limit (Equivalent to PM Floor)

Standards MACT Floor (lb/ton) Average Percent

Total Non

- Hg

HAP Metals Average
Production Rate (t ph ) Total Non

- Hg HAP
Metals lb/hr Limit a

Proposed 0.1 6 1. 36 10.54 0.02 3

Alternate

, Large Kilns 0.02 8 1.81 13.30 0.0 068

Alternate Small Kilns 0.063 NA NA 0.0 068 b

a Results are rounded at the end of the calculations

. b None of the kilns in the s mall kiln PM MACT floor have metals data; therefore, the non

- Hg HAP metals limit for small

kilns is set equal to the limit for large kilns.



## T he conversion of the new source PM limit to an equivalent total non

- Hg HAP metals

limit was calculated slightly differently because the best performing unit in the PM new source MACT floor pool did not have any non

- Hg HAP metals data. The best performing unit has a DIFF control device, so we used the production rates and percent non

- Hg HAP metals in the PM

from other DIFF kilns in the pro posed existing source MACT floor pool ; these are the same

conversion factor s used for the proposed existing limit conversion. The results are presented in

Table E

- 2.

Table E

- 2

. New Source Total Non

- Hg HAP Metals lb/hr Limit (Equivalent to PM Floor)

Option MACT Floor (lb/ton) Average Percent

Total Non

- Hg

HAP Metals Average

Produ ction Rate (t ph ) Total Non

- Hg HAP
Metals lb/hr Limit a

Proposed 0.0 22 1. 36 10.54 0.00 32

Alternate Large 0.01 8 1. 36 10.54 0.00 26

Alternate Small 0.029 NA NA 0.00 26 b

a Results are rounded at the end of the calculations

. b None of the kilns in the small kiln PM MACT floor have metals data; therefore, the non

- Hg HAP metals limit for small

kilns is set equal to the limit for large kilns.