i

National Emission Standards for Hazardous Air 

Pollutants for Brick and Structural Clay Products 

Manufacturing

Background Information for Final Rule

Summary of Public Comments and Responses

September 2015
ii

This page intentionally left blank.
iii

National Emission Standards for Hazardous Air Pollutants

for Brick and Structural Clay Products Manufacturing

Background Information for Final Rule

Summary of Public Comments and Responses

Contract No. EP-D-11-084

Work Assignment No. 3-12

U.S. Environmental Protection Agency

Office of Air Quality Planning and Standards

Sector Policies and Programs Division

Research Triangle Park, North Carolina 27711

September 2015
iv

Disclaimer

This report has been reviewed by the Sector Policies and Programs Division of the Office of Air 

Quality Planning and Standards, EPA, and approved for publication. Mention of trade names or 

commercial products is not intended to constitute endorsement or recommendation for use.
v

TABLE OF CONTENTS

LIST OF ACRONYMS AND UNITS OF MEASURE................................................................ vii

1.0 Introduction............................................................................................................................... 1

2.0 Legal ......................................................................................................................................... 4

3.0 Applicability ............................................................................................................................. 6

3.1 Source Category/NAICS Codes............................................................................................ 6

3.2 Affected Sources................................................................................................................... 6

3.3 Major/Area Sources.............................................................................................................. 7

4.0 Subcategories............................................................................................................................ 9

5.0 Test Data ................................................................................................................................. 15

6.0 Type of Standard..................................................................................................................... 18

7.0 MACT Floors.......................................................................................................................... 30

7.1 Determining Sources in Floor Pool .................................................................................... 30

7.2 UPL..................................................................................................................................... 31

7.3 Emission Limit.................................................................................................................... 43

7.3.1 Manipulation of Data for MACT Floor ....................................................................... 43

7.3.2 Equivalent Limits......................................................................................................... 49

7.3.3 3xRDL.......................................................................................................................... 50

7.3.4 Floor Calculations for Alternate Approaches .............................................................. 51

7.4 Achievability of Standards.................................................................................................. 53

8.0 Health-Based Standards.......................................................................................................... 55

8.1 Health Thresholds............................................................................................................... 55

8.2 Discretionary Authority ...................................................................................................... 55

8.3 Setting Level of Standard ................................................................................................... 55

8.3.1 Ample Margin of Safety .............................................................................................. 55

8.3.2 Risk Assessment .......................................................................................................... 55

8.3.3 Level of Standard......................................................................................................... 56

8.3.4 Other ............................................................................................................................ 58

8.4 General Support .................................................................................................................. 59

9.0 Work Practice Standards......................................................................................................... 61

10.0 Startup and Shutdown........................................................................................................... 64

11.0 Malfunction........................................................................................................................... 76

12.0 Testing and Initial Compliance Requirements...................................................................... 82

13.0 Continuous Compliance Requirements................................................................................. 84

14.0 Alternate Approaches............................................................................................................ 86

15.0 Costs and Impacts................................................................................................................. 88

15.1 Costs and Emissions Reductions ...................................................................................... 88
vi

15.2 Economic Impacts........................................................................................................... 102

16.0 Statutory and Executive Order reviews .............................................................................. 105

16.1 Executive Orders 12866 and 13563................................................................................ 105

16.2 Paperwork Reduction Act............................................................................................... 106

16.3 Regulatory Flexibility Act .............................................................................................. 112

17.0 General Comments.............................................................................................................. 115

17.1 General Opposition......................................................................................................... 115

17.2 Incorporation by Reference ............................................................................................ 115

18.0 Other Comments................................................................................................................. 116
vii

LIST OF ACRONYMS AND UNITS OF MEASURE

$ dollars

μg microgram

acfm actual cubic feet per minute

ACI activated carbon injection

ADL above detection limit

APCD air pollution control device

Ass’n association

ASTM American Society for Testing and Materials

ATSDR Agency for Toxic Substances and Disease Registry

BDL below detection limit

BIA Brick Industry Association

BSCP brick and structural clay products

CAA Clean Air Act

CBC Continental Brick Co.

CEDRI Compliance and Emissions Data Reporting Interface

CFR Code of Federal Regulations

Cir. Circuit Court

Cl2 chlorine

CO2 carbon dioxide

CWA Clean Water Act

D.C. District of Columbia

D/F dioxins/furans

DIFF dry injection fabric filter

DLA dry limestone adsorber

DLL detection level limited

DLS/FF dry lime scrubber and fabric filter

dscf dry standard cubic foot

dscm dry standard cubic meter

e.g. exempli gratia (for example)

EGU electric generating unit

EO Executive Order

EPA U.S. Environmental Protection Agency

ERT electronic reporting tool

ESP electrostatic precipitator

F Fahrenheit

FB field blank

FF fabric filter

FR Federal Register

ft3 cubic foot

FTIR Fourier transform infrared

gr grain

HAP hazardous air pollutants

HBEL health-based emission limit
viii

HCl hydrogen chloride

HCN hydrogen cyanide

HEM-3 Human Exposure Model, Version 3

HF hydrogen fluoride

Hg mercury

HI hazard index

hr hour

i.e. id est (that is)

ICR information collection request

id. idem (the same)

IRIS Integrated Risk Information System

KMnO4 potassium permanganate

kWh kilowatt-hour

lb pound

MACT maximum achievable control technology

MACT TF MACT Task Force

MDL method detection level

MMBtu million British thermal units

NACAA National Association of Clean Air Agencies

NACWA National Association of Clean Water Agencies

NAICS North American Industry Classification System

NBC Nash Brick Co.

NESHAP national emission standards for hazardous air pollutants

NOx nitrogen oxides

NRDC Natural Resources Defense Council

NSPS new source performance standard

O&M operation and maintenance

O2 oxygen

OM&M Operations, Maintenance and Monitoring

OMB Office of Management and Budget

PIC product of incomplete combustion

PM particulate matter

ppb parts per billion

ppm parts per million

PS performance specification

PTE potential to emit

PTFE polytetrafluoroethylene

QA quality assurance

QA/QC quality assurance/quality control

R2C Residual Risk Coalition

RDL representative detection level

RIA Regulatory Impact Analysis

RTR Risk and Technology Review

SAB Science Advisory Board

SBA Small Business Administration

SBREFA Small Business Regulatory Enforcement Fairness Act
ix

SD/ESP spray dryer with ESP

SO2 sulfur dioxide

SOx sulfur oxides

SSM startup, shutdown and malfunction

TOSHI target organ-specific hazard index

tpy tons per year

UPL upper prediction limit

v. versus

VE visible emissions
1

1.0 Introduction

Section 112(d) of the Clean Air Act (CAA) requires the U.S. Environmental Protection Agency 

(EPA) to set emissions standards for hazardous air pollutants (HAP) emitted by major stationary 

sources based on the performance of the maximum achievable control technology (MACT). The 

EPA issued the national emission standards for hazardous air pollutants (NESHAP) for Brick 

and Structural Clay Products (BSCP) Manufacturing on May 16, 2003. The NESHAP was

subsequently challenged, and the U.S. Court of Appeals for the D.C. Circuit vacated and 

remanded the standards on March 13, 2007. To address the vacatur and remand of the original 

NESHAP, new standards were proposed and published in the Federal Register on December 18, 

2014. The proposed standards regulate emissions of acid gases, hazardous metals, and 

dioxins/furans from affected sources in the BSCP category.

An initial 60-day period ending February 17, 2015 was provided for the public to submit 

comments to the EPA on the proposal. The public comment period was subsequently extended to 

90 days, ending March 19, 2015. The following sections of this document summarize the public 

comments received on the proposal and present EPA’s responses to those comments. A total of 

52 public comments were received on the proposed BSCP NESHAP. See www.regulations.gov, 

Docket ID No. EPA-HQ-OAR-2013-0291 for the complete public comments on the BSCP

NESHAP. Table 1 below lists the document numbers assigned to the public comments, the 

names of the commenters, and their titles and affiliations. For simplicity, only the last four digits 

of the document numbers specific to each commenter are presented in this document (e.g., 0543, 

instead of EPA-HQ-OAR-2013-0291-0543).
2

Table 1. List of Commenters on Proposed NESHAP for BSCP Manufacturing

Document Item No.

(EPA-HQ-OAR2013-0291-) Commenter/Title/Affiliation

0513 Ron Stroh, W.L. Tucker Supply Co., Inc.

0514 Employees of Whitacre Greer Co.

0515 Employees of Glen-Gery Corp.

0516 Dr. Garth Tayler, Technical Director, Acme Brick Co.

0517 Claudia R. Rodgers, Acting Chief Counsel, and David Rostker, Assistant 

Chief Counsel, Small Business Administration (SBA) Office of Advocacy

0518 Janet Whitacre Kaboth, Whitacre Greer Co.

0519 G. Vinson Hellwig, Michigan, and Robert H. Colby, Chattanooga, Tennessee, 

Co-Chairs, National Association of Clean Air Agencies (NACAA)

0520 Carol Conley, Vice President, Human Resources and Environmental Affairs, 

Cherokee Brick & Tile Co.

0521 Ryan L. Parker, President and CEO, Endicott Clay Products Co.

0522 John E. Miller, Engineering, Environmental, Health and Safety Manager, 

Whitacre Greer Co.

0523 Creighton H. McAvoy, President, The McAvoy Vitrified Brick Co.

0524 Glenn L. Unterberger and Ronald M. Varnum, Ballard Spahr LLP

0525 Michael H. Winek, Attorney at Law, Babst Calland

0526 Anonymous

0527 Donald B. Sult, Vice President, Continental Brick Co. (CBC)

0528 Allen Puckett III, President, Columbus Brick Co.

0529 Michael B. Foster, Chairman of the Board and CEO, Statesville Brick Co.

0530 Ray Leonhard, President and CEO, Brick Industry Association (BIA)

0531 Davis Henry, President, Henry Brick Co., Inc.

0532 Suzanne McAnaller, President, Donley Brick Co.

0533 SSM Coalition et al.

0534 Keith Depew, President, Cladding Operations, and Mary Ann Keon, 

Environmental Director, Boral Industries Inc.

0535 Gary S. Davis, V.P. of Sales, Endicott Clay Products Co.

0536 Matthew R. Welte, Chief Operating Officer, Summit Brick & Tile Co.

0537 Keith Depew, President, Cladding Operations, and Mary Ann Keon, 

Environmental Director, Boral Industries Inc.

0538 E. J. Biernesser, Skyline Brick

0539 Michael Hartman, Air-Tech Environmental, LLC

0540 B.T. Schimmel, Consultant, Boral Bricks, Inc., and Irene Kuo, RTP 

Environmental Associates, Inc., on behalf of the Brick Industry Association 

(BIA) MACT Task Force
3

Document Item No.

(EPA-HQ-OAR2013-0291-) Commenter/Title/Affiliation

0541 Michael Hartman, Principal Scientist, Air-Tech Environmental, LLC

0542 Paul G. Regina, Regulatory Specialist, Brick Industry Association (BIA)

0543 Susan J. Miller, Vice President, EH&S, Brick Industry Association (BIA), on 

behalf of the Brick Industry Association (BIA) MACT Task Force

0544 Paul G. Regina, Regulatory Specialist, Brick Industry Association (BIA)

0545 Mike Rixner, Technical Manager, Brampton Brick, Inc.

0546 Anonymous

0547 William L. Wehrum, Counsel, Hunton & Williams LLP, on behalf of the 

Brick Industry Association (BIA)

0548 J. R. Holton, Secretary, Lee Brick and Tile Co.

0549 Matthew Todd, Chairman, Residual Risk Coalition (R2C)

0550 Bill Spakes, Plant Manager, Hanson Brick Elgin Facility

0551 Jason Smith, Plant Manager, Hanson Brick Monroe Facility

0552 Bob Studer, Area Operations Manager, Hanson Brick Mineral Wells East and 

West Plants

0553 Steve Matsick, President, Glen-Gery Corp.

0554 Nicholas Morales, Earthjustice, on behalf of Natural Resources Defense 

Council & Sierra Club

0555 Warren Paschal, Manager of Environmental Compliance, General Shale 

Brick, Inc.

0556 Charles Smith, President and CEO, General Shale Brick, Inc.

0557 Martin Brown, Plant Manager, Hanson Brick Roseboro Facility

0558 Robert F. Belden, President and CEO, and Bradley H. Belden, Director, 

Support Services, The Belden Brick Co.

0559 Jeff A. Wyers, Plant Manager, Nash Brick Co. (NBC)

0560 Mass comment campaign, sponsoring organization unknown

0561 Mass comment campaign, sponsoring organization unknown

0562 Robert Clements, Plant Manager, Hanson Brick Michigan Plant, Corunna, 

Michigan

0563 W. Fletcher Steele, President, Pine Hall Brick Co., Inc.

0564 1 Harry Holder, Acme Brick Co.

Endicott 1 Ryan L. Parker, President and CEO, Endicott Clay Products Co.

1 Late comment
4

2.0 Legal

Comment 1: Commenter 0554 stated that the EPA’s failure to set a standard for hydrogen 

cyanide (HCN) for Brick and Clay Ceramics violates CAA section 112. The commenter noted 

that the CAA mandates that EPA “shall require the maximum degree of reduction in emissions 

of the hazardous air pollutants subject to [section 112].” Therefore, the EPA is required to limit 

all hazardous air pollutants emitted from the source categories. CAA section 112(d)(2)-(3); Nat’l 

Lime Ass’n v. EPA, 233 F.3d 625 (D.C. Cir. 2000). It is unlawful for EPA to not set a limit for a 

section 112-listed pollutant. Nat’l Lime Ass’n, 233 F.3d at 634.

The commenter noted that HCN is listed as a hazardous air pollutant. HCN exposure at high 

levels swiftly harms the brain and heart, beginning with rapid breathing, followed by 

convulsions, and loss of consciousness, and can even cause coma and death. More commonly, 

even low-level exposure to HCN is associated with breathing difficulties, chest pain, vomiting, 

headaches, and enlargement of the thyroid gland (see Agency for Toxic Substances and Disease 

Registry (ATSDR), ToxFaqs for Cyanide (July 2006)). 

The commenter noted that electric generating units burning coal emit HCN and stated that it is 

also likely, then, that brick and clay ceramics units burning coal emit HCN. The EPA requested 

that brick and clay ceramics facilities test for hydrogen chloride (HCl), hydrogen fluoride (HF), 

and chlorine (Cl2) emissions but did not request they test for HCN emissions. The commenter 

stated, the EPA’s failure to require testing cannot excuse the EPA from its legal obligation to 

regulate all emitted hazardous air pollutants. The commenter asserted that to fulfill its duty under 

the CAA, the EPA must set CAA section 112(d) standards for HCN.

Response 1: The EPA disagrees with the commenter that HCN standards must be set for coalfired BSCP tunnel kilns. In the BSCP manufacturing inventory, there are 18 active BSCP tunnel 

kilns out of 220 kilns nationwide using coal as the primary fuel, located in Georgia, Indiana, 

Kentucky, North Carolina, South Carolina, Tennessee, Virginia, and West Virginia. The 

commenter argued that because electric generating units (EGUs) burning coal emit HCN, it is 

also likely that BSCP tunnel kilns burning coal also emit HCN and, therefore, the EPA must set 

HCN standards under section 112(d) for BSCP tunnel kilns.

To evaluate the quantity of HCN emitted from coal-fired EGUs, we reviewed the available HCN 

data for EGUs fired with bituminous and subbituminous coal.

1 We reviewed the run-by-run 

HCN emissions data; evaluated the counts of emissions runs labeled as above detection limit 

(ADL), below detection limit (BDL), and detection level limited (DLL); and calculated the 

percentage for each label. We found that 72 percent of test runs were BDL for all coal-fired 

EGUs, and that 56 percent of the ADL test runs, for which there were emissions (lb/MMBtu) and 

heat input (MMBtu/hr) data provided, were less than 1 lb HCN/hr; establishing that there is not a 

significant quantity of HCN being emitted from coal-fired EGUs. We also found that coal-fired 

EGUs had an average heat input of 200 times the average for BSCP tunnel kilns firing coal. In 

addition, the highest EGU coal fired HCN lb/MMBtu run value multiplied by the highest BSCP 

 1 Spreadsheet Submissions from the Part III database, http://www.epa.gov/airtoxics/utility/utilitypg.html
5

coal fired kiln heat input rate results in an insignificant 0.2 lb HCN/hr value. Consequently, the 

EPA concludes that: (1) HCN is even less likely to be emitted in measurable quantities from 

coal-fired BSCP tunnel kilns, (2) we were correct in not requiring the BSCP facilities test for 

HCN in the 2010 survey, and (3) there is no reason to require BSCP facilities to test for HCN in 

the future.
6

3.0 Applicability

3.1 Source Category/NAICS Codes

Comment 1: Commenters 0524, 0525, and 0543 recommended the EPA clarify the rule 

applicability. Commenter 0524 mentioned that a change in the North American Industry 

Classification System (NAICS) codes between 2003 (when EPA promulgated the original 

NESHAP for BSCP manufacturing facilities) and date of this current proposal raises a potential 

ambiguity as to whether EPA is intending to regulate other facilities that were not subject to the 

original NESHAP and that are not part of the BSCP products manufacturing industry. To avoid 

any confusion, the commenter suggested the EPA clarify the scope of the proposed rule to 

conform to the scope of the 2003 NESHAP.

Commenter 0525 and 0543 stated that there are at least two other MACT standards that have the 

potential to overlap brick and structural clay operations, including the Refractories MACT and 

the Ceramic Tile MACT. The commenter noted that CAA section 112 plainly requires that only 

one categorical MACT standard apply to a given emission source. The commenter suggested that 

each rule should clearly delineate which emissions units are subject to the BSCP NESHAP and 

clarify that these emissions units are not simultaneously subject to another standard. Commenter 

0525 requested EPA revise the applicability text and the definition of BSCP manufacturing 

facility in subpart JJJJJ.

Response 1: The EPA agrees with the commenters that additional clarity is needed concerning 

the applicability of subpart JJJJJ to BSCP manufacturing facilities and the applicability of 

subpart KKKKK to clay ceramics manufacturing facilities. Consequently, for subpart JJJJJ, we 

have revised the applicability text in 40 CFR 63.8385(a) and the definition of BSCP 

manufacturing facility in 40 CFR 63.8515 to specifically exclude refractories manufacturing and 

clay ceramics manufacturing. Similarly, for subpart KKKKK, we have revised the applicability 

text in 40 CFR 63.8535(a) and the definition of clay ceramics manufacturing facility in 40 CFR 

63.8665 to specifically exclude refractories manufacturing and BSCP manufacturing. We have 

also added a footnote to preamble Table 3 (NESHAP and Industrial Source Categories Affected 

by this Action), which lists the affected NAICS codes, clarifying that refractories manufacturing 

is not included in the source categories affected by the final rule.

3.2 Affected Sources

Comment 1: Commenter 0525 requested the EPA revise proposed 40 CFR 63.8390(c) by adding

the underlined text:

(c) Process units not subject to the requirements of this subpart are listed in paragraphs 

(c)(1) through (3)(4) of this section.

(1) Kilns that are used exclusively for setting glazes on previously fired products are not subject 

to the requirements of this subpart.

(2) Raw material processing and handling.

(3) Dryers.

(4) Sources covered by subpart SSSSS of this part.
7

Response 1: The EPA agrees with the commenter that additional clarity is needed concerning 

the applicability of subpart JJJJJ (BSCP Manufacturing NESHAP). Consequently, we have 

revised 40 CFR 63.8390(c) as requested to exclude sources covered by subpart SSSSS (i.e., 

refractory sources). We have also revised 40 CFR 63.8540(c) of subpart KKKKK (Clay 

Ceramics Manufacturing NESHAP) similarly.

Comment 2: Commenter 0543 noted the EPA defined small and large kilns based on the kiln’s 

“design capacity.” The commenter stated that the “design capacity” of some kilns can vary based 

on the void space in the brick, the push rate for the kiln, and even the stacking pattern. The 

commenter suggested the EPA clarify that the “design capacity” for a kiln is the level that is 

federally-enforceable and listed in their Title V operating permit and typically expressed in units 

of tons of fired brick throughput per hour or per year. The commenter suggested that annual 

capacity should be converted to an hourly throughput for purposes of determining large or small 

by dividing annual throughput by 8,760 hours per year.

Response 2: The EPA disagrees with the commenter that the definition for “tunnel kiln design 

capacity” should be revised to refer to the level that is federally-enforceable and listed in the 

Title V operating permit. The large and small tunnel kiln subcategories were established based 

on the premise that there are distinct design differences between large and small tunnel kilns. 

Allowing a large tunnel kiln to be changed to a small tunnel kiln based on federally enforceable 

conditions provided in a Title V permit (such as limiting brick throughput) would be 

inappropriate because of the design difference between large and small tunnel kilns. However, 

we agree with the commenter that other factors such as void space can influence the design 

capacity, and we have added language to the definition for “tunnel kiln design capacity” to 

account for these factors.

3.3 Major/Area Sources

Comment 1: Commenter 0559 stated that as the proposed MACT will not apply to existing 

sources that are a true area source, or companies that do not grow or suffer major equipment 

damage that would require major repairs. The commenter noted that all area sources are affected 

by the new source MACT, which means that they and other small businesses (area sources) 

would be unable to expand or rebuild due to the prohibitive costs of controls. 

Response 1: Regarding the commenter’s concerns, the EPA has taken significant steps to 

minimize the impacts of the rule on small entities while still achieving the objectives of the rule. 

In particular, EPA has developed the rule to accept recommendations from the Small Business 

Advocacy Review Panel to the extent possible, including work practice standards for 

dioxins/furans and for periods of startup and shutdown, a health-based standard for acid gases, 

and kiln size subcategories. Post-proposal, EPA has taken additional steps to minimize the 

impacts of the rule on small entities, including developing raw material variability factors for 

mercury (Hg) emission limits based on raw material data received during the comment period,

and reevaluating stack test data used in developing the MACT floor particulate matter (PM)

emission limits.

Comment 2: Commenters 0531, 0537, and 0543 were concerned the “once in, always in”

provisions may prevent their plants from becoming synthetic minor sources. Commenter 0531 

noted that the EPA assumes sources can become synthetic minor sources rather than complying 
8

with the BSCP NESHAP. However, the commenter stated that when they contacted their state 

regulatory authority about the possibility of becoming a synthetic minor source, they were told 

that since they fell under the 2003 rule they would always be subject to MACT. Therefore, the 

commenter asserted that they do not have the option of becoming a synthetic minor source to 

avoid the proposed rule.

Commenter 0537 noted that another company’s application to become a synthetic minor source 

was denied based on the “once in-always in rule” for major sources.

Commenter 0543 asserted that the “once in, always in” policy is unlawful because the statutory 

definition of “major source” unambiguously specifies that a facility is a major source only if its 

potential to emit (PTE) exceeds the specified thresholds. If a facility is a major source and then 

reduces its PTE to below the HAP major source thresholds, then that facility ceases to be a major 

source and may no longer be subject to MACT standards for major sources.

Regardless of that assertion, Commenter 0543 noted one reason for the confusion regarding the 

when the “once in, always-in” provisions apply could be that 40 CFR part 63, subpart JJJJJ 

remains in the Code of Federal Regulations even though the rule was vacated almost 8 years ago. 

For those who could benefit from becoming a synthetic minor source, the commenter requested 

that EPA clarify that the “once in, always in” policy would not apply in this case since the 2003 

Brick MACT was vacated by the courts.

Response 2: Regarding the commenters’ concerns, the 2003 MACT rule was vacated in 2007

(see Sierra Club v. EPA, 479 F.3d 875 (D.C. Cir. 2007)) and the effect of that vacatur was to 

restore the status quo before the 2003 rule took effect. See Sierra Club v. EPA, 850 F.Supp. 2d 

300, 303-304 (D.D.C. 2012). Thus, the “once in/always in” policy does not apply based on the 

vacated 2003 rule. 
9

4.0 Subcategories

Comment 1: Commenter 0522 stated that the previous vacated BSCP MACT included a 

subcategory for small kilns, and argued that subcategorization of kilns by size should be included 

in this rulemaking. The commenter stated that, beyond the obvious economic factors, the 

installation of an air pollution control device (APCD) would have significant impact upon the 

products and, therefore, on the ability to successfully maintain the niche markets. As was 

acknowledged in the vacated MACT, brick color is an important factor in the consumer’s 

decision to buy one brick over another and it is critical that color duplication be achieved on a 

regular basis. The commenter also noted that color is a key factor in the success of their niche 

paver product line. Color is affected by changes in airflow, which is greatly affected by APCD,

certainly more so on a small tunnel kiln due to the slower production rates. According to the 

commenter, addition of an APCD would affect the historic color reproduction, possibly making 

duplication impossible.

The commenter stated that adding an APCD on an older small kiln would also be impractical, 

since the older kilns are not designed to be airtight, and the exit end has no door and the entrance 

to the kiln has a loosely fit non insulated sliding door. Sealing the kiln would cause changes in 

air pressure distribution, moving the balance points, which in turn could cause the mixing of the 

waste heat and the products of combustion. The commenter asserted that this would affect the 

color and quality of the pavers. In order for a manufacturer of pavers to account for years of 

wear, it is important that the color is consistent throughout the paver. Operating too lean or too 

rich of a mixture will result in a different firing curve, resulting in a different looking product 

and possibly weak inferior products.

Commenter 0522 noted several other specific differences between their small kilns and typical 

large kilns:

• The commenter’s small kilns are fired with high velocity side burners positioned at the 

bottom of the deck. Even with the high velocity burners, the temperature difference from 

top to bottom is as much as 100 degrees. Larger kilns are top-fired with a more even 

temperature distribution.

• The commenter’s kiln cars are narrow (6’ wide) but higher (5’ in the larger kiln, a bit 

lower in the smaller kiln) with a large gap in the middle and loosely hacked to enhance 

airflow. A modern larger kiln is low and wide; typically 1-2 feet high and as much as 20’

wide, more densely hacked and require less airflow to achieve even heat distribution.

• The commenter’s kiln is not sealed, with the exit end completely open and a very loose 

fitting door on the entrance. Larger kilns are sealed with a vestibule. The airflow and 

temperature remain constant while the smaller kiln temperatures and airflow changes 

when the entrance is opened and shut to admit a car.

• The walls and ceilings of older smaller kilns are constructed with sizeable amounts of 

refractory bricks in the walls and arched ceilings. The arched ceilings allow for open 

spaces and airflow above the cars, something not found in large kilns. Large kilns are 

typically designed with a fiber lined tight ceiling.

Response 1: The EPA agrees with the commenters that there are substantial differences based on 

size and type that warrant subcategorization. We will be retaining the small and large tunnel kiln 
10

size subcategories for the final rule for emissions of Hg. For the final rule, we are also exercising 

our discretion to subcategorize by kiln size for the PM and non-Hg metals limits.

Concerning the issue that the installation of an APCD would have significant impact upon the 

products (and color variations due to airflow), and, therefore, on the ability to successfully 

maintain the niche markets, the EPA did not receive data that would help to set a subcategory 

based on color or other categories for niche bricks, and thus cannot set a standard based on these 

types of products.

Comment 2: Commenters 0529, 0534, 0543, and 0559 recommended the EPA consider a 

subcategory for sawdust-fired kilns venting to a sawdust dryer. Commenters 0529 and 0543 

noted that sawdust dryers were treated as a separate emissions source type under the previous 

BSCP NESHAP because emissions were recognized to be different based on AP-42 testing. 

These commenters noted the previous rule required no additional numeric emission limits and 

exempted these units from control requirements. The commenters asserted that these sources 

may warrant separate treatment because there are no demonstrated controls for this source 

category. Commenters 0529 and 0543 stated that a sawdust-fired kiln with a sawdust dryer 

represents a distinctly different operating scenario from other brick manufacturing operations. 

Two commenters (0529 and 0543) are considering conducting stack tests of their sawdust dryer 

exhaust. 

Commenter 0534 stated that the proposed BSCP NESHAP would require that the exhaust from 

dryers meet the same emission requirements as exhaust from the kiln. The commenter stated 

their sawdust-fired kiln would be classified as a large kiln, and the exhaust stream from the 

dryers cannot achieve the rule emissions limits. Adding controls to the dryer is complicated by 

the required temperatures and treating outlet air is limited due to the saturated airstream. 

Furthermore, the units intermittent operation complicates what types of controls can be used. The 

commenter asserted that control options for their dryer appear to be limited, costly and would 

achieve minimal environmental benefits. Retrofitting the kiln and tunnel kiln to 100 percent 

natural gas would be expensive and would defeat the benefit of using a renewable fuel source. 

Commenter 0559 questioned whether MACT is a technology forcing program or a readily 

available proven and sound technology regulation. The commenter requested the EPA reinstate 

the appropriate subcategory for sawdust dryers that was included in the vacated 2003 BSCP 

NESHAP.

Response 2: The EPA does not agree with the commenters’ request for a subcategory for 

sawdust-fired kilns venting to a sawdust dryer. Commenter 0529 stated that they are currently 

evaluating the potential to conduct a stack test of both their kiln and sawdust dryer exhaust. 

Commenter 0543 stated that, to date, the company has been unable to finalize these plans but 

hopes to have the test conducted in the near future. Commenter 0543 further stated that this 

company is one of only two that currently operate in this potential subcategory and is the only 

small business. The commenters stated they will keep EPA informed of the progress of the 

testing and provide the data to EPA to support the consideration of a subcategory, if warranted.
11

Until data becomes available to support subcategorization, we cannot establish a separate 

subcategory for sawdust-fired kilns.

Comment 3: Commenters 0522, 0543, and 0551 requested that the EPA consider a subcategory 

for kilns with low stack temperatures. Commenter 0543 stated that there are numerous 

uncontrolled kilns in the Brick industry that never attain the necessary stack temperature to 

effectively vent their exhaust to the control devices currently identified by the EPA and used as 

the basis for all MACT burden calculations. These include kilns that never reach 300 degrees F 

and those kilns that do not maintain their stack temperatures above 300 degrees F. Commenters 

0522, 0543, and 0551 noted that venting the exhaust from these kilns through a dry injection 

fabric filter (DIFF) or a dry limestone adsorber (DLA) would not be possible because the stack 

temperature will not remain above the dewpoint for HF and HCl. Commenter 0543 noted that the 

EPA recognized the limitation of venting gas below the dewpoint when they established the 

proposed work practices for this proposed rule. Venting gas below the dewpoint would quickly 

and perhaps permanently render the controls useless. Commenter 0543 stated that, since the 

controllability of these kilns is inherently different, they warrant consideration for 

subcategorization as a different class or type of kiln. It is likely that these kilns will tend to be 

smaller and older kilns. Commenter 0522 agreed that these units represent a different class of 

kilns. Based on the differences in the emissions profile, and the inability to use the controls EPA 

has presented for other kilns, the commenter requested that EPA consider developing a 

subcategory for kilns with stack temperatures that never reach 300 degrees F.

Commenter 0543 noted that this issue was only identified recently, during the industry’s review 

of the proposed work practice requirements for startup and shutdown, and the commenter stated 

they do not yet have definitive information to provide to the EPA to support subcategorization. 

The commenter stated their intent to provide the information to the EPA by mid- to late-April, 

which will allow them time to gather the information on these sources and identify a 

recommended approach for subcategorization and regulation.

Response 3: The EPA does not agree with the commenters’ request for a subcategory for kilns 

with low stack temperatures. Commenter 0543 stated that they do not yet have definitive 

information to provide to the EPA to support subcategorization for kilns with low stack 

temperatures. Until we have received information to support subcategorization, we cannot 

establish a separate subcategory for these kilns.

Comment 4: Commenter 0517 stated the EPA should not set numeric Hg standards because no 

emissions controls have been demonstrated to be effective in controlling Hg emissions from the 

brick industry.

Commenter 0517 noted the BIA believes that any measured Hg emissions are the result of the 

input clay rather than any process differences between kilns or installed emissions control 

equipment (Memorandum to Jeff Telander from the Brick Industry Association MACT Task 

Force, October 22, 2014, Docket Item No. EPA-HQ-OAR-2013-0291-0202). The commenter 

stated this raises the question of whether any controls available to the industry would have any 

impact on Hg emissions, and whether they would be “achievable” according to the wording of 

the statute. 
12

Commenter 0517 recommended the EPA subcategorize based on raw material input type. 

According to the commenter, such a subcategorization may need to be combined with a 

significantly longer averaging time in order to avoid penalizing small businesses for the natural 

variation of clay at their location. The commenter suggested the EPA may need to delay 

promulgation of a Hg emission standard in order to gather the information necessary to establish 

such a standard.

Two commenters (0517 and 0547) noted the EPA considered creating subcategories for Hg that 

reflect “the mercury concentration of the raw materials in the kiln’s clay mine, or geographic 

location” (79 FR 75650), but currently lacks adequate data.

Commenter 0547 disputes the EPA’s claim that there is insufficient data and argued that:

(1) BIA data provides strong evidence that Hg emissions are tied to the Hg content of the 

clay raw material. The commenter noted that most brick kilns are fired by natural gas or a 

non-fossil fuel, which are inherently low in Hg

(2) BIA’s data show significant differences in the Hg content of clay both within particular 

mines and among the several mines that were tested. The commenter asserted this data 

allows the EPA to “differentiate among types of sources” for purposes of creating 

subcategories based on the Hg content of clay.

(3) Alternative sources of clay are not reasonably available to most brick plants for a variety 

of reasons, including the high costs of transporting clay and the character and quality of 

the finished brick depends of the type of clay used. 

(4) The EPA does not have the authority to prescribe the use of alternative sources of clay as 

a means of controlling Hg emissions. The EPA does not have the authority set a Hg

emissions limitation that would require plants to switch to low Hg clay.

Commenter 0547 stated that the most authoritative source of legislative history for the 1990 

CAA Amendments is the Conference Report, H. Rep. No. 101-952, 101 51 Cong. 2nd sess. 

According to the commenter, one of the issues addressed by the report is the use of mined 

materials in MACT standard setting. The entire passage is quoted in the commenter’s letter as 

found in the docket, EPA-HQ-OAR-2013-0291.

The commenter further noted that the BIA had raised “significant technological limitations” that 

would prevent the proper application of EPA Method 29 to emissions from brick plants. For 

example, the commenter noted that Method 29 was developed for gas streams with significantly 

higher concentrations of Hg than typically exists in brick plant emissions. In addition, 

Commenter 0547 noted that testing for Hg emissions is extremely costly and may be too 

expensive because of the marginal profitability of most brick plants. For these reasons, 

Commenter 0547 asserted there is ample justification for EPA to conclude that, due to these 

technical and economic limitations, it is not feasible for a typical brick plant to demonstrate 

compliance with a numeric Hg emissions limitation.
13

Response 4: The EPA disagrees with the commenters that there are no Hg emission controls 

available to the BSCP industry. Activated carbon injection, in concert with fabric filters like 

those used in the BSCP industry, has been demonstrated in a number of other industries as an 

effective control for Hg from their process units, including a similar process unit (kilns) used in 

the Portland Cement industry.

With respect to the suggestion that the EPA defer taking action on setting a Hg standard, the 

EPA notes that it is obligated to take final action to set NESHAP for BSCP facilities located at 

major sources on or before September 24, 2015 pursuant to the consent decree in Sierra Club v. 

EPA, Case No. 08-00424 (D.D.C.). Moreover, there are already sufficient stack test data 

available to set a Hg emission limit now, so there is no need to defer action.

The EPA disagrees with Commenter 0547 that they have proven there is a strong positive 

correlation between Hg emissions and Hg content of clay. Arguing that most fuels used by brick 

kilns are low in Hg and therefore, by default, the Hg must be coming from the raw materials, is 

not a strong positive correlation. Without actual data that demonstrates this correlation, the EPA 

cannot subcategorize on this basis. However, the EPA agrees that variations in the raw material 

can affect the long-term performance of the best performers when complying with a particular 

standard. Thus, the EPA has incorporated the data received during the post comment period (as 

discussed in the docket entry entitled “Final Maximum Achievable Control Technology (MACT) 

Floor Analysis for Brick and Structural Clay Products, Section IV.C.”) into the development of 

the final MACT Hg standard for this category.

The EPA disagrees with Commenter 0547 that there is ample information to differentiate among 

types of sources. The BIA itself notes that the association’s study is still a work in progress. 

Until comprehensive final results are available, we cannot justify creating subcategories based on 

the Hg content of clay. However, the EPA agrees with the commenter that the use of offsite raw 

materials is not a viable option for the BSCP industry.

The EPA disagrees that the measurement methodology for Hg emissions at a brick plant is not 

practical. During the information collection request (ICR), Method 29 was used successfully to 

determine Hg concentration in the emissions from the brick plants. A majority of the Hg

concentrations were above the detection limits. Since there are detectable numeric 

concentrations, a work practice standard is not legally permissible.

In response to the commenter’s citation to certain legislative history concerning the substitutions 

of materials and mined minerals, the EPA first disagrees this text from the legislative history 

supports the commenters’ argument. First, as the commenter notes, this is legislative history and 

not statutory language. Indeed, the “Joint Explanatory Statement” cited by the commenter carries 

less weight than the Conference Committee Report, Sierra Club v. EPA, 353 F.3d 976, 988 (D.C. 

Cir. 2004), and so is not even the most authoritative legislative history. This statement cannot be 

read to negate either EPA’s broader authority to set standards based on the MACT floor under 

section 112(d) or the specific statutory language in section 112(d)(2)(A) that expressly provides 

that EPA consider substitution of materials as a measure to reduce or eliminate emissions. See 

Sierra Club v. EPA, 479 F.3d 875, 882-82 (D.C. Cir. 2007) (in calculating MACT floors for 

brick and ceramics kilns, EPA cannot ignore non-technology measures such as the substitution of 

clay if those non-technology measures affect emissions levels).
14

Second, the quoted text itself refers to sources “engaged in mining, extraction, beneficiation, and 

processing” of minerals, and does not extend to sources who use the minerals as raw materials to 

make a final product, such as brick. The brick manufacturers covered by these standards are not 

“engaged in mining, extraction, beneficiation, and processing” of minerals. 

Third, even if this statement superseded the statutory text and case law (which it does not) and if 

the brick manufacturers covered by this rule would fall within the scope of this text (which they 

do not), the consideration of the substitution of materials that this text addresses arises in the 

context of a beyond-the-floor analysis under section 112(b)(2), which is not what EPA is 

engaged in here. In this rule, EPA is setting standards based on the MACT floor, and is not 

considering any substitution of materials in setting the standards as part of a beyond-the -floor 

analysis under CAA 112(d)(2)(A) or otherwise.
15

5.0 Test Data

Comment 1: Commenter 0554 stated that extending the testing time with Method 23 or other 

methods allows for the taking of a larger dioxin/furan sample. Thus, dioxin/furan emission levels 

that could not be measured in a one-hour test can be measured in a two-hour or five-hour test. 

Moreover, it is well established that dioxins/furans can be measured down to levels measured in 

femtograms per cubic meter. [California Ambient Dioxin Air Monitoring Program (Oct. 2004)] 

In addition, dioxin/furan continuous emission monitors are available, and EPA could use these to 

measure emissions. [EPA, Environmental Technology Verification Program, Dioxin Emission 

Monitoring Systems]

Response 1: The EPA thanks the commenter for their comments. The EPA agrees that extending 

the sampling time increases the detection limit. In the tests conducted as part of the ICR for 

dioxin emissions, we required that EPA Method 23 be used and that the source collect a 

minimum volume of 2.5 cubic meters or have a minimum sample time of 4 hours per run that 

would result in low method detection levels (MDLs) in order to increase the possibility of 

collecting measurable amounts of dioxins and minimize the number of non-detects. The EPA 

recognizes the existence of other dioxin measurement methods and yet also recognizes the 

importance of consistency in measurements of these low magnitudes as well as the necessity of 

using the measurement technique for compliance determinations that was used to establish the 

emissions limit. At this time the EPA holds that Method 23 is the appropriate tool for dioxin and 

furan emissions determinations. We disagree that dioxin continuous emission monitors are 

available. There is currently no performance specification (PS) for continuous chlorinated 

dibenzo-p-dioxin (dioxins) or chlorinated dibenzofuran (furans) monitoring. None of the 

approaches evaluated during the Environmental Technology Verification Program for Dioxin 

Emission Monitoring Systems met our nominal performance criteria requirement of 20 percent 

relative accuracy. While EPA believes there is potential to improve one or more of the 

continuous monitoring approaches for dioxins and furans to meet our performance requirements, 

we would need to further evaluate monitoring system performance and promulgate a PS before 

we would consider requiring continuous monitoring for dioxins/furans on a broad basis.

Comment 2: Commenter 0543 stated that EPA Method 29, the test method used for gathering 

the data used to set the standard and required for demonstrating compliance, was designed for 

significantly higher concentration stacks. As a result, the lack of detailed quality assurance 

procedures that could lead to small errors could have significant impact on final assessments, 

since the size of the errors can be as large as or larger than the values being measured.

Response 2: The EPA thanks the commenter for their comments. For a majority of the tests, the 

concentration of the Hg was above the Method 29 detection limits. Therefore, the detection 

limits were sensitive enough for the brick plants tested and do not have a negative effect on 

measuring HAP metals from Brick sources. There were very few test reports for Hg not detected 

in any of the 5 fractions of the Method 29 test. The EPA will continue to use Method 29 data for 

developing MACT floors and use for compliance.

Comment 3: Commenter 0541 stated the existing Hg data collected using Method 29 indicated 

that the HCl rinse was much higher than the potassium permanganate (KMNO4) component of 

the analysis. The commenter stated that the HCl rinse part of the method to capture the last 

portions of the KMNO4 solution that adheres to the side of the impinger, and it should be orders 
16

of magnitude lower than the KMNO4 solution in total Hg. However, the commenter noted it is as 

much as two orders of magnitude higher than the impinger solution in the BSCP data set.

Commenter 0541 noted that one possible explanation for this could be that the KMNO4 solution 

was expended during the test due to interference of nitrogen oxides (NOx) and carbon dioxide 

(CO2), which are also collected in the KMNO4 solution. The commenter noted while the method 

does not call for it, most samplers know that the solution turns clear when the solution is 

expended; these test reports did not have any comments one way or the other. The commenter 

stated due to the suspected interference of NOx and CO2 this would not be advisable for this 

industry.

Response 3: The EPA thanks the commenter for their comments. However, in reviewing the 

KMNO4 fraction data, there were no comments from the testers or laboratories indicating that the 

permanganate solution was spent. Also, in comparison to Boilers, the results for brick kilns are 

comparable in terms of the ratio of the HCl and KMnO4 fractions. In general, the largest 

concentration of Hg was found in the nitric acid/hydrogen peroxide fraction. All five fraction 

concentrations are combined to get a total Hg concentration. The EPA will continue to use 

Method 29 data for developing MACT floors and use for compliance.

Comment 4: Commenter 0541 stated there were no field blanks or proof blanks with the Method 

29 Hg data. The commenter found no evidence of the required blanks; the only blanks indicated 

were pre-test filter blanks, post-test filter blanks as well as field reagent blanks. All the blanks 

were the lab blanks, which did not allow for the correct subtraction of the blanks as allowed for 

in the method. The commenter asserted that the only way to achieve a true method blank is to 

take field blanks and proof blanks; the proof blank is obtained by assembling the clean glassware 

and then recovering it in the prescribed manner. The resulting numbers indicate the cleanliness 

of the sampling equipment and an approximate detection level.

Commenter 0541 stated the field blank is taken after the glassware has been used for at least one 

run; it is assembled as a normal run, taken to the test location, leak checked and then recovered 

as a normal sample. The results indicate train contamination and carry over as well as ambient 

air components and sample handling biases; none of these blanks were performed for this data 

and therefore not calculated for the standards.

Response 4: The EPA thanks the commenter for their comments. When following Method 29, 

field and proof blanks are not required. The test results are not invalid due to the lack of these 

types of blanks. Reagent blanks are required by the method. In terms of “blank correction” to 

sample mass, the only subtraction allowed by the method is residue from the reagent blank. Field 

blanks are “informative” (and very good practice) but not required by the method. The correct 

blank in terms of data correction is the one labeled “blank” (FB would mean “field blank”). The 

EPA will continue to use Method 29 data for developing MACT floors and use for compliance.

Comment 5: Commenter 0541 stated that the Hg data reported is all total Hg; it would be 

impossible to design or evaluate a control device based on this data. Mercury reduction requires 

differing controls based on the oxidation state of the emitted Hg; Method 29 does not 

differentiate these. There are methods that do but none of that data is presented.
17

Response 5: The EPA thanks the commenter for their comments. The commenter is correct that 

Method 29 did not speciate Hg but gave a total Hg concentration. The EPA only has Method 29 

data available for total Hg from Brick kilns. The ASTM D6784-02 Ontario Hydro Method 

quantifies Hg in different states, elemental, oxidized, and particulate bound, however, that 

method was not a part of the Section 114 testing request. As such, the EPA does not have any 

oxidation state specific data available for Brick kilns. However, even without speciated mercury 

data it is still possible to develop cost estimates for potential controls based on typical emission 

control designs from other industries. 

Comment 6: Commenter 0541 stated the detection limits and blanks presented in the Method 29 

Hg results are only analytical data; no field or method detection data was presented. The 

commenter noted the method stated variation in the metal analysis but did not include the Hg

analysis.

Response 6: The EPA disagrees with this comment. The EPA used the detection limits that were 

made available by the laboratories performing the analyses for both the metals and the Hg

fractions. The EPA’s electronic reporting tool (ERT) was used by testers to calculate the 

emission concentration and rates utilizing the field sampling and laboratory data. If both 

fractions had non-detectable quantities, the analytical detection limit was multiplied by the field 

sampling volume to calculate the test- specific detection limit. This data was presented in the 

performance test reports.
18

6.0 Type of Standard

Comment 1: Commenter 0543 stated that the use of work practices is justified under CAA 

section 112(h) for the reasons detailed in the preamble and commended the EPA on their use. 

Commenters 0543 also stated that the use of work practice standards should be expanded. 

Commenters 0555, 0556, and 0558 supported the EPA’s proposal of work practice standards and 

noted that their concerns with other provisions of the proposed rule do not take away from their 

support of work practice standards.

Response 1: The EPA appreciates the commenters’ support for the use of work practice 

standards in the BSCP rule. Our response regarding Commenter 0543’s request for expansion of 

work practice standards is presented elsewhere in this section.

Comment 2: Commenter 0554 stated that the work practice standards for dioxin/furan emissions 

from brick tunnel kilns violate CAA section 112(h) and section 112(d) because the EPA did not 

identify any particular technological limitation associated with the measurement method. The 

EPA’s argument that some test results were below the detection limits does not meet the relevant 

statutory standard. The EPA did not claim that it is not practicable to apply measurement 

technology to dioxins/furans. Measurement technology has been applied to dioxins/furans and 

generated significant emissions test data. The commenter asserted that setting work practice 

standards in lieu of emission standards for dioxins/furans would be unlawful and arbitrary.

Under CAA section 112(h), the test is whether “the application of measurement methodology to 

a particular class of sources is not practicable.” The EPA did not identify any class of sources to 

which measurement methodology for dioxins/furans is not practicable CAA section 112(h) does 

not allow the EPA to set work practice standards whenever a number of emission tests falls 

below detection limits. The EPA’s claim shows only that some sources’ emissions are lower than 

the detection limits for some measurement methods, not that “measurement methodology” for 

dioxin/furan emissions from brick tunnel kilns is not practicable.

The commenter stated that the fact that some units recorded test results below the particular 

detection limit does not show that application of measurement methodologies is impracticable.

The commenter noted that some sources used the cheapest and least accurate tests and submitted

data that lacked precision and incorporated high detection limits. The EPA cannot use these 

imprecise data as an excuse to avoid setting emission standards because the measurement 

methodologies that allowed many other kilns to use much lower detection levels are applicable to 

all sources.

Commenter 0554 quoted Sierra Club v. EPA, 479 F.3d 875, which vacated prior work practice 

standards for certain brick and clay ceramics plants on holding that the lack of available data 

does not provide a valid justification for work practice standards under CAA section 112(h)).

The commenter also noted that the CAA expressly authorizes the EPA to issue a “prohibition”

on emissions where achievable, and a fortiori, the EPA can issue standards at a specific detection 

limit higher than zero even if emissions cannot be measured below that detection limit. . Even if 

the test results that fall below a particular source’s detection limit are not used for the purposes 

of standard-setting, the EPA must base floors on the sources for which the Administrator does 
19

have usable emissions data pursuant to CAA section 112(d)(3)(A). Since the EPA has emissions 

data for dioxins/furans that are above the detection limits and has acknowledged that where 

“emissions can be precisely measured for at least some units in [a] subcategory ... the statutory 

test for establishment of work practice standards -- i.e., that measurement of emissions is 

impracticable due to technological and economic limitations -- is not met.” National Emission 

Standards for Hazardous Air Pollutants for Major Sources: Industrial, Commercial, and 

Institutional Boilers and Process Heaters, 76 FR 15608, 15640 (Mar. 21, 2011).

The commenter stated that the fact that some kilns might always record emission levels below 

their particular detection levels is irrelevant since does not show the measurement methodology 

is impracticable, but merely the kiln has low emission levels, high detection levels, or both. The 

commenter asserted that low emissions from brick tunnel kilns can be measured by methods in 

use today and noted the EPA proposed roller kilns and first-fire tunnel kilns at ceramic facilities

measure dioxins/furans using EPA Method 23 or an approved alternative method (40 CFR 

63.7(f)). If EPA Method 23 and alternative methods are technologically feasible for clay 

ceramics first-fire tunnel kilns, then they should also be feasible for brick tunnel kilns.

The commenter stated that whatever imprecision is associated with monitoring emissions at 

levels near the detection level can be addressed by further statistical manipulations, adjusting the 

limit (e.g., with a safety factor) that accommodates any uncertainty (e.g., 50 percent above the 

detection level), or establishing monitoring protocols that reduce the uncertainty to an acceptable 

level.

The commenter stated that even if EPA could not for some reason set standards based on the 

sources achieving emissions below the detection level, the EPA still has data above the detection 

limit that represents greater than 12 percent of the sources with data. CAA section 112(d)(3) 

directs EPA to base floors on emissions achieved by the best performing sources “for which the 

Administrator has emissions information.” The EPA has acknowledged that where “emissions 

can be precisely measured for at least some units in [a] subcategory ... the statutory test for 

establishment of work practice standards -- i.e., that measurement of emissions is impracticable 

due to technological and economic limitations -- is not met.” 76 FR 15640. Thus, the EPA could 

base standards on these emissions and specify a test method that would detect emissions at these 

levels.

Finally, Commenter 0554 argued the EPA had claimed but failed to explain why methods for 

dioxins/furans would be economically infeasible. Even if the EPA is able to point to additional 

costs associated with use of a measurement methodology that would not demonstrate that 

economic limitations render the measurement of emissions “impracticable.”

Response 2: The EPA disagrees with the commenter’s objections to work practice standards for 

dioxins/furans (D/F) from BSCP tunnel kilns. In the tests conducted as part of the ICR for dioxin 

emissions, the EPA required that EPA Method 23 be used and that the source collect a minimum 

volume of 2.5 cubic meters or have a minimum sample time of 4 hours per run that would result 

in low MDLs in order to increase the possibility of collecting measurable amounts of dioxins and

minimize the number of non-detects. The EPA recognizes the existence of other dioxin 

measurement methods and yet also recognizes the importance of consistency in measurements of 
20

these low magnitudes, as well as the necessity of using the measurement technique for 

compliance determinations that was used to establish the emissions limit. At this time, the EPA 

holds that Method 23 is the appropriate tool for dioxin and furan emissions determinations.

The majority of the data collected in order to set the D/F standards for Brick MACT are at levels 

below the capability of the analytical and stack test methods to detect emissions of these 

compounds. Much of the test data are labeled as being below the method detection limit and the 

remainder of the data is often flagged as being below the level the laboratory can report with 

confidence.

The EPA based the need for implementing a work practice based on the low levels of emitted 

dioxin and furans and the resulting ability to accurately quantify and set emission limitations. In 

taking this action, the EPA recognizes that low emission levels are the result of good combustion 

practices. The EPA came to this same conclusion for electric utility boilers and also implemented 

dioxin and furan good combustion work practices in that rule. However, the clay ceramic dioxin 

data was detectable by Method 23, and therefore, it does not qualify for implementing a work 

practice.

Comment 3: Commenter 0554 stated that the proposed work practice standards for brick 

periodic kilns violate CAA section 112(h) and section 112(d). 

The commenter disagreed with the EPA’s reasons for setting work practice standard because 

they do not satisfy the CAA section 112(h) requirement that measurement methodology “is not 

practicable due to technological and economic limitations.” First, that breakthrough “can occur”

at times, which would require retesting, does not present a technological hurdle rendering the 

methods impracticable for the entire class of sources; it only means that additional time and costs 

may have to be expended in some instances. The commenter noted that the EPA had not 

demonstrated the additional costs or additional manpower for the methods make the

measurement methodology not technologically or economically practicable. 

Commenter 0554 stated that although the EPA’s data shows emissions spikes of HCl and HF, the 

EPA never asserted that emissions of other regulated pollutants would encounter the same issue. 

To the contrary, the EPA acknowledged that different methods (i.e., EPA Methods 5 or 17) 

would be used to test for PM as a surrogate for non-Hg HAP. 79 FR 75645. The commenter 

asserted that work practice standards are only allowable where it is not feasible to prescribe or 

enforce “an emission standard” for control of “a hazardous air pollutant or pollutants.” The 

commenter asserted the EPA must make a supportable determination that an emission standard is 

infeasible for each hazardous air pollutant for which it adopts work practice standards. 

Commenter 0554 agreed with the EPA that Fourier transform infrared (FTIR) (EPA Method 

320) is a practicable alternative to Methods 26 and 26A, but disagreed with the EPA’s 

determination that economic limitations prevent the application of FTIR. The commenter argued 

that Congress did not allow the EPA to set work practice standards in lieu of numerical emission 

limits because the costs of compliance would be too high. The commenter asserted that Congress 

required MACT-based emission limits be set at least as stringent as the floors, regardless of cost.

Commenter 0554 asserted that the EPA failed to explain why the cost-to-sales and cost-to-profit 

ratios it estimated would be economically infeasible. In addition, the cost ratios that the EPA 
21

calculated are on an individual kiln basis, yet the EPA used them to conclude that the ratios 

would force firm closures, without considering cost-to-sales or cost-to-profits on a firm-wide 

scale. The commenter argued that cost data for individual kilns is not interchangeable with cost 

data on firms.

The EPA asserted that variability would interfere with stack testing. However, the commenter 

noted that emissions can be variable over time and noted stack testing will be used by for tunnel 

kilns. The commenter stated that the EPA failed to rationally explain why stack testing is 

practicable for tunnel kilns but not for periodic kilns, as they both can have variable emissions.

Response 3: The EPA disagrees with the commenter that testing of periodic kilns using Method 

26 or 26A poses no technological or economic limitation. As noted in the subject memo, due to

the variations in emissions during firing cycles and variations in emissions across the tests, 

“sampling a single kiln cycle might not be adequate for characterizing periodic kiln emissions

and would mean testing each periodic kiln for more than 100 hours [emphasis added] in order to 

determine an emission rate that is representative of normal operating conditions. Furthermore, 

because periodic kilns are used to fire specialty products that may have significantly differently 

time-temperature profiles, it may be necessary to test the same kiln multiple times to characterize 

emissions from different types of products.” Add to that the possibility that such lengthy testing 

might have to be redone in the event of HCl breakthrough, and it is clear that Method 26/26A 

testing is not a practical method for testing acid gas emissions from periodic kilns. Consequently, 

the rest of our analysis focused on FTIR as the only practical alternative left to review.

While the commenter is correct that no costing was done for Method 26 or 26A, the exorbitant 

costs that would be expended for such testing are self-evident, given the extremely lengthy 

period of testing that would be required. However, for purposes of this analysis, we estimated a 

cost of $46,000 for 100 hours of testing, which is likely to be an underestimate, given the need to 

test the same kiln multiple times to characterize the emissions from different types of products 

and the possible of retesting due to HCl breakthrough. Assuming the same kiln is tested three 

times for three different products and then retested due to breakthrough, the cost of Method 

26/26A testing for a single kiln could be as high as $276,000. It should also be noted that some 

BSCP facilities have multiple periodic kilns--on average, eight per facility for BSCP facilities 

with periodic kilns.

The same argument about cost could also be made for FTIR, since the cost for testing by FTIR is 

estimated to be $49,750 for a single 50-hour kiln cycle. To develop a representative emission 

rate, it might be necessary to test for two cycles at a cost of almost $100,000, and the cost would 

be even higher when done again for different products. If testing were extended into the cooling 

period, the costs would be even higher. Additional costs would also be incurred for testing the 

kilns for PM and Hg emissions, which would have to be tested using a manual test method, such 

as EPA Method 5/29, multiple times over very lengthy periods. This amount of testing and 

retesting for such lengthy periods poses substantial technological and economic limitations. 

Therefore, we clearly believe that the section 112(h) criteria for setting work practice standards 

have been met.
22

The cost to sales ratios were calculated on a firm basis rather than a kiln basis. The RIA clearly 

states this in Section 5.3.1 and gives the details of how the upper and lower bound estimates of 

closures were calculated. The section also addresses why the estimated range of closures might 

be too high or low.

Finally, the EPA disagrees with the commenter’s contention that the emissions variability for 

periodic kilns is comparable to that for tunnel kilns. As stated above, periodic kilns have 

variations during firing cycles and variations in emissions across tests. These variations are 

substantially greater than those observed for continuously operating tunnel kilns. In addition, 

unlike tunnel kilns, periodic kilns are used to fire specialty products that may have significantly 

different time-temperature profiles, which also increases variability for a particular periodic kiln.

Comment 4: Numerous commenters (0514-0516, 0520, 0521, 0522, 0523, 0528, 0529, 0536, 

0537, 0543, 0545, 0548, 0550, 0551, 0552, 0555, 0556, 0558, 0560, and 0562) stated that the 

EPA should replace the numeric limits for Hg and non-Hg HAP metals with work practice 

standards under the authority of section 112(h) of the CAA. Section 112(h) allows for the use of 

a work practice standard when compliance demonstration is technically and economically 

impracticable. Commenters asserted that the use of work practices is justified because the small 

uncontrolled emission levels and small potential incremental reductions would be technically and 

economically infeasible to demonstrate on a consistent and repeatable basis.

Commenter 0543 stated that there is adequate information available for the EPA to conclude that 

a numeric emission limit is both technically and economically impracticable to enforce with 

reasonable confidence and repeatability and provided, along with other commenters, the 

following reasons that work practice standards are appropriate and necessary.

Commenter 0543 noted that test data submitted by the BSCP industry, developed by numerous 

stack testing firms and testing labs across the country, required significant manipulation to arrive 

at revised “usable” data. This is largely because data are very close to the detectable/measurable 

limits. Many BSCP companies will not have the technical expertise onsite to make these same 

adjustments. Therefore, they will be unable to assess their own compliance status. The 

commenter contended that this makes the standard technically infeasible to enforce.

Commenter 0543, along with Commenters 0522 and 0523, stated that the EPA also did not 

account for the additional cost of hiring consultants to conduct the compliance activities, review 

the test results to ensure their validity, and make any necessary test data adjustments. Commenter

0543 stated that these additional expenses would make compliance demonstrations economically 

infeasible.

Commenter 0543 noted that the EPA identified a number of issues with stack test reports, such 

as sample contamination, manganese contamination, and filter failure. If any of these errors are 

identified after a compliance stack test is completed, the facility will have to rerun a stack test to 

attempt to get three acceptable runs. The commenter asserted that these expenses make 

compliance demonstrations economically infeasible.

Commenter 0543, along with commenters 0527 and 0558, also expressed concern about the 

reliability of the Method 29 stack test itself. Commenter 0558 noted that stack testing results for 
23

Hg cannot be considered 100 percent reliable, as Method 29 was designed to be used on 

significantly higher concentration streams. Commenter 0527 asserted that there is too much 

uncertainty in the consistency of the stack test results to place numeric emission limits on BSCP 

plants.

Commenter 0553 asserted that there is not enough information or data available at this time to 

understand the true form or amounts of Hg being emitted to justify a specific Hg limit. Stack 

testing results from the EPA’s own 2010 survey revealed obvious inconsistencies between 

testing firms and laboratories. These inconsistencies lead to discrepancies in the values reported 

that were in many cases below the detection levels of Hg. Imposing a strict numeric limit on Hg

without fully understanding its true form, quantity, and controllability within the BSCP industry 

is not responsible policy. A fair estimate of costs to control Hg at such low levels cannot be 

developed when there is not a true basis of understanding of what the EPA and industry are 

trying to control. Commenter 0553 requested that the EPA reevaluate the numeric limits on Hg

and consider removing them from the rule until a better understanding of Hg is established 

within the BSCP industry, or at the very least, consider increasing the proposed limits to more 

reasonably attainable levels while still allowing facilities to operate efficiently.

Multiple commenters (0516, 0520, 0521, 0522, 0523, 0527, 0536, 0537, 0545, 0548, 0550, 0551, 

0552, 0553, 0555, 0556, 0558, 0562, and 0563) stated that a plant’s ability to meet the proposed 

Hg and non-Hg metal HAP limits would be completely dependent on the trace elements in the 

mined raw material. Commenter 0516 added that Hg may be present in the natural gas used to 

fire the commenter’s kilns. Commenter 0563 noted that Hg is typically present in extremely 

small quantities if at all; in many tests, the levels are undetectable. Commenter 0522 noted that 

the small amount of data used to set the proposed limits did not take into account the variability 

of the mined raw materials and stated that, at the very least, this is a flawed assumption due to 

the variability of the mined materials.

Commenter 0527 noted that most BSCP plants use raw material that is located near the plant site. 

Since dirt and brick both have low values to weight, no plant can afford to switch its source of 

raw material simply to try and comply with EPA emissions limits. There are no alternative 

operating methods that can change the raw material or reduce the minerals contained within it.

Commenter 0558 noted that the BSCP industry is conducting a raw material study and is

learning that Hg contents vary across raw material type (clay, shale), by facility location, and 

even possibly within a mine. 

Commenter 0543 stated that EPA is precluded from basing any MACT limits on mined 

materials. However, the commenter stated that the industry is ready to work with EPA to 

establish work practice limits that are reasonable and meet the requirements of section 112.

Multiple commenters (0516, 0520-0523, 0527, 0529, 0530, 0536, 0537, 0543, 0545, 0548, 0550-

0553, 0555, 0556, 0558, 0559, and 0562) also asserted that the EPA failed to demonstrate that 

the controls for Hg and non-Hg HAP metals that EPA cited are warranted or effective for the 

BSCP industry. Commenter 0522 added that rather than the fabric filter used as a cost basis in 

the proposed rule, many kilns would require a DIFF, since the small amounts of HF and HCl in 

the gas stream would need to be controlled to maintain the integrity of the DIFF. Commenter
24

0537 specifically noted that no one has ever installed a stand-alone fabric filter (FF) without the 

dry injection system and no one has installed a fabric filter after a DLA in the BSCP industry, so 

there is no way of knowing that this would actually work.

Commenters 0537, 0543, and 0562 noted that there is no way to know if activated carbon 

injection (ACI) would work with the low Hg concentrations and other loadings in kiln exhaust 

airstreams. Commenter 0559 understood that there have never been Hg controls on a BSCP kiln; 

the commenter asserted that the EPA should only be permitted to require control when it has 

been demonstrated that control is possible. According to Commenter 0543, if the ACI does not 

work, then the cost effectiveness of controlling Hg is infinite. If the cost effectiveness is infinite 

due to no available control, there is no technically or economically practicable way to 

demonstrate compliance with the limits.

Commenter 0545 expressed concern that here is simply no way to know that the technology 

proposed by EPA will get the reductions necessary to comply. Installing an “add-on” to the 

existing DIFF will be operationally difficult, economically unfeasible, and force the company to 

commit more time, talent, and treasure to compliance and testing than the limited staff is capable 

of, and in the end, the device may not work. The commenter also noted that they consulted with 

the DIFF manufacturer, and the manufacturer expressed great concern that any Hg reduction 

equipment may cause underperformance of the scrubbing of the HAP that it was built to control, 

and that system replacement may be necessary. If replacing the DIFF altogether is necessary to 

achieve the Hg limit, the commenter stated they would cease their business operations.

Commenter 0559 noted that since they provide a cosmetic product to homeowners and builders 

and they understand the vast effect of small changes of airflow in the tunnel kiln, they are 

concerned that the addition of a control device will make their product less desirable.

Commenters noted that the proposed rule includes limits that are based on very little data, 

including just a single controlled source for small kilns used as the basis for Hg limits. However, 

based on this single controlled source meeting the Hg limit, the EPA assumed that all 

uncontrolled small kilns will meet the limit. The EPA also assumed that the majority of untested 

large sources will meet the limit. Multiple commenters (0516, 0520, 0522, 0527, 0537, 0545, 

0551, 0553, 0555, 0556, 0558, 0562, and 0563) asserted that they will not or may not be able to 

meet the proposed Hg and non-Hg HAP metals limits with current control configurations, and 

the installation of controls would be expensive and may cause their plants to shut down. 

Multiple commenters (0516, 0527, 0529, 0530, 0545, 0551, 0553, 0558, 0559, 0562, and 0563) 

expressed concern about the expense of installing unproven controls if they cannot comply with 

current controls. Commenter 0530 stated that, even assuming that technology is available and is 

effective, many companies in the BSCP industry will be unable to obtain the financing required 

for add-on controls and will therefore be forced to shut down. Commenter 0516 stated that the 

cost would be crippling to the company, and would factor into management’s decision of 

whether or not to re-open many of the currently closed plants. Commenter 0527 noted that they 

will simply shut down if it is determined that the plant is not in compliance with the BSCP 

MACT standards contained in the final rule.
25

Commenter 0563 stated that if they cannot meet the Hg limits without control, they assume that 

all of their currently uncontrolled kilns would need to install DIFF with ACI and the two DLAcontrolled kilns would need to be retrofit with the same systems. The commenter asserted that 

they do not agree with EPA’s belief that stand-alone fabric filters are demonstrated, so they used 

the EPA’s estimated costs for DIFFs with ACI for all kilns. The commenter also questioned the 

low cost of ACI systems but did use those numbers in their estimates. The commenter stated that 

the EPA’s estimated installed cost of the controls they would need is around $17.5 million and 

the estimate of the annual operating cost of these controls would be an additional $5.7 million. 

Industry-wide calculations show the cost per ton of HAP reduced would be in the millions of 

dollars. The commenter asserted that the cost-to-benefit ratio of this approach is unreasonable 

and it will be economically impossible for this company and other companies in the industry to 

implement this part of the rule as proposed. The financial burden this rule will impose will force 

doors to close in many companies, possibly the commenter’s. At a minimum, the commenter 

noted they have kilns that will never reopen if the upfront capital cost estimate is correct. 

Employees may lose their jobs.

Multiple commenters (0516, 0520, 0521, 0523, 0529, 0536, 0537, 0545, 0548, 0550, 0551, 0552, 

0553, 0555, 0556, 0558, 0562, and 0563) also noted that the levels of potential emission 

reductions from BSCP facilities, by the EPA’s own estimates (i.e., 2-6 pounds of Hg per year 

and 150-380 pounds of non-Hg HAP metals), are small. However, the commenters noted that the 

EPA assumed that multimillion dollar controls could be financed and operated to get the small 

reductions claimed by this rule. Commenters stated that there would be no benefit to human 

health and the environment resulting from these expenditures. Commenters 0523 and 0545 stated 

that the stack tests would also be very costly and would create a significant financial burden 

simply to determine the levels of these HAP. Commenters 0545 and 0562 asserted that costs in 

the millions or hundreds of millions of dollars per ton clearly indicate that EPA may have missed 

creating a necessary subcategory.

Finally, several commenters (0516, 0527, 0543, and 0563) provided suggestions for Hg work 

practice standards. Commenter 0543 stated that work practices could take several approaches. 

The work practices that were proposed in the rule for dioxin/furan, i.e., burner checks, would 

ensure effective production of brick and reduce any additional trace Hg emissions that would 

occur for replacing lower quality brick with acceptable brick. Commenter 0527 requested that 

the EPA modify the rule to include a work practice standard which would establish the best 

operating practice for BSCP plants and monitor the compliance of the plants within these 

reasonable standards. Commenters 0516 and 0563 stated that work practices for Hg could be as 

simple as the work practices in the Boiler MACT, alone or in combination with facility-specific 

measures. According to Commenter 0516, these measures could involve a requirement to set 

bench-mark Hg levels using raw material mass balance measures at each facility. Commenter 

0563 suggested some assessment of the Hg content of the raw material for individual plant 

locations, with a more extensive material monitoring plan when significant amounts of Hg are 

found.

Response 4: The EPA does not agree with the commenters’ request for EPA to replace the 

numeric limits for Hg and non-Hg HAP metals with work practice standards, for the reasons 

discussed in the paragraphs below. We have prepared responses to commenters’ arguments 
26

against emission limits for Hg and non-Hg HAP metals and their arguments supporting work 

practice standards for those pollutants.

The EPA disagrees with Commenter 0543 that significant data manipulation is required for 

BSCP companies to determine their compliance status with the Hg and non-Hg metals emission 

limits. The types of data manipulations necessary to determine MACT floors are not required 

when comparing compliance testing results to an emissions limit.

The EPA also disagrees with commenters that external consultants must be accounted for in the 

cost estimates for complying with the Hg and non-Hg metals emission limits. As commenters 

have noted elsewhere in their comments, such costs would be company-specific, so the extent of 

these costs and the number of affected facilities would not be clear.

With regard to the issues with stack test reports that Commenter 0543 noted, in its test data 

review, the EPA did discard test runs when the EPA reference method was not followed or the 

required quality assurance (QA) elements within the method failed, or sample contamination 

occurred. The EPA generally requires three test runs for demonstration of compliance, but 

delegated authorities can approve less than three test runs at their discretion. Consequently, 

facilities may not need to rerun stack tests to get three acceptable runs.

The EPA disagrees with commenters that the measurement methodology for Hg emissions at a 

BSCP plant is not reliable. During the 2010 testing program, Method 29 was used successfully to 

determine Hg concentration in the emissions from the BSCP plants. Method 29 was sensitive 

enough to have a majority of the test report above detection levels. Accordingly, because the Hg

is at measurable levels, work practice standards are not applicable. With respect to the suggestion 

by Commenter 0553 that the EPA defer taking action on setting Hg emission limits until more 

information becomes available, the EPA notes that it is obligated to take final action to set 

NESHAP for BSCP facilities located at major sources on or before September 24, 2015 pursuant 

to the consent decree in Sierra Club v. EPA, Case No. 08-00424 (D.D.C.). However, the EPA 

agrees with commenters that variations in the raw material can affect the long-term performance 

of the best performers when complying with a particular standard. Thus, the EPA has 

incorporated the data received during the post-comment period into the development of the final 

Hg emission limits for the BSCP source category; see Final Maximum Achievable Control 

Technology (MACT) Floor Analysis for Brick and Structural Clay Products Manufacturing for 

more information.

2

The EPA agrees with Commenter 0527 that the use of offsite raw materials is not a viable option 

for the BSCP industry. We are not requiring the use of offsite raw materials in this rule.

The EPA disagrees with commenters that there are no demonstrated Hg or non-Hg HAP metals

emission controls available to the BSCP industry. Activated carbon injection and fabric filters 

have been demonstrated in a number of other industries as an effective control for Hg and nonHg HAP metals from their process units, including a similar process unit (kilns) used in the 

 2 Raymond, G., and K. Sroka. Final Maximum Achievable Control Technology (MACT) Floor Analysis for Brick 

and Structural Clay Products Manufacturing. Memorandum from Gabrielle Raymond and Kristin Sroka, RTI 

International, to Sharon Nizich, EPA/OAQPS/SPPD. September 24, 2015.
27

Portland Cement industry. However, it is up to each facility to determine the type of emission 

control that works best for their particular situation.

Concerning the issue cited by Commenter 0559 that the installation of a control device would 

have significant impact upon the products due to airflow, and, therefore, on the ability to 

successfully market their products, the EPA has not received any data to support the 

commenter’s contention. We also note that a number of BSCP plants have retrofitted DIFFs with 

no apparent adverse impact.3 Similarly, we have not received any data to support Commenter 

0545’s contention that the addition of Hg control equipment would cause the DIFF to 

underperform, requiring replacement of the DIFF control device.

With regard to commenters’ concerns that they may not be able to comply with the Hg and nonHg HAP metals emission limits with their current controls and may need to install expensive 

controls to meet the limits, it should be noted that under section 112 we cannot consider costs 

and other impacts when establishing MACT floor requirements. However, the EPA has taken

significant steps to minimize the impacts of the rule on the small entities that are prevalent in the 

BSCP industry, while still achieving the objectives of the rule. In particular, the EPA has 

included kiln size subcategories in the Hg and non-Hg metals emission limits, incorporated raw 

material variability factors into the Hg emission limits, and reevaluated stack test data used in 

developing the MACT floor PM surrogate emission limits. Regarding the contention by 

Commenters 0545 and 0562 that we may have missed creating a necessary subcategory, we 

evaluated public comments requesting a subcategory based on the Hg content of clay, but 

insufficient data are available to support subcategorization.

As noted elsewhere in this document (see section 15.2), the EPA understands that firms may 

have difficulty obtaining longer-term financing needed to buy the control equipment and make 

process changes needed to comply with the proposed Hg and non-Hg HAP metals emission 

limits. The EPA’s closure estimates may be an underestimate because of the difficulty in 

obtaining financing at a 7 percent interest rate, or they might be an overestimate if the industry 

has become more robust by 2018 when the control must be in place. Overall market impacts for 

the standard are estimated to be a less than 2 percent national average price increase and a less 

than 2 percent national average reduction in production. Please see the RIA, Regulatory Impact 

Analysis: Final Brick and Structural Clay Products NESHAP found in the docket for more 

details.

Regarding commenters’ suggestions for work practice standards, the EPA notes that if a 

numerical emission limit can be supported under section 112(d), a work practice standard is not 

legally permissible.

Comment 5: Commenter 0543 reiterated a previous suggestion that the EPA should set a healthbased emission limit for Hg because it is a threshold pollutant. Commenter 0543 asserted that 

 3 Holloway, T., and K. Sroka, RTI International. Updated Inventory Database and Documentation for Brick and 

Structural Clay Products Manufacturing Final Rule. Memorandum from Thomas Holloway and Kristin Sroka, RTI 

International, to Sharon Nizich, EPA/OAQPS/SPPD. September 24, 2015.
28

given that Hg has a reference concentration, there is a level deemed safe by EPA with regard to 

human health. Therefore, the commenter requested that the EPA fully consider establishing a 

health-based emission limit for Hg emissions in lieu of a MACT floor-based emission limit. A 

methodology similar to that performed for the acid gases using acute health indices could be 

used to provide an allowable emission rate, below which, exposures would be considered safe.

Commenter 0547 agreed, adding that EPA has concluded that Hg is a threshold pollutant.

Commenter 0547 stated that as with the proposed health-based emission limit (HBEL) for HAP 

acid gases, the EPA could easily use this well-established threshold for Hg, in conjunction with 

the site-specific data the EPA has collected on virtually all of the potentially affected brick 

plants, to determine a health-protective alternative emissions limitation for Hg emissions.

Commenter 0543 also included a copy of a December 2013 memorandum they sent to the EPA 

outlining the results of modeling of Hg emissions from the 83 plants operating at the time. 

Specifically, the maximum individual non cancer health risks posted by existing major source 

kilns were modeled using the EPA Human Exposure Model version 3 (HEM-3). The 

memorandum showed that all facilities in the BSCP source category, under the worst case 

meteorological conditions and operating at full capacity, never exceeded a chronic neurological 

hazard index (HI) of 0.003, clearly below EPA’s “safe” level of 1. Further, 88 percent of the 

facilities modeled below an HI of 0.001.

Commenter 0543 noted that in order to provide a complete assessment for the source category, 

the kilns with no data were modeled with “worst case” default values, which are so conservative 

that it is unlikely that a kiln with such stack parameters could actually produce brick due to 

insufficient airflow. Emissions data used for each facility were based on site-specific 

information, where available. If no data were available, industry average values were used.

Response 5: The EPA disagrees with the comment that a health-based emission limit should be 

established for Hg. Also, the comment that the EPA has derived a reference concentration for Hg

is incorrect. The EPA has derived a reference dose (for the oral route) for a form of Hg, methyl 

mercury, and in this assessment the EPA notes that there is no evidence for a biological threshold 

for the critical effect of neurological deficits in children in the principal studies of the Integrated 

Risk Information System (IRIS) assessment for this chemical. In addition, methyl mercury has 

been classified by the EPA as a possible human carcinogen.4 For these reasons the EPA does not 

consider Hg a threshold pollutant.

Comment 6: Commenter 0534 requested alternative compliance options regarding the exhaust 

from a new subcategory of wood byproduct dryers. As an alternative to numeric limits for these 

sources, the commenter suggested implementing work practice standards, as this is the most 

reasonable and environmentally beneficial option. Implementing a numeric standard for these 

sources could be both technically infeasible and cost prohibitive.

The commenter stated that a primary constituent of this work practice standard would be to 

efficiently maintain and operate the dryers in such a way as to minimize the hours that they have 

 4 Integrated Risk Information System Assessment for Methylmercury. 2001. Available at 

http://www.epa.gov/iris/subst/0073.htm.
29

to operate. During a recent permit renewal at Commenter 0534’s Salisbury plant, the company 

conducted extensive air modeling to demonstrate compliance with the air toxic standards in 

North Carolina. The company was able to demonstrate compliance with these stringent 

concentration based health and environmental standards using the operating scenario described 

above. The commenter asserted that this demonstration supports the claim that the environmental 

benefit to imposing numeric limits on the wood byproduct dryer exhaust is minimal if at all.

Response 6: The EPA disagrees with the commenter’s request. The commenter has provided no 

data to justify adding a new subcategory of wood byproduct dryers. In addition, the commenter 

has provided no information to support setting a work practice standard for this emission unit 

under section 112(h).

Comment 7: Commenter 0522 asserted that work practices are warranted for the subcategory of 

kilns with low stack temperatures because the small uncontrolled emission levels and small 

potential incremental reductions would be technically and economically infeasible to 

demonstrate on a consistent and repeatable basis. The commenter requested that the EPA 

consider that work practices would meet the requirements of the CAA while still allowing 

facilities to operate.

Response 7: The EPA disagrees with the commenter’s request. As noted in a previous response, 

the EPA does not yet have definitive information to support subcategorization for kilns with low 

stack temperatures. We cannot establish a separate subcategory for these kilns until we have 

received information to support such subcategorization.
30

7.0 MACT Floors

7.1 Determining Sources in Floor Pool

A major public comment on determining sources in the MACT floor pool and the EPA’s 

response to that comment can be found in section V.A of the preamble to the BSCP final rule. 

The remaining public comment on that subject and EPA’s response is presented below.

Comment 1: Commenter 0540 asserted that work practice standards for Hg should be 

considered in a final rule; however, the commenter provided recommendations for alternate 

consideration of how the numerical limits are determined in the event that the EPA does not 

agree to set work practice standards. The commenter stated that the primary underlying concern 

regarding the calculation of Hg upper prediction limits (UPLs) stems from EPA’s seemingly 

arbitrary selection of the number of sources to be included in the various UPL floor pools used in 

the calculation of proposed emission limits as well as in the discussion of the various alternate 

floor calculations that were not used in the final proposed limits. These variations range from PM 

UPL calculations based on 27 sources representing 12 percent of the “total source population” of 

227 kilns to only 3 sources representing 12 percent of 19 kilns (20 kilns with one test being 2 covented kilns and split as 2 in database) “sources with available data” in Hg UPL calculations for 

large kilns. The EPA should include all data from the best performing sources in a UPL floor 

determination.

Commenter 0543 stated EPA correctly describes why it is appropriate to base the MACT floor 

for PM on the top performing 12 percent of sources in the category (or subcategory), as opposed 

to 12 percent of the sources for which there is stack test data. The commenter noted that first, the 

dataset was knowingly skewed by the EPA to only include the best performing sources for PM 

and Hg, i.e., the DIFF-controlled systems; this was discussed at length during the ICR testing 

conducted for this proposed rule. Second, while stack test data may not be available for each 

source in the category or subcategory, there is sufficient information to estimate the emissions of 

each unit since size, fuel, and other emissions information is available. The commenter requested

that EPA extend the approach taken for PM to the approach for calculating the MACT floor for 

numeric Hg limits, if a numeric limits remain in the rule; this was specifically discussed with 

EPA during the ICR process and during a December 1, 2010 meeting with EPA upper 

management, when EPA assured industry that all tests would be included.

Commenter 0540 stated all but one of the Hg stack tests were done as a CAA section 114 

mandate from the EPA; the sources were handpicked by the EPA and all included APCDs -- all 

DIFFs and one electrostatic precipitator (ESP). The commenter stated that in verbal discussions 

with the EPA, BIA asked that some DLAs and uncontrolled sources be included, and it was 

stated that it made no sense to test what was not thought to be best performing. The commenter 

recognized that the EPA was somewhat limited by the 9 entity hurdle in demanding testing; 

however, many of the entities included in the 114 demand have DLAs and uncontrolled kilns that 

could have been included in the testing request. The commenter noted that the EPA stated that 

the industry was welcome to test any kilns they wanted included; however, given $15,000 

Method 29 testing costs and the economic times of 2010 just doing what was mandated in the 

114 requirement was challenging for the industry as a whole. The commenter stated in addition, 

in a meeting with the EPA in Washington, DC on December 1, 2010, the EPA stated that their 
31

intention was to use all data from the tests since these units represented the best performing 

sources. The commenter stated were there any thought that EPA would use only 12 percent of 

the sources with data as opposed to 12 percent of the source category kiln population as was 

done in the 2003 rule, the industry would have definitely considered the ramifications of this 

limited testing and would have possibly pursued further testing options in spite of the costs. The 

commenter stated the EPA’s comments at that meeting were critical to the BIA’s decision 

regarding additional testing.

Commenter 0540 stated in the proposed rule the EPA has demonstrated that DIFF controlled 

sources are the best source performers for PM of which 27 sources are used in the PM floor pool. 

The commenter stated of these 27 there are 13 DIFFs with Hg data plus the two small Belden 

kilns vented through an ESP discussed as being best performers in the proposed rule. The 

commenter stated as a minimum this should dictate the use of at least 15 sources in a Hg floor 

pool UPL determination.

Commenter 0540 stated the proper use of Hg test data available to the EPA results in UPL limits 

of 2.24E-04 lb/ton, 85.28 micrograms per dry standard cubic meter (μg/dscm) and 1.53E-03 lb/hr 

as contrasted to the proposed rule limits for large kilns of 2.2E-05 lb/ton, 29 μg/dscm and 2.7E04 lb/hr and small kiln limits of 2.0E-04 lb/ton, 70 μg/dscm and 1.1E-04 lb/hr.

Commenter 0540 contended that the proposed rule Hg numerical limits based on a 3 pool floor 

for large kilns in particular are not representative of the best performing sources in the source 

category; the commenter recommended that the EPA take a fresh look at Hg UPL determinations 

using all available data.

Response 1: The EPA disagrees with the commenter that it is a viable option to consider 12

percent of the industry when developing a MACT floor for Hg. As was the case between 

proposal and final for the PM MACT floor development, the EPA asked for, but did not receive 

additional data to justify using 12 percent of the universe of kilns to develop a MACT floor. In 

addition, the EPA had to remove several data points from the PM data base due to faulty 

emissions testing and thus further did not believe the entire dataset of best performing sources 

were on hand in order to develop a MACT floor based on 12 percent of the universe of kilns.

Since EPA only had Hg data for limited kilns, there is no avenue to develop a MACT floor based 

on 12 percent of the universe of kilns. Thus, the EPA is finalizing its proposed approach to use

12 percent of the data available to determine the number of kilns in the Hg MACT floor pools. 

As previously discussed above, the EPA is also using 12 percent of data available to determine 

the number of kilns in the PM MACT floor pools. However, as discussed in the MACT floor 

memo for the final rule, the EPA has developed a Hg raw material factor that has been 

incorporated in the Hg UPL calculations, which is based on data the EPA did receive between 

proposal and final. Please see the MACT floor memo for the final rule for more information 

about the Hg raw material factor and the revised Hg MACT floors. 

7.2 UPL

Comment 1: Commenter 0554 stated the EPA proposed to use the UPL to set floor standards, 

even after the D.C. Circuit remanded the EPA’s use of that method in NACWA. 734 F.3d at 
32

1139-45. The commenter stated the EPA’s use of the UPL in this rule is unlawful, arbitrary, and 

capricious for the following reasons.

Commenter 0554 stated the CAA section 112(d)(3) unambiguously requires floors to reflect the 

“average” emission level achieved by the relevant best-performing sources. The commenter 

stated by using the word “average,” Congress demanded a measure of ordinary, usual 

performance -- a central tendency -- of the “emissions limitation achieved by the best performing 

12 percent of the existing sources.” See Webster’s Seventh New Collegiate Dictionary at 61 

(1971) (defining “average” to mean “equaling an arithmetic mean,” “approximating or 

resembling an arithmetic mean in being about midway between extremes,” or “not out of the 

ordinary”). See, e.g., Leocal v. Ashcroft, 543 U.S. 1, 9 (2004) (“When interpreting a statute, we 

must give words their ‘ordinary or natural’ meaning.”) (quoting Smith v. United States, 508 U.S. 

223, 228 (1993)).

Commenter 0554 stated in the EPA’s previous attempt to establish a rule for brick and clay 

ceramics sources, the EPA formally adopted an “interpretation of average emission limitation”

acknowledging “that it is a measure of central tendency, such as the arithmetic mean or the 

median.” 68 FR 26700; see also 59 FR 29196, 29199 (Mar. 9, 1994) (formal rulemaking 

establishing that “EPA construes the word ‘average’ in section 112(d)(3) to authorize the Agency 

to use any reasonable method, in a particular factual context, of determining the central tendency 

of a data set”). The commenter stated according to the EPA, “Congress spoke with clarity in 

[section 112(d)(3)(A)] of the Clean Air Act,” and that the section “lends little support for an 

interpretation under which standards might be set at the emission limitation achieved by the 

worst performing member of the best performing 12 percent of existing sources,” while the Act’s 

legislative history “points strongly in the opposite direction” from any such “worst-of-the-best”

construction. 59 FR 29199.

Commenter 0554 stated the EPA has consistently reaffirmed that interpretation in its 

rulemakings. E.g., 68 FR 1276, 1286 (Jan. 9, 2003), (plywood); 67 FR 30848, 30853 (May 8, 

2002) (semiconductors); 66 FR 58,610, 58,618 (Nov. 21, 2001) (asphalt processing); 64 FR 

2611, 2612 (Jan. 15, 1999) (natural gas transmission & storage); 61 FR 48208, 48210 (Sept. 12, 

1996) (polymers & resins).

Commenter 0554 stated that CAA section 112(d)(3) also unambiguously requires that floors 

reflect the emission level actually “achieved” by the relevant best-performing sources (those with 

the lowest emission levels). Sierra Club, 479 F.3d at 880-81. The commenter stated the EPA 

may not override the floor requirements with its own notions about what is “achievable.” Id. at 

877-79, 880-81; Cement Kiln Recycling Coalition v. EPA, 255 F.3d 855, 861 (D.C. Cir. 2001). 

The commenter stated speaking consistently in the past tense, Congress used the word 

“achieved” four times in this provision. The commenter asserted that Congress meant what it 

said: “section [112](d)(3) requires floors based on the emission level actually achieved by the 

best performers.” Sierra Club, 479 F.3d at 880-81.

Commenter 0554 stated to satisfy the CAA, therefore, existing source floors must reflect the 

average (i.e., a “central tendency”) of the emission levels “actually achieved” by the relevant 

best-performing sources. The commenter stated floors must be “‘demonstrate[d] with substantial 
33

evidence - not mere assertions’ ....” Ne. Md. Waste Disposal Auth. v. EPA, 358 F.3d 936, 954 

(D.C. Cir. 2004) (quoting Cement Kiln, 255 F.3d at 866 and Sierra Club v. EPA, 167 F.3d 658, 

662 (D.C. Cir. 1999)).

Commenter 0554 stated although CAA section 112(d)(3) unambiguously requires floors to 

reflect the “average” emission level actually “achieved” by the best performing 12 percent of 

units, the EPA set floors at the upper prediction limit for the sources it claimed were the best 

performers.

Response 1: The EPA disagrees with the commenter. The NACWA court did not find the UPL to 

be an arbitrary approach, but simply asked for a better explanation from the Agency. The UPL 

memorandum in the docket for this rule provides the explanation of what the UPL represents 

sought by the NACWA Court. It also explains why the UPL is representative of the level of 

performance achieved by the best performing unit or units. The court did not state that the 

“average emissions limitation achieved by the best performing 12 percent” must be equal to the 

mean of the available data, as suggested by the commenter, and in past decisions the court has 

upheld that it is appropriate for EPA to account for variability when establishing numeric MACT 

standards. See Mossville Environmental Action Now v. EPA, 370 F.3d 1232, 1241-42 (D.C. Cir. 

2004). Thus, the EPA maintains the UPL approach to calculate the MACT floors for Brick 

tunnel kilns in the final rule. Please see the “Use of the Upper Prediction Limit for Calculating 

MACT Floors” memo (EPA-HQ-OAR-2013-0291-0128) found in the docket for this rule, for the 

EPA’s justification of the UPL approach.

Comment 2: Commenter 0554 stated as the EPA itself made clear, the upper prediction limit is 

the level that a best performing facility has one in 100 chance of exceeding. MACT Floor Memo 

- Brick at 3; MACT Floor Memo - Clay Ceramics at 3. The commenter stated in other words, it 

is a level that the EPA expects 99 out of 100 future compliance tests by any of the best 

performing facilities in the top 12 percent to “fall below.” 79 FR 75635. The “UPL estimates 

what the upper bound of future values will be.” MACT Floor Memo - Brick at 3; MACT Floor 

Memo - Clay Ceramics at 3.

Commenter 0554 stated the EPA’s UPL is not an “average” or a measure of “central tendency.”

The commenter stated it is, as its name indicates, an “upper limit” -- the emission limitation that 

every member of the best-performing 12 percent will “fall below,” virtually all of the time. 79 

FR 75635; UPL Memo at 5 (describing UPL as “a limit that can be met by all the existing 

sources in the floor at all times”). The commenter stated such a once-in-100 emission level is not 

a measure of “average” emissions any more than a hundred-year flood can be a measure of 

“average” water levels; thus, the EPA cannot support its claim that the UPL creates an estimate 

of the emission limitation “achieved by the average source.” UPL Memo at 10. The commenter 

stated the EPA does not adequately explain how the UPL is an “average.”

Commenter 0554 stated given its ordinary meaning and the meaning the EPA itself has adopted 

through notice-and-comment rulemaking, “the word ‘average’ in [section 112(d)(3)],” allows the 

EPA only to use a “reasonable method ... of determining the central tendency of a data set.” 59 

FR 29199. The commenter stated a level that the EPA expects 99 out of 100 future tests by any 

source in the top 12 percent to “fall below” is not a measure of the “central tendency” of the 

emission levels achieved by this group of sources; rather, it is a measure of one extreme, an 
34

“upper bound” on what any of those sources might emit in a future test. MACT Floor Memo -

Brick at 3; MACT Floor Memo - Clay Ceramics at 3. The commenter stated the UPL does not, 

as the EPA claims, estimate an emission limitation “achieved by the average source.” 79 FR

75636. The commenter stated a floor that the EPA expects even the worst performing source 

within the top 12 percent to meet in 99 out of 100 future tests is not, in any sense, representative 

of “average” source in that group. See Natural Res. Def. Council v. Daley, 209 F.3d 747, 754 

(D.C. Cir. 2000). The commenter stated the UPL does not aim for an “average,” it aims for an 

entirely different target: an “upper limit” that every source within the top 12 percent will meet at 

virtually all times.

Response 2: The EPA disagrees with the commenters that the UPL is not representative of the 

average emissions limitation achieved over time by the best performing sources or sources. The 

CAA leaves to EPA’s discretion the manner in which to calculate “the average emissions 

limitation achieved” by the best performing sources. The EPA has used the average of the lowest 

emission data from the top performing 12 percent of data available in calculating the MACT 

floors. The EPA has then incorporated variability in developing the final MACT floor limits in 

the final rule. The EPA has conducted traditional outlier analyses to remove from the data set 

any data determined to be statistical outlier data. The EPA believes that the data incorporated in 

the MACT floor pool represent the variability present at the various brick and clay ceramics 

manufactures.

As stated in the memorandum entitled “Use of the Upper Prediction Limit for Calculating 

MACT Floors” (Docket No. EPA-HQ-OAR-2013-0291-0128) (“UPL memorandum”), in “the 

context of development of MACT floors, the UPL is a value, calculated from a dataset, which 

identifies the average emissions level that a source or group of sources is meeting and would be 

expected to meet a specified percent of the time that the source is operating. That percent of time 

is based on the confidence level used in the UPL equation. For a single best controlled emission 

source that serves as the basis for a new source MACT floor, the 99 percent UPL is the 

emissions level that the source would be predicted to be below during 99 out of 100 performance 

tests, including emissions tests conducted in the past, present, and future, based on the short term 

stack test data available for that source. It is important to note that the UPL does not represent 

the worst emissions performance of the best performing units at any time, but rather the average 

level expected to have been achieved over time, as the first element of the UPL equation is the 

average of the short-term emissions test data from the best performing units. 

In other words, the 99 percent UPL is the level of emissions that we are 99 percent confident is 

achieved by the average source represented in a dataset (in the case of MACT standards, the 

dataset representing the performance of the best performers as specified in the CAA) over a 

long-term period based on its previous, measured performance history as reflected in short-term 

stack test data.”

Comment 3: Commenter 0554 stated the interpretation of the term “average” that the EPA 

advanced in this rulemaking is internally inconsistent. The EPA “interprets the average to mean 

the average emissions over time.” UPL Memo at 3. The EPA also claimed that the UPL 

represents “the average level expected to have been achieved over time” by the relevant sources, 

id. at 4, and represents a level of emissions the EPA does not expect the average source to 

exceed. Id. at 6. The EPA conceded the upper prediction limit is an “upper limit” on the relevant 
35

sources’ emissions. Id. at 3. Yet the EPA also implied that the upper prediction limit may satisfy 

the Act by describing the “average level” achieved by the best performers over time, Id. at 4-5, 

and at others, the EPA suggests it satisfies the Act by describing the emission level constantly 

achieved by a single “average source.” Id. at 4, 10. The commenter stated claiming that the same 

statutory provision means different things “diverges from any realistic meaning of the statute.”

Massachusetts v. Dep’t of Transportation, 93 F.3d 890, 893 (D.C. Cir. 1996). The commenter 

stated it is also arbitrary. Dep’t of Treasury v. FLRA, 739 F.3d 13, 21 (D.C. Cir. 2014) (“set[ting] 

forth two inconsistent interpretations of the very same term” is arbitrary and capricious).

Commenter 0554 stated the interpretation of the term “average” that the EPA advanced in this 

rulemaking is a departure from, and directly conflicts with, its own long-standing interpretation 

of the Act, which it adopted through notice-and-comment rulemaking and reaffirmed many 

times. 59 FR 29199. The commenter stated although the EPA previously rejected any 

understanding of the word “average” that would encompass an emission limitation “achieved by 

all members of the best performing 12 percent,” id. at 29,197, that is precisely the function of the 

UPL. The commenter stated the EPA does not acknowledge its prior interpretations, nor does it 

explain its reversals. See FCC v. Fox Television Stations, 556 U.S. 502, 515 (2009) (agencies 

may not “depart from a prior policy sub silentio”); Mountain Commc’ns v. FCC, 355 F.3d 644, 

648-49 (D.C. Cir. 2004) (action arbitrary where agency “changed direction without explanation, 

indeed without even acknowledging the change”).

Response 3: The EPA interprets the average to mean the average emissions over time, based on 

both the calculated average of all emissions test data from the best performing source or sources 

and the available information regarding the variability of emissions. The UPL, which EPA uses 

to account for variability among the best performing sources, reflects an upper limit for the 

emissions of those sources at times other than when the emissions tests occurred. This not only is 

a prediction of the emissions performance of those sources in tests conducted in the future, but is 

also an indication of the range of current average emissions performance of those units. 

Comment 4: Commenter 0554 stated the authorities on which the EPA seeks to rest its claim 

that the upper prediction is an average confirm that the upper prediction limit is not an average. 

See UPL Memo at 4 (citing Luko & Neubauer, Statistical Intervals Part 2: The Prediction 

Interval, Standardization News (October/Nov. 2011) (http://www.astm.org/standardizationnews/datapoints/ statistical-intervals-part-2-so11.html); Gibbons & Coleman, Statistical Methods 

for Detection and Quantification of Environmental Contamination (2001)). Luko and Neubauer 

state that the prediction limit is “different” from an “interval for the mean with some degree of 

confidence.” Luko & Neubauer at 1. Likewise, Gibbons and Coleman expressly note the 

difference between a prediction limit and a “confidence interval for the mean.” Gibbons & 

Coleman at 31. The commenter stated these sources further point out that prediction limits 

provide “wider” results -- that is, higher upper limits -- than an estimate of the mean, in part 

because they reflect “the variability of future observations,” rather than just the variability in 

sources’ actual performance. Id.

Commenter 0554 stated the EPA claimed that its upper prediction represents an average over 

time because “the first element of the UPL equation is the average of the short-term emissions 

test data from the best performing units.” UPL Memo at 4. The commenter stated the mere fact 

that the first element of the equation is an average does not demonstrate that the final product of 
36

the equation is the average over time. The EPA provided no basis on which it could reasonably 

conclude that just because its upper prediction equation starts with an average and then adds a 

number to “address variability,” this equation yields the average over time.

Commenter 0554 stated the EPA also argued that because the average is in the first half of the 

equation, the UPL “goes up or down” with average emissions. Id. at 11. The EPA also admitted, 

however, that the upper prediction also goes up or down with factors that are entirely unrelated 

to the average: “the number of runs in the dataset” and “the number of runs averaged for each 

emissions test.” Id.; see also NACWA, 734 F.3d at 1144-45. The commenter stated that the record 

shows that the number of runs in a dataset can make the EPA’s upper prediction go up (i.e., get 

worse) even when the average emissions achieved go down (i.e., get better). See NACWA, 734 

F.3d at 1144.

Response 4: As discussed above, the NACWA court did not state that the “average emissions 

limitation achieved by the best performing 12 percent” must be equal to the mean of the 

available data, as suggested by the commenter, and in past decisions the court has upheld that it 

is appropriate for EPA to account for variability when establishing numeric MACT standards. 

See Mossville Environmental Action Now v. EPA, 370 F.3d 1232, 1241-42 (D.C. Cir. 2004).

Also the CAA leaves to EPA’s discretion the manner in which to calculate “the average 

emissions limitation achieved” by the best performing sources.

Comment 5: Commenter 0554 stated the EPA claimed that an emissions test dataset from 

another rulemaking demonstrates that the UPL for that dataset “represents the average emission 

level achieved by the best performing sources.” UPL Memo at 12-15. The commenter stated that 

EPA conceded, however, “no source among the best performing 12 percent had an overall 

average above the 99 percent UPL,” and only the worst performing source in the top 12 percent 

had even one “3-run test average above the UPL.” Id. at 14. The commenter asserted that to 

argue that just because one test result is higher than the UPL that the UPL is an “average” is like 

arguing that because a river will sometimes reach its 100-year flood level, the 100-year flood 

level is an “average” height for the river. The commenter stated that four units had “one test run 

value” above the EPA’s upper prediction, id., is irrelevant. The commenter stated according to 

the EPA, the UPL produces an estimate of a 3-run test average, not a single “test run.” Id. The 

commenter asked if, as the EPA asserts, the UPL predicts the emission limitation consistently 

achieved by the “average source” among the best performers, id. at 4, 10, or (as the EPA also, 

and contradictorily, contends) the “average emissions limitation” achieved by the best 

performing units - why do all the best performers fall below it, virtually all of the time.

Response 5: The Case B example from the UPL Memo is an example from sewage sludge

incinerators, where there are 150 existing units in the multiple hearth subcategory nationwide 

with 18 sources in the MACT floor pool. In general, the closer each individual unit’s average is 

to the overall MACT floor pool average, the greater the likelihood that the unit will be able to 

meet the calculated UPL MACT floor. In the Case B example provided by EPA in the UPL 

Memo located in the docket for this rule, 13 out of 18 sources had a unit average that was less 

than the average of the overall MACT floor pool. For the other 5 units of the 18 their average 

was above the overall MACT floor pool, thus their ability to meet or not meet the calculated 

UPL depends on the quantity of the variability component of the UPL equation being added to 

the average component of the UPL equation. The variance component of the UPL equation is 
37

dependent on the variability of the test runs from the entire MACT floor pool. In the Case B 

example provided by the EPA in the UPL Memo the variance component added enough 

variability that all of the 18 units of the MACT floor pool could meet the calculated UPL. That is 

not always the case for every UPL calculation, adding the variance component to the average 

component in the UPL equation does not always result in “all the best performers falling below 

the calculated UPL.” For MACT floor pools that contain sources with little variability between 

all the runs resulting in a low variability component, the likelihood of all the sources in the pool 

being able to meet the calculated UPL decreases. For MACT floor pools that contain sources 

with a great amount of variability between all the runs resulting in a high variability component, 

the likelihood of all the sources in the pool being able to meet the calculated UPL increases.

Comment 6: Commenter 0554 stated by setting floors at the upper prediction limit, the EPA also 

contravenes CAA section 112(d)(3)’s unambiguous requirement that floors reflect what the best 

sources “actually achieved.” Sierra Club, 479 F.3d at 880-81. The commenter stated the statute 

unambiguously requires floors to reflect what the best performing sources “achieved,” not what 

EPA predicts they will achieve in the future. See Sierra Club, 479 F.3d at 880-81. The 

commenter stated the UPL is not a measure of the performance of the source but a prediction 

value and does not represent the current sources; the UPL does not merely address the variability 

in the emission levels that sources actually “achieved”; rather, it further inflates the floors to 

ensure that they will be higher than the level the EPA is 99 percent confident no source in the top 

12 percent will exceed in a hypothetical “future” compliance test. The commenter stated by 

requiring floors to reflect what the relevant best sources actually “achieved,” however, the text of 

CAA section 112(d)(3) eliminates any discretion to set floors at levels EPA expects the relevant 

sources not to exceed in “future” compliance tests. The commenter stated for the new source 

floors, the UPL does not reflect what any source actually “achieved,” but rather is a value that 

the EPA expects the best controlled source to always fall below; the UPL approach is contrary to 

the CAA’s plain meaning.

Commenter 0554 stated Congress enacted section 112(d)(3) to put an objective constraint on the 

EPA’s discretion. New Jersey v. EPA, 517 F.3d 574, 578 (D.C. Cir. 2008). The commenter stated 

by substituting its subjective upper-limit-prediction for an objective measure of what sources 

have “actually achieved,” Sierra Club, 479 F.3d at 880-81, the EPA impermissibly “nullifies [a] 

textually applicable provision[] meant to limit its discretion.” Whitman v. Am. Trucking Ass’ns, 

531 U.S. 457, 485 (2001).

Commenter 0554 stated to promulgate a non-arbitrary rule, “EPA ‘must demonstrate with 

substantial evidence - not mere assertions’” that its floors satisfy the statute. NACWA, 734 F.3d 

at 1131. The commenter stated nowhere in the record has the EPA demonstrated that its UPL is 

an accurate estimate of the “average” emission level that the relevant best sources have actually 

“achieved,” or that it reflects what the best controlled source “achieved in practice.” The 

commenter stated the UPL is neither the average emission level achieved by the best performing 

sources nor the emission level achieved by an average source; rather, it is a level the EPA 

expects sources in the top 12 percent -- including the worst -- to fall below in any future test, and 

the best controlled source to always fall below.

Commenter 0554 stated even if the EPA could base floors on what it thinks the best-performing 

sources will achieve in the future rather than what they actually achieved in the past -- which it 
38

cannot for the reasons given above -- the EPA’s formula assumes that sources’ future will vary 

randomly. The commenter stated that sources’ performance is not random but, rather, is 

constrained by the steps that different operators take to control their emissions, including fuels 

they choose to burn, controls they install, and the care with which they operate those controls. 

Sierra Club, 479 F.3d at 880-83; 67 FR 47907. The commenter stated the assumption that all 

variability is inherent variability over which operators have no control is unsupported and 

inaccurate; counting the effects of these factors as inherent variability results in floors that do not 

reflect the best source or sources’ actual performance. The commenter stated the EPA does not 

provide any explanation for its apparent assumption that sources’ actual emission levels will vary 

to the full extent of the 99th percent UPL.

Response 6: The EPA disagrees with the commenter’s statement that the UPL does not reflect 

emission levels “actually achieved.” The commenter misunderstands the purpose of the UPL 

calculation. It is not intended to only predict the best performing sources’ future performance, 

although it can be used to do that. Rather, for the purpose of setting MACT standards, it is used 

to estimate the best performing sources’ current emissions over time, rather than during the very 

short-term periods measured during stack testing.

The EPA interprets “emissions performance,” as used in section 112(d)(3) to mean the emissions 

of a source over the long term, rather than just during a short-term stack test. This is a reasonable 

interpretation of the statutory directive that the MACT standard be no less stringent than the 

average emissions limitation “achieved by” the best performing sources, since the emissions 

level of a source is not expected to always be the same as it is during stack testing. The EPA thus 

uses the UPL to assess the emissions achieved and achievable, for a prescribed confidence level, 

by the source based on its tested performance at times other than when stack testing was 

conducted. This enables EPA to calculate the average emissions performance of the best 

performing sources over time. The EPA uses the UPL approach in its MACT floor analysis 

because it incorporates the average performance of the best performing sources and the 

variability of the performance during testing conditions. The commenter is incorrect that the 

UPL calculation results in an emissions level that the worst source in the top 12 percent of 

sources will fall below. As explained in the “Use of the Upper Prediction Limit for Calculating 

MACT Floors” memo (EPA-HQ-OAR-2013-0291-0128), the UPL calculation begins with the 

average emissions level of the best performing sources, and then applies a second step in order 

to account for the variability in emissions performance of those sources. For the development of 

the Hg floor, the variability of the raw material was also taken into account. The UPL represents 

the value which one can expect the mean of a specified number of future observations to fall 

below for a specified level of confidence based upon the results of an independent sample from 

the same population. Please see the “Use of the Upper Prediction Limit for Calculating MACT 

Floors” memo (EPA-HQ-OAR-2013-0291-0128) for the EPA’s justification of the UPL 

approach.

The EPA disagrees with the commenter regarding randomness of emissions from sources 

imposed by use of the UPL formula. Use of that formula provides a way to restrict the effect of 

randomness to a known range of values calculated from short term testing, as opposed to the 

commenter’s notion that the effect of randomness is varied and unknown. Of course, similar 

operation of the source, consistent with the conditions under which it was tested, is a necessary 

component of the UPL calculations; otherwise, the randomness to which the commenter refers 
39

could creep in. As the emission limits are established on a certain set of practices and operations 

associated with a successful performance test of the best-operating source, those good practices 

and operations are contained in the values calculated by the UPL and should also serve to reduce 

the randomness of which the commenter expresses concern.

Comment 7: Commenter 0554 stated the UPL is a particularly inaccurate representation of what 

the best source or sources “actually achieved” where the emissions dataset is small; as the D.C. 

Circuit has recognized, the results generated by the EPA’s upper prediction approach depend 

heavily “on the size of the dataset.” NACWA, 734 F.3d at 1144-45. The commenter stated a 

smaller dataset causes the EPA’s statistical approach to generate higher (i.e., weaker) floors. Id. 

The commenter stated in this record, the EPA “recognize[s] that the use of the UPL” for small 

datasets introduces “uncertainty” in the calculation of MACT standards. EPA, Approach for 

Applying the Upper Prediction Limit to Limited Datasets at 2 (Sept. 17, 2014), Docket Item No. 

EPA-HQ-OAR-2013-0291-0127 (hereinafter “Limited Datasets Memo - Brick”). The 

commenter stated the “number of values in a particular dataset[] is an important component of 

the UPL approach,” Id. at 1; the t-score (or z-score, depending on which equation is used) is used 

by the EPA to estimate the uncertainty and variability for a certain confidence level, and “is 

highly variable at the smallest sample sizes” and “can have a disproportionate effect, 

overwhelming the other components” of the UPL calculation. Id. at 2. The commenter stated 

moreover, the sample size itself is a separate variable in the EPA’s UPL equation, and as the 

sample size gets smaller, the UPL gets larger (all other variables being constant). Id. at 4. The 

sample size is a “key component” in the calculation of two other variables in the EPA’s UPL 

equation: the mean and variance; “larger sample sizes provide better estimates of the population 

mean and variance.” Id. The commenter stated also, the confidence level chosen by the EPA 

influences the t-score (or z-score), which in turn is “highly variable” where there is limited data. 

Id.

Commenter 0554 stated in light of the significant and pervasive uncertainty that small sample 

sizes introduce into the UPL calculation, the UPL cannot represent the performance that the best 

sources “actually achieved,” as the Act requires, where sample sizes are small; and the EPA is 

frequently faced with the task of establishing floors where it has limited data. The commenter 

stated for example, in these rules alone, the EPA identified 20 floors for which the EPA had 

fewer than 7 data points. See id. at 8; EPA, Approach for Applying the Upper Prediction Limit to 

Limited Datasets at 8 (Sept. 17, 2014), Docket Item No. EPA-HQ-OAR-2013-0290-0218 

(hereinafter “Limited Datasets Memo - Clay Ceramics”). The commenter stated the serious 

shortcomings in the UPL for small datasets alone highlights the need to abandon the UPL 

approach.

Commenter 0554 stated the EPA recognizes that the UPL generates higher and potentially 

inaccurate and unrepresentative floors where the sample size is smaller; yet to address this 

fundamental problem with the UPL approach, EPA proposes that for sample sizes of fewer than 

7, it will “further evaluate” the data in “one or more” ways “on a case-by-case basis” to check to 

see if “the uncertainty associated with a limited dataset does not cause the calculated emission 

limit to be so high” as to be illegal. Limited Datasets Memo - Brick at 6. The commenter stated 

the EPA offers few details as to how, exactly, it will know when the small sample size causes the 

UPL to be unacceptably “high,” except that the EPA will use its “experience” and “technical 
40

expertise” in its evaluation. Id. at 6-7. The EPA specifies no standards to guide this ad hoc 

evaluation.

Commenter 0554 stated the EPA’s proposed solution to the significant flaw in the UPL identified 

by the D.C. Circuit provides no assurance that the UPL will produce accurate limits. The 

commenter stated the EPA is asking that it be trusted to take a second look at an admittedly 

flawed formula and make sure it is “reasonable.” Id. at 7 (“we ... would ensure that the emission 

limit is reasonable”); id. at 6 (“The evaluation will include one or more of the following ...: 

confirming that the data distribution was selected correctly” and “ensuring that we use the most 

appropriate UPL equation.”). The commenter stated the reasonableness is not the legal standard: 

the EPA must demonstrate with “substantial evidence” that use of the UPL for small datasets 

represents what the best source or sources “actually achieved.” The commenter stated the EPA 

needs to do more than double-check its math to make such a showing where the standard-setting 

method being applied is undisputedly defective.

Commenter 0554 stated the EPA’s application of its approach to evaluating and addressing UPLbased floors derived from limited data shows how insufficient this evaluation is; of the twenty 

floors based on small datasets, the EPA concludes without much reasoning that no adjustments 

were warranted.

Commenter 0554 stated also, the EPA fails to rationally explain why sample sizes smaller than 7 

require further evaluation, but slightly larger sample sizes do not. The commenter stated the 

EPA’s own data demonstrates that uncertainty continues to decrease beyond 6 samples as the 

sample size increases. Id. at 3, 5-6 (showing a “7% reduction from 6 to 7 samples” and a “5% 

reduction from 7 to 8” samples). The commenter stated the EPA fails to point to any statistical 

reason why the uncertainty caused by sample sizes greater than 6 can be ignored; it is irrelevant 

that the test data itself may have some uncertainty, as the EPA points out: uncertainty elsewhere 

in the standard-setting process does not justify use of a method to account for variability that 

adds even more uncertainty to the outcome. The commenter stated if anything, additional 

uncertainty caused by the EPA’s proposal to use a UPL is less justifiable if it compounds 

existing concerns about accuracy.

Response 7: As discussed above, the EPA disagrees with the commenter’s statement that the 

UPL does not reflect emission levels “actually achieved,” including the UPL for limited datasets.

A limited dataset does not automatically mean that the calculated UPL is flawed and should not 

be used; however, given the potential impact of uncertainty due solely to the number of samples, 

it is appropriate for the EPA to assess all factors used in the UPL calculations when determining 

an emissions limit, so that the emissions limit reflects the average performance of the units upon 

which the limit is based. The basis for the 6 sample cut off for limited datasets was determined

based on the effect of the sample size dependent component of the UPL equation, the t-statistic. 

As the Limited Dataset Figure 1 and Table 1 demonstrate, the t-statistic for sample sizes below 7 

have a greater value and thus a greater contribution to the UPL equation. The t-statistic for 

sample sizes at and above 7 start to level off and have a lesser contribution to the UPL equation.

As such, the limited dataset cutoff was determined to be below 7 samples.
41

Please see the “Approach for Applying the Upper Prediction Limit to Limited Datasets” memo 

(EPA-HQ-OAR-2013-0291-0127) for more information regarding the UPL approach for limited 

datasets.

Comment 8: Commenter 0554 stated the EPA’s specific selection of the 99 percent UPL as 

opposed to a 95 percent UPL, a 90 percent UPL, or some other UPL is not adequately explained. 

The commenter stated the EPA merely states in conclusory fashion that the 99 percent level 

provides “reasonable assurance that the limit can be met all times” by a best performing source, 

without any analysis or explanation of why a different level of confidence would not provide 

such “reasonable assurance.” UPL Memo at 10. The commenter stated the EPA fails to reconcile 

its choice of a confidence level that “can be met all times” with the statutory language, which 

requires that EPA use an “average;” thus, the EPA’s choice of this particular UPL, which then 

determines the outcome of its floor analysis, is arbitrary. The commenter stated the EPA’s reason 

for deciding not to be more conservative in standard setting for air toxics with significant adverse 

public health effects should be adequately justified in the record; and yet, it is not.

Response 8: While the UPL can be calculated at different confidence levels, the EPA selected 

the 99 percent level in order to provide reasonable assurance that the limit can be met at all times 

by a source with emissions at the average level achieved by the best performing source or 

sources.

5

In the context of development of MACT floors, the UPL is a value, calculated from a dataset, 

which identifies the average emissions level that a source or group of sources is meeting and 

would be expected to meet a specified percent of the time that the source is operating. That 

percent of time is based on the confidence level used in the UPL equation, as explained in more 

detail below. For a single best controlled emission source that serves as the basis for a new 

source MACT floor, the 99 percent UPL is the emissions level that the source would be 

predicted to be below during 99 out of 100 performance tests, including emissions tests 

conducted in the past, present, and future, based on the short term stack test data available for 

that source. It is important to note that the UPL does not represent the worst emissions 

performance of the best performing units at any time, but rather the average level expected to 

have been achieved over time, as the first element of the UPL equation is the average of the 

short-term emissions test data from the best performing units. In other words, the 99 percent 

UPL is the level of emissions that we are 99 percent confident is achieved by the average source 

represented in a dataset over a long-term period based on its previous, measured performance 

history as reflected in short term stack test data.

Comment 9: Commenter 0540 supports the EPA’s consideration of equivalent compliance 

methods for Hg and total non-Hg metals; however, in developing the equivalent standards, the 

EPA relied on oxygen content data that may be difficult to replicate. The commenter stated for 

19 of 27 sources in the non-Hg floor and 2 of the 4 sources in the combined subcategories for 

Hg, oxygen content was obtained using Method 3 (Gas Analysis for the Determination of Dry 

 5 Telander, J. Use of the Upper Prediction Limit for Calculating MACT Floors. Memorandum from Jeff Telander to 

Docket ID No. EPA-HQ-OAR-2013-0291. September 9, 2014. Docket Item No. EPA-HQ-OAR-2013-0291-0128.
42

Molecular Weight).6 The commenter stated the field reliability of the Orsat Analyzer used in 

Method 3 has been documented by the EPA to potentially introduce sizeable errors in the 

correction of particulate catches to reference conditions.7 The commenter stated the results of the 

EPA’s study further concluded that the operator criterion in Method 3 does not ensure that 

accurate results will be obtained. The commenter recommended that the equivalent standards be 

adjusted to UPL with 99.9 percent or 99.99 percent confidence interval to account for the 

uncertainty of the Method 3 oxygen content data; this approach will reasonably ensure that the 

equivalent emission limit selected as the MACT floor adequately represents the level of emission 

actually achieved by the average of the units in the top 12 percent.

Response 9: Without being able to evaluate and quantify how “uncertain” the Method 3 

measurements were, the EPA is not adjusting the confidence interval used in the UPL equation

for the alternate concentration limits based on oxygen corrected data. However, the EPA has 

revised the equivalent concentration based limits to be developed from 17 percent oxygen 

corrected concentrated data. The EPA asserts that correcting at 17 percent rather than 7 percent

as proposed, with provide more representative values of kilns’ operating conditions. The EPA is 

retaining the 99 percent confidence interval in all UPL calculations. 

Comment 10: Commenter 0540 supported the EPA’s use of discretion to account for variability 

in setting the Hg standard, but recommends that if numerical emission limits are set for Hg, that 

they be revised to reflect the variability of the Hg in the mined material for the sources in the 

floor. The commenter stated just as the EPA determined the need to adjust the emission limits in 

the Boiler MACT to account for the variability of Hg in the fuel, so should the EPA consider the 

variability of Hg in the raw materials used to manufacture brick.

According to Commenter 0540, in the preamble to the proposed Boiler MACT, the EPA stated:

However, after review of the available HAP data, including both emission test data and 

fuel analyses, we determined that it was inappropriate to use only the MACT floor 

approach to determine variability and to establish emission limits for boilers and process 

heaters, because this approach considers only the emissions test data. The main problem 

with using only the HAP emissions test data is that the data, which may reflect the 

variability of fuel-related HAP of the best performing units, may not reflect the 

variability of fuel-related HAP from the best performing units over the long term.

Commenter 0540 stated this logic is applicable to brick kilns not only with regard to the longterm variability of fuel Hg content, but to the variability of Hg in the clay and shale within a 

mine and between mines. The commenter stated subsequent to the stack testing performed in 

response to the EPA’s ICR, the brick industry began a raw material testing program to gather 

data to better understand the Hg levels in the clay; while the average raw material data results in 

emission estimates that are in general alignment with Method 29 stack test results, the range of 

Hg raw material content for some facilities suggest that the variability within a mine could be 

 6 Of the three sources in the Hg floor for large kilns, one used Method 3, one used Method 3A, and one is unknown. 

Attachment to Test Data Used in BSCP Proposed Rule, November 6, 2014. Docket Item No. EPA-HQ-OAR-2013-

0291-0121. 7 William J. Mitchell & M. Rodney Midgett (1976) Field Reliability of the Orsat Analyzer, Journal of the Air 

Pollution Control Association, 26:5, 491-495, DOI 10.1080/00022470.1976.10470276
43

considerable. The commenter stated for example, one facility has raw material data that ranges 

from 23 to 114 parts per billion (ppb); using a mass balance approach, emissions from a kiln at 

this facility are estimated to range from 2.5E-5 lb/ton to 1.2E-4 lb/ton. The commenter stated the 

UPL calculations based on this kiln clearly would be based on a single short term assessment of 

emissions (i.e., 3 one hour tests) and by default a short term, single assessment of the Hg content 

in the clay. The commenter stated as the EPA noted in the Boiler MACT preamble, the 

variability over the long term may not be adequately reflected in a UPL calculation based on a 

stack test alone. The commenter recommends that the EPA include the variability in the raw 

material in setting the Hg numerical limits by adjusting the stack test based UPL by a raw 

material variability factor and/or by adjusting the test results prior to the UPL determination by 

an average raw material variability factor.

Commenter 0558 stated a stack test for one of their company’s kiln was used to set the Hg limit 

for small kilns, however the very plant that was tested may have difficulty meeting the limit that 

was established as a result. The commenter stated their raw material contains varying amounts of 

Hg, especially between shale and fireclay; lab tests have shown that fireclay contains more Hg 

than shale. The commenter stated during the stack test that ultimately helped establish the limit, 

there was approximately 77 percent fireclay and 23 percent shale in the brick. The commenter 

asserted that had this test been performed with 100 percent fireclay, there is the strong possibility 

that the Hg result would have been higher, which may have ultimately resulted in a higher limit 

set by the EPA. The commenter also noted that there may be a wide variation of Hg even within 

fireclay itself, so setting a limit based on one stack test with 77 percent fireclay does not seem 

prudent unless the EPA also accounts for the variability of the raw material. The commenter 

stated if EPA wants their assumption that no small kilns require Hg control to be valid, 

significant adjustments must be made to this floor calculation.

Response 10: The EPA has received Hg raw material data during the comment period. The EPA 

has evaluated the data and developed a raw material variability factor that has been incorporated 

into the variability of the MACT floor pool data for each Hg MACT floor UPL equation. Please 

see the MACT floor memo for the final rule for more information. 

7.3 Emission Limit

7.3.1 Manipulation of Data for MACT Floor

Comment 1: Commenter 0543 stated the EPA identified a number of issues with stack test 

reports, often discarding a test run and evaluating only two runs for a facility; these tests were 

discarded for problems like sample contamination, manganese contamination, filter failure, and 

other failures that were not identifiable during the tests. The commenter stated some of these 

issues are due to the tested values being so close to method and analytical detection limits.

Response 1: The EPA agrees there were issues with stack reports; however, the EPA disagrees 

that some of these issues were due to tested values being so close to method and analytical 

detection limits. No reports were discarded due to tested values being close to method and 

analytical detection limits. The stack test reports list the filter temperatures in the field data 

collected during stack test. BIA identified several tests where the filter temperatures were below 

the required temperature for certain stack tests. The PM test reports were reviewed, and test runs

outside the required temperature for the filter were excluded in the floor calculations. Manganese
44

(Mn) contamination was identified by a simple calculation of the ratio of the back half Mn mass 

to the front half Mn mass. If the ratio was over 5, that test run was assumed to have Mn 

contamination, and were excluded. 

Comment 2: Commenters 0543 and 0547 stated data from synthetic area sources should not 

have been used in MACT floor calculations.

Commenter 0543 asserted that the EPA can only consider kilns within the source category when 

establishing the MACT floor for each category or subcategory. The commenter stated the EPA 

incorrectly equates the terms “source category” and “industry” throughout this proposal; they are 

not the same, as the industry includes area sources (both “true” and “synthetic”), as well as the 

major sources in the regulated source category. The commenter stated the EPA is permitted to 

consider the area sources only when evaluating options “above the floor,” but not for 

establishing the MACT floor. The commenter asserted that the EPA is unlawfully ignoring the 

phrase “in the category or subcategory” that is included in the CAA Section 112(d)(3)(A) 

because of an incorrect belief that it would be “unreasonable” to ignore the best controlled 

sources in the industry. The commenter asserted that since the MACT floor precludes the 

consideration of costs that it is unreasonable to arbitrarily ignore key phrases within the CAA 

with respect to how the “floor” is established.

Commenter 0547 stated the proposed rule applies only to brick manufacturing operations located 

at a major source of HAP. See, e.g., 79 FR 75673 (proposed section 63.8385 - “You are subject 

to this subpart if you own or operate a BSCP manufacturing facility that is, is located at, or is 

part of, a major source of HAP emissions .... “). The commenter stated in other words, the rule 

applies to a major source category and is not applicable to non-major sources, which do not 

belong to the source category. Yet the EPA relied on emissions data from a class of non-major 

sources -- the so-called “synthetic area sources” -- in determining existing source MACT floors 

and the corresponding MACT standards.8 The commenter stated relying on emissions data from 

sources that do not belong to the source category being regulated violates the unambiguous 

requirements of section 112(d); to correct this problem, EPA must recalculate the existing source 

standards using emissions data only from major source brick manufacturing plants.

Commenter 0547 stated CAA section 112(d)(3)(A) and (B) are the provisions that describe how 

EPA is required to determine the MACT floor for existing sources. These provisions state the 

following:

Emission standards promulgated under this subsection for existing sources in a category 

or subcategory may be less stringent than standards for new sources in the same category 

or subcategory but shall not be less stringent, and may be more stringent than - (A) the 

average emission limitation achieved by the best performing 12 percent of the existing 

sources (for which the Administrator has emission information) ... in the category or 

subcategory for categories and subcategories with 30 or more sources, or (B) the average 

 8 See, e.g., 79 FR 75635 (“As of January 1, 2014, there were 225 operating BSCP tunnel kilns in the industry 

(including kilns at major sources and synthetic area sources); the top 12 percent of the kilns in the industry would be 

represented by the 27 best performing kilns. Therefore, we ranked the kilns with a FF-based APCD in terms of 

lb/ton (as described in section IV.E of this preamble) and identified the 27 best performing sources from that 

group.”).
45

emission limitation achieved by the best performing 5 sources (for which the 

Administrator has or could reasonably obtain emissions information) in the category or 

subcategory for categories or subcategories with fewer than 30 sources.

Commenter 0547 stated these provisions plainly state the EPA’s obligations; the Agency must 

base the existing source MACT floor for source categories or subcategories containing 30 or 

more sources on emissions information from the best performing 12 percent of existing sources 

“in the category or subcategory.” The commenter stated similarly, the EPA must base the 

existing source MACT floor for source categories or subcategories containing fewer than 30 

sources on emissions information from the 5 best performing sources “in the category or 

subcategory.” The commenter stated in other words, for both large and small categories or 

subcategories, the existing source MACT floor must be based on emissions information from the 

better performing sources “in the category or subcategory.” The commenter stated this language 

is not ambiguous and cannot be construed to mean that the EPA may use emissions information 

from sources outside the given category or subcategory.

Commenter 0547 stated the U.S. Supreme Court has established clear rules to guide 

administrative agencies in construing the statutes they implement; in Chevron USA. v. NRDC, 

467 U.S. 837 (1984), the court explained that “[i]f the intent of Congress is clear, that is the end 

of the matter; for the court, as well as the agency, must give effect to the unambiguously 

expressed intent of Congress.” Id. at 842-43.9 The commenter stated under this so-called 

“Chevron I” analysis, because EPA is unambiguously directed to use emissions information from 

sources “in the category or subcategory” being regulated, the Agency has no choice but to follow 

this command.

Commenter 0547 stated the current proposal does not include any explanation as to why the EPA 

thinks it has authority to consider emissions data from synthetic area sources in setting existing 

source standards for facilities belonging to the major source category. The commenter stated in 

the 2003 BSCP rulemaking, however, an explanation was provided; the EPA reasoned that, in 

the section 112(a)(l) definition of “major source,” “the reference to a source’s potential to emit 

considering controls allows the interpretation that a source’s potential to emit before and after 

controls is relevant, such that synthetic area sources may be considered within the meaning of 

this definition and included in MACT floor determinations for categories of major sources.” 68 

FR 26698.

Commenter 0547 stated this is an irrational interpretation of the definition of “major source” and, 

as such, it provides no support for the EPA’s position. The commenter stated under this 

interpretation, a synthetic area source actually would meet the definition of “major source” and, 

thus, should be regulated as a major source under applicable MACT standards; yet, the EPA has 

not sought to regulate synthetic area sources under this rule or any major source MACT standard 

issued to date.10 The commenter stated if a “synthetic minor” area source is not a major source 

 9 The court goes on to explain that, if the statute is ambiguous, then courts should defer to any reasonable 

interpretation adopted by the implementing agency- the so-called “Chevron II” analysis. 10 See, e.g., 79 FR 75665 (“There are no major sources producing ceramic tile. The five facilities that were major 

sources at the time of the 2008 and 2010 EPA surveys have already taken the necessary steps to become synthetic 
46

for purposes of applying a potentially applicable MACT standard for major sources, there is no 

rational basis for asserting that emissions data from the same source can be used in determining 

the existing source MACT floor for the major source standard.

Commenter 0547 stated alternatively, although the EPA has not advanced such an argument, the 

only way that the EPA could use emissions information from area sources in setting existing 

source MACT floors in the BSCP rule would be to include area sources within the source 

category and to regulate major and area sources together under a single standard. The commenter 

stated but, this approach is not plausible because it too would run afoul of unambiguous CAA 

requirements; Section 112(c)(3) provides authority for the EPA to list “each category or 

subcategory of area sources which the Administrator finds presents a threat of adverse effects to 

human health or the environment ... warranting regulation under this section.”11 The commenter 

stated this provision unambiguously authorizes the EPA only to list “categor[ies] or 

subcatego[ies] of area sources” based on findings specific to the given categories or 

subcategories. Id. (emphasis added). The commenter stated this language cannot be construed as 

meaning that an area source category or subcategory for which the requisite finding is made can 

somehow be extended such that it also include major sources or otherwise merged with a major 

source category. The commenter stated a “category or subcategory of area sources” must include 

only area sources- plain and simple; in any event, there no longer is an area source category for 

brick plants.

Commenter 0547 stated this is consistent with the BSCP area source listing notice, which 

unambiguously characterized the source category as a new “area source category.” See 67 FR 

70428 (“The additional area source categories being listed pursuant to section 112(c)(3) and 

112(k)(3)(B)(ii) are ... Brick and Structural Clay Products Manufacturing.”). The commenter 

stated thus, the statute requires an area source category for a given sector to be listed separately 

from a major source category for the same sector; the EPA is without authority to take any other 

approach.

Response 2: The EPA is continuing to use data from synthetic area sources (synthetic minor 

sources) in the rankings of sources and if applicable MACT floor calculations.

Section 112(d) of the CAA directs us to establish emission standards for each category or 

subcategory of major sources and minor sources of HAP listed for regulation pursuant to section 

112(c) of the CAA. Each such standard must reflect a minimum level of control known as the 

MACT floor. (See CAA section 112(d).) However, section 112 of the CAA does not specifically 

address synthetic minor or synthetic area sources, which include those sources that emit fewer 

than 10 tons per year (tpy) of any HAP or fewer than 25 tpy of any combination of HAP because 

 

area sources. Consequently, none of the known tile facilities will be subject to the provisions of the Clay Ceramics 

manufacturing rule...”). Also note that this assessment does not take into account EPA’s “once in, always in” policy, 

where EPA asserts that once a major source is subject to substantive requirements under a major source MACT 

standard, that source cannot subsequently avoid the applicability of the standard by becoming an area source. The 

commenter asserted that policy also is legally flawed and, thus, has no bearing on these arguments.

11 This was the authority EPA cited in listing BSCP as an area source category in 2002. See 67 FR 70427 (Nov. 22, 

2002). EPA also cited section 112(k)(3)(B)(ii) as authority for the listing, but that provision is limited to “source 

categories or subcategories ... that are or will be listed pursuant to subsection (c).” So, section 112(k) provides no 

additional authority to list area source categories.
47

they use some emission control device(s), pollution prevention techniques or other measures 

(collectively referred to as controls in this preamble) adopted under Federal or State regulations. 

If not for the enforceable controls they have implemented, synthetic minor sources would be 

major sources under section 112 of the CAA.

We believe that the appropriate interpretation of the CAA’s language and legislative history is

that synthetic minor sources be included in MACT floor determinations. First, the statute makes 

clear that our MACT floor determinations are to reflect the best sources in a category. For new 

sources in a category or subcategory, the MACT floor shall not be less stringent than the 

emission control that is achieved in practice by the best-controlled similar source, as determined 

by EPA. (See CAA section 112(d)(3), emphasis added.) For existing sources in a category or 

subcategory with 30 or more sources, the MACT floor may be less stringent than the floor for 

new sources in the same category or subcategory but shall not be less stringent than the average 

emission limitation achieved by the best performing 12 percent of the existing sources (for which 

the Administrator has emissions information). (See CAA section 112(d)(3)(A), emphasis 

added.12) Thus, section 112(d)(3) of the CAA requires that MACT floors reflect what the bestcontrolled new sources and the best-performing existing sources achieve in practice. These 

phrases contain no exemptions and are not limited by references to sources with or without 

controls. Therefore, they suggest that all of the best-controlled or best-performing sources should 

be considered in MACT floor determinations, regardless of whether or not such sources rely 

upon controls.

Furthermore, section 112(d)(3) of the CAA expressly excludes certain sources that meet LAER 

requirements from MACT floor determinations for existing sources. (See CAA section 

112(d)(3)(A).) The fact that Congress expressly excluded such LAER sources but did not also 

exclude synthetic minor sources suggests that no exclusion was intended for synthetic minor 

sources.

Indeed, nothing in the statute suggests that EPA should exclude a control technology from its 

consideration of the MACT floor because the technology is so effective that it reduces source 

emissions such that the source qualifies as a synthetic area source. (See 67 FR 36460 and 36464, 

May 23, 2002, stating this rationale for including synthetic minor sources in the floor 

determination for the proposed NESHAP for municipal solid waste landfills.)

Some commenters argue that because the BSCP source category only includes major sources and 

synthetic minor sources are not covered by the major source standard , synthetic minor sources 

(like true area sources) fall outside the regulated source category and should not be considered in 

MACT floor determinations. EPA agrees that the BSCP source category includes only major 

sources. (See 79 FR 75622 and 75626, December 18, 2014.) However, EPA disagrees that the 

CAA contemplates that synthetic minor sources must be treated like true area sources and 

 

12 If a category or subcategory has fewer than 30 sources, the floor shall be ‘‘the average emission limitation 

achieved by the best performing 5 sources (for which the Administrator has or could reasonably obtain emissions

information) in the category or subcategory.” (See CAA section 112(d)(3)(B), emphasis added.)
48

excluded from MACT floor determinations. Section 112(a) of the CAA defines a major source 

as: 

any stationary source or group of stationary sources located within a contiguous area and 

under common control that emits or has the potential to emit considering controls, in the 

aggregate, 10 tons per year or more of any hazardous air pollutant or 25 tons per year or 

more of any combination of hazardous air pollutants * * *.

(See CAA section 112(a)(1).) An area source is defined as any stationary source of hazardous air 

pollutants that is not a major source. (See CAA section 112(a)(1).) In the major source definition, 

the reference to a source’s potential to emit considering controls allows the interpretation that a 

source’s potential to emit before and after controls is relevant, such that synthetic minor sources 

may be considered within the meaning of this definition and included in MACT floor 

determinations for categories of major sources.13 Some commenters appear to suggest that the 

reference to a source’s potential to emit considering controls can only mean a source’s potential 

to emit after controls have been implemented. While it is possible to read the phrase in this 

manner in isolation, this interpretation would have the effect of excluding the best-performing 

sources in a category from MACT floor determinations and therefore would be contrary to the 

statutory mandate that EPA set MACT floors based on the levels the best-controlled new sources 

and the best-performing existing sources achieve in practice. We believe the statutory reference 

to potential to emit considering controls should be read in a manner consistent with the other 

requirements of section 112(d) of the CAA to allow for the consideration of synthetic minor 

sources in MACT floor determinations for categories of major sources.

In addition, the legislative history suggests that synthetic minor sources should be included in 

MACT floor determinations. In a floor statement, Senator Durenberger stated that in 

implementing section 112(d)(3) of the CAA, ‘‘the [Senate] managers intend the Administrator to 

take whatever steps are necessary to assure that [the Administrator] has collected data on all of 

the better-performing sources within each category. [The Administrator] must have a datagathering program sufficient to assure that [EPA] does not miss any sources that have superior 

levels of emission control.’’ (See Environment and Natural Resources Policy Division, 

Congressional Research Service, 103d Cong., S.Prt. 103–38 (prepared for the U.S. Senate 

Committee on Environment and Public Works), A Legislative History of the Clean Air Act 

Amendments of 1990 at 870, Nov. 1993, emphasis added.) This statement underscores that 

Congress intended for MACT floor determinations to reflect consideration of all of the sources in 

each category with the best emission controls. We believe it would be inconsistent with 

Congress’s intent and the plain language of the CAA to exclude synthetic minor sources—those 

sources with superior controls which became synthetic minor sources by implementing such 

controls—from MACT floor determinations.

 13 We believe this approach is not inconsistent with our policy that existing sources that limit their potential to emit 

to below the major source threshold prior to the first compliance deadline under a MACT standard will not be 

subject to the standard, as one commenter suggests. (See Memorandum from John S. Seitz, Director, Office of Air 

Quality Planning and Standards, EPA, to EPA Regions, “Potential to Emit for MACT Standards— Guidance on 

Timing Issues,” May 16, 1995.) Including synthetic minor sources in MACT floor determinations ensures that 

MACT floors reflect the best-performing sources, as the CAA requires. At the same time, our policy recognizes that 

sources that already achieve or perform better than the MACT floors need not be subject to the MACT standards.
49

We believe that the inclusion of synthetic minor sources in MACT floor determinations is 

justified because of the reasons explained above.

Comment 3: Commenter 0554 stated it does not appear that the EPA excluded startups and 

shutdowns from the data used to determine the MACT floor. See 79 FR 75626. The commenter 

stated by including such data in its floor analysis, EPA inflated the proposed limits substantially 

(especially in light of the variability adjustment). The commenter stated that inflation is wholly 

unjustified if the limits do not apply during startup and shutdown; startup and shutdown 

emissions do not reflect the sources’ actual emissions during other operations.

Response 3: The EPA does not agree with the commenter’s statement that EPA included 

startups and shutdowns from the data used to determine the MACT floor. The EPA does not 

have any data during startup or shutdown periods to exclude from the data set.

Comment 4: Commenter 0543 requested that the impact of counting co-vented sources twice in 

a floor calculation be reevaluated.

Response 4: The EPA disagrees with the commenter. Co-vented sources were treated as separate 

sources as opposed to one source, to be consistent with the methodology used in the Mercury and 

Air Toxics Standards (MATS). Having co-vented sources’ data repeated in a floor calculation 

does not always bias the variability one way.

There are several components of the UPL equation that have an effect on the final UPL value--

the average of the data in the MACT floor pool, variability of the data in the MACT floor pool, 

t-statistic, and “m” future compliance term. Adjusting any one of these can affect the values of 

the other terms and the final UPL value.

In general, the variability within the test runs for the unit affects the variability of the entire 

MACT pool. If the run-by-run data of the unit has little variability, then removing the duplicate 

kiln from the MACT floor pool will usually increase the overall variance and increase the UPL 

value. If the run-by-run data of the unit has significant variability, then removing the duplicate 

kiln from the MACT floor pool will usually decrease the overall variance and decrease the UPL 

value.

7.3.2 Equivalent Limits

A major public comment on equivalent limits and the EPA’s responses to that comment can be 

found in section V.A of the preamble to the BSCP final rule. The remaining public comment on 

that subject and EPA’s response is presented below.

Comment 1: Commenter 0519 noted that, for sources in the Brick and Structural Clay 

Manufacturing category, the EPA proposed two compliance options for Hg and total non-Hg

HAP metals: a numerical emission rate limit as a mass of pollutant emitted per ton of bricks 

produced and a numerical emission limit in units of concentration. The commenter expressed 

concern that through the use of the mass-based option, there will be many smaller kilns that will 

be able to meet the standard without the use of additional pollution controls. The commenter 

asserted that this outcome is not only inconsistent with the intent of section 112 of the CAA, but 
50

by allowing a significant number of sources to avoid additional controls altogether, it will limit 

the degree of health protection expected from this program.

Response 1: The EPA has set standards based on mass per ton of production/output for several 

industry rules, including Portland Cement, MATS, Boilers, etc. The EPA does not agree that 

through the use of the mass-based option, small kilns will automatically be able to meet the 

lb/ton limits just because their production rate is smaller. That statement assumes the pounds of 

emissions for a small kilns are not relative to the amount of product going through the kiln. The 

EPA is retaining the lb/ton limits for PM and Hg in the final rule.

7.3.3 3xRDL

Comment 1: Commenter 0554 stated for source datasets that contained BDL or DLL data, after 

the subcategory UPL is calculated, the EPA compares the results to “the 3xRDL value of the 

relevant performance test method(s),” where “RDL” means “representative detection level.”

MACT Floor Memo - Brick at 9; see also MACT Floor Memo - Clay Ceramics at 11. The 

commenter stated after a conversion step, the 3xRDL is compared to the calculated UPL; as 

the EPA explains:

“If the calculated 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 precision 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.” MACT Floor 

Memo - Brick at 10; see also MACT Floor Memo - Clay Ceramics at 11.

Commenter 0554 stated the following standards are based on the 3xRDL value rather than the 

UPL:

• New brick tunnel kilns (for non-Hg HAP only)

• Existing clay ceramics floor tile press dryers

• Existing clay ceramics tile glaze lines (for Hg only)

• New clay ceramics floor tile press dryers

• New clay ceramics floor tile spray dryers

• New clay ceramics wall tile spray dryers

• New clay ceramics tile glaze lines for Hg

Commenter 0554 stated the EPA did not “demonstrate with substantial evidence” that a 3xRDL 

value represents the level achieved in practice by the best performing source or sources, as is 

required by CAA section 112(d)(3). Ne. Md., 358 F.3d at 954. The commenter stated the record 

does not show that actual emissions of units reporting emissions below the detection limit are 

triple the detection limit. The commenter stated the RDL itself has nothing to do with the 

emission level achieved by a source; rather, according to the EPA, it is just the average of the 

method detection levels that were used by all the sources the EPA considered in its floor 

calculations for existing sources. EPA, Data and Procedure for Handling Below Detection Level 

Data in Analyzing Various Pollutant Emissions Databases for MACT and RTR Emissions Limits 

1 (Dec. 13, 2011), EPA-HQ-OAR-2013-0291-0133. The commenter stated method detection 
51

levels are, themselves, simply the levels at which the laboratories that evaluated emission test 

results for the relevant sources could provide non-zero readings; none of the method detection 

levels EPA considered is in any way an estimate of any source’s performance, let alone the 

performance of the best performing source or sources; nor does the average of those method 

detection levels purport to be an estimate of any source’s performance. The commenter stated 

therefore, a number equal to three times the RDL is not an estimate of the single best source’s 

emission level and cannot possibly satisfy CAA section 112(d)(3)’s floor requirements.

Response 1: The purpose of the 3xRDL value is to confirm that a MACT floor value will be at a 

measureable value. UPLs developed from test data with BDL and DLL runs have a level of 

measureable uncertainty. If a calculated UPL is below the 3xRDL, then that means setting the 

MACT floor limit at the UPL would be setting the standard at a potentially unmeasurable value.

The EPA used the data from the sources in each MACT floor pool to convert the standard 

3xRDL value14 into the units of measure of each UPL in order to be comparable. As such, the 

3xRDL values are related to the sources in the MACT floor pools.

7.3.4 Floor Calculations for Alternate Approaches

Comment 1: Commenter 0540 stated in setting the alternate BSCP MACT floor for New Small 

Tunnel Kilns, the EPA deviated from the methodology presented in the memorandum for 

applying the upper prediction limit to limited datasets by setting arbitrary conditions on the 

variability for selecting the best performing small kiln. As presented in the memo, the EPA 

decided that while the variability of the lb/ton test results for Kiln 599 is acceptable, the 

variability of the equivalent grains per dry standard cubic foot (gr/dscf) test results is not. The 

commenter stated this decision is based upon the determination that the variability of the 

equivalent gr/dscf results is approximately twice that of the dataset for the pool of best 

performing units used to calculate the existing source MACT floor. The commenter could not 

make the same conclusion; using the concentration data presented in Appendix_B1_Proposed_Standards_Existing_Source_UPL_Tables.xls, the variance of the existing source 

dataset is 7.3E-5 which is higher than that of Kiln 599.

Response 1: The commenter is correct that the EPA followed limited dataset guidance when 

dealing with the alternate BSCP MACT floor for New Small Tunnel Kilns. However, the 

commenter’s reference of the variance of the existing dataset is 7.3E-5 from Appendix_B1_Proposed_Standards_Existing_Source_UPL_Tables.xls is an incorrect reference because that 

is the variance for the proposed PM gr/dscf at 7 percent oxygen (O2) standard, NOT the variance 

for the alternate PM gr/dscf at 7 percent O2 Small Tunnel Kiln standard. The variance of 

the alternate PM gr/dscf at 7 percent O2 standard for Small Tunnel Kilns existing dataset is 1.2E6 from the ”PM-Small-conc” worksheet of the Appendix_B3_Alternate_Standards_Existing_Source_UPL_Tables.xlsx file [EPA-HQ-OAR-2013-0291-

0119].

 14 Westlin, P., and R. Merrill. Data and procedure for handling below detection level data in analyzing various 

pollutant emissions databases for MACT and RTR emissions limits. Memorandum from Peter Westlin, SPPD/MPG 

and Raymond Merrill, AQAD/MTG, to SPPD management and MACT rule writers. December 13, 2011. Docket 

Item No. EPA-HQ-OAR-2013-0291-0133.
52

The Kiln 599 gr/dscf at 7 percent O2 variance is 1.8E-6. As such, the EPA’s determination that 

“the variability of the equivalent gr/dscf results is approximately twice that of the dataset for the 

pool of best performing units used to calculate the existing source MACT floor” is accurate

because 1.8E-6 divided by 1.2E-6 is approximately 2.

Further, the EPA has revised its methodology for oxygen correcting data and is now using 17 

percent. The EPA has also revised it ranking methodology for the equivalent limits to use the 

same units of measure for ranking as for the floor calculation (at proposal used lb/ton ranking for 

equivalent floor limits). The limited dataset issue of the new source variance being 

approximately twice that of the existing source variance is no longer an issue. In addition for 

those sources that did not have a reported O2 percent available, they were not oxygen corrected 

and further removed from the oxygen corrected concentration rankings. Please see the MACT

floor memo for the final rule for more information about the rankings and units used to calculate 

the new source limits. 

Comment 2: Commenter 0540 stated in regards to the alternate small tunnel kiln equivalent PM 

gr/dscf at 7 percent O2 new source limited dataset, even if selection of a different kiln as the best 

performer is considered, the logical progression would be to consider the second ranked kiln in 

terms of lb/ton, Kiln 549. The commenter stated the alternate MACT floor using data for Kiln 

549 is 0.0065 gr/dscf, which is directly comparable to that of the top ranked kiln, Kiln 599 at 

0.0072 gr/dscf.

Response 2: The commenter is correct that the logical progression would be to consider the 

second rank kiln in alternate small tunnel kiln equivalent PM gr/dscf at 7 percent O2 new source 

limited dataset evaluation. The EPA did consider the second ranked unit, 549, and it was 

not chosen for the basis of the new source because the average of kiln 549 was 3.7E-3 which 

was greater than the existing alternate equivalent small tunnel kiln PM gr/dscf at 7 percent O2

MACT pool average of 2.9E-3; which results in a new source alternate equivalent small tunnel 

kiln PM 0.0065 gr/dscf at 7 percent O2 UPL greater than the existing source alternate equivalent 

small tunnel kiln PM 0.0050 gr/dscf at 7 percent O2 UPL. In accordance with the limited data set 

memo, EPA has the discretion to review the data from alternate units that would provide a more 

representative new source limit, as such the EPA reviewed and set the small tunnel kiln 

equivalent PM gr/dscf at 7 percent O2 new source floor on the third ranked unit 665.

Further the EPA has revised its methodology for oxygen correcting data and is now using 17 

percent. The EPA has also revised it ranking methodology for the equivalent limits to use the 

same units of measure for ranking as for the floor calculation (at proposal used lb/ton ranking for 

equivalent floor limits). In addition for those sources that did not have a reported O2 percent 

available, they were not oxygen corrected and further removed from the oxygen corrected 

concentration rankings. Please see the MACT floor memo for the final rule for more information 

about the rankings and units used to calculate the new source limits.

Comment 3: Commenter 0540 stated any further consideration of Kiln 665 as the best 

performing kiln for setting the alternate equivalent standard should address the lack of a 

measured oxygen content for the data being used. The commenter stated in correcting the 

measured PM concentration to 7 percent, the EPA assumed the oxygen content in the stack was 
53

zero; based on other available stack test data, the average oxygen content is approximately 17

percent.

15 The commenter stated at this level, the UPL is 0.0278 gr/dscf at 7 percent O2.

Commenter 0540 stated this comment is in direct response to the EPA’s request for comment on 

any of the alternate approaches under consideration.

Response 3: The commenter is correct that kiln 665 gr/dscf at 7 percent O2 data were incorrectly 

oxygen corrected. This occurred because kiln 665 did not have a reported O2 percent available

and as the commenter identified 0 percent was erroneously used in the calculation.

The EPA has since reviewed all the brick tunnel kiln PM test data, identified sources that did not 

have a reported O2 percent available, revised data to not oxygen correct their concentration to 17

percent O2 (revised from 7 percent at proposal to 17 percent for final), and further removed them 

from the oxygen corrected concentration rankings. As a result kiln 665 is no longer in the 

alternate small tunnel kiln equivalent PM gr/dscf at 7 percent O2 ranking. Please see the MACT 

floor memo for the final rule for more information about the rankings and units used to calculate 

the new source limits.

7.4 Achievability of Standards

Comment 1: Commenters 0551, 0562, 0558, 0516, 0545, 0553, 0548, and 0563 asserted that the 

EPA has set unreasonably low Hg and non-Hg metals limits that do not reflect the requirements 

of the CAA and that these limits should be revised. Alternatively, Commenter 0553 stated the Hg

and non-Hg metals limits should be eliminated from the rule.

Commenters 0551, 0562, 0558, 0516, 0545, and 0548 stated if numeric limits remain in the final 

rule, all three compliance alternatives should remain or EPA should re-propose this rule. 

Commenter 0553 stated EPA should reevaluate the cost impacts of this rule.

Commenter 0563 stated their North Carolina operations, there are two controlled kilns and 4 

uncontrolled kilns which operate or don’t operate depending on demand for products; the 

controlled kilns have DLAs. The commenter stated that they have not been required to conduct a 

stack test for Hg emissions from their kilns, so they cannot be certain that they can comply with 

any of the compliance options. The commenter is currently participating in an industry raw 

material testing program to determine whether these limits are attainable for their operations.

Commenter 0545 stated the CAA was never meant to be a technology driver; this seems to be 

entirely contradicting that; there seems to be little to no proof that available technologies can 

achieve the levels warranted in the MACT.

Response 1: The EPA does not agree with the commenter that the Hg and non-Hg limits are 

unreasonably low and do not reflect the requirements of the CAA. As such, the EPA is retaining 

the Hg and non-Hg limits, but with some revisions. The EPA has received Hg raw material data 

during the comment period. The EPA has evaluated the data and developed a raw material 

 15 Attachment to Memorandum “Test Data Used in BSCP Proposed Rule,” Docket Item No. EPA-HQ-OAR-2013-

0291-0121, November 6, 2014.
54

variability factor that has been incorporated into the variability of the MACT floor pool data for 

each Hg MACT floor UPL equation. Please see the MACT floor memo for the final rule for 

more information. The EPA is also retaining the alternative concentration (μg/dscm at 17 percent

O2) and emission rate (lb/hr) floors in addition to the emission factor (lb/ton) MACT floors. The 

EPA also revised the calculation of the non-Hg total HAP limit, discussed further in the MACT 

floor memo for the final rule. 
55

8.0 Health-Based Standards

8.1 Health Thresholds

The major public comments on health thresholds and the EPA’s responses to those comments 

can be found in section V.B of the preamble to the BSCP final rule. The remaining public 

comment and EPA’s response are presented below.

Comment 1: Commenters 0547 and 0549 stated that, as EPA demonstrated in the proposed rule, 

the available health data indicate that HCl, HF, and Cl2 are all threshold pollutants. The 

commenter stated that the data show that each of these pollutants has a discernible exposure 

threshold below which adverse human health effects are not expected to occur; in addition, none 

of the available data suggest that these pollutants reasonably should be expected to act as a 

carcinogen or mutagen, or exhibit a mode of action that would result in non-threshold effects. 

See 79 FR 75638-75641.

Response 1: The EPA appreciates the commenters’ support for EPA’s conclusions that the acid 

gases HCl, HF, and Cl2 are threshold pollutants.

8.2 Discretionary Authority

The public comments on co-benefits, ecosystem impacts, and cumulative effects and EPA’s 

responses to those comments can be found in section V.B of the preamble to the BSCP final rule.

8.3 Setting Level of Standard

8.3.1 Ample Margin of Safety

The public comments on ample margin of safety and the EPA’s responses to those comments can 

be found in section V.B of the preamble to the BSCP final rule.

8.3.2 Risk Assessment

The major public comment on risk assessment and the EPA’s response to that comment can be 

found in section V.B of the preamble to the BSCP final rule. The remaining public comment and 

EPA’s response are presented below.

Comment 1: Commenter 0546 stated that the rationale and accompanying technical documents 

make it very difficult or impossible to determine the impact of this rule because they never report 

the ambient air concentrations that would result if this rule were adopted and compare that to 

what they would be if the usual MACT approach were used. The commenter noted this is an 

essential step in any assessment process, because it is there concentrations that are germane to 

estimate exposures or to compare to concentrations already known to represent various hazards 

or risks.

Commenter 0546 stated there are concerns here for both acute and chronic effects, so this 

omission seems especially unfortunate. The commenter stated the attention of the writers was on 
56

the modeling of the emissions but that should not preclude estimation of what is related to health 

effects, which is the ambient concentration.

Response 1: The EPA disagrees with the commenter’s assertion that there was insufficient 

information provided to determine the impact of the rule. The purpose of EPA’s risk assessment 

was to determine an emissions level that would ensure adverse health effects would not occur at 

any facility in the source category. The EPA did this by assigning the HBEL level of emissions 

to each facility, then determining whether that emissions level resulted in a chronic target organspecific hazard index (TOSHI) exceeding one (or the potential for acute health effects) at any 

facility. The purpose of the assessment was not to characterize the exposures at each facility due 

to the HBEL emissions level (beyond ensuring no health effects), nor to assess the ambient 

concentration at each facility that would result after the application of MACT. However, the 

docket does include the model input files the commenter would need to generate each facility’s 

estimated ambient concentration. The model itself, the Human Exposure Model16 is also publicly 

available.

8.3.3 Level of Standard

Comment 1: Commenters 0543, 0547, 0549, and 0558 supported the health-based approach for 

acid gases, but stated that an overly conservative approach was used to establish the limit.

Commenter 0543 contended that the current proposed approach of setting a single “one limit fits 

all” for the entire industry is overly restrictive and would cause at least one facility to install 

controls with no benefits. The commenter noted that single limit based on a single worst-case 

source needlessly limits the potential for all facilities to expand at their current locations. The

commenter stated that expansion close to raw materials is important in the brick industry because 

the mineral content and other properties of their locally mined raw materials give each brick its 

distinctive look. The commenter stated that there is no reason to limit growth for an existing 

plant when there is no adverse impact on the environment.

Despite using worst-case modeling, the commenter noted that no facility was over 0.4 

cumulative for all kilns in any single hour. The commenter stated that this demonstrates no 

facility should have to control acid gas emissions. Despite all facilities modeling well below the 

safe level, the commenter stated that the EPA’s proposed allowable emission level cannot be met 

by one facility and limits expansion and flexibility at other facilities. The commenter noted that 

the EPA identified Belden Brick in Sugarcreek, Ohio as the facility that would not be able to 

meet the health-based hourly emission limit for acid gases, however Belden’s cumulative HI 

when modeled using actual emissions and stack parameters is only 0.28. The commenter noted 

this indicates the concentrations at the fence-line would be below EPA’s safe levels even at 

maximum emissions. The commenter asserted that the proposed rule would needlessly require 

Belden to add controls to meet an overly restrictive emission limit that is well below levels 

required to protect human health and the environment. The commenter argued there is no 

justification to require this facility to install multimillion dollar controls. The commenter asserted

 16 http://www2.epa.gov/fera/risk-assessment-and-modeling-human-exposure-model-hem
57

that there should be no costs incurred when there is no benefit. Commenter 0558 concurred with 

this comment.

Commenter 0543 asked the EPA to consider whether a large source, such as Belden, that can 

demonstrate no adverse impacts, but is over the conservatively set limit represents a different 

subcategory. If the EPA promulgates only one limit, the commenter suggested the limit must be 

higher.

Commenters 0547 and 0549 suggested the EPA’s approach means that for most facilities in the 

source category the HBEL emission standard would more stringent than needed to meet the 

section 112(d)(4) “ample margin of safety” criterion and would impose needless restrictions on 

current operations and growth. The commenters stated that this is an unreasonable and arbitrary 

and should be rectified by setting multiple HBEL emission standards to accommodate facilities 

with specified emissions and site characteristics. Given the relatively limited number of affected 

facilities in this source category, the commenters suggested that this approach should not be out 

of the question. Commenter 0547 noted the EPA already has “site specific data on the operation 

of each tunnel kiln.”

The commenters further asserted that the EPA has the legal authority to take this approach

because CAA section 112(d)(1) states that the EPA “may distinguish among classes, types, and 

sizes of sources within a category or subcategory in establishing standards.” The commenters 

stated that this would fulfill Congress’s clear intent that MACT emissions standards should not 

be “far more stringent than is necessary to protect public health and the environment.” S. Rep. 

No. 101-228 at 171.

While disagreeing with the setting of a single limit for all sources, Commenter 0543 asserted the 

EPA has established the proposed limit incorrectly. The commenter noted that in setting the 

proposed emission limitation, the EPA modeled impacts an emission rate of 1 tpy from kilns at 

active, major sources in the category, and selected the facility with the highest modeled chronic 

impact to derive an emissions level equivalent to a TOSHI of one. Following the EPA’s 

methodology, Commenter 0543 stated that the top three ranking sources (i.e., worst performing) 

with respect to their modeled chronic impacts are: (1) International Chimney Corporation’s 

Continental Clay facility in Kittanning, Pennsylvania; (2) Interpace Industries Inc. located in 

Ogden, Utah; and (3) American Eagle Brick Co., located in Sunland Park New Mexico.

The commenter suggested that the first two facilities should be removed from the risk assessment 

because they do not meet the criteria of being active, major sources as specified in EPA’s

technical memorandum. The commenter stated that, per Pennsylvania Department of 

Environmental Protection records, the Continental Clay facility is a true area source of HAP and 

is not within the source category being regulated. The commenter also noted that, according to a 

local Ogden, Utah publication, the Interpace Industries Inc. facility ceased operations in 2012

and will not continue as a brick-manufacturing facility under its new ownership.

The commenter stated that they reevaluated the health-based emissions limit using the modeled 

chronic impact posed by the American Eagle Brick Co. facility and determined that a non-cancer 

TOSHI of one yields an emission level of 92 lb/hr HCl equivalent. Since the 92 lb/hr level of 
58

HCl-equivalent emissions is determined such that no facility would exceed a TOSHI of one, the 

commenter suggested that no facility in individual acid gas model runs should exceed this level.

Response 1: The EPA disagrees with the commenter that the emission limit should be raised to 

92 lb/hr HCl equivalent. The commenter does correctly list the facilities with the highest 

estimated TOSHI associated with chronic exposures, but there are other facilities that have the 

highest estimated acute hazard quotients. For the proposed limit of 57 lb/hr HCl equivalent 

emissions, the EPA concluded that there would be low potential for acute health effects for all 

facilities; however, increasing that limit by over 60 percent would increase the likelihood of 

acute health effects and would lessen the ample margin of safety. Therefore, the EPA has not 

revised the emission limit in the final rule.

8.3.4 Other

The major public comments and the EPA’s responses to those comments can be found in section 

V.B of the preamble to the BSCP final rule. The remaining public comments and EPA’s 

responses are presented below.

Comment 1: Commenter 0546 stated that studies have been published since the entries to the 

EPA IRIS database for the substances at issue, and these are readily available; especially when 

the database entries are 20 years old as in this case, EPA needs to consider the relevant scientific 

literature.

Response 1: The EPA disagrees with the commenter that more recent studies necessarily 

represent the best science. The EPA has an approach for selecting appropriate chemical specific 

toxicity assessments and health effect reference values, which is prioritized according to (1) 

conceptual consistency with EPA risk assessment guidelines and (2) level of review received.17

This prioritization approach, which favors EPA toxicity assessments and reference values when 

they exist, has been endorsed by the EPA’s Science Advisory Board (SAB). As part of the risk 

analysis conducted to support this rule, EPA thoroughly evaluated all the available and relevant 

scientific evidence of the substances at issue (see summary of the evidence in section V.A of the 

preamble to the final rule) and concluded that the current toxicity assessments and associated 

health effects reference values for HCl, Cl2 and HF from EPA, ATSDR and California EPA, 

respectively, are the most appropriate assessments and reference values to use in support of this 

regulatory decision.

Comment 2: Commenter 0546 stated that greater attention is needed to the environmental fate of 

Cl2; the gas may not last long in the environment but that is because it becomes an acidic liquid 

when coming into contact with water or the lungs. The commenter noted it does not disappear; 

the document seems rather ill informed about this.

 17 Science Advisory Board. Memorandum to Lisa Jackson, Administrator, U.S. EPA. Review of EPA’s draft 

entitled, “Risk and Technology Review (RTR) Risk Assessment Methodologies: For Review by the EPA’s Science 

Advisory Board with Case Studies – MACT I Petroleum Refining Sources and Portland Cement Manufacturing.”

May 7, 2010. Available at: 

http://yosemite.epa.gov/sab/sabproduct.nsf/4AB3966E263D943A8525771F00668381/$File/EPA-SAB-10-007-

unsigned.pdf.
59

Response 2: The EPA did not state that Cl2 disappears in the environment, rather the EPA 

describes Cl2 as a gas that is highly reactive with both organic and inorganic substances that 

comes into contact with. When Cl2 gas is released into water, such as during water chlorination, 

it quickly dissolves and converts into chloride and hydrochlorous acid. With regard to inhaled 

Cl2, at low levels (1-5 parts per million (ppm)), 95 percent of the Cl2 that touches the lung 

surface is rapidly cleared from the respiratory system with chloride eventually joining the 

chloride pool that already exists in the body.18

Comment 3: Commenter 0548 stated their company is currently permitted under North Carolina 

112j using the health-based standard. The commenter stated that Kiln #696 with a DLA control 

device is subject to certain recordkeeping and reporting requirements associated with its 

operation; the other, uncontrolled kilns are subject to recordkeeping and reporting requirements 

under work practices. The commenter stated that testing requirements are also in place to verify 

compliance with modeled emission rates. The commenter supported EPA’s decision to propose a 

health-based approach and work practices in the standard. The commenter stated this has shown 

to work well for facilities in North Carolina; North Carolina should be used as a model for 

application of the standard.

Response 3: The EPA appreciates the commenter’s support for the health-based emission limit.

Comment 4: Commenters 0521 and 0545 noted that while they believe it is a reasonable 

assumption that the health-based limits can be achieved without additional control, their facilities 

have not tested for Cl2; as a small amount of Cl2 will have a significant impact on the compliance 

determination, they cannot be assured that they will meet the health-based limits until they stack 

test.

Response 4: The EPA appreciates the commenters’ concern, but our impacts estimates indicate 

that all BSCP facilities except one will be able to meet the health-based emission limit.(reference 

promulgation impacts memo--to be drafted). Our test data also show Cl2 emissions are, on 

average, a factor of ten less than HCl (reference promulgation test data memo--to be drafted).

8.4 General Support

Comment 1: Multiple commenters (0514-0516, 0520-0523, 0528-0530, 0535-0537, 0543, 0545, 

0547-0553, 0555, 0556, and 0560-0563) commended the EPA for making positive steps in this 

regulation with health-based standards for acid gases and work practice standards in lieu of 

numeric limits. However, the commenters suggested that additional steps are required to make 

this rule reasonable and attainable.

Commenter 0530 commended the EPA on the cooperation and willingness it has shown in 

considering and evaluating the data and testimony provided by their industry. The commenter 

was pleased that the EPA evaluated that data along with its own to reach the conclusion that a 

health-based approach will protect the environment and public safety while at the same time 

reducing the tremendous financial burden faced by their industry without a health-based rule. 

 18 U.S. Department of Health and Human Services, Agency for Toxic Substances and Disease Registry. 

Toxicological Profile for Chlorine. 2010. Available at http://www.atsdr.cdc.gov/toxprofiles/tp172.pdf.
60

The commenter noted that the health-based approach covers over ninety-nine percent of their 

industry’s emissions.

Response 1: The EPA appreciates the commenters’ support for the health-based emission limit.
61

9.0 Work Practice Standards

Comment 1: Multiple commenters (0521, 0545, 0550, 0551, 0552, 0553, and 0562) provided 

general support of EPA’s proposal of multiple work practice standards in lieu of numeric limits. 

None of their concerns with other provisions of the proposed rule take away from their support 

of that decision.

Commenter 0554 asserted that the work practice standards that EPA proposed to set for 

dioxin/furan emissions from brick tunnel kilns, startup and shutdown period emissions for all 

brick plants, and for all emissions from brick periodic kilns do not satisfy the CAA’s 

requirements. The commenter’s rationale for their objection to the work practice standards for 

dioxin/furan emissions and periodic kilns is summarized later in this section. The commenter’s 

rationale for their objection to the startup and shutdown period emissions is summarized in 

section 10.0 of this document, “Startup and Shutdown.”

Commenter 0554 noted that section 112(h) of the CAA allows EPA to set a work practice 

standard for a category or subcategory of industrial sources, only if it is “not feasible ... to 

prescribe or enforce an emission standard for control of a hazardous air pollutant or pollutants.”

Congress defines in the statute “not feasible to prescribe or enforce an emission standard” as 

meaning that:

(A) a hazardous air pollutant or pollutants cannot be emitted through a conveyance 

designed and constructed to emit or capture such pollutant or that any requirement for, or 

use of, such a conveyance would be inconsistent with any Federal, State or local law, or

(B) the application of measurement methodology to a particular class of sources is not 

practicable due to technological and economic limitations.

Id. CAA section 112(h)(2). If this requirement is met, the work practice standard nonetheless 

must be “consistent with the provisions of subsection [112](d).” Id. CAA section 112(h)(1).

Response 1: The EPA appreciates the support from multiple commenters for the work practice 

standards. The EPA’s responses to Commenter 0554 regarding their objection to the work 

practice standards for dioxin/furan emissions and periodic kilns are provided later in this section. 

The EPA’s response to the Commenter 0554 regarding their objection to the work practice 

standard for startup and shutdown period emissions is provided in section 10.0 of this document, 

“Startup and Shutdown.”

Comment 2: Commenter 0543 stated that the proposed work practice requirements for control 

of dioxin/furan emissions from tunnel kilns are acceptable and reasonable. Since tunnel kilns are 

designed to operate for extended periods of time, the maximum of a 3-year time period between 

checks will allow owners and operators to check the systems during normal shutdown and 

maintenance time. The commenter requested that the EPA allow the inspections conducted 

within 3 years of the initial compliance demonstration to be accepted.

Commenter 0554 disagreed with the proposed work practice standards for tunnel kilns’

emissions of dioxins/furans. The commenter noted that even if was authorized to set work 
62

practice standards for these emissions, the work practice standards the EPA proposed would 

contravene CAA section 112(h)(1). To be consistent with CAA section 112(d), as section 

112(h)(1) requires, any work practice standards would have to reflect measures that yield the 

maximum achievable degree of reduction in these pollutants (i.e., pollutant reductions consistent 

with the reductions that would be achieved by a numerical standard) and that at a minimum 

reflect the measures adopted by the facilities with the lowest emission levels of dioxins/furans. 

The commenter noted that the EPA’s proposal did not purport to satisfy this requirement: these 

standards merely require sources to maintain and periodically tune up their kilns. The EPA did 

not attempt to show what level of emissions reduction, if any, such requirements would achieve, 

and the record-keeping and reporting requirements themselves are neither work practices nor 

means for reducing emissions.

Commenter 0554 stated that the EPA’s previous MACT rules, including its standards for medical 

waste incinerators, show that the EPA knows perfectly well that the composition of the fuel 

being burned, temperature of the burner, the residence time in the burner, the temperature of the 

gas exiting that burner, the rapidity of the cooling of the gas, and the temperature of the air 

pollution control device all have significant effects on dioxin emissions. EPA, Chlorinated 

Dioxin and Furan Formation, Control and Monitoring (1997).

Commenter 0554 also stated that the EPA is well aware that dioxin/furan emissions are 

influenced by factors such as the content of surface coatings, body additives, and raw materials, 

as well as the fuel fired in the kilns, and that these factors could be addressed through work 

practice standards. See National Emission Standards for Hazardous Air Pollutants for Brick and 

Structural Clay Products Manufacturing; and National Emission Standards for Hazardous Air 

Pollutants for Clay Ceramics Manufacturing, 67 FR 47984, 47907 (July 22, 2002) (“HAP metals 

may emanate from trace quantities of metals found in raw materials, metallic body additives and 

surface coatings commonly used in the industry, or from the fuels fired in the kilns.”); Id. at 

47899. It is completely arbitrary and unlawful that these work practice standards do not even 

include limits on firing times, temperature cycles, and maximum loads that the EPA is proposing 

for brick and clay periodic kilns, see 79 FR 75646, or requirements to use natural gas as the kiln 

fuel, as the EPA is proposing for clay ceramics sanitaryware shuttle kilns, Id. at 75663.

Response 2: The EPA appreciates the support from Commenters 0543 for the work practice 

standards for dioxin/furan emissions from tunnel kilns. We agree with the commenter’s request 

to allow the inspections conducted within 3 years of the initial compliance demonstration to be 

accepted as the initial compliance demonstration as long as the inspection met the requirements 

of the regulation. The subsequent inspection must occur no later than 36 calendar months after 

the previous tune-up. 

The EPA disagrees with Commenter 0554 that the standards do not address dioxin/furan 

emissions from tunnel kilns. As noted in the preamble to the proposed rule (79 FR 75647), the 

work practice standard ensures that equipment is maintained and run so as to minimize emissions 

of dioxins and furans. Dioxins/furans are products of incomplete combustion (PIC) and 

optimizing combustion limits the formation of PICs, thereby minimizing emissions of 

dioxins/furans. Optimizing combustion addresses many of the factors noted by the commenter, 

such as temperature and residence time. The analogy that the commenter provided with regard to 

HAP metals is not applicable in this case, since any dioxin/furan from BSCP kilns would be 
63

formed as a result of incomplete combustion, and not due to any dioxins/furans in the raw 

materials, additives, or coatings.

Comment 3: Commenter 0516 stated that the EPA has proposed logical and practicable work 

practice standards for periodic kiln operations and noted that the requirements are feasible and 

applicable. Commenter 0543 agreed that the proposed work practice requirements for periodic 

kilns are acceptable and reasonable and requested that the EPA clarify that the facility may opt to 

list the maximum load on the required label in either dry or fired tons.

Conversely, Commenter 0554 stated that the EPA’s proposed work practice standards do not 

reflect measures that yield the maximum achievable degree of reduction in these pollutants (i.e., 

pollutant reductions consistent with the reductions that would be achieved by a numerical 

standard) and that at a minimum reflect the measures adopted by the periodic kilns with the 

lowest emission levels. Therefore, they are not “consistent with” CAA section 112(d) and violate 

CAA section 112(h). The proposed standards do not reflect the use of any control technology at 

all. EPA is well aware that hazardous air pollutant emissions are influenced by factors such as 

the content of surface coatings, body additives, and raw materials, as well as the fuel fired in the 

kilns, and that these factors could be addressed through work practice standards. See 67 FR 

47907 (“HAP metals may emanate from trace quantities of metals found in raw materials, 

metallic body additives and surface coatings commonly used in the industry, or from the fuels 

fired in the kilns.”); Id. at 47,899. At a minimum, EPA could require sources to use natural gas 

(or the cleanest available alternative) as a fuel. Cf. 79 FR 75663 (proposed work practice 

standards for clay ceramics sanitaryware shuttle kilns would require each kiln “to use natural gas 

or equivalent as the kiln fuel”).

Response 3: The EPA appreciates the support from Commenters 0516 and 0543 for the work 

practice standards for periodic kilns. However, we are not revising the work practice standards to 

allow facilities to list the maximum load in either dry or fired tons. The maximum load refers to 

the tons of product that can be fired in the kiln during a single firing cycle and is compared to the 

total tonnage of product placed in the kiln, which is referring to dry tons (before firing) and not 

fired tons (after firing).

As provided under CAA section 112(h)(1), a work practice standard "reflects the best 

technological system of continuous emission reduction which (taking into consideration the cost 

of achieving such emissions reductions, and any non-air quality health and environmental impact 

and energy requirements) the Administrator determines has been adequately demonstrated. The 

EPA disagrees with Commenter 0554 that the work practice standards for emissions from 

periodic kilns do not address emissions from those sources. As noted in the preamble (79 FR

75645-6), “information provided to the EPA indicates there are six operational factors that have 

a direct bearing on HAP emissions from BSCP periodic kilns: Temperature, firing cycle, product 

quality, automatic control, combustion control and kiln load/kiln technology.” The work practice 

standards address each of these factors to limit the emissions from periodic kilns.
64

10.0 Startup and Shutdown

The major public comments on startup and shutdown standards and the EPA’s responses to those 

comments can be found in section V.B of the preamble to the BSCP final rule. The remaining 

public comments and the EPA’s responses are presented in this section.

Comment 1: Multiple commenters (0516, 0520, 0521, 0528, 0533, 0537, 0543, 0548, 0551, 

0553, and 0558) approved of the use of work practice standards for periods of startup and 

shutdown.

Commenter 0554 stated that the EPA’s proposed work practice standards for periods of startup 

and shutdown are unlawful because the EPA is authorized to set work practice standards only for 

classes of sources, not for periods of operation. CAA sections 112(d)(1) and (2), read together, 

demonstrate that separate standards may be set only for categories or subcategories of sources, 

which must be of a different class, type, or size. The commenter stated that because the EPA 

does not claim or demonstrate that measurement is impracticable for the categories of brick, or 

for subcategories of brick tunnel kilns as a class, the proposed work practice standards are 

unlawful.

Commenter 0554 stated that the EPA’s statements in support of its proposal to implement work 

practice standards do not amount to the “determin[ation]” required by CAA section 112(h) that 

either section 112(h)(2)(A) or (2)(B) has been satisfied. The EPA does not articulate that 

measurement of emissions during startup and shutdown “is not practicable” due to technological 

or economic limitations. And, to the extent that EPA believes work practice standards are 

authorized under section 112(h)(2)(A), the EPA does not “determine[]” that a pollutant “cannot 

be emitted through a conveyance designed and constructed to emit or capture such pollutant”

during startup shutdown periods. The absence of the requisite statutory determination under 

section 112(h)(2) by the Administrator alone renders the proposed work practice standards 

unlawful.

Commenter 0554 further stated that the EPA has not satisfied the statutory requirement that 

testing “is not practicable due to technological ... limitations,” nor would the record support such 

a claim with substantial evidence. See Ass’n of Data Processing Serv. Org. v. Bd. of Governors 

of Fed. Reserve System, 745 F.2d 677, 684 (D.C. Cir. 1984) (substantial evidence standard 

applicable to agency’s factual judgments in informal rulemaking); Ne. Md.. 358 F.3d at 954 

(applying substantial evidence standard to the EPA’s MACT floor determination); NACWA, 734 

F.3d at 1138 (same). The EPA’s conclusory statements do not constitute a determination of 

impracticability under CAA section 112(h)(2)(A), nor do they amount to substantial evidence 

that it is not practicable to apply measurement technology during startup and shutdown periods 

under CAA section 112(h)(2)(B). The commenter stated that the EPA has not considered 

whether measurement methods other than the ones the EPA is proposing could be used for 

startup and shutdown periods, and the record does not contain information about such methods. 

The EPA did not specifically address, or support with substantial evidence, why fluctuating 

conditions would make it impracticable to measure each type of hazardous air pollutant. The 

EPA must select a different method for such periods, or make and support with substantial 

evidence a determination that no such method is available. Work practice standards are permitted 
65

only where it is entirely “infeasible to prescribe or enforce an emission standard,” not just 

infeasible during certain periods.

Commenter 0554 noted that the EPA has not claimed that continuous emissions monitoring 

systems could not be used to measure emissions during startup and shutdown periods, and stated 

that the EPA must also consider whether the use of mass-based limits would be technologically 

feasible. Methods of estimating emissions during startup and shutdown, such as emission 

estimates based on the operating parameters of PM controls, could substitute for the direct 

monitoring of emissions.

Commenter 0554 stated that the problem the EPA identifies with using the “equivalent” emission 

limits during startup and shutdown is irrelevant to the statutory standard, which is whether use of 

measurement methodology “is not practicable due to technological and economic limitations.”

Id. CAA section 112(h)(2)(B). The format of the emissions standard is not a “technological” or 

“economic” limitation, and has no bearing on whether there are methods that are technologically 

practicable for application to kilns during startup and shutdown. The commenter stated that, as 

the EPA recognized, the emission limits pounds per ton are appropriate and practicable for 

startup and shutdown periods. Nothing requires the EPA to provide the other “equivalent”

emission limits, and if such limits are inappropriate for startup and shutdown periods as the EPA 

claims, then the EPA need not offer them for such periods. Further, the EPA cannot devise the 

“equivalent” limits itself (which are not required by the Act), and then point to them as a reason 

why MACT standards cannot be set for periods of startup and shutdown.

Commenter 0554 further stated that even if the EPA’s startup and shutdown work practice 

standards for plants with APCDs are valid, concerns about those sources’ ability to vent exhaust 

through the control devices lend no support to setting work practice standards for sources that do 

not employ control devices.

Commenter 0554 stated that the EPA’s proposed work practice standards for startup and 

shutdown periods contravene CAA section 112(h)(1) because they do not reflect measures that 

yield the maximum achievable degree of reduction in these pollutants (i.e., pollutant reductions 

consistent with the reductions that would be achieved by a numerical standard) and that at a 

minimum reflect the measures adopted by the facilities with the lowest emission levels during 

startup and shutdown. The EPA does not claim the work practice standards are “consistent with 

the provisions of subsection (d) or (f)” of section 112. The EPA provides no basis for assuming 

that sources operating during startup and shutdown periods would necessarily meet the pertinent 

section 112(d) numeric limits. Under the proposed work practice standards, sources would not be 

required to engage their pollution control devices during startup and shutdown periods, and the 

recordkeeping and reporting requirements themselves are neither work practices nor means for 

reducing emissions. Even if the sources are not feeding bricks into the kiln, they will be burning 

fuel (including coal) during those time periods, which will result in hazardous air pollutant 

emissions that might be higher than the numerical limits.

Commenter 0554 stated that the D.C. Circuit has specifically held that the CAA requires that 

“there must be continuous section 112-compliant standards.” Sierra Club v. EPA, 551 F.3d 1019, 

1027 (D.C. Cir. 2008). But the revised final rule includes no continuous, section 112-compliant 
66

work practice or other emission standard to limit the rate of emissions during startup and 

shutdown. The commenter suggested that at a minimum, the EPA could require sources to use 

natural gas or the cleanest available alternative as a fuel during periods of startup and shutdown. 

Further, the EPA needs to set limits on the time that sources spend in startup and shutdown mode 

to prevent the startup and shutdown provisions from being abused as a means to avoid 

compliance with emission standards.

Response 1: The EPA appreciates the support from multiple commenters for the use of work 

practice standards for periods of startup and shutdown. As discussed later in this section, the 

EPA has revised the work practice standards for periods of startup and shutdown for BSCP 

tunnel kilns to provide requirements for minimizing emissions that are feasible for all kilns.

The EPA disagrees with Commenter 0554 that work practice standards for periods of startup and 

shutdown are unlawful. We disagree with the commenter that the standards were set for periods 

of operation, rather than classes of sources. The standards were set for tunnel kilns, which is a 

subcategory of sources in the BSCP manufacturing source category. We also disagree with the 

commenter that we did not state that measurement was impracticable due to technological 

limitations. As we stated in the preamble to the proposed rule, “we recognize that it is not 

feasible to conduct emission testing during periods of startup and shutdown.” 79 FR 75647. The 

infeasibility of measuring emissions during periods of startup and shutdown is documented in the 

memorandum “Summary of Startup, Shutdown, and Malfunction Data for Brick and Structural 

Clay Products Industry,” in the docket for this rulemaking.

The EPA further disagrees with Commenter 0554 that EPA must also demonstrate that a 

pollutant “cannot be emitted through a conveyance designed and constructed to emit or capture 

such pollutant” during startup and shutdown periods. Section 112(h)(1) allows work practice 

standards only if pollution is not emitted through a conveyance or “the application of 

measurement methodology to a particular class of sources is not practicable. (emphasis added) 

As noted in the previous paragraph, the EPA has already demonstrated the latter.

As stated previously, the EPA has revised the standards for promulgation, based on public 

comments and additional information provided by the BSCP industry following proposal on the 

procedures used during startup and shutdown for BSCP tunnel kilns that are more representative 

of the best performing kilns. Consequently, the EPA is confident that these standards will 

provide the maximum limitation of emissions possible during periods of startup and shutdown, 

ensuring that the BSCP Manufacturing NESHAP includes continuous section 112-compliant 

standards during all periods of operation.

Comment 2: Commenter 0533 asked that the rule language be modified in sections 63.8405 and 

63.8420(a) to include an exclusion from the numeric limit for periods of startup and shutdown.

In support of this request for the rule language change, Commenter 0533 discussed requirements 

for the determination of an emission limit, and how the EPA had not met those requirements 

when setting an emission limit that is applied to startup and shutdown periods in the proposed 

rule. The commenter agreed with the reasons stated in the preamble that support work practice 

standards for startup and shutdown periods. However, the commenter also questioned whether 

the EPA had the data and had conducted sufficient analysis to demonstrate the achievability of 
67

the MACT emission limits established for normal operations during startup and shutdown 

events. Commenter 0533 stated the following concerns:

• It is not apparent from the preamble discussion of alternate standards for startup and 

shutdown periods that the EPA has actually analyzed sufficient data on emissions during 

startup and shutdown to justify the Agency’s conclusion that, “the EPA has taken into 

account startup and shutdown periods.” 79 FR 75626. Instead, based on the EPA’s 

statements about the timing of startup and shutdown of control equipment, as discussed 

above, it may be more that the EPA has merely assumed the preamble’s discussion to be 

correct (without need for such analysis).

• There are several reasons why adequate data often do not exist to allow EPA to conclude 

that an emission limitation established for normal operations also represents the 

performance of the best demonstrated control technology during startups and shutdowns, 

which would cause the EPA to understate emissions.

o To the extent emissions data come from required performance tests, the applicable 

regulations generally prohibit testing during startup, shutdown, and malfunction 

(SSM) conditions, and further require that data not be used for compliance 

purposes if obtained during a startup, shutdown, or malfunction event.19

o To the extent the EPA evaluates emissions data collected through continuous 

monitoring, the applicable regulations often require or allow the source to exclude 

from its reporting of continuous monitoring data those data reflecting SSM 

conditions.

o Atypical pollutant concentrations and other stack conditions that may exist during 

startup and shutdown can result in the continuous monitoring system producing 

unusable data, because the pollutant concentration may be outside of the 

monitoring equipment’s span or the stack conditions may not meet monitoring 

system QA/QC parameters, or the data may be truncated on the high end because 

of limitations of the monitoring equipment.20

Commenter 0533 stated that it can be unclear whether a condition that leads to excess emissions 

should be characterized as a startup or shutdown event, or a malfunction event. Without a clear 

demarcation (both in EPA regulations and in practice), the EPA may be analyzing data sets that 

exclude events that the source treated as malfunctions but the Agency would instead say should 

be included in calculating average performance as startup or shutdown conditions.

Response 2: The EPA disagrees with the commenter that we are requiring sources to meet the 

same emission limits during periods of normal operation and periods of startup and shutdown. 

As noted in Table 3 to both the BSCP Manufacturing NESHAP and the Clay Ceramics 

Manufacturing NESHAP, we have set work practice standards to apply during periods of startup 

 19 See, for example, the NESHAP General Provisions, which state that performance tests can only be conducted 

under representative conditions and which specify that: “Operations during periods of startup, shutdown, and 

malfunction shall not constitute representative conditions for the purpose of a performance test....” 40 CFR 

63.7(e)(1); see also 40 CFR 60.8(c) (same for performance testing for NSPS).

20 Note that data from periods when a monitoring system is outside of control limits are required to be excluded 

from emission averages under the NESHAP General Provisions. See 40 CFR 63.8(c)(7)(ii).
68

and shutdown. As stated in the previous response, the EPA has revised these standards for 

promulgation to provide requirements for minimizing emissions that are feasible for all kilns.

Comment 3: Commenter 0533 asserted that emission limitations should not apply at all times, as 

is implied in 40 CFR 63.8420(a). The commenter noted that although the Sierra Club v. EPA

(D.C. Cir. 2008) decision recognized that different standards, including non-numerical standards, 

may (and, in some cases, must) apply during non-standard operating conditions, the Sierra Club

decision does not prevent EPA from adopting emission standards for SSM periods that are 

different from those required during periods of normal operation. The commenter stated that the 

Sierra Club decision does not bar the EPA from using a “requirement relating to the operation or 

maintenance of a source to assure continuous emission reduction” as the emission standard for 

SSM events. See 551 F.3d at 1027. The Sierra Club decision only rejected EPA’s assertion that 

it had discretion to decide not to impose any emission standard covering SSM periods. See id. at 

1027-28, 1030 (noting that EPA was not claiming that the General Provisions SSM exemption 

was either an emission standard under CAA section 112(d) or a design, equipment, work 

practice, or operational standard under section 112(h)). The commenter stated that the majority 

opinion was that “Congress gave no indication that it intended the application of MACT 

standards to vary based on different time periods,” 551 F.3d at 1028: (1) is contradicted by other 

statements in the opinion, referenced above, that a MACT standard need not continuously apply 

a single emission limitation, (2) is dicta, because that was not the situation presented by the 

challenged regulations and argued by EPA, (3) ignores the extensive case law about technologybased limitations referenced above, and (4) does not in any event say that the CAA precludes 

EPA from adopting different emission limitations that apply during SSM events.

Commenter 0533 stated that Cement Kiln Recycling Coalition v. EPA, 255 F.3d 855 (D.C. Cir. 

2001) is the only court decision that addresses SSM issues under CAA section 112, and noted the 

decision for this case is consistent with Essex Chemical and the other new source performance 

standard (NSPS) cases. In Cement Kiln Recycling Coalition, the D.C. Circuit court decided to 

vacate the standards partly because of the Court’s concerns about EPA’s failure to exempt 

hazardous waste combustors from numerical emission limits during SSM periods, instead of 

“permitting sources to return to compliance by following the steps of a startup, shutdown, and 

malfunction plan filed with the Agency....” The Court had “similar doubts about EPA’s decision 

to require sources to comply with standards even during openings of emergency safety valves 

caused by events beyond the sources’ control.” Id. at 872. In response to that decision, EPA 

revised the rule to exempt facilities from the limitations during SSM events. See 40 CFR 

68.1206(b)(1); 67 FR 6792, 6798, 6813 (February 13, 2002).Commenter 0533 disagreed with the 

EPA’s statement that its treatment of excess emissions during SSM events was “required” in 

order to make the standards “consistent with” the D.C. Circuit’s decision in Sierra Club v. EPA, 

551 F.3d 1019 (D.C. Cir. 2008), cert. denied, 130 S. Ct. 1735 (2010). The commenter stated that 

the D.C. Circuit’s Sierra Club decision does not compel or even support EPA’s proposed SSM 

provisions. The commenter argued that the Sierra Club decision did not address what the EPA 

may or may not include in category-specific MACT standards. The commenter noted that court 

decisions have emphasized the need for standards to recognize and accommodate higher 

emission levels that occur at times other than normal operations. See, e.g., Sierra Club v. EPA, 

167 F.3d 658, 665 (D.C. Cir. 1999) (Section 112(d) standards based upon the performance of the 

best-performing facilities are supposed to represent “the emissions control that is achieved in 

practice” by the best performers; this means that the best-performing facilities will not violate the 
69

standards, and that will “only result[] if ‘achieved in practice’ is interpreted to mean ‘achieved

under the worst foreseeable circumstances.’”); Cement Kiln Recycling Coalition v. EPA, 255 

F.3d 855 (D.C. Cir 2001) (the Court choosing to vacate rather than simply remand MACT 

standards, based in part on the Agency’s failure to exempt hazardous waste combustors from 

numerical emission limits during SSM periods and the Court’s “similar doubts about EPA’s 

decision to require sources to comply with standards even during openings of emergency safety 

valves caused by events beyond the sources’ control.” Id. at 872).

The commenter further noted the Sierra Club decision did not say that the same emission 

limitations derived for normal operations must apply during SSM events. Sierra Club does not 

preclude EPA from applying different standards during SSM events than apply during normal 

operations. In fact, the opinion acknowledges that section 302(k)’s “inclusion of [the] broad 

phrase” “any requirement relating to the operation or maintenance of a source to assure 

continuous emission reduction” in the definition of “emission standard” suggests the EPA can 

establish MACT standards consistent with CAA section 112 “without necessarily continuously 

applying a single standard.” See 551 F.3d at 1027. The commenter stated their interpretation is 

also supported by the legislative history of section 302(k), which stated that “accepting that 

‘continuous’ for purposes of the definition of ‘emission standards’ under CAA section 302(k) 

does not mean unchanging” and referring to “the CAA’s requirement that some section 112 

standard apply continuously.” Moreover, the commenter noted, because it was addressing only a 

generic SSM exemption, the Sierra Club decision did not consider whether EPA, in the context 

of individual categorical standards, could determine that it is infeasible to apply the same limits, 

or any limits at all on the mass or concentration of pollutants emitted, during SSM events, or that 

it would lead to absurd results to do so.

The commenter also argued there is precedent for the EPA applying a different standard during 

SSM events. They stated that for over 30 years the EPA has not required sources to meet NSPS 

emission limitations under CAA section 111 established for normal operations during SSM 

events. See 40 CFR 60.8(c). According to the commenter, Congress enacted the “continuous 

basis” language in section 302(k) with the knowledge that EPA’s emissions standards under 

section 111 exempted SSM periods. The commenters argue there is nothing in the legislative 

history of the 1977 amendments to the CAA that suggests Congress intended to overturn that 

practice. Moreover, the commenter noted that court decisions both before and after the CAA

Amendments of 1977 have affirmed the appropriateness of including special SSM provisions in 

standards issued under section 111 despite the “continuous basis” language in the definition of 

“emission limitation.” Similarly, there is nothing in the legislative history of the CAA

Amendments of 1990 that suggests Congress meant something completely different when it used 

the same defined terms, “emission standard” and “emission limitation,” in directing EPA, in 

amendments to section 112 that establish MACT standards.

The commenter also noted the Sierra Club decision did not address whether EPA could use a 

“design, equipment, work practice or operational standard,” as authorized under CAA section 

112(h) and included in the definition of “emission limitation” and “emission standard” in CAA 

section 302(k), in lieu of a numerical emission limitation during SSM events. The EPA told the 

Court that the General Provisions SSM exemption struck down in Sierra Club was not an 

alternative standard based on the work practice standard authority (See 551 F.3d at 1028) but 
70

argued in that case that section 112(h) was irrelevant to its authority to exempt excess emissions 

during SSM events (see Id. at 1030 (Randolph, J. dissenting)).

Commenter 0533 stated that under CAA section 112(d)(2), MACT emission standards, including 

those that apply during SSM events, must be “achievable” with available technology, “taking 

into consideration the cost of achieving such emission reduction, and any non-air quality health 

and environmental impacts and energy requirements.” An emission limitation that applies during 

SSM events has not been demonstrated to be “achieved” by the best-performing 12 percent of 

units in the category under CAA section 112(d)(3), unless EPA can show that those best 

performers actually meet that emission limitation during SSM events. The commenter argued the 

EPA cannot establish “continuous section 112-compliant standards” because EPA has not 

demonstrated that the emission would comply with section 112 when applied during SSM 

events.

Commenter 0533 explained that the courts have recognized that a “technology based standard 

discards its fundamental premise when it ignores the limits inherent in technology.” NRDC v. 

EPA, 859 F.2d 156, 208 (D.C. Cir. 1988). For example, the D.C. Circuit recognized, in Portland 

Cement Ass’n v. Ruckelshaus, 486 F.2d 375, 398 (D.C. Cir. 1973), a decision reviewing 

standards under CAA section 111, that “‘start-up’ and ‘upset’ conditions due to plant or emission 

device malfunction, is an inescapable aspect of industrial life and that allowance must be made 

for such factors in the standards that are promulgated.” Id. at 399. Similarly, in Essex Chem. 

Corp. v. Ruckelshaus, 486 F.2d 427, 432 (D.C. Cir. 1973), cert. denied, 416 U.S. 969 (1974), 

another section 111 case, the D.C. Circuit held that SSM provisions are “necessary to preserve 

the reasonableness of the standards as a whole.” Id. at 433. In National Lime Ass’n v. EPA, 627 

F.2d 416 (D.C. Cir. 1980), another case reviewing emission standards promulgated under CAA 

section 111, the D.C. Circuit held that the CAA requirement that NSPS be “achievable” means 

that the standards must be capable of being met “on a regular basis,” including “under most 

adverse circumstances which can reasonably be expected to recur,” including during periods of 

SSM. 627 F.2d at 431 n.46.

Commenter 0533 also discussed analogous Clean Water Act requirements and noted that in one 

case the court held that where the EPA knew that there would be periods even with “exemplary 

use of” the identified best technology, the emissions would exceed the effluent limitations 

because of conditions “beyond the control of the permit holder,” EPA had violated the Clean 

Water Act by failing to provide an “upset provision” to address those periods. Marathon Oil Co. 

v. EPA, 564 F.2d 1253, 1273-74 (9th Cir. 1977). See also, e.g., NRDC v. EPA, 859 F.2d at 207 

(distinguishing between technology-based effluent limitations, where some provision for 

“upsets” is required, and water-quality-based effluent limitations, which are tied to achieving 

water quality standards rather than based on available technology, and, therefore, need not 

include an upset provision).

The commenter asserted that the Weyerhaeuser Co. v. Costle decision EPA cites in the preamble 

to the Proposed Rule (i.e., 590 F.2d 1011 (D.C. Cir. 1978), does not support EPA’s position. In 

that case, the court was discussing a “technology-forcing” standard and not a MACT standard

that must be based on what is demonstrated to be achievable. The commenter also notes that 

SSM events are unusual “uncontrollable acts of third parties, such as strikes, sabotage, operator 
71

intoxication, or insanity” that the Court was considering in the passage quoted by EPA, see id. 

Industry is not requesting that the NESHAP provide relief from numerical emission limitations 

during those unusual types of events. Moreover, most of the cited events would not constitute 

“malfunctions,” as EPA defines that term in 40 CFR 63.2 and in other policy statements, since 

they are the result of deliberate actions (e.g., deciding to continue to operate with inadequate 

staffing during a strike) or would constitute “careless operation” (e.g., operator intoxication). The 

commenter also pointed out that the Weyerhaeuser decision was made before NRDC v. EPA, 859 

F.2d 156 (D.C. Cir. 1988) which affirmed the need for an upset provision to address 

circumstances where compliance with effluent limitations is impossible through no fault of the 

permittee, and which endorsed Marathon Oil.

Response 3: Exemptions for startup and shutdown are inconsistent with the holding in Sierra 

Club that emissions limitations under section 112 must apply continuously. The Sierra Club

decision does not constrain our authority to prescribe unique standards or work practice 

standards during SS periods where such standards are justified. We evaluated whether different 

standards during startup and shutdown periods are justified, and in this case, we established work 

practice standards to apply during startup and shutdown periods. The decision to use a work 

practice standard is wholly within the discretion of the EPA. CAA section 112(h) (“[T]he 

Administrator may, in lieu [of a numeric standard], promulgate a design, equipment, work 

practice, or operational standard, or combination thereof.”). In exercising the option to establish 

a work practice standard, that standard must “in the Administrator’s judgment [be] consistent 

with the provisions of subsection (d) or (f).” CAA section 112(h)(1) (emphasis added). These 

subsections make clear that the EPA is to base emission standards on the emission levels already 

achieved by the best performing sources and to ensure that public health is protected, as

applicable. This means that work practice standards, although written in non-numeric form, must 

still satisfy statutory requirements such as those applicable to MACT standards, including the 

requirement to be no less stringent than the MACT floor.

Contrary to the commenter’s argument, we believe that the standards that apply during startup 

and shutdown periods will establish “continuous section 112-compliant standards” that the 

Sierra Club decision concluded are required. We also disagree with the comment that the Sierra 

Club decision “did not by its terms” concern what EPA may or may not include in categoryspecific MACT standards. (Citing letter to counsel from Adam Kushner, Director of EPA’s 

Office of Civil Enforcement, July 22, 2009 (see Table 2 of the letter)). This letter, which 

addressed potential compliance issues arising from the Sierra Club court decision, contained 

EPA’s plans for addressing those concerns, including potential future revisions to section 112(d) 

standards. As explained in the letter, our initial analysis indicated that certain rules, such as the 

mineral wool production NESHAP, included specific regulatory text exempting or excusing 

compliance during SSM events in addition to cross-references to 40 CFR. Sections 63.6(f)(1) 

and 63.6(h)(1). At the time, we indicated that the vacatur in Sierra Club would have no direct 

impact on such source category-specific SSM provisions because we believed these provisions 

were not challenged in Sierra Club. We, however, also recognized that the legality of those 

source-category specific provisions may have been called into question and indicated that we 

were evaluating them in light of Sierra Club. “The tables attached to this letter are based on the 

EPA’s initial analysis and are, therefore, subject to change.” (p. 3) [footnote omitted]. We have 

now evaluated the relevant provisions and determined that they need to be revised to address the 

Sierra Club decision.
72

We disagree with commenter’s claim that case law under the CAA and Clean Water Act (CWA)

supports its argument that EPA’s approach to startup and shutdown periods is inconsistent with 

CAA section 112. As explained above and in the preamble to the 2013 and 2014 proposed rules, 

the EPA has taken into account startup and shutdown periods in determining appropriate 

standards. The relevance of Portland Cement and Essex Chem. Corp. is questionable in light of 

subsequent case law and the 1977 amendments to the CAA definition of emission standard 

requiring that such standards be continuous. As the D.C. Circuit noted in National Lime v. EPA, 

627 F.2d. 416, 434 at n 54, “[w]hether the 1977 Amendments have effectively repealed the 

regulations permitting flexibility to account for startups, shutdowns and malfunctions regulations 

applauded by this court in Portland Cement I, 486 F.2d at 398-99 is certainly unclear.”

The NRDC v. EPA (859 F. 2d 156, 207(D.C. Cir. 1988)) case cited by commenter interprets 

provisions of the CWA that are different in nature than provisions governing standards under 

section 112 of the CAA. Furthermore, the discussion of technology-based standards in the NRDC

case is dicta. Nevertheless, the EPA’s approach to malfunctions is also consistent with NRDC. 

NRDC does not require exemptions or less stringent standards for malfunction periods. Further, 

the regulatory affirmative defense included in today’s final rule is consistent with the case cited 

in the NRDC decision; Marathon Oil Co. v. EPA, 564 F.2d 1253, 1272 (9th Cir. 1977). The court 

in Marathon Oil held that EPA must formalize its approach to upsets under the CWA. The 

affirmative defense does so. See, Mont. Sulphur & Chem. Co. v. United States EPA, 2012 U.S. 

App. LEXIS 1056 (5th Cir. Jan 19, 2012) (in rejecting industry argument based on Marathon Oil 

that reliance on the affirmative defense was not adequate, court stated “[h]owever, here the EPA 

does not rely on enforcement discretion alone, but specifically promulgates an affirmative 

defense in the FIP, which clearly defines the requirements to avoid penalties.”). But see, 

Weyerhaeuser v. Costle, 590 F.2d 1011, 1057-58 (D.C. Cir. 1978) (holding that an informal 

approach is adequate).

Comment 4: Numerous commenters (0516, 0518, 0520, 0521, 0522, 0528, 0531, 0537, 0543, 

0545, 0551, 0555, 0556, and 0563) asserted that the startup and shutdown procedures listed in 

the proposed rule cannot be met by all BSCP kilns and must be modified. Commenters (0516, 

0520, 0521, 0522, 0528, 0537, 0543, 0545, 0548, 0551, 0553, 0555, 0556, 0558, 0563) requested

that the final language allow a more basic construct for the work practice requirements in the 

final rule and require facilities to develop site-specific temperatures as part of their permitting 

process. Alternatively, two commenters (0555, 0556) suggested the EPA require site-specific 

start-up and shutdown procedure plan similar to the one required by the vacated 2003 Brick 

MACT. Commenter 0543 agreed and stated that the final rule should allow facilities to formalize 

their procedures for various types of start-up conditions, with approval by the regulating 

authority. The commenter noted that the EPA proposed site-specific startup practices in the 

startup provisions for the Boiler MACT (80 FR 3090, 3095; Jan. 21, 2015). As a third option, the 

commenter suggested that the EPA could specify several different procedures in the final rule 

that reflect the variety of standard practices currently in use, and then allow affected facilities to 

select the procedure that matches their circumstances.

Multiple commenters (0516, 0518, 0520, 0522, 0537, 0543, 0545, 0548, 0551, 0553, 0558, and 

0563) specifically stated that the requirement for an exhaust temperature of 400 °F at startup is 

not workable because the kiln exhaust temperature in some kilns never reaches 400 °F. 

Commenters provided examples of about 10 kilns with average stack exhaust temperatures 
73

ranging from 250-390 °F; two of these kilns had average exhaust temperatures below 300 °F. 

Commenter 0548 has a controlled kiln with exhaust that reaches 450 °F during startup but drops 

during normal operation to 375 °F.

Numerous commenters (0516, 0518, 0520, 0521, 0522, 0528, 0531, 0543, 0454, 0551, 0553, 

0558, and 0563) noted that kilns must have product at startup. Commenter 0537 stated that a 

tunnel kiln is always full of brick unless it is taken cold for a maintenance activity. Commenter 

0543 stated that in a tunnel kiln, the kiln cars form the bottom of the kiln envelope. A continuous 

line of kiln cars is needed to protect the wheels and underside of the kiln cars from damage from 

the high heat. Typically, if a kiln has been previously fired, the bricks that were in the tunnel kiln 

during the previous firing are put back in the kiln in the position they were before a shutdown, or 

in some cases, moved back in the process a few car lengths. Commenter 0516 added that the 

owner or operator must push the kiln cars forward during the startup cycle to facilitate the 

development of the kiln’s temperature profile as it approaches normal production operational 

conditions. This procedure needs to take place before the exhaust temperature reaches the 

operating range. Commenter 0545 noted that some kilns cannot achieve 400 °F in the stack 

unless there are bricks in the kiln to trap the heat.

Therefore, Commenter 0543 requested that the startup provisions apply to the introduction, or 

charging, of new brick or structural clay product through a kiln and do not impact the initial 

staging of kiln cars in a kiln before start-up. Two commenters (0537 and 0543) agreed that 

facilities would not push product through a kiln before proper temperature is achieved because to 

do so would impact the final quality of the brick or structural clay product. Several other 

commenters (0520, 0521, 0537, and 0545) agreed that it would be appropriate to specify that no 

new production take place during startup, but the rule should not prohibit the presence of any 

bricks in the kiln during startup.

Specifically, two commenters (0543 and 0553) suggested revisions to the proposed language to 

“not put any bricks into the kiln” below specified temperatures. Commenter 0553 requested that 

the language reflect actual operating scenarios and read “Do not push or index any brick into the 

kiln until the kiln exhaust temperature reaches...” Commenter 0543 suggested that the EPA 

clarify that this language is intended to mean that brick production, i.e., pressing brick to make a 

saleable product, should not occur before the kiln is vented to the air pollution control device, if 

present. Further, the commenter suggested revising the proposed shutdown procedure language 

to read “Do not charge new product into the kiln once kiln shutdown begins and the temperature 

in the exhaust stack reaches the shutdown temperature approved as part of your site-specific 

parameters.” The commenter noted that kilns burning solid fuel may sometimes need to push 

product from the initial gas fired zones into solid fired zones until a temperature proof can be 

established such that the solid fuel ignition temperatures in those zones is high enough to achieve 

combustion, so a one-size-fits-all standard is not possible.

Multiple commenters (0516, 0520, 0537, and 0545) agreed with the language that requires a kiln 

to vent to an APCD before the exhaust gas reaches 400 degrees F, because it can vent at any time 

up to that temperature. Multiple commenters (0516, 0537, 0543, and 0548) stated that for a 

controlled kiln, it is acceptable to require that no new product is allowed to be introduced to the 

controlled kiln until the kiln is vented to an APCD. Commenter 0516 stated that a feasible work 
74

practice standard would be for the exhaust gases to be vented through the APCD during the 

startup process, with the reagent feed started on an intermittent basis during this period and then 

brought up to full feed rate once the exhaust temperature has reached the normal operating 

temperature range.

A few commenters also requested specific revisions to the production requirements for periods 

of shutdown. Commenter 0516 stated that during shutdown, a kiln operator would not be pushing 

any cars in the kiln after reaching a range of 250 to 300 °F in the exhaust stack (depending on the 

type of kiln and its operating parameters). The commenter asked that a minimum operating range 

be allowed during a shutdown cycle. Commenter 0543 noted that a limitation for a kiln to cease 

charging in new product before a kiln stops venting to an APCD may be a reasonable alternative 

to temperature requirements. Commenter 0543 asserted that to require anything different than 

typical operation for BSCP tunnel kilns during startup or shutdown would be considered 

“beyond the floor” for the industry, and EPA must consider costs as well as the practicality of the 

revised procedures.

Response 4: The EPA evaluated these comments and agrees that the proposed standards would 

not be achievable for some kilns. The intent of the proposed standards was to minimize 

emissions by limiting the amount of brick being fired and limiting the amount of time the 

exhaust is not being routed to the APCD, if applicable. As noted at proposal, the standards were 

based on information received through the 2010 EPA survey. Based on additional information 

received following proposal, the EPA has revised the work practice standards for periods of 

startup and shutdown for BSCP tunnel kilns to provide requirements for minimizing emissions 

that are feasible for all kilns.

Specifically, instead of defining the minimum inlet APCD temperature as 400 °F, the EPA is 

requiring the owner or operator to determine the minimum inlet temperature for each APCD. If a 

kiln does not have an APCD, the owner or operator is required to determine the product-specific 

kiln temperature profile that must be achieved before the kiln can reach full production. In 

addition, instead of specifying that no product can be introduced to the kiln during startup, the 

EPA is requiring the owner or operator to determine the production rate needed to start up the 

kiln. The final startup standards specify that this startup production rate cannot be exceeded until 

the kiln exhaust reaches the APCD minimum inlet temperature or the product-specific kiln 

temperature profile, whichever is applicable. The final shutdown standards specify that no 

additional product can be introduced once the kiln exhaust falls below the APCD minimum inlet 

temperature or the product-specific kiln temperature profile, whichever is applicable.

Comment 5: Commenters made a number of requests for EPA to allow for alternate procedures 

with regard to startup and shutdown. Multiple commenters (0516, 0521, 0537, 0543, and 0545) 

suggested that in the case of a kiln car crash inside the kiln, the EPA should allow for an 

alternate procedure when the typical procedure cannot be followed. Commenter 0520 similarly 

asked that the EPA allow for an alternate procedure when the typical procedure cannot be 

followed. Commenter 0537 requested exemptions from generalized, routine written start-up 

shutdown requirements for unanticipated, site specific non-routine occurrences. Commenters 

0537 and 0543 also asked that facilities be allowed to establish alternate procedures for cold start 

up.
75

Response 5: The EPA does not agree with the commenters’ requests for alternate procedures. 

Kiln car crashes and “unanticipated, site specific non-routine occurrences” meet the definition of 

malfunction, and exemptions from standards during malfunctions are no longer allowed.

Comment 6: Multiple commenters (0537, 0543, 0545, 0551, and 0553) stated that the 

requirements should be modified to pertain to control devices only, and not the kilns. 

Commenters 0516, 0520, 0521, 0537, 0543, and 0553 stated that for uncontrolled kilns, there is 

no environmental benefit gained from requiring specific start-up or shutdown procedures.

Response 6: The CAA requires that NESHAP emissions limitations under section 112 must 

apply continuously, including during periods of startup and shutdown. This would apply to all 

kilns, controlled and uncontrolled. The EPA has revised the work practice standards for periods 

of startup and shutdown for BSCP tunnel kilns to provide requirements that are less prescriptive 

and more representative of the best performing kilns and ensure continuous section 112-

compliance standards.

Comment 7: Commenter 0543 asked that the EPA correct the rule to not simultaneously enforce 

work practice requirements under section 112(h) of the CAA and numeric limits under section 

112(d). In the proposed rule, 40 CFR 63.8420(a) states that:

“You must be in compliance with the emission limitations (including operating limits) in 

this subpart at all times, except during periods of routine control device maintenance as 

specified in paragraph (d) of this section.”

Commenter 0543 stated that unless EPA adds the exclusion for periods of start-up and shutdown 

to this paragraph, the rule would be simultaneously requiring compliance with both a numeric 

limit under section 112(d) and a work practice limit under section 112(h). Section 112(h) clearly 

states that a work practice is allowed “in lieu of” a limit established under section 112(d). The 

commenter asked that EPA clarify that only the work practice requirements are in effect during 

periods of start-up and shutdown by revising 40 CFR 63.8420 to read:

“You must be in compliance with the emission limitations (including operating limits) in 

this subpart at all times, except during periods of routine control device maintenance as 

specified in paragraph (d) of this section and during periods of start-up and shutdown.”

Response 7: The EPA agrees with the commenter that 40 CFR 63.8420(a) should be clarified. 

We have revised 40 CFR 63.8420(a) as follows to account for start-up and shutdown and also the 

alternative standard for routine control device maintenance: 

You must be in compliance with the emission limitations (including operating limits) in 

this subpart at all times, except during periods that you are approved for and in 

compliance with the alternative standard for routine control device maintenance as 

specified in paragraph (d) of this section, and except during periods of start-up and 

shutdown, at which time you must comply with the applicable work practice standard 

specified in Table 3 to this subpart.
76

11.0 Malfunction

Comment 1: Multiple commenters (0516, 0520, 0537, 0543, and 0558) stated that it is not 

reasonable to take a stack test that was conducted on a kiln during normal operation and apply 

that emission limit to the kiln during a malfunction, nor does the variability of three test runs 

during normal operation account for periods of non-normal operation. Commenters 0520, 0537, 

and 0558 stated that to apply a stack test that occurs during steady operation and apply it to 

malfunction periods is going beyond what is “achieved” by a source and into what EPA is 

assuming is “achievable.”

Multiple commenters (0516, 0537, 0543, and 0558) stated that if a facility were going to be able 

to be in compliance with numeric limits during a malfunction, a redundant control would be 

needed. Commenter 0537 stated that this is probably not even economically or technically 

feasible, nor has it been included in the proposed rule cost.

Multiple commenters (0516, 0520, 0533, 0537, 0543, 0555, 0556, and 0558) stated that it is not 

possible to test during a malfunction. Multiple commenters (0516, 0520, 0533, 0537, 0543, and 

0558) also stated that because it is not technically or economically feasible to test during these 

periods, malfunctions meet the criteria of section 112(h) of the CAA that allows for work 

practice standards.

Response 1: The EPA disagrees with the commenters’ argument that stack test data from periods 

of normal operation cannot be used to adequately account for the variability during periods of 

non-normal operation. We have set the MACT standards at a level that a well-operated source 

should be able to meet during 99 percent of all stack tests, which we believe sufficiently 

accounts for variability. Consequently, we disagree that a redundant control would be necessary 

to comply with emission limits during periods of malfunction. With respect to the commenters’

suggestion that the EPA consider work practice standards for periods of malfunction, we refer to 

our response to the third comment in this section.

Comment 2: Multiple commenters (0516, 0537, 0543, 0555, 0556, and 0558) stated that a 

reasonable work practice would be to require each facility with a control device to develop a 

malfunction plan, similar to the one required by the now-vacated 2003 Brick MACT. 

Commenters 0558 and 0563 suggested that the work practice could require a facility to develop, 

maintain, and follow a plan for periods of malfunctions and revise a plan, as needed. For 

example, a plan revision would be warranted if a malfunction occurred that was not included in 

the current malfunction plan. It would be a deviation from the work practice, and a possible 

violation, if the plan was not followed during a malfunction or not updated.

Response 2: The EPA does not agree with the commenters’ request for a work practice standard 

requiring facilities with control devices to develop a malfunction plan. In exercising the option to 

establish a work practice standard, that standard must “in the Administrator’s judgment [be] 

consistent with the provisions of subsection (d) or (f).” CAA section 112(h)(1) These subsections 

make clear that the EPA is to base emission standards on the emission levels already achieved by 

the best-performing sources and to ensure that public health is protected, as applicable. There is 

no way to prescribe the specific requirements within a malfunction plan to ensure that each plan 

reflects the level of emission reductions achieved by the best-performing sources.
77

Comment 3: Commenter 0533 stated that CAA section 112 does not require or even allow the

EPA to ignore malfunctions when setting MACT standards. The commenter stated the EPA 

cannot ignore the requirement that MACT floor standards reflect performance actually achieved.

The commenter asserted that statutory language, congressional intent, and case law support EPA 

promulgating alternative emission standards for malfunction events(either numerical limits or 

work practices) . By setting standards for malfunction events, the EPA would not have to affect 

the stringency of the emission standards that apply during normal, steady-state operations.

Commenter 0533 also disagreed with the EPA’s view that applying the concept of “bestperforming” is inconsistent with a source experiencing a malfunction. See 79 FR 75626. The 

commenter argued that best performers experience malfunctions and there are work practices 

(such as monitoring of operating parameters to identify a malfunction and stopping or cutting 

back the process accordingly) that represent the best practices for minimizing emissions during a 

malfunction. Commenters 0516, 0533, and 0537 noted that the measures representing these best 

practices will depend on facility-specific issues. 

Commenter 0533 stated that facility-specific best practices represent the “the maximum degree 

of reduction in emissions of the hazardous air pollutants...achievable...through application of 

measures, processes, methods, systems or techniques” and reflect “the emission control that is 

achieved in practice by the best controlled similar source[s]” CAA section 112(d)(2) and (3).

Commenter 0533 stated that there is no basis for EPA’s conclusion that malfunction events are 

not representative of best-performing sources. See id.; see also, e.g., Cement Kiln Recycling 

Coalition, 255 F.3d at 862-865 (recognizing that there is variability in the performance of control 

technologies, which needs to be taken into account in establishing emission limitations based on 

the MACT floor); Sierra Club v. EPA, 167 F.3d 658, 665 (D.C. Cir. 1999). The commenter 

asked that the EPA acknowledge the fact that best performing sources experience malfunction 

events and not set MACT standards that even the best performing existing sources cannot 

achieve part of the time. The commenter asserted that the EPA is going beyond the MACT floor

without making the demonstrations that the statute and case law require the Agency to make in 

order to impose beyond-the-floor MACT standards (including the Agency’s obligation to 

consider costs). Commenters 0516, 0537, and 0543 concurred with this comment.

Commenter 0533 stated that when a facility experiences exceedances due to a malfunction, even 

though affirmative defense was struck down, the EPA’s response will be based on whether the 

facility had conducted “root cause analyses to ascertain and rectify excess emissions.” 79 FR 

75627. The commenter argued the EPA made no attempt to justify those conditions as 

reasonable “taking into consideration the cost of achieving such emission reduction, and any 

non-air quality health and environmental impacts and energy requirements,” as required by CAA 

section 112(d)(2).

Commenter 0533 stated the EPA should include emissions data representing malfunctions (if 

such data exist) in calculating the MACT floor (see 79 FR 75626) or considering alternative 

work practice standards, instead of requiring that the MACT floor limitations be met even during 

malfunctions. If it is possible to gather sufficient representative data reflecting emissions during 

malfunctions, then the EPA is obligated to consider those data in its MACT floor calculations for 
78

steady-state operating conditions. To the extent EPA had access to continuous monitoring data 

for emission units covered by the NESHAP, the commenters asserted the EPA could have 

conducted analyses of emissions levels during malfunction events. The commenter stated that 

even if continuous monitoring data are for parameters not regulated by the proposal, the 

monitoring data might form a reasonable basis for EPA’s assessment of what standards are 

achieved or achievable during malfunctions. Also, many types of sources are required by many 

state agencies to submit deviation reports or malfunction reports when they experience a 

malfunction that causes an exceedance of an applicable limitation. The commenters stated that 

the EPA does not appear to have made any attempt to obtain and analyze such reports, in order to 

assess what type of requirement might reasonably apply during malfunctions.

Commenter 0533 stated that before affirmative defense was struck down, the Agency believed 

that an affirmative defense provision was necessary so that MACT standards would be based on 

what is achievable with available technology. The EPA not only does not include an affirmative 

defense, it does not explain why it is reasonable to treat exceedances associated with 

malfunctions as violations. The commenter recommended the EPA include many of the concepts 

that it incorporated into the affirmative defense provisions of other recent NESHAP proposals 

into alternative, work practice standards that would apply during malfunctions. They argue that 

this approach would be consistent with NRDC v. EPA.

Commenter 0533 stated that the EPA’s statement “. . . the EPA would determine an appropriate 

response based on, among other things, the good faith efforts of the source to minimize 

emissions during malfunction periods, including preventative and corrective actions, as well as 

root cause analyses to ascertain and rectify excess emissions,” (79 FR 7527) are inadequate. The 

commenter questioned whether there would ever be an appropriate time for EPA not to use its 

enforcement discretion. The EPA has provided no analysis that would supersede its longstanding determination that it is not appropriate to rely on enforcement, rather than regulatory 

language, to address the inability to comply with technology-based standards during SSM events. 

See 37 FR 17214 (Aug. 25, 1972) (establishing SSM provision in NSPS). The commenter 

asserted that the courts have adopted the same view. See, e.g., Portland Cement, 486 F.2d at 398 

n.1; National Lime, 627 F.2d at 431 n.46 (“the flexibility appropriate to enforcement will not 

render ‘achievable’ a standard which cannot be achieved on a regular basis, either for the reasons 

expressly taken into account in compliance determination regulations (here startup, shutdown 

and malfunction), or otherwise.”).21

Commenter 0533 also noted the EPA’s exercise of its discretion not to bring an enforcement 

action for excusable malfunctions does nothing to prevent a source from having to defend itself 

from a citizen suit or state enforcement action for the same malfunctions, nor does the Agency 

 21 See also Marathon Oil Co. v. EPA, 564 F.2d at 1273 (explaining why EPA’s statement that it would not take 

enforcement action against sources that exceeded effluent limitations because of upset events was “not an adequate 

response” to the argument that standards that cannot be met during unavoidable upsets fail to reflect available 

technology). Also for these reasons, the commenter stated that EPA’s statements in the Proposed Rule preamble that 

EPA will “determine an appropriate response” to reported exceedances of the Proposed Standards, based on, 

“among other things, the good faith efforts of the source to minimize emissions during malfunction periods, 

including preventative and corrective actions, as well as root cause analyses to ascertain and rectify excess 

emissions” (79 FR 75627), are not in any way a substitute for EPA setting the standards at an achievable level in the 

first place.
79

state that it will exercise its enforcement discretion for events that meet the criteria it has applied 

in the past to the affirmative defense. The commenter noted that after-the-fact determinations of 

whether or not to penalize a source that has a malfunction do not require or encourage measures 

that may reduce the magnitude or duration of exceedances associated with malfunctions. The 

commenter recommended that the EPA address compliance during malfunctions by 

promulgating an achievable alternative standard.

Commenter 0533 noted in a district court enforcement action or in a citizen enforcement action, 

“similarly, the presiding officer in an administrative proceeding can consider any defense raised 

and determine whether Administrative penalties are appropriate.” 79 FR 75627. The commenter 

noted that in NRDC v. EPA, the Court specifically recognized the EPA has authority to limit the 

situations in which it will impose administrative penalties in that manner. See 749 F.3d at 1063 

(“By contrast, EPA’s ability to determine whether penalties should be assessed for CAA

violations extends only to administrative penalties, not to civil penalties imposed by a court.”

(citation omitted)). The commenter recommended the EPA affirmatively state in the final rule 

that the Agency will not seek administrative penalties for excess emissions caused by 

malfunctions.

Commenter 0533 noted that in the portion of the proposed rule dealing with air pollution control 

device maintenance, the EPA allowed sources to bypass an APCD under certain circumstances to 

perform control device maintenance(see 40 CFR 63.8420(d)). The commenter stated that 

proposed 40 CFR 63.8420(d) is an example of how EPA has used its work practice authority to 

establish alternative emission standards in situations that are analogous to addressing emissions 

during malfunction events.

Response 3: The EPA disagrees with the comment that it is required to take malfunctions into 

account when adopting MACT standards and that a separate standard be set for periods of 

malfunction. As explained in the preamble, the EPA has determined that CAA section 112 does 

not require that “emissions that occur during periods of malfunction...be factored into 

development of CAA section 112 standards...There is nothing in CAA section 112 that directs 

the agency to consider malfunctions in determining the level “achieved” by the best-performing 

sources when setting emission standards. As the U.S. Court of Appeals for the District of 

Columbia Circuit has recognized, the phrase “average emissions limitation achieved by the best 

performing 12 percent of” sources “says nothing about how the performance of the best units is 

to be calculated.” Nat’l Ass’n of Clean Water Agencies v. EPA, 734 F.3d 1115, 1141 (D.C. Cir. 

2013).”

As we further explained, “accounting for malfunctions in setting emission standards would be 

difficult, if not impossible, given the myriad different types of malfunctions that can occur across 

all sources in the category and given the difficulties associated with predicting or accounting for 

the frequency, degree, and duration of various malfunctions that might occur. For these reasons, 

the performance of units that are malfunctioning is not “reasonably” foreseeable. See, e.g., Sierra 

Club v. EPA, 167 F.3d 658, 662 (D.C. Cir. 1999) (‘‘The EPA typically has wide latitude in 

determining the extent of data-gathering necessary to solve a problem. We generally defer to an 

agency’s decision to proceed on the basis of imperfect scientific information, rather than to 

‘invest the resources to conduct the perfect study.’”)
80

With respect to the commenters’ suggestion that EPA consider work practice standards, the 

decision to use a work practice standard is wholly within the discretion of the EPA. CAA section 

112(h) (“[T]he Administrator may, in lieu [of a numeric standard], promulgate a design, 

equipment, work practice, or operational standard, or combination thereof.”). In exercising the 

option to establish a work practice standard, that standard must “in the Administrator’s judgment 

[be] consistent with the provisions of subsection (d) or (f).” CAA section 112(h)(1) (emphasis 

added). These subsections make clear that the EPA is to base emission standards on the emission 

levels already achieved by the best-performing sources and to ensure that public health is 

protected, as applicable. This means that work practice standards, although written in nonnumeric form, must still satisfy statutory requirements such as those applicable to MACT 

standards, including the requirement to be no less stringent than the MACT floor.

It is just as difficult to establish a work practice standard for malfunctions that can approximate 

the level of emission reduction achieved by the best-performing sources during malfunctions as 

it would be to factor emission levels that occur during malfunctions into the numeric standards. 

The EPA would have to design a single work practice standard that applies equally to a tank 

explosion as it does to innumerable types of operator error, computer glitches or a myriad of 

other unknown events, or alternatively create innumerable work practice standards.

In summary, the EPA believes that, based on this rulemaking record, it would be clearly 

inappropriate to set a work practice standard for malfunctions in lieu of the otherwise applicable 

numerical emission limit. We also note that we would consider any response to violations caused 

by a malfunction on a case-by-case basis through the exercise of enforcement discretion.

However, we disagree with the commenter’s suggestion that the EPA limit its discretionary 

authority by affirmatively stating in the final rule that it will not seek administrative penalties for 

excess emissions caused by malfunctions.

Comment 4: Commenter 0533 noted that in the proposed rule, the EPA replaced the NESHAP

General Provisions section that establishes a “general duty” to operate a source consistent with

safety and good air pollution control practices for minimizing emissions, 40 CFR 63.6(e)(1), 

with somewhat different “general duty” language in proposed 40 CFR 63.8420(b). The D.C. 

Circuit did not vacate the provision EPA replaced, 40 CFR 63.6(e)(1), in Sierra Club v. EPA

(which vacated the “exemption” for SSM events in 40 CFR 63.6(f)(1) and (h)(1), not the 

requirement for good air pollution control practices), and, contrary to EPA’s assertion in the 

preamble to the Proposed Rule, 40 CFR 63.6(e)(1) does not reference provisions that were 

vacated in Sierra Club v. EPA. Compare Table 8, 79 FR 75691, and Table 9, Id. at 75716 of the 

Proposed Rule with 79 FR 75626. The Agency must provide a cogent explanation of why the old 

rule was unacceptable and the new rule is necessary. The commenter suggested that the proposed 

new general duty provisions be deleted, and delete proposed 40 CFR 63.8420(b) from the final 

rule. If the EPA does not delete 40 CFR 63.8420(b), the Agency should re-propose the provision 

with some explanation of the basis and purpose for the provision, to allow the public an 

opportunity to provide meaningful comments, as required by CAA section 307(d)(3).

Response 4: Section 63.6(e)(1)(i) describes the general duty to minimize emissions. The current

language in 40 CFR 63.6(e)(1)(i) characterizes what the general duty entails during periods of 

SSM. With the elimination of the SSM exemption, there is no need to differentiate between 

normal operations, startup and shutdown, and malfunction events in describing the general duty. 
81

Consequently, we proposed that the entry for 40 CFR 63.6(e)(1)(i) in the General Provisions 

table (Table 8 to Subpart JJJJJ) in column 4 should be “no.” We also proposed adding general 

duty regulatory text at 40 CFR 63.8420(b) that reflects the general duty to minimize emissions 

while eliminating the reference to periods covered by an SSM exemption. Therefore, the 

language the EPA proposed for 40 CFR 63.8420(b) does not include the current language in 40 

CFR 63.6(e)(1). The proposed changes were necessary to clarify the general duty requirements 

in light of the elimination of the SSM exemption. Consequently, we must deny the commenter’s 

request to have proposed 40 CFR 63.8420(b) deleted from the final rule. Reproposal of the 

section, with some explanation of the basis and purpose for the provision, is also unnecessary

and is denied.
82

12.0 Testing and Initial Compliance Requirements

Comment 1: Commenter 0540 suggested a mass balance calculation should be used instead of 

stack testing to determine compliance with the Hg standard. The commenter stated that stack 

testing at up to $15,000 per test is a significant economic burden to the industry. The method 

recommended by this commenter use inexpensive raw material testing to determine compliance 

with the standard. 

The commenter has conducted a preliminary study in which they tested over 175 brick samples 

before and after firing using test method M7473 with a reported detection of < 1.83 ppb. The 

brick materials tested include alluvial clay deposits, various shale materials and coal major 

fireclays. Mercury content in the various materials before firing range from non-detect levels to 

levels of slightly over 200 ppb. 

The commenter estimated the Hg emissions using the raw material Hg test data (i.e., the 

difference between the Hg levels in the fired and unfired samples) and the estimated Hg 

emissions from fuel combustion (estimated using AP-42 or other documented emission factors 

from the Boiler MACT). Where fired brick samples measured below detection, the commenter 

assumed all of the Hg in the unfired sample was released. For comparison to an existing Method 

29 test, the commenter used the production rate during that test to determine a lb/ton emission 

rate. Since the lb/ton emission rate is expressed in terms of fired brick, the weight lost on ignition 

was factored into the determination. Although the raw material samples were not collected 

concurrently with the Method 29 tests, the commenter noted the results are nonetheless 

promising for the use of raw material data as an indicator of emissions. According to the 

commenter, 85 percent of the predicted emissions using raw material data concur with the 

Method 29 tests The data for only three kilns did not show good agreement; however, the 

commenter noted that the data for only one kiln suggested compliance when the stack test does 

not. Raw material based emissions for this particular kiln were 60 percent of the stack test 

emissions. Of the 20 kilns with raw material and Method 29 data, 10 had a higher emissions 

estimate using the mass balance approach than the stack test. For the 10 with lower emissions, 

the raw-material-based emission estimates ranged from 60 percent to 94 percent of the stack test 

emissions. The suggested that this disparity could be address by the EPA setting a percentage of 

the numeric MACT limit that the raw material mass balance based emission estimate would have 

to meet to demonstrate compliance. The commenter further argued that the mass balance 

approach may be a better tool to demonstrate a compliance given the problems associated with 

Method 29 detailed in other comments submitted by Mike Hartman of AirTech Environmental.

Based on their initial findings, the commenter suggested that with continued raw material 

testing, the mass balance approach can be used as an adequate if not conservative indicator of 

kiln Hg emissions and a viable alternative to Method 29 testing. The commenter further 

recommended that if the EPA requires Method 29 testing for the initial compliance 

demonstration, then raw material testing could be used as a surrogate for Method 29 testing for 

subsequent demonstrations of compliance.

Response 1: The EPA disagrees with the mass balance approach. Mass balance of Hg is very 

difficult to complete correctly. There would need to be complete HF digestion of the raw 

material and a complete accounting of all sources of Hg. A 60 percent to 85 percent comparison
83

is not a good correlation. The raw material may be the major source of the Hg but it could not be

the only source of Hg in a kiln. Because there is a measureable concentration of Hg in most of 

the ICR test data, work practice standards are not applicable. Method 29 can be utilized to 

determine the concentration of Hg being emitted from the kiln stack. The variability of the raw 

material was taken into account in the development of the MACT floor within the UPL 

calculations. The data collected utilizing Method 29 is the emission concentration from the stack

and will be utilized to demonstrate compliance with the Hg limit unless an alternative method is 

petitioned and approved by the Measurement Technology Group of the EPA. The alternative 

method needs to demonstrate similar results and a high correlation to Method 29 data.

Comment 2: Commenter 0543 noted the EPA identified a number of issues with stack test 

reports and had discarded test runs because of sample contamination, manganese contamination, 

filter failure, and other failures (e.g., reported values being close to method and analytical 

detection limits) that were not identifiable during the tests. The commenter stated that while the 

EPA used only two of three runs for establishing emission limits, the proposed Brick MACT 

requires a minimum of three qualifying test runs for demonstrating compliance.

Response 2: The EPA disagrees with this comment. The EPA did discard test runs when the 

EPA Reference method was not followed or the required QA elements within the method failed, 

or sample contamination occurred. Data did not get discarded if the test values were close to 

method and analytical detection limits.

For demonstrating compliance, the EPA requires in 40 CFR 63.7(e)(3) that “[u]nless otherwise 

specified in a relevant standard or test method, each performance test shall consist of three 

separate runs using the applicable test method. Each run shall be conducted for the time and 

under the conditions specified in the relevant standard. For the purpose of determining 

compliance with a relevant standard, the arithmetic mean of the results of the three runs shall 

apply.”

Allowing for the use of less than three test runs to demonstrate compliance is generally not 

allowed. Under certain circumstances, results of a test run may be replace with an additional test 

run. This requires approval from the Administrator or a delegated authority. The specific 

circumstances when a test run may be replaced are listed in section 63.7(e)(3) of the general 

provisions and include:

(i) A sample is accidentally lost after the testing team leaves the site; or 

(ii) Conditions occur in which one of the three runs must be discontinued because of forced 

shutdown; or 

(iii) Extreme meteorological conditions occur; or 

(iv) Other circumstances occur that are beyond the owner or operator’s control.
84

13.0 Continuous Compliance Requirements

Comment 1: Multiple commenters (0516, 0520, 0521/Endicott, 0543, 0552, 0553, and 0558) 

argued that EPA should provide an alternative to the “no visible emissions” requirements.

The commenters noted that the proposed rule requires that all facilities demonstrate that they can 

meet the non-Hg metal standard (or PM surrogate) by conducting a stack test. Ongoing 

compliance is then demonstrated by daily documentation of “no visible emissions.” However, a 

facility may be able to demonstrate compliance with the PM emission limits even though 

periodic visible emissions may be witnessed during their performance test. Having “no visible 

emissions” 100 percent of the time is not a feasible condition to maintain during normal 

production operations. For that reason, visible emissions (VE) is not a reasonable parameter to 

prescribe for purposes of assessing ongoing compliance with the non-Hg metals/PM standard. At 

a minimum, in those instances, the facility should be allowed to prove ongoing compliance by 

demonstrating that the percent of operating time with visible emissions does not exceed the 

percent of time with visible emissions observed during the performance test.

The commenters also made the following points:

1. In some normal operating scenarios, periodic “puffs” of visually detectable opacity are 

sometimes observed. This can happen in uncontrolled scenarios when product is charged 

into the kiln. It can also happen when a DLA cycles limestone and during some flashing 

operations. In rare instances, a “puff” may be detected even on DIFFs during bag 

cleaning cycling. This is a normal part of these processes and does not mean there is a 

malfunction or even (necessarily) that any additional HAP are being emitted.

2. If a facility can demonstrate compliance with one of the HAP emission limits (most likely 

the total metals per hour option if the visible emissions are carbon or limestone based) 

while having these periodic visible emissions, they should not be required to eliminate 

them under this MACT.

3. VE may also be visible during the filling of fresh reagent silos and emptying of spent 

reagent containments. This is normal operation and should not be considered a violation 

of the standard.

4. In some cases, visible emissions have nothing to do with HAP emissions. For example, 

condensable vapors, including water, can be visible under certain conditions. If a facility 

has demonstrated compliance with the hourly HAP metal limit, a “no visible emissions”

requirement would be unnecessarily problematic.

Commenter 0558 noted that they observe visible emissions from their kiln stacks as a result of 

sulfur dioxide (SO2) release. There is a possibility that these emissions could be visible while 

still complying with MACT requirements for HAPs. Furthermore, there may be instances where 

a facility may be able to demonstrate compliance with the PM emission limits while still 

observing periodic visible emissions from control devices during their performance test. If 

visible emissions were observed during the compliance test, then the rule should not limit those 

facilities to “no visible emissions” to demonstrate compliance going forward.
85

Commenter 0543 stated that there should be an alternative approach that a facility could opt into 

if they have the visible emissions issues discussed above. The commenter would not recommend 

that EPA remove the current option – just add an additional option if the duration of the puff is 

regular and anticipated. The commenter suggested an addition to section 63.8470(f) that would 

allow periods of visible emissions during normal operations to accommodate circumstances like 

those described above.

Commenter 0521/Endicott argued that ill-chosen compliance demonstration requirements can 

needlessly cause a huge burden on a facility, particularly when compliance may be initially 

demonstrated during a performance test, but then ongoing compliance cannot be demonstrated. 

The commenter expressed regret that EPA was not in a position to share such key requirements 

during the SBREFA panel process, as this would have allowed more time to consider other 

compliance demonstration requirements. The commenter asked that the rule be changed to 

accommodate a reasonable alternative method of ongoing compliance, such as the following:

1. An opacity reading below 20 percent to demonstrate compliance, or

2. Demonstrating that the percent of operating time with visible emissions does not exceed 

the percent of time with visible emissions observed during the performance test, if the 

average opacity measured during the stack test did not exceed 20 percent.

The commenter asserted that this approach is more reasonable, demonstrates compliance as 

effectively, and does not penalize a small business such as theirs. The commenter estimated that 

their company will be forced to install approximately $6 million dollars of unnecessary air 

pollution control devices to comply with a no visible emission compliance requirement while 

having already complied with the underlying numerical limits of the rule in the first place. The 

commenter stated that they do not have the ability to pass these costs to their customers and that 

this requirement will create a huge financial burden on their company with little to no positive 

effect on the environment.

The commenter further noted that, based on their recent stack test, they comply with the PM 

limit as proposed for existing sources. In addition, the commenter indicated they have personnel 

that are trained and certified in Method 9 and their kiln stack test readings have been at or below 

10 percent opacity.

Response 1: In response to this comment, we are revising the VE monitoring option to allow 

sources to conduct a Method 9 opacity test if VE are observed during any daily Method 22 test. 

If opacity greater than 10 percent is observed, sources are required to initiate and complete 

corrective actions according to their Operations, Maintenance and Monitoring (OM&M) plan. As 

an additional alternative, in lieu of meeting the VE monitoring requirements, sources may 

conduct an annual Method 5 PM performance test.
86

14.0 Alternate Approaches

Comment 1: Commenter 0554 stated that CAA section 112(h) does not authorize the EPA set 

work practice standards for HAP metals emitted by brick tunnel kilns. The commenter noted 

CAA section 112(h) allows the EPA to set a work practice standard for a category or subcategory 

of industrial sources, only if it is “not feasible ... to prescribe or enforce an emission standard for 

control of a hazardous air pollutant or pollutants.” The commenter also noted that the Congress 

defines in the statute “not feasible to prescribe or enforce an emission standard” as meaning that 

(A) a hazardous air pollutant or pollutants cannot be emitted through a conveyance designed and 

constructed to emit or capture such pollutant or that any requirement for, or use of, such a 

conveyance would be inconsistent with any Federal, State or local law; or (B) the application of 

measurement methodology to a particular class of sources is not practicable due to technological 

and economic limitations. The commenter stated it would be unlawful for the EPA to set work 

practice standards for HAP metals. The commenter also disagreed with the industry’s 

justification that work practice standards were needed because some test runs are below the 

detection limit. The commenter stated that for Hg all test runs are above detection limits and for 

the other HAP metals only one is below the detection limit. 

Commenter 0554 stated there is no technological limitation making “the application of 

measurement methodology to a particular class of sources impracticable,” and even for units 

where test results fall below the detection limit, the application of measurement methodology is 

not impracticable. Furthermore, the commenter stated that the EPA cannot use its own choice to 

not set a detection limit as an excuse to avoid setting emission standards. The commenter noted 

that measurement methodologies with much lower detection levels exist and therefore, the fact 

that some data are below detection limits does not demonstrate technological barriers to 

measurement. See Sierra Club v. EPA, 479 F.3d 875 (vacating prior work practice standards for 

certain brick and clay ceramics plants on holding that the lack of available data does not provide 

a valid justification for the EPA to set work practice standards under CAA section 112(h)).

The commenter noted the CAA authorizes the EPA to prohibit emissions where achievable and 

can, a fortiori, set standards at a specific detection limit higher than zero even if emissions 

cannot be measured below that detection limit. The commenter also mentioned that CAA section 

112(d)(3) directs the EPA to base floors on the emission limitation achieved by the best 

performing sources “for which the Administrator has emissions information.” CAA section 

112(d)(3)(A). The commenter noted that the EPA can set standards based on the sources for 

which the Administrator does have usable emissions data. As long as the EPA has test run data 

above the detection limit that represents greater than 12 percent of the sources with data, the 

EPA can set standards and specify a test method that would detect emissions at these levels. The 

commenter stated that the fact that some kilns might record emission levels below the detection 

limit is irrelevant because this fact does not show the application of the measurement 

methodology is impracticable, but rather that the source has low emissions or the method has 

high detection levels.

Response 1: The EPA appreciates the commenter’s support for our decision not to set work 

practice standards for non-Hg HAP metals.
87

Comment 2: Two commenters (0519 and 0554) opposed facility-wide emissions averaging as an 

alternative means of compliance with Hg and non-Hg HAP standards for existing brick and clay 

tunnel kilns. Commenter 0554 argued that it is arbitrary for the EPA to view a “source” as an 

individual unit to set the floors, and then as a collection of individual units at a facility or plant, 

as the EPA does in the emissions averaging alternative. The commenter also noted that the EPA 

does not explain this inconsistency, and the unexplained inconsistency renders the emissions 

averaging alternative arbitrary and capricious.

Commenter 0554 further stated that allowing emissions averaging is likely to result in higher 

facility-wide emissions than if each kiln is required to comply with the MACT standards because 

many existing kilns are already meeting the proposed MACT standards. The commenter stated 

that, for the Hg and non-Hg HAP standards, the EPA estimates that under the proposed rule, 93 

out of 132 brick tunnel kiln stacks will not need to change their air pollution control equipment 

in order to comply with the standards. The commenter stated that averaging would allow some 

kilns that emit more than the standard to avoid installing control devices. Since the EPA did not 

factor the value of those lost pollution reductions in its impact analyses, the commenter 

suggested the EPA should not allow emissions averaging.

Commenter 0519 was concerned about implementation challenges, such as complications that 

averaging poses for inspectors and enforcement personnel in determining the requirements for 

individual units. This commenter expressed concern that inter-pollutant trading may be allowed 

under an emissions averaging compliance approach. If the EPA decides to adopt emissions 

averaging, the commenter urged the EPA to require (1) assurance that the environmental benefits 

of the averaging will be equal to or greater than if each individual unit had complied separately;

(2) averaging is prohibited for new sources; (3) averaging between different pollutants, sources 

or source categories is prohibited; and (4) a discount factor be applied to ensure the average is as 

stringent as the MACT floor limits without averaging.

Response 2: The EPA has conducted an analysis of the costs and impacts of the emissions 

averaging option as compared to the individual MACT emission limits and has determined that 

the emissions averaging option will result in substantially higher costs for the industry than the 

individual MACT limits. Consequently, we have decided to finalize the individual MACT limits 

and not promulgate the emissions averaging option.
88

15.0 Costs and Impacts

15.1 Costs and Emissions Reductions

Comment 1: Commenters 0530 and 0543 stated that the EPA has significantly underestimated 

the cost, reliability, and effectiveness of available air pollution control devices and the number of

brick manufacturers that will be impacted by the proposed numerical limits. Commenter 0543 

stated that this rule, as proposed, has the potential to significantly and detrimentally impact the 

brick industry, while providing no commensurate improvement to human health or the 

environment; Commenters 0514 and 0560 agreed with this comment.

Commenter 0543 stated that the EPA made numerous unsupported, unsupportable, and

unrealistic assumptions in the proposal and supporting documentation, including assumptions 

that virtually all sources that remain in the category can comply with the standard.22 Without 

considering the complex factors that go into such a decision, the EPA assumed that numerous 

sources would become non-major sources of HAP and avoid applicability of the rule. In fact, 

nearly all benefits reported for this proposed rule, including both HAP and non-HAP emission 

reductions, result from the sources that the EPA assumed will install controls to avoid the rule. 

All but 4 of the 440 tons of the HAP emission reductions claimed in the proposal are for HF and 

HCl emission reductions, primarily from sources that the EPA assumes will become synthetic 

area sources; However, the commenter asserted that the EPA has already demonstrated through 

modeling that the HF and HCl emissions from these sources cause no adverse impact to the 

environment.

The commenter asserted that the EPA incorrectly reduced the reported burden estimate for the 

proposed MACT by more than 90 percent from the more accurate estimate provided during the 

Small Business SBREFA panel review, when the EPA estimated that the rule could cost $188 

million per year. The commenter noted that the $188 million per year did not include the control 

of Hg, which adds significantly to overall costs. While the proposal of a health-based standard 

negates the requirement for new APCD to control HF and HCl in most instances, the commenter 

stated that the regulation of small amounts of Hg and non-Hg HAP metals has the potential to 

require the same multi-million dollar controls plus the additional of an undemonstrated activated 

carbon system to reduce Hg emissions. Multiple commenters (0516, 0520-0523, 0529, 0536, 

0537, 0545, 0550-0553, 0555, 0556, 0558, and 0562) supported this comment.

Commenter 0543 noted that by the EPA’s own estimates, these controls (and controls used to 

avoid MACT applicability) would reduce 118 pounds of Hg and 3.79 tons of PM HAP, but 

would cost $19 million each year. The commenter asserted that the costs could actually be 

significantly higher, with substantially more sources being impacted. The commenter stated that 

the minimal, if any, emission reductions would not be commensurate with these additional costs.

 22 See “Methodology and Assumptions Used to Estimate the Model Costs and Impacts of BSCP Air Pollution 

Control Devices” (EPA-HQ-OAR-2013-0291-0118) and “Development of Cost and Emission Reduction Impacts for 

the BSCP NESHAP” (EPA-HQ-OAR-2013-0291-0117).
89

Commenter 0543 was concerned about the model cost memorandum since it contains numerous 

assumptions that are either not supported by anything and are just “assumed” or are supported by 

a single telecon from a vendor who is clearly motivated to state that his equipment can meet any 

requirement. However, the commenter stated that the EPA appears to have been selective in 

which pieces of information it accepts from a vendor and which it does not, ignoring costs or 

other information provided. The commenter provided the following examples:

• In the previous cost analyses for the 2003 MACT, the EPA used a lifetime for APCDs of 

10 years. However, in the analysis to support this rule, the EPA changed the lifetime used 

in the analysis to 20 years, without justification of documentation. Other costs were 

simply escalated to 2011 dollars.

• The costs are reported in 2011 dollars with no explanation. A rule proposed in 2014, 

promulgated in 2015 and largely implemented in 2018 and 2019 should have been 

estimated in more recent dollar years.

• In one of the telecons documenting a discussion with a vendor (EPA-HQ-OAR-2013-

0291-0221), in which the vendor says that ACI systems would work for brick operations. 

The telecon then discusses the vendor statement, stating, “He said that they sell silos of 

carbon for $500K to $600K.” Instead of following up to get the details of this cost, the 

EPA dismisses this cost because it was reportedly two to three times higher and “may 

have been referring to processes with much higher flow rates than brick kilns.” Instead, 

the EPA took a lower number from a 2005 rulemaking and then still reduced that cost by 

scaling down to the flow rate of an average brick kiln.

• The justification for this less costly approach appears to be due to a second vendor who 

claimed that you could just use a bag of activated carbon and a blower. The commenter 

stated that this is not a practical way to operate a system required for compliance. The 

commenter asserted that facilities would install a storage silo with a reliable, accurate 

injection system with a variable injection rate so carbon isn’t wasted, and they could 

document the carbon flow rate, as required by the proposed MACT. No one would dump 

a bag of carbon in a bin with a blower, especially when they could have to inject 250 

lb/day. In addition, the commenter stated that some of the vendors that the brick industry 

has spoken to have indicated a concern that the addition of carbon could create an 

explosion danger that would need to be mitigated. The algorithm in the Hazardous Waste 

Combustor document is $90,000 capital cost scaled by (flow rate in actual cubic feet per 

minute (acfm)/150,000)^0.7, making the cost for the much smaller flows in a typical 

brick plant about $30,000 for a 30,000 acfm kiln, before escalation to 2011 dollars. The 

commenter stated that it is not appropriate to scale something as simple as the system 

they have casted by size - it would likely be the same size system, you would just get 

deliveries of carbon more frequently for bigger kilns. The commenter noted that this 

algorithm also results in some ridiculous indirect costs for the model kilns (startup $538-

$772, performance test $538-$772, model study $1,076-$1,544).

• The total capital investment is only $102,224 for the small model kiln, which is 

unrealistic and not based on current day facts. The commenter asserted that the EPA 

must, at a minimum, use costs that were provided for this industry and for a system that 

the vendor “believed” would work. The commenter noted that sound science would 

dictate that both the applicability to the industry and the costs should be based on more 
90

than a vendor claims. The commenter noted that mixing costs for one system and claims 

for a more expensive system is bad science and should be corrected in the final rule.

• The EPA appears to use vendor claims that bag degradation will “usually” not occur if 

“the bags are continuously operated above the acid gas dew points.” (p. 6 of Model Cost 

memo) The commenter stated that the EPA apparently uses this to justify costing out a 

fabric filter rather than a dry injection fabric filter for some applications, however, the 

EPA then goes on to use less than continuous operation for both small and large kilns by 

using only 7300 and 7800 hours per year for small and large kilns, respectively. The 

commenter pointed out that there is no way that a kiln operated only those hours would 

remain above the acid gas dewpoints; therefore, the EPA either needs to use 8760 hours 

per year or cost out a DIFF. The commenter stated that there are some documents in the 

docket where the EPA is apparently trying to figure out if they can just use a fabric filter 

to control PM/Hg on a brick kiln and refute industry concerns about the acid gas 

destroying the bags and a concern about bags degrading at high temperature. EPA-HQOAR-2013-0291-0217 is correspondence from Gore that says “HF destroys fiberglass, so 

PTFE bags would be needed if HF emissions are a concern. He noted that PTFE bags, 

unlike fiberglass bags, are chemically inert, but are very expensive, about 2 to 5 times 

more expensive than fiberglass.” The commenter mentioned that there is no difference in 

bag cost between their DIFF model and their standalone FF model. The cost used in the 

analysis is based on the average from Section 114 survey response per cost memo EPAHQ-OAR-2013-0291-0118 Table B-2. The commenter noted that these would not be the 

polytetrafluoroethylene (PTFE) bags. The commenter also asserted that the EPA ignores 

the particulate reduction benefit that stems from the reagent filter cake buildup on the 

bags.

• While it is possible that a straight average of values reported in a 2008 survey would give 

you average operating hours of 7300 and 7800 for small and large kilns, respectively, 

these are not reasonable hours to use for estimating the costs of a system. The average 

hours likely resulted from averaging full operating kilns with kilns that were seasonal or 

only operated a fraction of the year, due to the downturned economy. In addition, as the 

commenter mentioned above, the EPA assumes that the temperature in the systems never 

drops below the dewpoint for the compounds when they determined that a DIFF was not 

needed and they based the rule costs on a DLA. The commenter stated that, as the EPA is 

aware, kilns are designed to remain operating constantly for months or even years once 

they begin operation. To realistically estimate the impacts of a control, the EPA should 

use the more accurate estimate of 8760 hours. If not, the commenter suggested that the 

EPA must cost a DIFF for all applications and not a FF, as the HF and HCl, even in the 

small amounts emitted by a brick kiln would impact the APCD physical integrity and 

greatly reduce the lifetime of the unit.

• The EPA should also use the lower level of operating hours, perhaps as low as 50 percent 

of a full year, to better understand the impacts of these controls on companies with kilns 

that operate only part of the year due to low demand. These kilns are often located at their

smallest businesses that will be most severely impacted by this rule.

Commenter 0543 stated that they conducted a brief survey of the industry to confirm or refute 

other key cost elements used in the cost analysis, the results of which were presented in a 

separate comment letter by Commenter 0542. In the comment letter, Commenter 0542 provided 
91

a summary table (presented below) with several key factors that the commenter asserted the EPA 

had underestimated based on their findings, which provided the high, low, and average value 

obtained in their survey, as well as the number of respondents.

EPA

Number of 

respondents High Low Average

Hours of operation--small 

kiln (hours per year)

7300 7 8760 8760 8760

Hours of operation--large 

kiln (hours per year)

7600 7 8760 6840 8405a

Electricity cost ($/kWh)b 0.07 19 0.143 0.055 0.083

Waste disposal cost ($/ton) 40 12 100 10 51.9

Limestone ($/ton) 40 12 120 10 58.17

Compressed air cost 

($/1000 ft3

) c

0.024 3 0.4 0.3 0.363

a The commenter stated that the use of an average for this value is misleading, as 5 of the 7 respondents reported operating hours 

of 8760 and only 2 reported something other than 8760.

b kWh = kilowatt-hour

c ft3 = cubic feet

Commenter 0523 stated that the EPA underestimated the time and cost it will take for their 

company to implement this rule. The commenters requested that the EPA accept the information 

from their operations, along with other facilities within the industry, and develop more accurate 

estimates for implementing this regulation. The commenters believed that the actual costs are 

unreasonable and unjustified giving the questionable ability for the untested controls to actually 

result in emission reductions. The commenter listed some examples of the EPA’s 

underestimations:

• The EPA assumed that it takes about 2 hours per shift to operate a control device, with 

one hour of maintenance labor and 9 minutes of supervisory involvement.

• The EPA assumed that control devices will last for 20 years and that the bags on limebased systems will last for 5 years before they need replacement.

• The EPA assumed no turnover or need for retraining for APCD operators.

• The EPA assumed that they would have staff with enough technical expertise and 

available time to implement this regulation.

• The EPA estimates did not account for the higher costs associated with the use of outside 

consultants, which would need to be utilized by small companies such as theirs.

Response 1: The EPA disagrees with the commenters’ argument that EPA incorrectly reduced 

the burden estimate for the proposed MACT by more than 90 percent from the estimate provided 

during the SBREFA panel review. The commenters’ argument is based on a faulty comparison. 

The commenters mistakenly compared the $188 million capital cost provided during the 

SBREFA panel review with the $18.4 million annual cost stated at proposal. The capital cost 

stated at proposal was $54.9 million. The difference in the $188 million and $54.9 million capital 

costs is due to several factors. The $188 million cost estimate was for straight MACT floors for 

both acid gases and PM, did not include compliance flexibilities such as the health-based 
92

standard for acid gases, and did not account for the expectation at proposal that facilities would 

install less expensive DLAs to become synthetic area sources rather than install more expensive 

DIFFs to meet the MACT limits.

The EPA disagrees with Commenter 0543’s objection to the assumptions used in the proposal 

cost estimates. The cost memoranda document the assumptions that had to be made where EPA 

did not have data. The commenter referred to these assumptions as “unsupported” but did not 

provide anything better that EPA could use instead.

The EPA also disagrees with Commenter 0543 that EPA’s change of APCD lifetime from 10 to 

20 years was unjustified and undocumented. In fact, the reverse is true. We reviewed the 

documentation cited for the APCD costs for the 2003 MACT and could find no basis for the 10-

year equipment life that was used at that time. The OAQPS Control Cost Manual suggests an 

equipment life of 5 to 40 years for baghouses, with 20 years being typical. Consequently, a 

typical 20-year equipment life was used in the proposal costs. Regarding the comment about 

documentation, the model cost memorandum clearly states that DIFF costs were estimated 

following guidelines in the OAQPS Control Cost Manual, which includes equipment life.

Regarding Commenter 0543’s comment concerning the 2011 base year for proposal costs, the 

proposal costs were provided in 2011 dollars because, at the time that costs were first being 

developed for the proposed rule, 2011 was the latest year for which an annual cost index value 

was available for scaling costs. 

The EPA agrees with the changes to the operating hours suggested by Commenter 0543, and we 

have revised the costs to use the 8,760 hours per year suggested by the commenter from the 

results of their 2015 survey of the brick industry. We have also revised the costs to incorporate 

the suggested unit costs for electricity, waste disposal, limestone, and compressed air from the 

commenter’s 2015 survey results.

Regarding Commenter 0543’s objections to the proposal ACI costs, the ACI costs were 

developed based on the best information available from vendors and were extrapolated to apply 

to the BSCP model sizes using standard extrapolation methods. While the commenter provided 

specific objections to the ACI costs in their public comments, the commenter did not provide any 

changes specific to the ACI costs that can be incorporated into the costs for the final rule. 

However, we have incorporated the commenter’s suggested changes regarding operating hours, 

electricity cost, and waste disposal cost into the final ACI costs.

Commenter 0523 argued that EPA underestimated the cost to implement the rule and provided 

some examples of what they considered EPA’s underestimations. The commenter requested that 

EPA accept the information from their operations. However, the commenter did not provide any 

specific changes in their public comments.

Comment 2: Multiple commenters (0514, 0516, 0518, 0520-0523, 0529, 0536, 0537, 0545, 

0550-0553, 0555, 0556, 0557, 0558, 0559, and 0562) stated that the proposed rule represents 

unreasonable and unwarranted levels of control for PM, Hg and non-Hg metal HAPs that are too 

expensive for the industry. The commenters argued that installing and operating controls for PM, 
93

Hg and non-Hg metal HAPs could cripple their facilities and the industry as a whole, while 

providing little to no protection to the environment. 

Commenters 0514, 0522, 0527, 0557, and 0558 argued the controls necessary for PM, Hg, and 

non-Hg HAPs are not cost effective. Commenters 0514 and 0522 noted that the costs for 

installing and operating DIFF on a small uncontrolled kiln will require capital costs of

$1,368,356 million and annual operating costs of $437,121. This would result in an average 

emission reduction of 170 pounds of PM HAP and less than 3 pounds of Hg. The cost 

effectiveness of the Hg and PM is $7,422,000 per ton, while the effectiveness of Hg alone just 

under $471,268,000 per ton. The commenters noted that these costs are based on using DIFF, 

because the commenters believed that a FF will not work.

Commenter 0557 noted the HAP reductions for Hg and non-Hg metal HAP total less than 4 tpy

and that the average cost would be $4,750,000 per ton of HAP reduced. The commenter noted 

that the remaining 336 tons of HAP reduction claimed as a benefit of this rule is HF and HCl, 

which the EPA demonstrated do not impact human health and the environment in the quantities 

emitted. This commenter suggested the EPA reassess whether the rule is justifiable given the 

costs of this rule compared to the benefits. 

Commenter 0527 stated the EPA’s estimate of the cost to install and operate FF ($1.22 million 

with an annual operating cost of $544,000) is too expensive for their company.

Commenter 0558 stated that their company has multiple kilns that do not have control devices 

but may be required to purchase and install control devices to comply with the Hg and non-Hg 

metal/PM limits. Even if their kilns meet the acid gas emission limit without controls, the 

commenter noted that the limits for Hg and non-Hg metal/PM emissions would still require them 

to purchase and install control devices. This would mean that millions of dollars will be spent to 

control emissions that represent less than 1 percent of the HAPs originally considered for 

regulation in this rule. The commenter recommended the EPA consider the costs for situations 

where a plant must install a DIFF with lime and activated carbon injection to meet the Hg and 

non-Hg metal/PM limits. Commenter 0518 stated that the ability of clay brick manufacturers to 

meet the proposed Hg and non-Hg metals has been over simplified and is a costly item. 

Some commenters (0518 and 0537) thought the EPA’s cost estimates were oversimplified and 

unrealistic, and asserted that EPA had underestimated the true costs of installing and operating 

controls. Commenter 0537 noted the EPA based costs on operating hours of 7300 and 7800 

hours per year for small and large kilns, respectively. This commenter stated that kilns are 

designed to operate continually and the average used by the EPA appears to be based on a kiln 

that only operated for a fraction of the year.

Commenter 0559 expressed concern that the costs of control devices will make their product less 

desirable and that they would need to make changes to all the product styles.

Commenters 0514, 0522, 0559, and 0563 stated that the controls are unproven and some of the 

controls may not work. These commenters stated that if there is no assurance the controls will 

work, there can be no assurance that the limits will be met, and a huge amount of money could 
94

be spent for nothing.. Commenter 0563 asserted that fabric filters with carbon injection has never 

been used in their industry, therefore, there is no assurance that it would technically work. 

Commenter 0537 stated that the controls are not demonstrated since no one has installed a fabric 

filter after a DLA in the brick industry. This commenter also noted that no one has ever installed 

a standalone fabric filter without the dry injection system. Commenter 0527 noted that the FF for 

PM control has never been used at a brick plant and may not be feasible. 

Commenter 0537 stated that the control devices they currently have installed (all DIFFs and 1 

DLA) demonstrate very limited if any Hg reduction. They further noted that in one case of 

concurrent inlet and outlet testing, the Hg emissions were slightly higher at the control outlet. As 

a result, the commenter questioned the EPA’s modeling results and asked what the cost of 

controls would be if they can’t make the limit using the modeled add on controls.

Response 2: Regarding commenters’ objections to the high cost effectiveness of meeting the 

limits for PM, Hg and non-Hg metal HAPs, while cost cannot be considered a factor for MACT 

floor standards, EPA has revised the Hg emission limits for the final rule based on information 

received from the industry, which is estimated to reduce the number of sources subject to the 

limits and thereby reduce the compliance costs. Regarding commenters’ claims that the emission 

controls needed to meet the limits may not be feasible, the commenters have not provided 

specific data to demonstrate the infeasibility of the emission controls, which have been 

demonstrated for similar sources, e.g., Portland cement kilns.

Comment 3: Commenter 0539 commented on the cost of Hg sampling for compliance with the 

Brick MACT. The commenter mentioned the EPA suggested the testing be done by EPA Method 

29. The commenter noted that the sampling costs for 3 runs and blanks coupled with the pre-test 

cleaning and calibrations are $6,900 including a normal report, and the analytical costs for the 

samples and blanks are $2,000. The commenter stated that these costs include the method stated 

blanks and the field/proof blanks that should be included. The commenter stated the new 

requirements are Audits ($1,000), ERT ($2,000) and Compliance and Emissions Data Reporting 

Interface (CEDRI) ($2,000), which makes the total cost about $15,000.00 per test. The 

commenter stated that method 29 is one of the more expensive test methods. The commenter 

stated that this cost does not include the other metals that might be required, and suggested that 

the EPA needs to adjust all of their cost estimates to include realistic costs.

Response 3: The EPA agrees with the commenter’s request and has revised the testing costs for 

the final rule to incorporate the additional cost items mentioned above. 

Comment 4: Commenter 0543 stated that the EPA assumed numerous facilities are already or 

will become synthetic minor/area sources if they have existing APCD on all tunnel kilns within 

the facility. According to the commenter, the EPA stated that the sources would already be 

synthetic area/minor sources and not subject to the MACT because the change could be made “at 

little to no cost” and then accounted for no costs from these sources. The commenter asserted 

that this is not valid because such facilities would need to conduct stack tests to verify emissions, 

develop a permit application, and develop and implement a program to implement the permit 

requirements. The commenter suggested that these costs would not be incurred in the absence of 

the rule and must be considered as costs imposed by this rule. This commenter mentioned that 

the EPA’s approach also ignores the following additional concerns that must be addressed:
95

• According to the EPA, if the tunnel kilns are co-located with periodic kilns, the periodic 

kiln emissions must be included in the determination of major source status. There is no 

evidence in this memorandum that the EPA included emissions from co-located periodic 

kilns in their analysis.

• According to the EPA, the remainder of the EPA’s assessment basically concludes that 

virtually all small kilns can meet the proposed rule. If the EPA makes this assumption, it 

is unclear why a facility would unnecessarily take a limit that could potentially impact 

future growth.

• According to the EPA, a synthetic minor/area permit can also have an impact on future 

growth and can also add to a facility’s reporting burden as some states have different 

requirements for sources that are attempting to remain below regulatory limits. The EPA 

cannot simply assume that a facility that has thus far elected to remain a major source has 

not considered the options and chosen to remain a major source.

Commenter 0543 suggested that any potential cost savings would need to be considered and 

weighed against the impacts of becoming synthetic minor/area. The commenter noted that it 

appears that the EPA’s assumption reduced the annual cost of the rule by less than $2 million per 

year, less than other assumptions discussed in this section, however, the assumptions seemed to 

be used to provide the EPA with virtually all of the benefits claimed by this rule. The commenter 

noted that, in total, the 14 sources assumed to install DLAs to avoid the rule provide 87.7 percent 

of the annual HAP emission reduction claimed by this rule (386 tons of the 440 tons),23 as well 

as 99.6 percent (254 of the 255 tons) of the annual SO2 reduction. The commenter suggested the 

EPA reassess the potential for sources becoming synthetic area/minor sources, and greatly 

reduce the number of kilns assumed to do this. While it is a viable approach that the industry will 

consider, the commenter asserted that the EPA’s analysis does not address the real evaluations 

that must be considered. While 14 sources is not a large percent of the industry, it represents 25 

percent of the sources that the EPA had determined would otherwise be subject to the Brick 

MACT. The commenter also questioned whether the ability for the sources to borrow the money 

to “avoid” the rule was included in the Regulatory Impacts Analysis.

Multiple commenters (0516, 0518, 0521, 0522, 0523, 0528, 0536, 0543, 0545, 0550, 0555 0556,

and 0557) argued that EPA has oversimplified or does not understand the complexity of the 

decision to become a synthetic minor/area source. While companies will evaluate whether 

installing a DLA to become a synthetic minor source is a possible and less expensive option,

other factors must be addressed. Commenters gave the following reasons for this assertion:

• A facility could not make the determination of non-major status exempt from the MACT 

requirements without completing stack tests.

• Becoming a minor source can be an expensive proposition. At the June 2013 SBREFA 

meeting, the costs to “opt-out” were estimated as $2.6 million with annual operating 

expenses of $800,000. Commenter 0522 suggested the EPA refer to the attached 

comments submitted after the June SBREFA meeting.

 23 An additional 46.8 tons of the HAP emission reduction (10.6 percent) is shown by EPA as coming from gaseous 

HAP emission reductions from one facility needlessly removing an ESP/SD and replacing it with a DIFF to meet the 

HCl equivalent standard. This facility models as well below the level established by EPA as safe, but would be 

required to install a control nonetheless to meet the HCl equivalent limit.
96

• One commenter observed that the kiln exhaust stack temperature for one of their kilns 

never/rarely reaches 300 degrees F, the temperature at which the EPA states facilities 

must stop venting to the control device to avoid damaging the system.

• State agencies can impose additional permit limits, special requirements, and restrictions 

on facilities that become synthetic minor/area sources. The commenters asserted that 

these restrictions and special requirements would limit their ability to respond to market 

changes and grow if demand for their product increases.

• The majority of the small kilns in the EPA’s analysis have never been stack tested. Even 

though the EPA used slightly more conservative assumptions for facilities with no test 

data, there is no assurance that a facility would be able to comply with the synthetic 

area/minor emission levels without a stack test and any regulatory authority would 

require such a test.

• There may be additional state limits and restrictions that, should they become a synthetic 

minor, may limit their ability to respond to market changes.

• Switching back to a major source would be burdensome and costly, if a company 

becomes a minor source and then needs to expand. 

• Some companies currently have facilities with a DLA (installed as a result of the first 

NESHAP) that will not meet the synthetic minor source definition and will require 

additional controls.

• Commenter (0528) stated that, while their company is operating a dry limestone absorber, 

DLA, on one kiln, they also have two small uncontrolled kilns that would also need to be 

controlled to consider this option.

• Companies would need to evaluate whether they could comply with the MACT limits 

before they expend any effort to determine whether they could become a synthetic minor 

source.

• Commenter 0528 stated that they have heard of cases where a state will include 

additional restrictions on plants that request synthetic minor source status and that these 

restrictions limits the facilities ability to fully operate and grow. The commenter asserted 

that such operating limits would affect a company’s ability to survive long term because 

they must be able to grow their business. 

Multiple commenters (0516, 0521, 0522, 0523, 0536, 0537, 0543, 0548, and 0550) stated that 

DLAs are not effective if SO2 and HCl concentrations are too high. Another commenter stated 

that DLA would be impractical for plants that use clay that is very high in sulfur due the high 

sulfur dioxide concentration. Before considering installing a DLA, the commenters stated that 

they would need to evaluate their overall stack emissions and determine whether a DLA is a 

viable option. The commenters noted that, according to one vendor experienced with the brick 

industry, SO2 emissions above 18 ppm would make DLAs impracticable [see docket for 2003 

Brick MACT, Docket A-99-30, Item IV-H-5], which means that the more expensive DIFF option 

would be required for many sources, resulting in additional capital expenditure. Therefore, 

before making multimillion dollar decisions, the commenters asserted that companies would 

have to evaluate far more information than the EPA considered in their analysis.

Commenters asserted that they would need to consider all of these factors when deciding how 

best to approach compliance with the proposed Brick MACT.
97

Commenter 0557 stated that installing a DLA to become a synthetic minor source was a 

reasonable approach, but questioned why they should be asked to install a DLA to control other 

pollutants (HF and HCl) that do not have a significant impact on human health or the 

environment, when the DLA would not control Hg and non-Hg hazardous air pollutants. This 

commenter noted that installing the DLA would be a multi-million dollar cost that may put the 

facility out of business.

Five commenters (0521, 0523, 0536, 0537, and 0550) suggested the only reasonable approach 

for evaluating the impacts of the rule, was to assume all impacted plants would be required to 

install a DIFF with ACI unless comprehensive test data for that plant is available to demonstrate 

otherwise.

Response 4: The EPA agrees with the commenters that the cost to become a synthetic area 

source should include the cost to conduct a stack test to verify emissions. Consequently, we have 

revised the cost to include the cost of Methods 26A and 29 testing for tunnel kilns. Because 

testing for periodic kilns is considered technically and economically infeasible, facilities would 

be expected to estimate their potential-to-emit through other means (e.g., emission factors), so no 

testing cost would be applied to periodic kilns.

The cost to apply for a permit modification would vary from facility to facility, depending on 

their location and how close they are to permit renewal. If the facility is in the last 2 years of its 

permit, then the permit would simply be revised during the next permit renewal, with no 

additional cost expected. If the facility is in the first 3 years of its permit, then the permit would 

need to be revised prior to the compliance date 3 years after promulgation, with no additional 

cost expected above what would be incurred if the facility decided to comply with the rule.

Any impact of this option on the potential future growth of a facility would be hypothetical and 

cannot be estimated. Similarly, the impact of any additional compliance requirements that a state 

might potentially inflict also cannot be estimated.

Regarding the comment about the viability of DLA installation if sulfur oxides (SOx) stack 

emissions are >18-20 ppm, the amount of sulfur in the raw materials would be very site-specific, 

even within a particular site, and the commenters have not provided any specific information to 

the EPA in their public comments to enable the EPA to include such information in its analysis. 

With the addition of Method 26A/29 testing costs, we have reevaluated the potential for sources 

to become synthetic area sources and revised the cost analysis accordingly. The results are 

documented in the nationwide impacts memorandum for the final rule.

The Regulatory Impact Analysis has also been revised for the final rule to consider the ability of 

sources to borrow the funds necessary to install controls to become synthetic area sources. The 

results are documented in the final RIA.

Comment 5: Commenter 0543 stated while the use of sources with data as a predictor of 

compliance percentage for units with no data has a history in MACT development, it must be 

used with caution. It is important to consider the population of sources that are being evaluated 
98

to ensure that the types of sources are reasonably similar and that the data has a reasonable 

potential to predict the likely outcome of remaining sources. The commenter stated for example, 

when evaluating the ability to comply with the PM limits, the EPA grouped kilns by control 

status and evaluated percent of sources with data meeting the proposed limit within these distinct 

categories; it is impossible with the data provided in this memorandum to calculate the percent of 

kilns within the category with stack data since the EPA changes between the number of sources 

in the category and the number of sources in the industry interchangeable and generally without 

explanations.24 However, the commenter recognizes that there is a reasonable population of data 

for large kilns and concur that it is reasonable to assume that the PM data for DIFF and dry lime 

scrubber and fabric filter (DLS/FF) controlled units that meet the standard represent a reasonable 

estimate of the number of similarly controlled kilns without data that would be able to meet the 

limits; however, the EPA should assess whether these assumptions make sense each time they 

use them and use more conservative approaches, as necessary, to ensure that they are not 

irresponsibly lowering their burden estimates.

Commenter 0543 stated the EPA should not base the ability for all 77 small, uncontrolled kilns 

to meet the Hg standard on a single stack test of a controlled kiln, even if that control is 

“believed” to not control Hg. This is particularly egregious when a single test was the only test 

used to set the standard. The commenter stated it is clear that the stack test that was used to set 

the emissions limit would meet the standard based on that single stack test; however, that same 

facility has identified that the brick being produced on the day of the test do not represent the 

material believed to be the highest Hg emitting; therefore, this same kiln may not be able to 

demonstrate compliance with the current limits if the test were to be conducted with a different 

product.

Commenter 0543 stated using the fact that the stack test for the single tested small kiln could 

meet the limit that was calculated based on that stack test, the EPA assumed all small kilns could 

meet the standard, thus avoiding inclusion of any Hg controls on 77 small kilns; without this 

assumption, the EPA would have had to include the cost, at a minimum, to install and operate a 

FF and ACI system. The commenter asserted a DIFF with ACI would be need to be costed out 

for this scenario, although the commenter continued to assert that there is no data to support the 

EPA’s assumption that these controls could reduce Hg to the proposed limits. The commenter 

stated the EPA does not even present the costs of a DIFF with ACI option on a small kiln in the 

memorandum; the EPA estimates that the FF alone would cost $1.2 million control, with an 

annual cost of $437,849. The commenter stated an ACI system for a large kiln is estimated by 

the EPA to cost $146,697 in capital costs with annual costs of $96,482. The commenter asserted 

that these costs are an underestimate for a large system, as well as a small system. The 

commenter used the large kiln ACI cost as an estimate for a small kiln to calculate cost 

effectiveness; using the available the EPA costs, installation of a DIFF with ACI on a small kiln 

 24 Table provides the Nationwide Baseline Estimates for the source category; however, when assessing data, EPA 

considered the entire industry, including synthetic minor sources that are not part of the regulated category. 

Therefore, for example, Table 3 lists 14 DIFF or DLS/FF controlled kilns in total for the category, but Table 5 lists 

28 DIFF or DLS/FF having data.
99

would cost $534,331 annually to reduce approximately 0.00136 tons (2.7 pounds) for a cost 

effectiveness of $393 million per ton, if ACI would even work for brick sources.

Commenter 0543 stated because there is no Hg testing for uncontrolled small kilns, there is no 

way to able to accurately predict at this time what percent of the facilities would be able to 

comply with this standard. The brick industry has begun a raw material testing program to begin 

to assess the potential compliance;25 based on preliminary review of the data, the commenter 

asserted that some fraction of small kilns will be able to comply with the standard, but the Hg

study is not complete. The commenter stated those that cannot meet the standard will face these 

astronomical costs that the EPA ignores in their analysis.

Commenter 0543 asserted that it is wrong for the EPA to assume 100 percent of small kilns can 

achieve compliance with the Hg standard; the ability to comply or not comply will completely 

depend on the amount of Hg that was deposited in the mined material millennia ago. The 

commenter stated if a facility cannot meet the limit without control, they will either have to 

install the control listed above and hope that it works, attempt to become a non-major source if 

that is possible, or cease operations.

Commenter 0543 stated similar to small kilns, the EPA grouped uncontrolled and controlled 

large kilns into a single evaluation; this time the EPA has data from 18 DIFF-controlled kilns and 

found that 16.7 percent met the lb/ton limit and 55.6 percent met the concentration limit. The 

commenter stated the EPA then applied 55.6 percent to all categories of large kilns to arrive at 

the number of kilns that they believed could meet the standard; without a determination that a 

DIFF achieves no Hg control, there is no justification for applying this percentage to any other 

group. In fact, absent data, the commenter stated the EPA should take the conservative approach 

of assuming that no kiln meets the Hg limits; at most, the lower percentage of 16.7 might be 

used; however, there is no real basis for its application.

Commenter 0543 stated this highlights the brick industry’s concern that there is simply 

insufficient data available to justify a numeric limit for Hg at this time; absent more data, the 

EPA must assume a higher percentage of noncompliant sources and accept that the potential cost 

of this rule is far higher than they stated in the proposed rule.

Commenter 0543 listed some additional assumptions made in the “Development of Cost and 

Emission Reduction Impacts for the BSCP NESHAP” memorandum that apparently have data 

support; while the commenter understands that assumptions need to be made, the commenter 

requests that the EPA provide some justification and support in the final memorandum to support 

this rulemaking.

Commenter 0543 stated for large kilns with a DIFF or DLS/FF, it was assumed that the kiln 

stack not meeting either the PM lb/ton or concentration limits would meet the total non-Hg HAP

metals lb/hr limit.

• There is no reference to a memo or data that supports this assumption.

 25 See BIA MACT TF letter submitted by Terry Schimmel and Irene Kuo for more information on this study.
100

• The EPA based the lb/hr limit on an average percentage of the best performing sources in 

the floor pool; taking an average of the best performing sources further biases the data 

set. The commenter did not assert that this is the correct approach since it would 

automatically mean that anyone above this “average” metal content would be out of 

compliance with the rule. The commenter asserted that this overstates the number of 

sources that will comply with this limit format.

• The high potential for problems Test Method 29, used for metals measurements, such as 

permanganate contamination, could further challenge sources to demonstrate compliance 

with this alternate limit.

Commenter 0543 stated for large kilns with a DLA, it was assumed that one of the kiln stacks 

not meeting the Hg lb/ton or concentration limits would meet the Hg lb/hr limit; it was also 

assumed that this kiln stack is one of the 12 stacks that can meet one of the PM limits, so no FF 

would be needed.

• No basis or reference to a memo or to data that supports that this one kiln can meet any 

one of these numbers; since the two emission rates were established from completely 

separate populations of sources, there is absolutely no data to support that both limits 

would be able to be met by the same source.

Commenter 0543 stated based on the results of the analysis described in Section III of this 

memorandum, a total of 12 large uncontrolled kiln stacks are located at facilities that could 

become synthetic area sources with installation of a DLA on those stacks; for large uncontrolled 

kilns, it was assumed that owners or operators of three-fourths of these kiln stacks, or nine total 

stacks, would elect to install a DLA. The commenter stated to be conservative, it was estimated 

that most of the remaining kiln stacks would not be able to meet any of the Hg limits.

• In other areas of this memo, the EPA assumes that all who could potentially meet the 

synth levels automatically do; while assuming that only 75 percent meet it may be 

slightly more conservative, there is again, no basis for even this high an assumption 

provided by the EPA.

Commenter 0543 stated it was expected that most small uncontrolled kilns would be able to meet 

the total non-Hg HAP metals lb/hr limit and would not need to install DLA to become a 

synthetic area source; therefore, for small uncontrolled kilns, it was assumed that a little over 5 

percent of the total kiln stacks, or five total stacks, were located at facilities that would elect to 

become synthetic area sources by installing a DLA. The commenter stated it was also assumed 

that 21 of the 24 remaining kiln stacks not meeting the PM lb/ton or concentration limits (88 

percent) would be able to meet the total non-Hg HAP metals lb/hr limit.

• There is no basis provided for any of these numbers; the decision to become a synthetic 

area source is complicated and not without limitations.

• The metals percentage used for this calculation was not based on the subset of small 

kilns, further weakening any rationale for its use.

Response 5: When the EPA does not have emissions data for all sources that are expected to be 

affected by a rulemaking, some assumptions and estimation procedures are necessary to estimate 
101

the cost and emission reduction impacts of the rulemaking on those sources. The assumptions 

and estimation procedures are based on the best information available at the time. However, 

where data are not available and there is not a clear “best” estimation procedure, the EPA must 

use best engineering judgment to complete the analysis. Some of the assumptions noted by the 

commenter are the result of engineering judgment based on experience with air emission controls 

from similar industries. The EPA does note that some assumptions and calculations were updated 

for the final rule analysis, including the incorporation of Hg content in raw material samples 

provided to the EPA by BIA. The methodology that the EPA used for the final BSCP 

Manufacturing NESHAP is documented in Development of Cost and Emission Reduction 

Impacts for the Final BSCP Manufacturing NESHAP in Docket ID No. EPA-HQ-OAR-2013-

0291.

26

Comment 6: Commenter 0543 stated that there are several places within the cost and emission 

reduction impacts memorandum where numbers do not agree with previous tables. The 

commenter asserted that the EPA does not clearly state when the population they are counting 

includes only those major sources in the regulated source category and when they are referring to 

the entire industry. The commenter disagreed that the EPA uses these terms interchangeably, 

especially when looking at the MACT floor for existing sources. However, the commenter noted 

that it is clear that the EPA understands that these are two distinct populations when determining 

the impacts of the proposed rule. The commenter suggested that EPA clarify the table headings 

or footnotes to indicate which group they are summarizing in each table.

In addition, Commenter 0543 noted the following apparent typos in the memorandum:

• Table 3 indicates a total of 75 small kiln stacks (out of a total of 150) with one vented to a 

DIFF; Table 4 shows 79 small kiln stacks (out of a total of 132 stacks, reduced based on 

first “synth” cut) with 1 vented to a spray dryer with ESP (SD/ESP); Table 5 repeats the 

numbers contained in Table 4.

• Page 5 states that 15 of 86 would become synthetic sources; Page 8 says 14 sources 

would become synthetic area sources.

• Table 6, p 9, has a typo- the large kiln, DIFF line indicates 4 kilns would install ACI , but 

the total in that column is only 3.

• Table 7 indicates that 3 small kilns would need to install a FF to comply with the rule 

(this is supported by the text that states that “21 of 24” would meet the hourly rate). 

However, the next two tables include only 2 small kilns.

Response 6: The EPA agrees with the commenter that the population counts should be clear in 

the memorandum documenting costs and emission reduction impacts. The memorandum for the 

final rule, Development of Cost and Emission Reduction Impacts for the Final BSCP 

Manufacturing NESHAP in Docket ID No. EPA-HQ-OAR-2013-0291,

27 includes revisions to 

clarify those populations.

 26 Sroka, K. Development of Cost and Emission Reduction Impacts for the Final BSCP Manufacturing NESHAP. 

Memorandum from Kristin Sroka, RTI International, to Sharon Nizich, EPA/OAQPS/SPPD. September 24, 2015. 27 Sroka, K. Development of Cost and Emission Reduction Impacts for the Final BSCP Manufacturing NESHAP. 

Memorandum from Kristin Sroka, RTI International, to Sharon Nizich, EPA/OAQPS/SPPD. September 24, 2015.
102

Specific apparent typos are addressed below:

• The difference between Table 3 and Table 4 is related to the difference between kiln size 

and APCD size. Two small kilns vented to one stack may have a large enough capacity to 

require a “large” size APCD. Table 3 is grouped by APCD size, and Table 4 is grouped 

by kiln size. For example, the SD/ESP controls multiple small kilns with a combined 

capacity large enough that the APCD is modeled as large. Therefore, it shows up as a 

large APCD in Table 3, but as controlling three small kilns in Table 4. We note that this 

difference was explained on page 11 of the memorandum, and we agree that the concept 

should be introduced earlier. Therefore, it has been moved in the final memorandum.

• The commenter is correct that the numbers of potential synthetic area sources and the kiln 

stack summations were not consistent at proposal; the errors have been fixed for the final 

version.

• Again, this is related to the difference between APCD size and kiln size. The total 

number of FF expected to be installed is four in both Table 7 and Table 8, and the bottom 

of page 11 explains that Belden Brick Company’s facility in Sugarcreek, Ohio, operates 

one of the small kilns that would not be able to meet the PM limit and would need a FF. 

This kiln is co-vented with two other small kilns though, so for the purposes of this 

analysis, it was assumed that a large FF would be needed on one of the small kiln stacks.

15.2 Economic Impacts

Comment 1: Numerous commenters (0515, 0527, 0529, 0532, 0534, 0535, 0538, 0556, 0559, 

0560, and 0562) expressed concern about the economic impacts the proposed rule could have 

on their companies and the industry as a whole. Three commenters (0515, 0532, and 0538) 

argued the proposed rule is overly stringent and would force brick manufacturers to install 

unnecessary air pollution control devices. The commenters argued that the high costs of control 

devices would do irreparable harm to the industry by causing some companies to take on large 

amounts of debt and many businesses to close. Commenter 0559 stated that their plant will be 

unable to add even a small kiln because the proposed standard would impose an “unbearable 

economic burden.” Other commenters indicated their companies have been impacted 

substantially as a result of the economic downtown and will be further impacted by the proposed 

rule. Commenter 0523 noted that obtaining financing for controls would hurt a company’s ability 

to obtain future financing for other projects, such as cost saving capital projects or 

expansion. This commenter also noted that incurring the amount of debt necessary to finance 

control devices would impede a small company’s ability to weather future economic downturns. 

Many small companies in his industry, borrowed to finance expansions and other plant 

improvements before the last recession. More than a few of them went into bankruptcy, 

foreclosure, liquidation, or were forced to sell their plant to a large corporation because of that 

debt. Commenter 0556 argued the industry has already suffered the consequences of a poorly 

supported and constructed rule due to the previous MACT being vacated in 2007. They noted 

that their company installed 10 controls at its brick manufacturing facilities and spent 

considerable resources ensuring compliance with the MACT prior to the rule being vacated. 

Commenter 0538 noted that the proposed rule would require kiln refurbishing that could cost up 

to two million dollars per kiln and cripple their industry. For their industry to make up two 

million dollars, the commenter noted that each kiln would have to produce at least 7 million 
103

extra bricks each, but doubted there would be demand due to continuing economic weakness in 

the construction sector.

Commenter 0559 stated that the rule would prevent their company increasing production because

if they build a new small kiln or replace their existing kiln they would have to install costly 

control devices that may not even work. They argued that the proposed rule prevents them from 

becoming more efficient and more competitive.

Commenter 0560 argued that companies would have to finance multi-million dollar controls that 

have not been demonstrated to be effective in the brick industry. If the controls are installed and 

fail to perform as assumed, companies would have to close.

Many commenters (0518, 0522, 0523, 0529, 0530, 0531, 0548, and 0563) stated that their 

companies may be unable to obtain the financing for add-on controls and may be forced to close.

Several commenters (0522, 0518, 0523, 0548, and 0563) indicated the funding required to add 

controls may not be available to small businesses. These commenters argued that such loans are 

not available for projects that do not increase production, enhance their product, or increase 

quality. Commenter 0518 stated that their recent experience indicated it would be impossible for 

their company to borrow enough money for control devices. Another commenter stated that their 

company has been under strict borrowing limits since 2008 and have had to internally finance 

any equipment replacements or upgrades. They noted that although they were able to recently 

obtain $4 million for new equipment, this financing was possible because they were able to 

demonstrate that the purchase had a 3-4 year payback. Equipment financing without an economic 

benefit that will pay back the loan is currently not available to their company through normal 

banking channels. Commenter 0548 stated that financing the controls would be out of range for 

small businesses and noted that their company recently had to seek protection under Chapter 11.

Other commenters (0518, 0531, 0515, 0527, 0531, and 0532) stated that they may have to close 

the plant if they are unable to obtain a loan. Commenter 0531 also noted that the economy for the 

last 8 years has been extremely hard and stated that the financial burden placed on their company 

by adding Hg controls could mean the end of their company. The commenter was not sure that a 

bank would be willing to loan them 7 to 8 million dollars based on their financial situation over 

the last 8 years.

Two commenters (0518 and 0531) were concern about the cost of compliance with the Hg and 

non-Hg metals standards.

Commenter 0529 argued that small kilns with production under the 10 ton/year threshold should 

not be required to install and operate expensive control devices. This commenter noted their 

company spent millions of dollars to upgrading their existing plants but keeping their existing 

kiln in order to remain “under 10 tons per hour” to meet the definition of a small kiln. Without 

this limitation, they would have built an entirely different facility that would have been larger 

and more efficient. This commenter also noted that they have heard from a vendor that the costs 

for controls on kilns operating at less than 10 tons will be about the same as controls for a kiln at 

10 ton per hour. The commenter asserted it is definitely not cost-effective to install control 

devices on small kilns such as theirs -- existing or new.
104

Two commenters (0535 and 0559) asserted that the costs of installing and operating controls 

could not be passed onto their customers. The commenters stated that in today’s still recovering 

construction environment, passing on the costs of controls is not feasible.

Two commenters (0531 and 0532) asked the EPA to take a hard look at the costs and find a way 

to keep small family businesses viable, while still meeting the requirements of the CAA. 

Response 1: The EPA has been informed that firms may have difficulty obtaining longer-term 

financing needed to buy the control equipment and make process changes needed to comply with 

the proposed standards. Firms may not have cash on hand or the ability to convert assets into 

cash in order to make these purchases; as a result, firms would have to consider other long-term 

financing options. Affected firms are less likely to be publicly traded and thus would be more 

likely to consider debt versus equity options. The additional liabilities can put firms at additional 

risk of closure if market conditions do not improve during the period when the rule is adopted. In 

addition, if creditors are concerned about existing or future market conditions in the brick 

industry, they may be less willing to enter a loan contract or may require higher rates of interest 

than the 7 percent interest rate used to annualize the capital costs associated with the rule. The 

EPA estimates of the range of the number of ultimate parent companies that may close rather 

than comply with the regulation may be an underestimate because of the difficulty in obtaining 

financing at a 7 percent interest rate. The estimates might be an overestimate if the industry has 

become more robust by 2018 when the control must be in place. The closure estimate did not 

include net effects on revenue due to price increases or reductions in sales attributable to the 

regulation.

Overall market impacts for the standard are estimated to be a less than 2 percent national average 

price increase and a less than 2 percent national average reduction in production. Please see the 

RIA, Regulatory Impact Analysis: Final Brick and Structural Clay Products NESHAP found in 

the docket for more details.
105

16.0 Statutory and Executive Order reviews

16.1 Executive Orders 12866 and 13563

Comment 1: Commenters 0530 and 0543 stated that the requirements of Executive Orders (EO) 

13563/12866 were not met by this proposal because EO 13563 “Improving Regulation and 

Regulatory Review,” which supplements and reaffirms EO 12866 “Regulatory Planning and 

Review,” requires all federal agencies to adopt the least burdensome regulations that obtain 

regulatory objectives. EPA has failed to meet these requirements in this rulemaking since a 

significantly less burdensome option that achieves indistinguishable benefits exists, but was not 

proposed by EPA. While the EPA requested comment on a lower-burden alternative that would 

require work practices rather than a numeric limit, the alternative was not the option selected by 

the EPA for the proposed rule language. Compliance with the proposed numeric limit poses a 

significant economic burden for this industry and needlessly threatens the viability of numerous 

small businesses. However, EPA has not provided any information to support that the more 

burdensome numeric limits creates any additional environmental benefit. Besides simply 

relieving costs, the commenter contended that a work practice standard is allowed under the 

requirements of the CAA section 112(h) because it is technically and economically infeasible to 

demonstrate compliance with a numeric limit. A work practice standard would fully meet the 

requirements for standards for these pollutants. Since this option is both acceptable under the 

CAA and represents less burden to the industry, the commenter believes EO 13563 clearly 

directs the EPA to propose work practices for both Hg and non-Hg metal HAP/PM.

According to the commenter, the EPA has yet to demonstrate that the controls they describe for 

costing purposes would even be viable for the process stream characteristics (e.g., volumetric 

flow, PM loading, acid gas) found in a brick plant. Instead, the EPA justified the control of Hg

from brick kilns using a transfer of technology demonstrated on larger process flows in other, 

larger industries and based on claims and assurances from control device vendors posturing to 

market their products. If the controls were as effective as EPA claims, EPA’s proposed approach 

would cost in excess of $300,000,000 per ton of Hg reduced. This per ton cost estimate is based 

on EPA’s own analysis of the likely need to install and operate multi-million dollar APCD to 

potentially reduce only a few pounds of Hg per year from a brick kiln. Since work practices 

under section 112(h) are justified in this case, selection of a more costly option based on 

undemonstrated technology is not justifiable.

Response 1: The EPA disagrees with commenters’ contention that EPA was obligated to set 

work practice standards instead of emission limits for Hg. During the 2010 testing program, 

Method 29 was used successfully to determine Hg and non-Hg HAP metals in the emissions 

from BSCP plants. Method 29 was sensitive enough to have a majority of the test report above 

detection levels. Accordingly, because Hg and non-Hg HAP metals are at measurable levels, 

work practice standards for these pollutants are not applicable under CAA section 112(h).

The EPA also disagrees with commenters that there are no demonstrated emission controls 

available to the BSCP industry. Activated carbon injection and fabric filters have been 

demonstrated in a number of other industries as an effective control for Hg from their process 

units, including a similar process unit (kilns) used in the Portland Cement industry. However, it 
106

is up to each facility to determine the type of emission control that works best for their particular 

situation.

Regarding commenters’ argument about cost, it should be noted that under section 112 we 

cannot consider costs and other impacts when establishing MACT floor requirements. However, 

the EPA has taken significant steps to minimize the impacts of the rule on the small entities that 

are prevalent in the BSCP industry, while still achieving the objectives of the rule. In particular, 

the EPA has included kiln size subcategories, incorporated raw material variability factors into

the Hg emission limits, and reevaluated stack test data used in developing the MACT floor PM 

surrogate emission limits.

16.2 Paperwork Reduction Act

Comment 1: Multiple commenters (0523, 0542, 0543, and 0563) asserted that the EPA has 

underestimated the burden and cost for the BSCP industry to comply with the proposed rule. The 

commenters variously gave the following reasons supporting their argument that the EPA

significantly underestimated the burden estimate:

• The EPA underestimated the amount of time needed for each activity, the number of 

occurrences of each activity, and the level of staff needed to comply with the rule.

• EPA underestimated time needed for “reading and understanding” the regulation. The 

EPA estimated it will take a facility 2 hours to “Read and understand rule requirements”

and argued this was insufficient time for an individual to read both the final preamble and 

regulation, particularly if the final rulemaking is as long as the proposal. The preamble 

and rule for the proposal the BSCP was 57,658 words and argued a single individual 

would have to read at a speed of 480 words per minute to read the preamble and rule in 2 

hours. The BSCP rule is 18,088 words and would require the person to read and retain 

information at a speed of 150 words per minute. The 2-hour estimate is not reasonable 

and argued the average person can proofread at about 200 words per minute on paper and 

180 words per minute on a monitor.28 The EPA incorrectly assumes only one person 

would read the regulation for a facility. A rule of this importance would be reviewed by 

managers and not by hourly, technical staff, as indicated in the EPA’s burden estimates. 

A manager would spend significantly more than the 6 minutes the EPA allocated to “read 

and understand” this rulemaking and would need to not only read the rule, but would 

need to develop calculations to determine how the rule would impact their operations and 

determine which sections of the rule required more understanding. For the brick industry, 

this level of expertise does not always exist at the plant or company level and consultants 

would need to be hired. These costs should be reflected in the burden analysis.

• The EPA underestimated the number of hours for annual employee retraining and

training new employees. The EPA used data provided by stakeholders and the estimate of 

six plant personnel for 40 hours each is likely still reasonable; however, it is not 

reasonable to assume this is a one-time training. Most facilities would need at least 

annual training, as well as training of new employees. A more reasonable approach 

would be to include a lesser level of training every year after the first year..

 28 Ziefle, M (December 1988). “Effects of Display Resolution on Visual Performance.” Human Factors 40 (4): 554-

68.
107

• The EPA incorrectly attributed costs to each facility, when those costs apply to each kiln.

Compliance demonstration through initial performance tests, monitoring of parameters, 

and submittal of compliance tests must be conducted for each kiln. In some instances 

where kilns are co-vented through a single APCD, counting each facility may seem 

reasonable; however, in most cases there is no co-venting, and costs would be incurred 

for each individual tunnel and periodic kiln. It is not reasonable to assume all kilns within 

a facility will be ready for compliance testing at the same time. 

• The EPA omitted costs to research untested control strategies. These control devices 

would require significant research and probably pilot studies before a control device can 

be selected, costs quotes from vendors reviewed and the unit installed. Many facilities 

would likely require a preliminary stack test to determine their baseline and to ensure the 

controls will meet numeric limits. These costs, whether incurred by the individual 

companies or the industry as a whole, cannot be ignored when assessing the financial 

impacts of the regulation, because they are costs the industry “would not have been 

incurred in the absence of a rule” and should be included in the “capital/startup” costs 

beginning in the first year.

• The EPA failed to correctly include hours for completing daily VE checks and preparing 

documentation of the checks. It would take a trained hourly technician three-quarters of 

an hour to an hour per kiln per day to conduct VE checks, including arriving at 

appropriate spot, conducting the minimum 15 minute of observations, and returning to 

office and documenting results. For 67 affected entities, this would be a minimum 

increase in the average burden per facility of 274 to 365 hours per entity. The EPA 

should not include the burden estimate for the daily VE checks in the “annual O & M 

costs” because this approach masks a significant annual burden and incorrectly excludes 

the total hours for daily VE checks from the total hours. 

• The EPA made unrealistic assumptions that were not based on input from industry. While 

the brick industry did provide some limited data to the EPA during the previous and now 

vacated rulemaking, the EPA made little attempt to gather new or additional data during 

the current rulemaking. The EPA omitted costs incurred by sources that the EPA 

anticipates will become synthetic area sources to avoid MACT applicability. If a facility 

opts to become a synthetic area source, it will continue to have reporting, recordkeeping 

and monitoring requirements. These burdens would not have been incurred in the absence 

of this rulemaking and therefore, they should be counted as a direct impact from this 

rulemaking. It is reasonable to assume that these burdens would be similar to most, if not 

all, of the burdens associated with compliance. While it may be reasonable to exclude 

their count from some requirements (e.g., electronic filing of reports, burner checks), the

costs for these facilities should be included for performance testing, some level of 

parametric monitoring, and maintenance procedures.

• The EPA failed to provide the basis for the number of facilities estimated to become 

synthetic area sources. The EPA’s burden estimates assumed 25 sources would become 

synthetic area sources to avoid MACT applicability. The proposal did not clearly indicate

whether the 67 facilities impacted by the rule refers to individual kilns or total facilities,

and the numbers of sources/facilities in the memorandum that addresses the capital and 
108

annualized costs of the rule29 do not match this count. The supporting statement should 

fully explain all assumptions. 

• The EPA’s estimates are based on unsupportable assumptions about the number of kilns 

that will be able to meet the floor limits. The EPA assumed all 78 small kilns would be 

able to meet the Hg limits because the one small kiln with stack data, which was used to 

set the standard, could meet the limit that was set based on their own performance test.

• The EPA incorrectly divided the total number of average hours by an average number of 

“responses.” The EPA should have calculated an average burden per respondent or 

affected entity. By dividing by responses rather than respondents, the EPA is artificially 

lowering the burden estimates. Since a facility may have multiple “responses” in a single 

year, the total responses should be in excess of the 67 facilities the EPA estimates are 

impacted by the rule, particularly for Years 4-6 (e.g., Table 1-4 in Appendix 1). The 

number of reports submitted does not provide useful information as the EPA could 

arbitrarily lower the impact per “response” simply by adding in another report per 

facility. Correcting this error decreases the average cost per respondent for Years 1-3, but 

increases the costs per respondent for Years 4-6. The EPA should use the average cost 

per respondent in all analyses. The EPA failed to account for the costs associated with 

preparing the documentation needed to request a routine maintenance exemption under 

40 CFR 63.8420(d)(1). It is reasonable to assume that managerial level staff would 

develop this request, with some support from technical/hourly workers.

• The EPA underestimated burden for preparing the notification of compliance status and 

the first compliance report. The EPA estimated these documents would take 16 hours of 

an hourly technical staff to complete. Both reports would take longer, with the initial 

compliance report taking significantly longer and would be prepared by managerial staff, 

not hourly workers. The EPA underestimated the costs of developing an operating, 

maintenance, and monitoring plan. The EPA used stakeholder data from 2003 to estimate 

costs for developing an operating, maintenance and monitoring plan. Even if the 

estimates are reasonable, the plan would be prepared by key senior staff from several 

departments and not by hourly technical staff as included in the cost estimate. 

Consultants are also generally used to help generate these documents. It is incorrect to 

assume that no revisions are required to these documents after initial development. These 

documents are typically reviewed and revised as new issues are identified.

• The EPA has not clearly indicated how many tests EPA is assuming or the costs of the 

tests. For example, it is impossible to definitively determine whether EPA used 67 

facilities and whether that number accurately reflects the number of kilns that will require 

stack tests or if EPA erroneously assumed that all kilns at a single facility would be tested 

simultaneously for the price to test a single kiln.

• The EPA estimates do not account for the higher costs associated with the use of outside 

consultants. The EPA should include as an operation and maintenance (O&M) cost the 

cost of external consulting help that will be required for most sources, particularly the 

small businesses, to assess their company-specific impacts from this rule, assess 

compliance options, and obtain necessary quotes and permits to install and operate air 

pollution control devices.

 29 “Development of Cost and Emission Reduction Impacts for the BSCP NESHAP,” November 6, 2014. K. Sroka, 

RTI International to J. Telander, EPA/OAQPS/SPPD.
109

One commenter (0542) provided the EPA with results of a survey of 14 companies they 

conducted to assess the validity of the EPA’s hours and other cost factors used in the cost 

estimations for monitoring and reporting. The results are summarized below:

• Time required for reading the preamble and the regulation: Survey responses ranged from 

twelve (12) hours to forty (40) hours for technical persons, one (1) hour to sixteen (16) 

hours for management persons and a half hour to ten hours (10) for clerical persons. 

These numbers are consistently higher than what the EPA has assumed.

• Time required for preparing an OM&M plan: The average time spent on this is expected 

to be 214 hours. The EPA did not include annual updates to the plan, which survey 

responses indicate would require an average of 34 hours for updates. Member 

companies estimated that they will be spending far more time on the OM&M plan than 

the EPA assumed, including some use of consultants at hourly rates far exceeding EPA’s 

estimates for plant personnel.

• Additional work not accounted for in the estimated burden: Members of the brick 

industry that were surveyed noted the following additional work will be need to comply 

with the rule:

o Update System for recording all monitoring parameters--Brick Industry estimated 

an average of 20 hours per facility.

o Recalculating all values in test report based on EPA’s guidance on how to report 

values that are at or below the detection level of the test: Brick Industry estimated 

an average of 21 hours per facility.

o Annual re-training or training of new employees: Brick Industry estimated 104 

hours per facility.

• When it comes to annual maintenance and inspection, the EPA estimated that 20 hours of 

a technical person, one hour of management, and two hours of clerical would be 

sufficient to complete the work. Respondents to the BIA survey asserted that this number 

is not so far off for a single kiln; however, for companies who have multiple kilns, or 

multiple plants, this number becomes an underestimation of the actual time needed. The 

EPA assumed a facility needs 20 hours of a technical person to complete all the 

maintenance and inspection regardless of facility size. In their industry, a facility could 

have a single tunnel kiln or can have multiple tunnel kilns (up to 8 is known to occur) and 

dozens of periodic kilns. Clearly, the more kilns or locations, the more time will be 

dedicated to this task. The EPA also has numbers for annual burner inspection and tuneup that seem more appropriate for one kiln.

Response 1: The EPA disagrees with commenters that capital/startup costs must include costs 

associated with demonstrating the use of control devices for the BSCP industry. The control 

devices in question, baghouses and activated carbon injection, have already been demonstrated 

on similar processes (kilns) in other industries (Portland Cement). 

The EPA agrees with commenters that the 67 sources refers to plants, not kilns. The supporting 

statement for the proposal referred to “92...major sources of HAP,” 25 of which “are projected 

to become synthetic area sources,” with “the remaining 67...expected to be subject to the rule.”

Major and synthetic area sources are determined on the facility level, not the affected source 
110

(e.g., kiln) level. The EPA disagrees with commenters that the number of kilns subject to a 

particular limit is relevant in the calculation of facility burden for the BSCP rule.

The EPA agrees with commenters that performance test costs associated with demonstrating 

synthetic area status should be included in the cost of the rule, and the performance test costs for 

the final rule have been revised to include those costs. However, the EPA disagrees that the costs 

of continuous compliance, such as parametric monitoring and maintenance procedures, and the 

costs of recordkeeping and reporting should be included for these synthetic area sources. Once 

the facilities have demonstrated their synthetic area source status, they are no longer subject to 

the requirements of the major source rule, including any continuous compliance requirements or 

recordkeeping and reporting requirements.

The EPA agrees with commenters that the facility burden estimates should account for the 

number of kilns at a facility, and we have increased the burden estimates for each facility where 

necessary, based on the average number of kilns per facility. The performance test costs already 

account for whether kilns are vented individually or co-vented (see BSCP Impacts memo).

The EPA disagrees with commenters’ objection to the calculation of the burden per response. 

This calculation is required for Office of Management and Budget (OMB) review.

In response to commenters’ concerns about the burden of the rule being underestimated, we have 

made a number of changes to the burden estimates for the final rule. We have increased the 

burden estimates for respondents to read and understand the rule requirements, calculating a total 

of 12 hours for this task, using the methodology suggested by commenters, based on a 

conservative reading rate of 100 words per minute for the 72,054-word draft preamble and final 

rule (BSCP portions only). This burden estimate is within the range of the estimates provided in 

BIA’s survey of the BSCP industry. We have also revised the burden calculation to include only 

technical and managerial labor for this task, split 50/50, in response to commenters’ concern.

We have also increased the burden estimates for requesting a routine maintenance exemption

(i.e., alternative standard as revised in the final rule), preparing the notification of compliance 

status and first compliance report, developing the OM&M plan, etc., based on estimates from the 

BIA survey. The EPA agrees with Commenter 0542 that annual updates to the OM&M plan 

should also be accounted for, and we have estimated the burden for this task based on estimates 

from the BIA survey. The EPA disagrees with commenters that we assumed only one person 

would be involved in conducting these and other tasks, since we also included managerial and 

clerical staff in the burden estimates. In addition, the burden estimates do not specify the number 

of people involved in conducting these tasks, only the number of hours. The EPA disagrees with 

commenters that managerial staff should account for the majority of the burden for these tasks, 

which also conflicts with the labor breakdown of the burden estimates provided in BIA’s own 

survey results. There is also a great deal of variability in the labor breakdown (technical, 

managerial, clerical) in the BIA survey results, between companies and between burden items. 

Consequently, for consistency, we have retained the current ratio of technical to managerial and 

clerical burden for these and all remaining burden estimates. The EPA disagrees with 

commenters that external consulting labor must be accounted for in the burden estimates. As one 
111

commenter noted, these impacts are “company-specific.” The extent of this burden and the 

number of affected facilities are not clear, based on public comments. 

In response to comments from commenters on the burden estimate associated with training 

personnel, we have increased the estimate of training burden from 40 to 48 hours based on 

estimates from the BIA survey, and we have also added burden estimates for annual training 

from the survey results, to allow for initial training for new staff and refresher training for 

existing staff.

The EPA agrees with commenters that additional clarification is needed for the basis for the VE 

and stack testing costs at the bottom of the burden tables. We have added a statement in the 

corresponding footnote to clarify that these estimates come from the nationwide BSCP cost 

estimates in the BSCP Impacts memo. We direct the commenters to this memo for further 

information on how these nationwide costs were estimated. We disagree with commenters’

contention that the VE tests are not an O&M activity but a labor burden. The VE tests are used as 

a monitoring method for demonstrating continuous compliance, and are not a recordkeeping or 

reporting requirement.

The EPA disagrees with Commenter 0542 that burden estimates need to be added for the 

following:

• Development of title V permit application--all major source BSCP facilities already have 

title V permits, which would already be updated every 5 years even in the absence of a 

BSCP rule.

• Evaluation of control devices--the control devices that facilities may need to install to 

meet the BSCP emission limits have already been demonstrated on similar processes 

(kilns) in other industries (Portland Cement).

• Selection of control device vendor--this cost should already be included in the capital 

cost of the control device.

• Recalculating test report values at or below the detection level--this task is unnecessary to 

demonstrate compliance.

• Updating system for recording monitoring parameters--the BSCP rule has been designed 

to allow facilities to use existing systems to gather the necessary information to 

demonstrate compliance, so no system updating should be necessary.

Comment 2: Commenter 0543 stated that the EPA should not use Years 1-3 after promulgation 

as representative of the actual data collection burden of this rule. The formal analysis of the 

three-year average burden for the Brick MACT should not start in the year the rule is 

promulgated, since the rule primarily impacts existing sources, where compliance is not required 

until after the end of Year 3. Therefore, while control device costs would be occurring, the 

majority of reporting and recordkeeping requirements would be more limited until Years 4-6.

According to the commenter, by focusing on Years 1 through 3, EPA essentially cuts the true 

ongoing annual burden to one-third of the actual burden using this approach. To truly evaluate 

the impact of a rule that largely impacts existing sources, the commenter stated that EPA should 

be required to conduct their formal burden assessment for Years 4-6 and address Years 1-3 in an 

appendix.
112

Response 2: The EPA disagrees with the commenter’s argument that the EPA should not have 

used Years 1-3 after promulgation in estimating the data collection burden of the rule. The EPA 

is required to follow the requirements of the PRA in conducting its evaluation of the burden 

associated with a particular rule. Under the PRA, the EPA is required to estimate the burden 

every 3 years, beginning with the effective date of the rule (i.e., Years 1-3). Consequently, the 

EPA is following accepted guidance in providing the burden estimates for Years 1-3. As the 

commenter noted, most of the burden for the BSCP rule falls in Years 4-6 and beyond. While the 

EPA was not required under the PRA to do so, to provide a better understanding of the burden of 

the rule, we provided estimates of the burden for Years 4-6 in an appendix to the supporting 

statement. The burden estimates for Years 4-6 will be formally updated by the EPA 3 years after 

the effective date.

16.3 Regulatory Flexibility Act

Comment 1: Commenter 0517 stated that the burden a new MACT would impose on small 

businesses in the industry exceeds the purpose and intent of the CAA. The commenter noted that 

MACT is a technology-based standard, set without respect to costs and benefits, and also noted 

that subsequent changes to the NESHAP must take into account costs. While the CAA provides 

no guarantees that all sources should be able to continue operating under a MACT-based 

standard, the commenter mentioned that this particular industry had already complied with a 

MACT, and the need to set a new, more stringent MACT is due to the court’s decision to vacate 

and remand the previous rule rather than simply remand. The commenter therefore suggested 

that EPA should exercise its discretion under the CAA to the maximum extent possible to 

minimize the impacts on these already-struggling small businesses. The commenter supported 

EPA’s proposals to set work practice standards and health-based emission standards in all 

instances allowed by statute.

Commenter 0517 expressed concern that some of EPA’s assumptions in the economic analysis 

(as discussed in the paragraphs below) lead to significant underestimates of the disruption this 

rule would have on small brick producers.

First, Commenter 0517 suggested that the annualization of EPA’s cost estimates at seven percent 

over 20 years is inappropriate when considering the small business impacts. The commenter 

noted that annualization of costs assumes the availability of financing at these same terms, seven 

percent over 20 years. The commenter has heard from small businesses and BIA that financing is 

generally unavailable to small firms in the industry, even to expand productive capacity, and 

definitely not at these terms. The commenter stated that if financing is unavailable, then the 

small business must finance the initial capital costs out of cash-on-hand and profits. The 

commenter stated that, given the size of the businesses involved and the capital costs required, 

most small businesses would have difficulty complying without financing.

Second, Commenter 0517 was concerned that EPA has underestimated the impact of the rule by 

assuming a number of small business can avoid compliance with the MACT by reclassifying 

themselves as “synthetic minor” sources, i.e., sources that do not emit enough to be major 

sources. The commenter noted that EPA estimates that 15 of the 86 facilities affected by this rule 

would only need to submit paperwork to come into compliance, but was concerned that this 

oversimplifies the decision. The commenter pointed out that if a small entity is already emitting 
113

below the threshold, it is unclear why they would not already have been classified as a “synthetic 

minor” when negotiating their CAA permits. Given the permitting requirements that accompany 

the “major source” designation, the commenter asserted that it is more likely that small entities 

have other reasons for remaining “major source,” such as the desire to maintain capacity in the 

hope that demand for bricks will recover to pre-2007 levels. The commenter noted that, if so, 

reclassification can have real costs to the future viability of the firm.

Third, Commenter 0517 stated that EPA makes assumptions about the cost of reducing Hg

emissions that affect its estimated impact on small entities. The commenter noted that EPA has 

Hg emission data for less than 10 percent of kilns but assumes some mix of controls used in 

other industries will be effective in bringing all sources into compliance with the Hg standard. 

The commenter stated that EPA’s estimates may not accurately capture the range of costs that 

would be imposed on small entities. The commenter also mentioned that small entities may not 

have the ability to develop a compliance strategy or understand what control equipment may be 

necessary, and providers of control equipment may be unwilling to guarantee performance. The 

commenter was concerned that EPA has not recognized the significant disruption this proposed 

rule would have on the industry, and suggested that the economic analysis should reflect the 

practical difficulties this industry will likely experience in planning for compliance.

Finally, Commenter 0517 stated that small brick producers are very concerned that EPA’s 

proposed NESHAP for their industry will put many of them out of business. The commenter 

suggested EPA use its discretion to minimize the significant economic impact on small entities 

consistent with the stated objectives of applicable statutes. The commenter recommended further 

consultation with small businesses to gather the data necessary to justify greater flexibilities, 

including a delay in promulgating a Hg emission standard to better understand the sources and 

possible controls for Hg in this industry if necessary.

Response 1: Regarding the commenter’s concern about some of the EPA’s assumptions in the 

economic analysis, the EPA understands that firms may have difficulty obtaining longer-term 

financing needed to buy the control equipment and make process changes needed to comply with 

the rule. Further discussion of this issue is provided in our response to the public comments in 

section 15.2 of this document and in the RIA, Regulatory Impact Analysis: Final Brick and 

Structural Clay Products NESHAP found in the docket for this rule.

With respect to the commenter’s concern about the EPA’s assumptions regarding the number of 

small entities that may choose to avoid compliance with the MACT by reclassifying themselves 

as synthetic area sources, we have reevaluated the potential for sources to become synthetic area 

sources and revised the cost analysis accordingly. In response to other public comments, we have 

also revised the cost to become a synthetic area source to include the cost to conduct a stack test 

to verify emissions. These results are documented in the nationwide impacts memorandum for 

the final rule. Concerning the commenter’s assumption for why small entities choose to remain 

major sources, such speculation on the potential future growth of a facility would be purely 

hypothetical and, therefore, was not accounted for in our cost analysis.

Regarding the commenter’s suggestion that the EPA should exercise its discretion to minimize 

the impacts of the BSCP manufacturing NESHAP on small entities, it should be noted that in 
114

addition to the work practice standards and HBEL mentioned by the commenter, the EPA has 

taken other significant steps to minimize the impacts of the rule on small entities, while still 

achieving the objectives of the rule. In particular, the EPA has included kiln size subcategories,

incorporated raw material variability factors into the Hg emission limits, and reevaluated stack 

test data used in developing the MACT floor PM surrogate emission limits. The incorporation of 

raw material variability factors into the Hg emission limits and the inclusion of updated cost 

factors from industry into our cost analyses were designed to address the concern about the 

adequately estimating the impact on small entities of complying with the Hg standards.

With respect to the suggestion by the commenter that the EPA defer taking action on setting Hg 

emission limits until more information becomes available, the EPA notes that it is obligated to 

take final action to set NESHAP for BSCP facilities located at major sources on or before 

September 24, 2015 pursuant to the consent decree in Sierra Club v. EPA, Case No. 08-00424 

(D.D.C.).
115

17.0 General Comments

17.1 General Opposition

Comment 1: Commenter 0561 asserted that the rule could have unwarranted and unreasonable 

negative impacts on brick manufacturing operations and encouraged EPA to minimize these 

impacts. They acknowledged the government has the responsibility to protect human health and 

the environment, but asserted the country’s manufacturing base should be supported and 

encouraged to prosper at the same time. The CAA provides the tools for EPA to balance both of 

these goals, and the commenter encouraged the EPA ensure that the regulation of small amounts 

of emissions from trace minerals in the mined materials does not needlessly jeopardize the 

viability of the American brick industry. The commenter urged EPA to do more to create a rule 

that meets the requirements of the CAA and allows brick manufacturing to remain a viable 

American industry.

Response 1: As stated previously, the EPA understands that variations in the raw material can 

affect the long-term performance of the best performers when complying with a particular 

standard. Thus, the EPA has incorporated the data received during the post comment period into 

the development of the final MACT Hg standard for this category; see Final Maximum 

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

Manufacturing for more information.30

17.2 Incorporation by Reference

Comment 1: Multiple commenters (0513, 0514, 0515, 0516, 0520, 0521, 0522, 0523, 0529, 

0532, 0534, 0535, 0536, 0537, 0545, 0548, 0549, 0550, 0551, 0552, 0553, 0555, 0556, 0558, 

0559, 0560, 0562, and 0563) stated they supported the comment letter submitted on their 

industry’s behalf by the Brick Industry Association (BIA), as well as all supplemental letters 

mentioned in that letter (letter from Susan Miller, Brick Industry Association, submitted March 

2015 to Docket ID No. EPA-HQ-OAR-2013-0291).

Response 1: The EPA acknowledges the commenters’ incorporation by reference of BIA’s 

comment letter and all supplemental letters mentioned therein.

 30 Raymond, G., and K. Sroka. Final Maximum Achievable Control Technology (MACT) Floor Analysis for Brick 

and Structural Clay Products Manufacturing. Memorandum from Gabrielle Raymond and Kristin Sroka, RTI 

International, to Sharon Nizich, EPA/OAQPS/SPPD. September 24, 2015.
116

18.0 Other Comments

Comment 1: Commenter 0543 noted the following typographical errors and clarifications in 

regulatory language:

• In Table 5 of the regulation, in the first column, the “8. Existing, new or reconstructed 

periodic kilns” is missing.

• The BIA MACT TF requests that EPA allow that stack tests conducted within 5 years of 

date of notification of compliance status be acceptable as long as the company can assert 

that the operations a during the test are still representative of current operations and that 

all required data were collected during the test.

• In some cases, two or more kilns are vented to a single control device. EPA 

acknowledges this in their analyses. However, the compliance demonstration 

requirements do not appear to address this situation. The BIA MACT TF requests that 

EPA clarify that co-venting through a common control device is acceptable.

• The EPA provides compliance demonstration procedures for the HCl equivalent standard 

for uncontrolled kilns and for controlled kilns. The BIA MACT TF requests that EPA 

specifically state that a combination of controlled and uncontrolled kilns can be used to 

meet this limit.

• EPA should provide specific instruction on the use of “non-detects” when demonstrating 

compliance with the HCl equivalent standard. Specifically, a “zero” emission rate should 

be used for non-detects found during Method 26A testing. Any value other than zero used 

for a non-detect for Cl2 would be multiplied by 133 and could make it appear that a 

facility was violating the HCl equivalent standard when they have non-detectable Cl2

emissions.

Response 1: Concerning the comments on the regulatory language, we have the following 

responses:

• We have revised Table 5 to subpart JJJJJ include the missing language for existing, new 

or reconstructed periodic kilns.

• We have elected not to provide for the use of prior test results in lieu of initial 

performance testing that the commenter requested. Given the recurring testing required 

under this rule, the allowance for prior test results seems unnecessary as a general 

allowance. However, a source can discuss with their delegated authority whether this 

option is available and feasible for their plant. In addition, a source may seek a waiver of 

testing under 40 CFR 63.7(h) of the General Provisions.

• Item 1 in Table 4 to subpart JJJJJ already specifies that sampling sites be located at the 

outlet of the APCD. No further clarification is necessary.

• Section 63.8445(f)(2) refers to each tunnel kiln at the facility, which would include all 

controlled and uncontrolled kilns. No further clarification is necessary.

• Regarding the commenter’s question regarding how non-detects discovered during

Method 26A testing should be treated, calculation of the analytical detection limit is 

described in Section 13.3 of Method 26A. The detection limit needs to be calculated on a 

run-by-run basis, and the non-detects should be the detection limit of the run which will 

include the analytical detection limit of the laboratory and the gas sample volume

measured by the dry gas meter.
117

Comment 2: Commenter 0544 noted one of the challenges with an indexless, searchable docket 

is that you also need to have a general idea of the title of the document in order to find it. The 

commenter stated that when you have limited resources and limited time to find and read 

everything, using multiple search parameters for the documents delays forward progress. The 

commenter suggested that a docket index would help speed up the process.

In addition, Commenter 0544 noted that once you are actually able to find the documents you are 

looking for, any attachments they may have are not labeled, have no page numbers, and are not 

formatted to be readable without printing and cutting out each page and reassembling it into 

usable format. The commenter noted that this frequently happened with large tables that were 

“printed to file” without first being formatted for printing. The commenter stated that what it 

comes down to is that the attachments to documents in their current form are often essentially 

worthless, unless you know exactly what you are looking for. The commenter asserted that being 

able to quickly understand what you are seeing when looking at an attachment is critical with 

thousands of documents to go through. The commenter stated that it is impossible to reference 

these pages in a comment letter and impossible to follow where key decisions were made. The 

commenter also stated that when writing a comment on the rule, understanding the assumptions 

that were made is very important. The commenter was concerned that if a comment letter cannot 

properly reference an attachment, how would the EPA even be able to figure out what the 

commenter is trying to say, or even be able to look into the claims of the commenter?

In addition, Commenter 0544 noted that there seemed to be issues with the docket being loaded 

to regulations.gov early in the comment period. The commenter asserted that every moment that 

you have a document is critical to understanding the rule and preparing your comments. The 

commenter noted that Brick MACT appeared in the federal register on December 18, 2014, but 

as of December 19, there were no documents uploaded to the docket. The commenter noted that 

there were still many documents that were not available and many that had a title had no PDFs or 

other documents to download by December 22. The commenter criticized that this was a loss of 

critical time before the holidays. The commenter also noted that it was not until we moved past 

Christmas that most of the documents were available, and even then, there were duplicate copies 

of some documents under different item numbers, requiring additional review to determine 

whether they are in fact identical, which they were. The commenter noted that it was not until 

sometime later when going back to review these identical files for this comment letter that we 

noted that they were changed to different files. The commenter stated that it would have been 

beneficial to have these files initially as the main comment letter for the Brick Industry 

Association was formed. The commenter also noted that there were also docket items that 

apparently belong in the Ceramic Tile MACT docket. The commenter stated that this raises the 

question of whether all brick documents are included in the docket and how industry would ever 

be able to know if items are missing, and also leaves concerns if these documents were meant to 

go into the Brick MACT docket because the EPA used it to make assumptions or if their 

placement was just an accident.

Commenter 0544 listed the docket items that were at one point duplicated:

• Docket Items 121 and 221 were once the same document, but are long and verification 

ended up being a waste time as the document was eventually corrected.
118

• Docket Items 123 and 291 were once identical

• Docket Items 125 and 220 were once identical

• There are several Clay Ceramics MACT related documents in the Brick docket. The 

commenter stated they assumed these were included in error since they did not see them 

referenced in any of the memoranda that were reviewed. If this is not in error, the 

commenter asked for additional time to review these items.

Following is Commenter 0544’s list of items that were believed to be missing from the docket 

and should be added. The commenter attached copies of each to their letter.

• March 16, 2009 BIA to Jeff Telander

• September 4, 2009 BIA to Jeff Telander

• May 10, 2010 letter from Pinehall Brick to Jeff Telander

• July 1, 2010 letter from BIA to Peter Tsirigotis

• September 29, 2010 Letter from BIA to Jeffrey Telander

• December 13, 2010 letter from members of the United States Senate to Lisa Jackson

• January 17, 2013 BIA letter to Jeff Telander

The commenter stated that the EPA inconsistently docketed items related to the SBREFA panel 

meetings in 2010 and 2013. For example, several short emails sent after the first informal 

SBREFA meeting in 2010 are included in a separate docket item. The commenter noted that 

several items submitted after the informal SBREFA panel in 2013 are also separately docketed, 

however comment letters submitted after the formal SBREFA panel are generally only included 

as an attachment to the final SBREFA report, rather than being listed as separate correspondence 

to the EPA in the docket. The commenter stated that this is not a consistent practice, however, as 

at least one of the comment letters on the SBREFA process (a letter from Continental Brick) is 

included as both an attachment and as a separate docket item (see docket item 189). The 

commenter asserted that this inconsistent treatment of documents naturally caused them to worry 

that there are additional items missing from this docket.

In conclusion, Commenter 0544 asserted that the lack of organization in the docket has made a 

difficult task for a small association more difficult. The commenter stated that they have spent 

numerous hours tracking down information, verifying duplicate documents, and searching for 

missing items. The commenter questioned whether the docket meets the requirements of a 

complete docket required by law for a rulemaking and requested that the EPA conduct a more 

thorough review of all correspondence and certify that the final docket is complete. If significant 

omissions are noted, the commenter requested that the EPA re-open the public comment period 

to allow us to comment on the new material. The commenter also recommended that the EPA 

provide clear docket indices for rules to eliminate confusion and create the transparent 

rulemaking process that they profess to have.

Response 2: The EPA disagrees with the commenter that no docket index was available for the 

BSCP manufacturing NESHAP. An index can be generated at regulations.gov by first entering 

the docket number on the main page, opening the docket folder on the next page, selecting 

“View all documents and comments in this Docket” on the next page, and then selecting 

“Export.”
119

The commenter did not identify which documents in the docket they had difficulty reviewing, so 

it is not possible to evaluate their claim. However, the commenter should be aware that some 

attachments are Excel spreadsheets, which due to their size are more easily reviewed on screen in 

their spreadsheet form than as printouts.

With regard to the timing of materials appearing in the docket, all materials supporting the 

proposed rule were uploaded to the docket by the date of publication, as required. No materials 

were uploaded late to the docket. However, there can be a delay from when we upload materials 

to the docket and when the docket office posts them to regulations.gov. With regard to the 

commenter’s finding some duplicate items in the docket, we acknowledge there was some 

duplication by the docket office of some docket items, for reasons unknown.

The commenter did not identify which documents in the BSCP Manufacturing docket they think 

belong to the Clay Ceramics Manufacturing docket, so it is not possible to evaluate their claim. 

There are some BSCP companies that include the word “Ceramics” in their name. However, we 

are certain that no BSCP docket items were accidentally placed in the Clay Ceramics 

Manufacturing docket and left out of the BSCP Manufacturing docket. The items included in the 

BSCP and Clay Ceramics Manufacturing dockets were compiled separately into different folders 

prior to any indexing or uploading.

We have reviewed the list of docket items that the commenter indicated were missing from the 

docket. We were able to find the first three in the docket--under items EPA-HQ-OAR-2013-

0291-0215, 0210, and 0197--but we were unable to find the rest. We thank the commenter for 

providing copies of the letters.

Concerning the commenter’s statement that the SBREFA panel items were docketed 

inconsistently, the EPA tries to avoid duplication of docket items where possible, which is why 

the docket items attached to the final SBREFA report were not duplicated in the index as 

separate items.

Based on a review of the missing materials, the EPA has found no significant omissions that 

would require re-opening the public comment period. We thank the commenter for adding these 

items to the record as attachments to their public comment.

Comment 3: Commenter 0543 expressed concern that there are inconsistencies across the EPA’s 

supporting documentation. For example, the commenter noted that the reported number of 

sources potentially impacted by the regulation does not match in at least two memoranda:

• The Supporting Statement (Docket Item No. EPA-HQ-OAR-2013-0291-0129), states that 

there are 92 major sources and projects 25 will become synthetic area sources to avoid 

the MACT, leaving 67 major sources subject to the rule. The commenter stated it was not 

clear whether this number is referencing facilities or kilns at major source facilities.

• The memorandum Development of Cost and Emission Reduction Impacts for the BSCP 

NESHAP (Docket Item No. EPA-HQ-OAR-2013-0291-0117) states that there are 86 

major sources and that 15 sources plus 14 stacks located at an unidentified number of 

sources would become synthetic area.
120

In order to provide comments on the overall preamble and rule, the commenter stated that it is 

important that all underlying documents consistently support the overall proposed rule and 

preamble. Due to these inconsistencies, the commenter requested an additional opportunity to 

review and comment on these memoranda once they are fixed and consistent.

Response 3: The number of major source facilities in the Supporting Statement includes 

facilities with tunnel kilns and periodic kilns, as all major sources would incur some burden to 

comply with the rule. The number of major source facilities in the Impacts memo excludes 

facilities with only periodic kilns, as those facilities would only be subject to work practice 

standards, which were not expected to have significant costs. Therefore, the two documents are 

working from two sets of inventory data. Regardless, both documents have been revised for 

promulgation, with revised facility counts. The facility counts in both documents have been 

reviewed for promulgation and found to be consistent. We see no need for additional review and 

comment.

Comment 4: Commenter 0548 noted that the current table for Lee Brick has the control device 

for Kiln ID #695 listed as “Other.” However, the commenter stated that this kiln has never been 

controlled and should be listed as “Uncontrolled.”

Response 4: We checked the MACT floor memo, and the control device for Lee Brick is listed 

as “None” in Table A-4. The test data memo appendices also list the APCD as “None.” We also 

checked the inventory memo, and the APCD column lists “Uncontrolled” for Kiln #695. The 

2008 BIA survey results are the only place the APCD is listed as “Other” for Kiln #695.

Therefore, we think the commenter is referring to the BIA survey summary when they say “the 

current table.” Our assessment that Kiln #695 is uncontrolled is based on the April 22, 2005 

stack test for this kiln, which specifies that the kiln is uncontrolled. We thank the commenter for 

confirming that the kiln is uncontrolled. Note: The inventory memo for proposal listed the APCD 

as “Uncontrolled” for all three kilns at the Lee Brick facility, but this is actually a copy-paste 

error, since we only have control device information for Kiln #695. The inventory memo has 

been revised for promulgation to correct this error.