Thursday, 

October 21, 2010 

Part II 

Environmental 

Protection Agency 

40 CFR Part 63 

National Emission Standards for 

Hazardous Air Pollutant Emissions: Hard 

and Decorative Chromium Electroplating 

and Chromium Anodizing Tanks; Group I 

Polymers and Resins; Marine Tank Vessel 

Loading Operations; Pharmaceuticals 

Production; The Printing and Publishing 

Industry; and Steel Pickling—HCl Process 

Facilities and Hydrochloric Acid 

Regeneration Plants; Proposed Rule 

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65068 Federal Register / Vol. 75, No. 203 / Thursday, October 21, 2010 / Proposed Rules 

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Part 63 

[EPA–HQ–OAR–2010–0600; FRL–9203–7] 

RIN 2060–AO91 

National Emission Standards for 

Hazardous Air Pollutant Emissions: 

Hard and Decorative Chromium 

Electroplating and Chromium 

Anodizing Tanks; Group I Polymers 

and Resins; Marine Tank Vessel 

Loading Operations; Pharmaceuticals 

Production; The Printing and 

Publishing Industry; and Steel 

Pickling—HCl Process Facilities and 

Hydrochloric Acid Regeneration Plants 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Proposed rule; and 

supplemental notice of proposed 

rulemaking. 

SUMMARY: This action proposes how 

EPA will address the residual risk and 

technology reviews conducted for two 

national emission standards for 

hazardous air pollutants (NESHAP), and 

this action is a supplemental notice of 

proposed rulemaking for an October 

2008 action that proposed how EPA 

would address the residual risk and 

technology reviews for four NESHAP. 

The six NESHAP include 16 source 

categories, 12 of which are the subject 

of residual risk and technology reviews 

in this package. This action proposes to 

modify the existing emissions standards 

for eight source categories in three of the 

six NESHAP to address certain emission 

sources not currently regulated under 

these standards. It also proposes for all 

six NESHAP to address provisions 

related to emissions during periods of 

startup, shutdown, and malfunction. 

Finally, this action proposes changes to 

two of the six NESHAP to correct 

editorial errors, make clarifications, or 

address issues with implementation or 

determining compliance. 

DATES: Comments. Comments must be 

received on or before December 6, 2010. 

Under the Paperwork Reduction Act, 

comments on the information collection 

provisions are best assured of having 

full effect if the Office of Management 

and Budget (OMB) receives a copy of 

your comments on or before November 

22, 2010. 

Public Hearing. We will hold a public 

hearing on November 5, 2010. Persons 

requesting to speak at the public hearing 

must contact EPA by November 1, 2010. 

ADDRESSES: Comments. Submit your 

comments, identified by Docket ID No. 

EPA–HQ–OAR–2010–0600, by one of 

the following methods: 

• http://www.regulations.gov: Follow 

the on-line instructions for submitting 

comments. 

• E-mail: a-and-r-docket@epa.gov. 

Attention Docket ID No. EPA–HQ– 

OAR–2010–0600. 

• Fax: (202) 566–9744. Attention 

Docket ID No. EPA–HQ–OAR–2010– 

0600. 

• Mail: U.S. Postal Service, send 

comments to: EPA Docket Center, EPA 

West (Air Docket), Attention Docket ID 

No. EPA–HQ–OAR–2010–0600, U.S. 

Environmental Protection Agency, 

Mailcode: 2822T, 1200 Pennsylvania 

Ave., NW., Washington, DC 20460. 

Please include a total of two copies. In 

addition, please mail a copy of your 

comments on the information collection 

provisions to the Office of Information 

and Regulatory Affairs, Office of 

Management and Budget (OMB), Attn: 

Desk Officer for EPA, 725 17th Street, 

NW., Washington, DC 20503. 

• Hand Delivery: U.S. Environmental 

Protection Agency, EPA West (Air 

Docket), Room 3334, 1301 Constitution 

Ave., NW., Washington, DC 20004. 

Attention Docket ID No. EPA–HQ– 

OAR–2010–0600. Such deliveries are 

only accepted during the Docket’s 

normal hours of operation, and special 

arrangements should be made for 

deliveries of boxed information. 

Instructions. Direct your comments to 

Docket ID No. EPA–HQ–OAR–2010– 

0600. EPA’s policy is that all comments 

received will be included in the public 

docket without change and may be 

made available online at http:// 

www.regulations.gov, including any 

personal information provided, unless 

the comment includes information 

claimed to be confidential business 

information (CBI) or other information 

whose disclosure is restricted by statute. 

Do not submit information that you 

consider to be CBI or otherwise 

protected through http:// 

www.regulations.gov or e-mail. The 

http://www.regulations.gov Web site is 

an ‘‘anonymous access’’ system, which 

means EPA will not know your identity 

or contact information unless you 

provide it in the body of your comment. 

If you send an e-mail comment directly 

to EPA without going through http:// 

www.regulations.gov, your e-mail 

address will be automatically captured 

and included as part of the comment 

that is placed in the public docket and 

made available on the Internet. If you 

submit an electronic comment, EPA 

recommends that you include your 

name and other contact information in 

the body of your comment and with any 

disk or CD–ROM you submit. If EPA 

cannot read your comment due to 

technical difficulties and cannot contact 

you for clarification, EPA may not be 

able to consider your comment. 

Electronic files should avoid the use of 

special characters, any form of 

encryption, and be free of any defects or 

viruses. For additional information 

about EPA’s public docket, visit the EPA 

Docket Center homepage at http:// 

www.epa.gov/epahome/dockets.htm. 

Docket. The EPA has established a 

docket for this rulemaking under Docket 

ID No. EPA–HQ–OAR–2010–0600. All 

documents in the docket are listed in 

the http://www.regulations.gov index. 

Although listed in the index, some 

information is not publicly available, 

e.g., CBI or other information whose 

disclosure is restricted by statute. 

Certain other material, such as 

copyrighted material, is not placed on 

the Internet and will be publicly 

available only in hard copy. Publicly 

available docket materials are available 

either electronically in http:// 

www.regulations.gov or in hard copy at 

the EPA Docket Center, EPA West, 

Room 3334, 1301 Constitution Ave., 

NW., Washington, DC. The Public 

Reading Room is open from 8:30 a.m. to 

4:30 p.m., Monday through Friday, 

excluding legal holidays. The telephone 

number for the Public Reading Room is 

(202) 566–1744, and the telephone 

number for the EPA Docket Center is 

(202) 566–1742. 

Public Hearing. We will hold a public 

hearing concerning this proposed rule 

on November 5, 2010, from 9 a.m. to 

7 p.m. Persons interested in presenting 

oral testimony at the hearing should 

contact Ms. Mary Tom Kissell, Sector 

Policies and Programs Division (E143– 

01), Office of Air Quality Planning and 

Standards, U.S. Environmental 

Protection Agency, Research Triangle 

Park, NC 27711, telephone number, 

(919) 541–4516, by November 1, 2010. 

The public hearing will be held at the 

U.S. Environmental Protection 

Agency—Research Triangle Park 

Campus, 109 T.W. Alexander Drive, 

Research Triangle Park, NC 27709. If no 

one requests to speak at the public 

hearing by November 1, 2010, then the 

public hearing will be cancelled and a 

notification of cancellation posted on 

the following Web site: http:// 

www.epa.gov/ttn/oarpg/t3main.html. 

FOR FURTHER INFORMATION CONTACT: For 

questions about this proposed action, 

contact Ms. Mary Tom Kissell, Sector 

Policies and Programs Division (E143– 

01), Office of Air Quality Planning and 

Standards, U.S. Environmental 

Protection Agency, Research Triangle 

Park, NC 27711, telephone (919) 541– 

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Federal Register / Vol. 75, No. 203 / Thursday, October 21, 2010 / Proposed Rules 65069 

4516; fax number: (919) 541–0246; and 

e-mail address: kissell.mary@epa.gov. 

For specific information regarding the 

risk modeling methodology, contact Ms. 

Elaine Manning, Health and 

Environmental Impacts Division (C539– 

02), Office of Air Quality Planning and 

Standards, U.S. Environmental 

Protection Agency, Research Triangle 

Park, NC 27711; telephone number: 

(919) 541–5499; fax number: (919) 541– 

0840; and e-mail address: 

manning.elaine@epa.gov. For 

information about the applicability of 

these six NESHAP to a particular entity, 

contact the appropriate person listed in 

Table 1 to this preamble. 

SUPPLEMENTARY INFORMATION: 

TABLE 1—LIST OF EPA CONTACTS FOR THE NESHAP ADDRESSED IN THIS PROPOSED ACTION

NESHAP for: OECA contact 1 OAQPS contact 2

Hard and Decorative Chromium Electroplating and Chromium Anodizing Tanks.Scott Throwe, (202) 564–7013, 

throwe.scott@epa.gov.

Phil Mulrine, (919) 541–5289, 

mulrine.phil@epa.gov. 

Group I Polymers and Resins Production .......................................... Scott Throwe, (202) 564–7013, 

throwe.scott@epa.gov.

Randy McDonald, (919) 541–5402, 

mcdonald.randy@epa.gov. 

Marine Vessel Loading Operations .................................................... Maria Malave, (202) 564–7027, 

malave.maria@epa.gov.

Steve Shedd, (919) 541–5397, 

shedd.steve@epa.gov. 

Pharmaceuticals Production ............................................................... Marcia Mia, (202) 564–7042, 

mia.marcia@epa.gov.

Randy McDonald, (919) 541–5402, 

mcdonald.randy@epa.gov. 

Printing and Publishing Industry ......................................................... Len Lazarus, (202) 564–6369,

lazarus.leonard@epa.gov.

David Salman, (919) 541–0859, 

salman.dave@epa.gov. 

Steel Pickling—HCl Process Facilities and Hydrochloric Acid Regeneration Plants.Maria Malave, (202) 564–7027, 

malave.maria@epa.gov.

Phil Mulrine, (919) 541–5289, 

mulrine.phil@epa.gov. 

1OECA stands for EPA’s Office of Enforcement and Compliance Assurance. 

2OAQPS stands for EPA’s Office of Air Quality Planning and Standards. 

I. Preamble Acronyms and 

Abbreviations 

Several acronyms and terms used to 

describe industrial processes, data 

inventories, and risk modeling are 

included in this preamble. While this 

may not be an exhaustive list, to ease 

the reading of this preamble and for 

reference purposes, the following terms 

and acronyms are defined here: 

AERMOD—The air dispersion model used by 

the HEM–3 model 

AEGL—Acute Exposure Guideline Levels 

ANPRM—Advance Notice of Proposed 

Rulemaking 

ASTM—An international standards 

organization that develops and publishes 

voluntary consensus technical standards 

ATCM—Airborne Toxics Control Measure 

ATSDR—Agency for Toxic Substances and 

Disease Registry 

BACT—Best Available Control Technology 

bbl/yr—Barrels per Year 

BID—Background Information Document 

CalEPA—California Environmental 

Protection Agency 

CARB—California Air Resources Board 

CAA—Clean Air Act 

CBI—Confidential Business Information 

CEEL—Community Emergency Exposure 

Levels 

CIIT—Chemical Industry Institute of 

Toxicology 

CFR—Code of Federal Regulations 

CMP—Composite Mesh Pad 

CO—Carbon Monoxide 

CO2—Carbon Dioxide 

D/F—Dioxin/Furan 

EED—Emission Elimination Device 

EPA—Environmental Protection Agency 

EPS—Eco Pickled Surface 

ERPG—Emergency Response Planning 

Guidelines 

HAP—Hazardous Air Pollutants 

HCl—Hydrochloric Acid 

HI—Hazard Index 

HEM–3—Human Exposure Model version 3 

HEPA—High Efficiency Particulate Air 

HON—Hazardous Organic National 

Emissions Standards for Hazardous Air 

Pollutants 

HQ—Hazard Quotient 

ICR—Information Collection Request 

IRIS—Integrated Risk Information System 

Km—Kilometer 

LAER—Lowest Achievable Emission Rate 

MACT—Maximum Achievable Control 

Technology 

MACT Code—A code within the NEI used to 

identify processes included in a source 

category 

mg/dscm—Milligrams per Dry Standard 

Cubic Meter 

MIR—Maximum Individual Risk 

MTVLO—Marine Tank Vessel Loading 

Operations 

NAC/AEGL Committee—National Advisory 

Committee for Acute Exposure Guideline 

Levels for Hazardous Substances 

NAICS—North American Industry 

Classification System 

NAS—National Academy of Sciences 

NATA—National Air Toxics Assessment 

NESHAP—National Emissions Standards for 

Hazardous Air Pollutants 

NEI—National Emissions Inventory 

NOX—Nitrogen Oxide 

NRC—National Research Council 

NSR—New Source Review 

NTTAA—National Technology Transfer and 

Advancement Act 

OECA—Office of Enforcement and 

Compliance Assurance 

OLD—Organic Liquids Distribution 

OMB—Office of Management and Budget 

PB–HAP—Hazardous air pollutants known to 

be persistent and bio-accumulative in the 

environment 

PFC—Perfluorinated Chemical 

PFOS—Perfluorooctyl Sulfonate 

PM—Particulate Matter 

POM—Polycyclic Organic Matter 

RACT—Reasonably Available Control 

Technology 

RBLC—RACT/BACT/LAER Clearinghouse 

REL—CalEPA Chronic Reference Exposure 

Level 

RFA—Regulatory Flexibility Act 

RfC—Reference Concentration 

RfD—Reference Dose 

RTR—Residual Risk and Technology Review 

SAB—Science Advisory Board 

SCC—Source Classification Codes 

SCS—Smooth Clean Surface 

SF3—2000 Census of Population and 

Housing Summary File 3 

SO2—Sulfur Dioxide 

SOP—Standard Operating Procedures 

SSM—Startup, Shutdown, and Malfunction 

TOSHI—Target Organ-Specific Hazard Index 

TPY—Tons Per Year 

TRIM—Total Risk Integrated Modeling 

System 

TTN—Technology Transfer Network 

UF—Uncertainty Factor 

UMRA—Unfunded Mandates Reform Act 

URE—Unit Risk Estimate 

VOC—Volatile Organic Compounds 

WAFS—Wetting Agent/Fume Suppressant 

WCSC—Waterborne Commerce Statistics 

Center 

WWW—Worldwide Web 

II. General Information 

A. Does this action apply to me? 

The regulated industrial source 

categories that are the subject of this 

proposal are listed in Table 2 to this 

preamble. Table 2 is not intended to be 

exhaustive, but rather provides a guide 

for readers regarding entities likely to be 

affected by the proposed action for the 

source categories listed. These 

standards, and any changes considered 

in this rulemaking, would be directly 

applicable to sources as a Federal 

program. Thus, Federal, State, local, and 

tribal government entities are not 

affected by this proposed action. The 

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65070 Federal Register / Vol. 75, No. 203 / Thursday, October 21, 2010 / Proposed Rules 

regulated categories affected by this 

proposed action include: 

TABLE 2—NESHAP AND INDUSTRIAL SOURCE CATEGORIES AFFECTED BY THIS PROPOSED ACTION

NESHAP and source category NAICS code 1 MACT code 2

Chromium Electroplating .............................................. Chromium Anodizing Tanks ......................................... 332813 1607 

Decorative Chromium Electroplating ............................ 332813 1610 

Hard Chromium Electroplating ..................................... 332813 1615 

Group I Polymers and Resins ...................................... Butyl Rubber Production .............................................. 325212 1307 

Epichlorohydrin Elastomers Production ....................... 325212 1311 

Ethylene Propylene Rubber Production ....................... 325212 1313 

HypalonTM Production 3 ................................................ 325212 1315 

Neoprene Production .................................................... 325212 1320 

Nitrile Butadiene Rubber Production ............................ 325212 1321 

Polybutadiene Rubber Production ................................ 325212 1325 

Polysulfide Rubber Production 3 ................................... 325212 1332 

Styrene Butadiene Rubber and Latex Production ....... 325212 1339 

Marine Vessel Loading Operations ......................................................................................................................... 4883 0603 

Pharmaceuticals Production .................................................................................................................................... 3254 1201 

Printing and Publishing Industry .............................................................................................................................. 32311 0714 

Steel Pickling—HCl Process Facilities and Hydrochloric Acid Regeneration Plants .............................................. 3311, 3312 0310 

1 North American Industry Classification System. 

2 Maximum Achievable Control Technology. 

3There are no longer any operating facilities in either the HypalonTM or Polysulfide Rubber source categories. Therefore, this proposal does 

not address these source categories. 

B. Where can I get a copy of this 

document and other related 

information? 

In addition to being available in the 

docket, an electronic copy of this 

proposal will also be available on the 

World Wide Web (WWW) through the 

Technology Transfer Network (TTN). 

Following signature by the EPA 

Administrator, a copy of this proposed 

action will be posted on the TTN’s 

policy and guidance page for newly 

proposed or promulgated rules at the 

following address: http://www.epa.gov/ 

ttn/atw/rrisk/rtrpg.html. The TTN 

provides information and technology 

exchange in various areas of air 

pollution control. 

Additional information is available on 

the residual risk and technology review 

(RTR) Web page at http://www.epa.gov/ 

ttn/atw/rrisk/rtrpg.html. This 

information includes source category 

descriptions and detailed emissions and 

other data that were used as inputs to 

the risk assessments. 

C. What should I consider as I prepare 

my comments for EPA? 

Submitting CBI. Do not submit 

information containing CBI to EPA 

through http://www.regulations.gov or 

e-mail. Clearly mark the part or all of 

the information that you claim to be 

CBI. For CBI information on a disk or 

CD–ROM that you mail to EPA, mark 

the outside of the disk or CD–ROM as 

CBI and then identify electronically 

within the disk or CD–ROM the specific 

information that is claimed as CBI. In 

addition to one complete version of the 

comment that includes information 

claimed as CBI, a copy of the comment 

that does not contain the information 

claimed as CBI must be submitted for 

inclusion in the public docket. If you 

submit a CD–ROM or disk that does not 

contain CBI, mark the outside of the 

disk or CD–ROM clearly that it does not 

contain CBI. Information not marked as 

CBI will be included in the public 

docket and EPA’s electronic public 

docket without prior notice. Information 

marked as CBI will not be disclosed 

except in accordance with procedures 

set forth in 40 CFR part 2. Send or 

deliver information identified as CBI 

only to the following address: Roberto 

Morales, OAQPS Document Control 

Officer (C404–02), Office of Air Quality 

Planning and Standards, U.S. 

Environmental Protection Agency, 

Research Triangle Park, NC 27711, 

Attention Docket ID No. EPA–HQ– 

OAR–2010–0600. 

D. How is this document organized? 

The information in this preamble is 

organized as follows: 

I. Preamble Acronyms and Abbreviations 

II. General Information 

A. Does this action apply to me? 

B. Where can I get a copy of this document 

and other related information? 

C. What should I consider as I prepare my 

comments for EPA? 

D. How is this document organized? 

III. Background 

A. What is the statutory authority for this 

action? 

B. How did we consider the risk results in 

making decisions for this proposal? 

C. What other actions are we addressing in 

this proposal? 

D. What specific RTR actions have 

previously been taken for these source 

categories? 

IV. Analyses Performed 

A. How did we estimate risk posed by the 

source categories? 

B. How did we perform the technology 

review? 

C. How did we perform the analyses for the 

other actions being proposed? 

V. Analyses Results and Proposed Decisions 

A. What are the results and proposed 

decisions for the Chromium 

Electroplating source categories? 

B. What are the results and proposed 

decisions for the Group I Polymers and 

Resins Production source categories? 

C. What are the results and proposed 

decisions for Marine Tank Vessel 

Loading Operations source category? 

D. What are the results and proposed 

decisions for the Pharmaceuticals 

Production source category? 

E. What are the results and proposed 

decisions for the Printing and Publishing 

Industry source category? 

F. What are the results and proposed 

decisions for Steel Pickling-HCl Process 

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Federal Register / Vol. 75, No. 203 / Thursday, October 21, 2010 / Proposed Rules 65071 

1 ‘‘Adverse environmental effect’’ is defined in 

CAA section 112(a)(7) as any significant and 

widespread adverse effect, which may be 

reasonably anticipated to wildlife, aquatic life, or 

natural resources, including adverse impacts on 

populations of endangered or threatened species or 

significant degradation of environmental qualities 

over broad areas. 

Facilities and Hydrochloric Acid 

Regeneration Plants source category? 

VI. Summary of Proposed Actions 

A. What actions are we proposing as a 

result of the technology reviews? 

B. What actions are we proposing as a 

result of the residual risk reviews? 

C. What other actions are we proposing? 

VII. Request for Comments 

VIII. Submitting Data Corrections 

IX. Statutory and Executive Order Reviews 

A. Executive Order 12866: Regulatory 

Planning and Review 

B. Paperwork Reduction Act 

C. Regulatory Flexibility Act 

D. Unfunded Mandates Reform Act 

E. Executive Order 13132: Federalism 

F. Executive Order 13175: Consultation 

and Coordination With Indian Tribal 

Governments 

G. Executive Order 13045: Protection of 

Children From Environmental Health 

Risks and Safety Risks 

H. Executive Order 13211: Actions 

Concerning Regulations That 

Significantly Affect Energy Supply, 

Distribution, or Use 

I. National Technology Transfer and 

Advancement Act 

J. Executive Order 12898: Federal Actions 

To Address Environmental Justice in 

Minority Populations and Low-Income 

Populations 

III. Background 

A. What is the statutory authority for 

this action? 

Section 112 of the Clean Air Act 

(CAA) establishes a two-stage regulatory 

process to address emissions of 

hazardous air pollutants (HAP) from 

stationary sources. In the first stage, 

after EPA has identified categories of 

sources emitting one or more of the HAP 

listed in section 112(b) of the CAA, 

section 112(d) of the CAA calls for us 

to promulgate NESHAP for those 

sources. ‘‘Major sources’’ are those that 

emit or have the potential to emit any 

single HAP at a rate of 10 tons per year 

(TPY) or more of a single HAP or 25 

TPY or more of any combination of 

HAP. For major sources, these 

technology-based standards must reflect 

the maximum degree of emission 

reductions of HAP achievable (after 

considering cost, energy requirements, 

and non-air quality health and 

environmental impacts) and are 

commonly referred to as maximum 

achievable control technology (MACT) 

standards. 

MACT standards are to reflect 

application of measures, processes, 

methods, systems, or techniques, 

including, but not limited to, measures 

which, (A) reduce the volume of or 

eliminate pollutants through process 

changes, substitution of materials or 

other modifications, (B) enclose systems 

or processes to eliminate emissions, (C) 

capture or treat pollutants when 

released from a process, stack, storage, 

or fugitive emissions point, (D) are 

design, equipment, work practice, or 

operational standards (including 

requirements for operator training or 

certification), or (E) are a combination of 

the above. CAA section 112(d)(2)(A)– 

(E). The MACT standard may take the 

form of a design, equipment, work 

practice, or operational standard where 

EPA first determines either that (A) a 

pollutant cannot be emitted through a 

conveyance designed and constructed to 

emit or capture the pollutant, or that 

any requirement for or use of such a 

conveyance would be inconsistent with 

law, or (B) the application of 

measurement methodology to a 

particular class of sources is not 

practicable due to technological and 

economic limitations. CAA sections 

112(h)(1)–(2). 

The MACT ‘‘floor’’ is the minimum 

control level allowed for MACT 

standards promulgated under CAA 

section 112(d)(3), and may not be based 

on cost considerations. For new sources, 

the MACT floor cannot be less stringent 

than the emission control that is 

achieved in practice by the bestcontrolled similar source. The MACT 

floors for existing sources can be less 

stringent than floors for new sources, 

but they cannot be less stringent than 

the average emission limitation 

achieved by the best-performing 12 

percent of existing sources in the 

category or subcategory (or the bestperforming five sources for categories or 

subcategories with fewer than 30 

sources). In developing MACT 

standards, we must also consider 

control options that are more stringent 

than the floor. We may establish 

standards more stringent than the floor 

based on the consideration of the cost of 

achieving the emissions reductions, any 

non-air quality health and 

environmental impacts, and energy 

requirements. 

The EPA is then required to review 

these technology-based standards and to 

revise them ‘‘as necessary (taking into 

account developments in practices, 

processes, and control technologies)’’ no 

less frequently than every 8 years, under 

CAA section 112(d)(6). In conducting 

this review, EPA is not obliged to 

completely recalculate the prior MACT 

determination. NRDC v. EPA, 529 F.3d 

1077, 1084 (District of Columbia Circuit, 

2008). 

The second stage in standard-setting 

focuses on reducing any remaining 

‘‘residual’’ risk according to CAA section 

112(f). This provision requires, first, that 

EPA prepare a Report to Congress 

discussing (among other things) 

methods of calculating risk posed (or 

potentially posed) by sources after 

implementation of the MACT standards, 

the public health significance of those 

risks, the means and costs of controlling 

them, the actual health effects to 

persons in proximity of emitting 

sources, and the recommendations 

regarding legislation of such remaining 

risk. EPA prepared and submitted this 

report (Residual Risk Report to 

Congress, EPA–453/R–99–001) in March 

1999. Congress did not act in response 

to the report, thereby triggering EPA’s 

obligation under CAA section 112(f)(2) 

to analyze and address residual risk. 

CAA section 112(f)(2) requires us to 

determine for source categories subject 

to certain MACT standards, whether the 

emissions standards provide an ample 

margin of safety to protect public health. 

If the MACT standards for HAP 

‘‘classified as a known, probable, or 

possible human carcinogen do not 

reduce lifetime excess cancer risks to 

the individual most exposed to 

emissions from a source in the category 

or subcategory to less than 1-in-1 

million,’’ EPA must promulgate residual 

risk standards for the source category (or 

subcategory) as necessary to provide an 

ample margin of safety to protect public 

health. In doing so, EPA may adopt 

standards equal to existing MACT 

standards if EPA determines that the 

existing standards are sufficiently 

protective. NRDC v. EPA, 529 F.3d 

1077, 1083 (District of Columbia Circuit, 

2008). (‘‘If EPA determines that the 

existing technology-based standards 

provide an ‘ample margin of safety,’ 

then the Agency is free to readopt those 

standards during the residual risk 

rulemaking.’’) EPA must also adopt more 

stringent standards, if necessary, to 

prevent an adverse environmental 

effect,1 but must consider cost, energy, 

safety, and other relevant factors in 

doing so. 

Section 112(f)(2) of the CAA expressly 

preserves our use of a two-step process 

for developing standards to address any 

residual risk and our interpretation of 

‘‘ample margin of safety’’ developed in 

the National Emission Standards for 

Hazardous Air Pollutants: Benzene 

Emissions from Maleic Anhydride 

Plants, Ethylbenzene/Styrene Plants, 

Benzene Storage Vessels, Benzene 

Equipment Leaks, and Coke By-Product 

Recovery Plants (Benzene NESHAP) (54 

FR 38044, September 14, 1989). The 

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65072 Federal Register / Vol. 75, No. 203 / Thursday, October 21, 2010 / Proposed Rules 

2Although defined as ‘‘maximum individual 

risk,’’ MIR refers only to cancer risk. MIR, one 

metric for assessing cancer risk, is the estimated 

risk were an individual exposed to the maximum 

level of a pollutant for a lifetime. 

first step in this process is the 

determination of acceptable risk. The 

second step provides for an ample 

margin of safety to protect public health, 

which is the level at which the 

standards are set (unless a more 

stringent standard is required to 

prevent, taking into consideration costs, 

energy, safety, and other relevant 

factors, an adverse environmental 

effect). 

The terms ‘‘individual most exposed,’’ 

‘‘acceptable level,’’ and ‘‘ample margin of 

safety’’ are not specifically defined in 

the CAA. However, CAA section 

112(f)(2)(B) preserves the interpretation 

set out in the Benzene NESHAP, and the 

United States Court of Appeals for the 

District of Columbia Circuit in NRDC v. 

EPA, 529 F.3d 1077, concluded that 

EPA’s interpretation of section 112(f)(2) 

is a reasonable one. See NRDC v. EPA, 

529 F.3d at 1083 (District of Columbia 

Circuit, ‘‘[S]ubsection 112(f)(2)(B) 

expressly incorporates EPA’s 

interpretation of the Clean Air Act from 

the Benzene standard, complete with a 

citation to the Federal Register’’). 

(District of Columbia Circuit 2008). See 

also, A Legislative History of the Clean 

Air Act Amendments of 1990, volume 1, 

p. 877 (Senate debate on Conference 

Report). We notified Congress in the 

Residual Risk Report to Congress that 

we intended to use the Benzene 

NESHAP approach in making CAA 

section 112(f) residual risk 

determinations (EPA–453/R–99–001, p. 

ES–11). 

In the Benzene NESHAP, we stated as 

an overall objective: 

* * * in protecting public health with an 

ample margin of safety, we strive to provide 

maximum feasible protection against risks to 

health from hazardous air pollutants by (1) 

protecting the greatest number of persons 

possible to an individual lifetime risk level 

no higher than approximately 1-in-1 million; 

and (2) limiting to no higher than 

approximately 1-in-10 thousand [i.e., 100-in1 million] the estimated risk that a person 

living near a facility would have if he or she 

were exposed to the maximum pollutant 

concentrations for 70 years. 

The Agency also stated that, ‘‘The EPA 

also considers incidence (the number of 

persons estimated to suffer cancer or 

other serious health effects as a result of 

exposure to a pollutant) to be an 

important measure of the health risk to 

the exposed population. Incidence 

measures the extent of health risk to the 

exposed population as a whole, by 

providing an estimate of the occurrence 

of cancer or other serious health effects 

in the exposed population.’’ The Agency 

went on to conclude that ‘‘estimated 

incidence would be weighed along with 

other health risk information in judging 

acceptability.’’ As explained more fully 

in our Residual Risk Report to Congress, 

EPA does not define ‘‘rigid line[s] of 

acceptability,’’ but considers rather 

broad objectives to be weighed with a 

series of other health measures and 

factors (EPA–453/R–99–001, p. ES–11). 

The determination of what represents an 

‘‘acceptable’’ risk is based on a judgment 

of ‘‘what risks are acceptable in the 

world in which we live’’ (Residual Risk 

Report to Congress, p. 178, quoting the 

Vinyl Chloride decision at 824 F.2d 

1165) recognizing that our world is not 

risk-free. 

In the Benzene NESHAP, we stated 

that ‘‘EPA will generally presume that if 

the risk to [the maximum exposed] 

individual is no higher than 

approximately 1-in-10 thousand, that 

risk level is considered acceptable.’’ 54 

FR 38045. We discussed the maximum 

individual lifetime cancer risk as being 

‘‘the estimated risk that a person living 

near a plant would have if he or she 

were exposed to the maximum pollutant 

concentrations for 70 years.’’ Id. We 

explained that this measure of risk ‘‘is 

an estimate of the upper bound of risk 

based on conservative assumptions, 

such as continuous exposure for 24 

hours per day for 70 years.’’ Id. We 

acknowledge that maximum individual 

lifetime cancer risk ‘‘does not 

necessarily reflect the true risk, but 

displays a conservative risk level which 

is an upper-bound that is unlikely to be 

exceeded.’’ Id. 

Understanding that there are both 

benefits and limitations to using 

maximum individual lifetime cancer 

risk as a metric for determining 

acceptability, we acknowledged in the 

1989 Benzene NESHAP that 

‘‘consideration of maximum individual 

risk * * * must take into account the 

strengths and weaknesses of this 

measure of risk.’’ Id. Consequently, the 

presumptive risk level of 100-in-1 

million (1-in-10 thousand) provides a 

benchmark for judging the acceptability 

of maximum individual lifetime cancer 

risk, but does not constitute a rigid line 

for making that determination. 

The Agency also explained in the 

1989 Benzene NESHAP the following: 

‘‘In establishing a presumption for MIR 

[maximum individual cancer risk], 

rather than a rigid line for acceptability, 

the Agency intends to weigh it with a 

series of other health measures and 

factors. These include the overall 

incidence of cancer or other serious 

health effects within the exposed 

population, the numbers of persons 

exposed within each individual lifetime 

risk range and associated incidence 

within, typically, a 50-kilometer (km) 

exposure radius around facilities, the 

science policy assumptions and 

estimation uncertainties associated with 

the risk measures, weight of the 

scientific evidence for human health 

effects, other quantified or unquantified 

health effects, effects due to co-location 

of facilities, and co-emission of 

pollutants.’’ Id. 

In some cases, these health measures 

and factors taken together may provide 

a more realistic description of the 

magnitude of risk in the exposed 

population than that provided by 

maximum individual lifetime cancer 

risk alone. As explained in the Benzene 

NESHAP, ‘‘[e]ven though the risks 

judged ‘‘acceptable’’ by EPA in the first 

step of the Vinyl Chloride inquiry are 

already low, the second step of the 

inquiry, determining an ‘‘ample margin 

of safety,’’ again includes consideration 

of all of the health factors, and whether 

to reduce the risks even further.’’ In the 

ample margin of safety decision process, 

the Agency again considers all of the 

health risks and other health 

information considered in the first step. 

Beyond that information, additional 

factors relating to the appropriate level 

of control will also be considered, 

including costs and economic impacts 

of controls, technological feasibility, 

uncertainties, and any other relevant 

factors. Considering all of these factors, 

the Agency will establish the standard 

at a level that provides an ample margin 

of safety to protect the public health, as 

required by CAA section 112(f). 54 FR 

38046. 

B. How did we consider the risk results 

in making decisions for this proposal? 

As discussed in section III.A. of this 

preamble, we apply a two-step process 

for developing standards to address 

residual risk. In the first step, EPA 

determines if risks are acceptable. This 

determination ‘‘considers all health 

information, including risk estimation 

uncertainty, and includes a presumptive 

limit on maximum individual lifetime 

[cancer] risk (MIR) 2 of approximately 1- 

in-10 thousand [i.e., 100-in-1 million].’’ 

54 FR 38045. In the second step of the 

process, EPA sets the standard at a level 

that provides an ample margin of safety 

‘‘in consideration of all health 

information, including the number of 

persons at risk levels higher than 

approximately 1-in-1 million, as well as 

other relevant factors, including costs 

and economic impacts, technological 

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3EPA’s responses to this and all other key 

recommendations of the SAB’s advisory on RTR 

risk assessment methodologies (which is available 

at: http://yosemite.epa.gov/sab/sabproduct.nsf/ 

4AB3966E263D943A8525771F00668381/$File/EPASAB-10-007-unsigned.pdf) are outlined in a memo 

to this rulemaking docket from David Guinnup 

entitled, EPA’s Actions in Response to the Key 

Recommendations of the SAB Review of RTR Risk 

Assessment Methodologies. 

feasibility, and other factors relevant to 

each particular decision.’’ Id. 

In past residual risk determinations, 

EPA presented a number of human 

health risk metrics associated with 

emissions from the category under 

review, including: The MIR; the 

numbers of persons in various risk 

ranges; cancer incidence; the maximum 

non-cancer hazard index (HI); and the 

maximum acute non-cancer hazard. In 

estimating risks, EPA considered source 

categories under review that are located 

near each other and that affect the same 

population. EPA provided estimates of 

the expected difference in actual 

emissions from the source category 

under review and emissions allowed 

pursuant to the source category MACT 

standard. EPA also discussed and 

considered risk estimation 

uncertainties. EPA is providing this 

same type of information in support of 

these actions. 

However, in contrast to past 

determinations, this notice presents and 

considers additional measures of health 

information to support our decisionmaking. These are discussed in more 

detail in later sections of this notice, 

and include: 

• Estimates of ‘‘total facility’’ cancer 

and non-cancer risk (risk from all HAP 

emissions from the facility at which the 

source category is located). 

• Demographic analyses (analyses of 

the distributions of HAP-related cancer 

risks and non-cancer risks, across 

different social, demographic, and 

economic groups within the populations 

living near the facilities where these 

source categories are located). 

• Additional estimates of the risks 

associated with emissions allowed by 

the MACT standard. 

The Agency is considering all of this 

available health information to inform 

our determinations of risk acceptability 

and ample margin of safety under CAA 

section 112(f). Specifically, as explained 

in the Benzene NESHAP, ‘‘the first step 

judgment on acceptability cannot be 

reduced to any single factor,’’ and, thus, 

‘‘[t]he Administrator believes that the 

acceptability of risk under section 112 is 

best judged on the basis of a broad set 

of health risk measures and 

information.’’ 54 FR 38044 and 38046, 

September 14, 1989. Similarly, with 

regard to making the ample margin of 

safety determination, the Benzene 

NESHAP state that ‘‘[I]n the ample 

margin decision, the Agency again 

considers all of the health risk and other 

health information considered in the 

first step. Beyond that information, 

additional factors relating to the 

appropriate level of control will also be 

considered, including cost and 

economic impacts of controls, 

technological feasibility, uncertainties, 

and any other relevant factors.’’ Id. 

The Agency acknowledges that the 

Benzene NESHAP provide flexibility 

regarding what factors the EPA might 

consider in making our determinations 

and how they might be weighed for each 

source category. In responding to 

comment on our policy under the 

Benzene NESHAP, EPA explained that: 

‘‘The policy chosen by the 

Administrator permits consideration of 

multiple measures of health risk. Not 

only can the MIR figure be considered, 

but also incidence, the presence of noncancer health effects, and the 

uncertainties of the risk estimates. In 

this way, the effect on the most exposed 

individuals can be reviewed as well as 

the impact on the general public. These 

factors can then be weighed in each 

individual case. This approach complies 

with the Vinyl Chloride mandate that 

the Administrator ascertain an 

acceptable level of risk to the public by 

employing [her] expertise to assess 

available data. It also complies with the 

Congressional intent behind the CAA, 

which did not exclude the use of any 

particular measure of public health risk 

from the EPA’s consideration with 

respect to CAA section 112 regulations, 

and, thereby, implicitly permits 

consideration of any and all measures of 

health risk which the Administrator, in 

[her] judgment, believes are appropriate 

to determining what will ‘protect the 

public health.’ ’’ 54 FR 38057. 

For example, the level of the MIR is 

only one factor to be weighed in 

determining acceptability of risks. The 

Benzene NESHAP explain ‘‘an MIR of 

approximately 1-in-10 thousand should 

ordinarily be the upper end of the range 

of acceptability. As risks increase above 

this benchmark, they become 

presumptively less acceptable under 

CAA section 112, and would be 

weighed with the other health risk 

measures and information in making an 

overall judgment on acceptability. Or, 

the Agency may find, in a particular 

case, that a risk that includes MIR less 

than the presumptively acceptable level 

is unacceptable in the light of other 

health risk factors.’’ Id. at 38045. 

Similarly, with regard to the ample 

margin of safety analysis, the Benzene 

NESHAP state that: ‘‘* * * EPA believes 

the relative weight of the many factors 

that can be considered in selecting an 

ample margin of safety can only be 

determined for each specific source 

category. This occurs mainly because 

technological and economic factors 

(along with the health-related factors) 

vary from source category to source 

category.’’ Id. at 38061. 

EPA wishes to point out that certain 

health information has not been 

considered in these decisions. In 

assessing risks to populations in the 

vicinity of the facilities in each category, 

we present estimates of risk associated 

with HAP emissions from the source 

category alone (source category risk 

estimates) and HAP emissions from the 

entire facilities at which the covered 

source categories are located (facilitywide risk estimates). We have not 

presented estimates of total HAP 

inhalation risks from all sources in the 

vicinity of the covered sources (i.e., the 

sum of risks from ambient levels, 

emissions from the source category, 

facility-wide emissions, and emissions 

from other facilities nearby). 

The Agency understands the potential 

importance of considering an 

individual’s total exposure to HAP in 

addition to considering exposure to 

HAP emissions from the source category 

and facility. This is particularly 

important when assessing non-cancer 

risks, where pollutant-specific exposure 

levels (e.g., Reference Concentration 

(RfC)) are based on the assumption that 

thresholds exist for adverse health 

effects. For example, the Agency 

recognizes that, although exposures 

attributable to emissions from a source 

category or facility alone may not 

indicate the potential for increased risk 

of adverse non-cancer health effects in 

a population, the exposures resulting 

from emissions from the facility in 

combination with emissions from all of 

the other sources (e.g., other facilities) to 

which an individual is exposed may be 

sufficient to result in increased risk of 

adverse non-cancer health effects. In 

May 2010, the EPA Science Advisory 

Board (SAB) advised us ‘‘* * * that RTR 

assessments will be most useful to 

decision makers and communities if 

results are presented in the broader 

context of aggregate and cumulative 

risks, including background 

concentrations and contributions from 

other sources in the area.’’ 3

While we are interested in placing 

source category and facility-wide HAP 

risks in the context of total HAP risks 

from all sources combined in the 

vicinity of each source, we are 

concerned about the uncertainties of 

doing so. At this point, we believe that 

such estimates of total HAP risks will 

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65074 Federal Register / Vol. 75, No. 203 / Thursday, October 21, 2010 / Proposed Rules 

have significantly greater associated 

uncertainties than for the source 

category or facility-wide estimates, 

hence, compounding the uncertainty in 

any such comparison. This is because 

we have not conducted a detailed 

technical review of HAP emissions data 

for source categories and facilities that 

have not previously undergone an RTR 

review or are not currently undergoing 

such review. We are requesting 

comment on whether and how best to 

estimate and evaluate total HAP 

exposure in our assessments, and, in 

particular, on whether and how it might 

be appropriate to use information from 

EPA’s National Air Toxics Assessment 

(NATA) to support such estimates. We 

are also seeking comment on how best 

to consider various types and scales of 

risk estimates when making our 

acceptability and ample margin of safety 

determinations under CAA section 

112(f). Additionally, we are seeking 

recommendations for any other 

comparative measures that may be 

useful in the assessment of the 

distribution of HAP risks across 

potentially affected demographic 

groups. 

C. What other actions are we addressing 

in this proposal? 

In this proposal, we are addressing 

three additional types of action for some 

or all of these six MACT standards. For 

eight source categories subject to three 

of the MACT standards, we identified 

significant emission sources within the 

categories for which standards were not 

previously developed. We are proposing 

MACT standards for these emission 

sources pursuant to CAA section 

112(d)(2) and (3). For four source 

categories subject to two of the MACT 

standards, we are also proposing 

changes to correct editorial errors, to 

make clarifications, and to address 

issues with implementation or 

determining compliance. We are also 

proposing to revise requirements in 

each of the six MACT standards related 

to emissions during periods of startup, 

shutdown, and malfunction (SSM). 

The United States Court of Appeals 

for the District of Columbia Circuit 

vacated portions of two provisions in 

EPA’s CAA section 112 regulations 

governing the emissions of HAP during 

periods of SSM. Sierra Club v. EPA, 551 

F.3d 1019 (District of Columbia Circuit, 

2008), cert. denied, 130 S. Ct. 1735 (U.S. 

2010). Specifically, the Court vacated 

the SSM exemption contained in 40 

CFR 63.6(f)(1) and (h)(1), that is part of 

a regulation, commonly referred to as 

the General Provisions Rule, that EPA 

promulgated under section 112 of the 

CAA. When incorporated into a CAA 

section 112(d) standard for a specific 

source category, these two provisions 

exempt sources within that source 

category from the requirement to 

comply with the otherwise applicable 

emission standard during periods of 

SSM. We are proposing to eliminate the 

SSM exemption in each of the six 

MACT standards addressed in this 

proposal. Consistent with Sierra Club v. 

EPA, we are proposing that the 

established standards in these rules 

apply at all times. We are also proposing 

to revise the General Provisions table in 

each of the six MACT standards in 

several respects. For example, we are 

removing the General Provisions’ 

requirement that the source develop an 

SSM plan. We are also removing certain 

recordkeeping and reporting 

requirements related to the SSM 

exemption, but we are retaining the 

recordkeeping and related requirements 

for malfunctions and request public 

comment on the requirements. EPA has 

attempted to ensure that regulatory 

language relating to the SSM exemption 

has been removed. We solicit comment 

on whether we have overlooked any 

regulatory provisions that might be 

inappropriate, unnecessary, or 

redundant based on our proposal to 

remove the exemption from compliance 

with the emission limit during periods 

of SSM. 

Periods of startup, normal operations, 

and shutdown are all predictable and 

routine aspects of a source’s operations. 

In contrast, malfunction is defined as a 

‘‘sudden, infrequent, and not reasonably 

preventable failure of air pollution 

control and monitoring equipment, 

process equipment or a process to 

operate in a normal or usual manner 

***’’ (40 CFR 63.2). EPA believes that 

a malfunction should not be viewed as 

a distinct operating mode, and, 

therefore, any emissions that occur 

during malfunctions do not need to be 

factored into development of CAA 

section 112(d) standards, which, once 

promulgated, apply at all times. In 

Mossville Environmental Action Now v. 

EPA, 370 F.3d 1232, 1242 (District of 

Columbia Circuit 2004), the Court 

upheld as reasonable standards that had 

factored in variability of emissions 

under all operating conditions. 

However, nothing in CAA section 

112(d) or in case law requires that EPA 

anticipate and account for the 

innumerable types of potential 

malfunction events in setting emission 

standards. See, Weyerhaeuser v. Costle, 

590 F.2d 1011, 1058 (District of 

Columbia Circuit 1978) (‘‘In the nature 

of things, no general limit, individual 

permit, or even any upset provision can 

anticipate all upset situations. After a 

certain point, the transgression of 

regulatory limits caused by 

‘uncontrollable acts of third parties,’ 

such as strikes, sabotage, operator 

intoxication, or insanity, and a variety 

of other eventualities, must be a matter 

for the administrative exercise of caseby-case enforcement discretion, not for 

specification in advance by regulation.’’) 

Further, it is reasonable to interpret 

CAA section 112(d) as not requiring 

EPA to account for malfunctions in 

setting emissions standards. For 

example, we note that CAA section 112 

uses the concept of ‘‘best performing’’ 

sources in defining MACT, the level of 

stringency that major source standards 

must meet. Applying the concept of 

‘‘best performing’’ to a source that is 

malfunctioning presents significant 

difficulties. The goal of best performing 

sources is to operate in such a way as 

to avoid malfunctions of their units. 

Moreover, even if malfunctions were 

considered a distinct operating mode, 

we believe it would be impracticable to 

take malfunctions into account in 

setting CAA section 112(d) standards. 

As noted above, by definition, 

malfunctions are sudden and 

unexpected events, and it would be 

difficult to set a standard that takes into 

account the myriad different types of 

malfunctions that can occur across all 

sources in each source category. 

Malfunctions can also vary in 

frequency, degree, and duration, further 

complicating standard setting. 

Under this proposal, in the event that 

a source fails to comply with the 

applicable CAA section 112(d) 

standards as a result of a malfunction 

event, 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. EPA 

would also consider whether the 

source’s failure to comply with the CAA 

section 112(d) standard was, in fact, 

‘‘sudden, infrequent, not reasonably 

preventable’’ and was not instead 

‘‘caused in part by poor maintenance or 

careless operation.’’ 40 CRF 63.2 

(definition of malfunction). 

Finally, EPA recognizes that, even 

equipment that is properly designed and 

maintained can sometimes fail, and that 

such failure can sometimes cause or 

contribute to an exceedance of the 

relevant emission standard. (See, e.g., 

State Implementation Plans: Policy 

Regarding Excessive Emissions During 

Malfunctions, Startup, and Shutdown 

(September 20, 1999); Policy on Excess 

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4There are no longer any operating facilities in 

the United States that produce polysulfide rubber, 

and we do not anticipate any will begin to operate 

in the future. 

5The Mineral Wool Production source category 

was also addressed in that same October 2008 

proposal. We are not proposing any additional 

action for that source category in this proposal, but 

will do so in a separate future action. We note that 

there are no longer any operating facilities in the 

United States that produce HypalonTM, and we do 

not anticipate that any will begin operation in the 

future. 

Emissions During Startup, Shutdown, 

Maintenance, and Malfunctions 

(February 15, 1983)). Therefore, 

consistent with our recently 

promulgated final amendments to 

regulations addressing the Portland 

Cement category (75 FR 54970, 

September 9, 2010), we are proposing to 

add regulatory language providing an 

affirmative defense against civil 

penalties for exceedances of emission 

limits that are caused by malfunctions 

in each of the six MACT standards 

addressed in this proposal. We are 

proposing to define ‘‘affirmative 

defense’’ to mean, in the context of an 

enforcement proceeding, a response or 

defense put forward by a defendant, 

regarding which the defendant has the 

burden of proof, and the merits of which 

are independently and objectively 

evaluated in a judicial or administrative 

proceeding. We are also proposing 

regulatory provisions to specify the 

elements that are necessary to establish 

this affirmative defense. (See 40 CFR 

22.24). The proposed criteria would 

ensure that the affirmative defense is 

available only where the event that 

causes an exceedance of the emission 

limit meets the narrow definition of 

malfunction in 40 CFR 63.2 (sudden, 

infrequent, not reasonably preventable, 

and not caused by poor maintenance 

and/or careless operation). The 

proposed criteria also are designed to 

ensure that steps are taken to correct the 

malfunction, to minimize emissions, 

and to prevent future malfunctions. In 

any judicial or administrative 

proceeding, the Administrator would be 

able to challenge the assertion of the 

affirmative defense and, if the 

respondent has not met its burden of 

proving all of the requirements in the 

affirmative defense, appropriate 

penalties could be assessed in 

accordance with section 113 of the CAA 

(see also 40 CFR 22.77). 

D. What specific RTR actions have 

previously been taken for these source 

categories? 

For some of the 16 source categories 

covered by these six MACT standards, 

we have previously taken certain 

actions under the RTR program. 

Following is a summary of these 

previous actions and also a summary of 

additional reviews we have 

subsequently conducted for each source 

category. 

1. Categories for Which RTR Decisions 

Have Been Finalized 

There are nine source categories 

regulated under the Group I Polymers 

and Resins MACT standard. For four of 

these source categories (Butyl Rubber 

Production, Ethylene Propylene Rubber 

Production, Neoprene Production, and 

Polysulfide Rubber Production), we 

previously proposed and promulgated a 

decision not to revise the standards for 

purposes of the RTR provisions in CAA 

sections 112(d)(6) and (f)(2).4 See 72 FR 

70543, December 12, 2007 (proposed 

rule), and 73 FR 76220, December 16, 

2008 (final rule). These four categories 

were determined to be ‘‘low-risk,’’ as the 

maximum lifetime individual cancer 

risks were less than 1-in-1-million, and 

there were no other health concerns of 

significance. Therefore, we determined 

that conducting additional risk analyses 

for these categories was not warranted. 

We are not re-opening the RTR in this 

notice for these four source categories, 

and do not seek additional comments on 

that prior RTR. 

However, for three of these four 

Group I Polymers and Resins source 

categories (Butyl Rubber Production, 

Ethylene Propylene Rubber Production, 

and Neoprene Production), we have 

identified significant emission sources 

for which MACT standards were not 

previously developed. In this proposal, 

we are proposing MACT standards for 

these emission sources, and we are also 

proposing that the residual risks after 

implementation of these new MACT 

standards will not change our previous 

finding that these source categories 

present low risks and that our obligation 

to review the residual risk under CAA 

section 112(f) has also been satisfied. 

2. Categories for Which RTR Decisions 

Have Been Proposed, but Not 

Promulgated 

For eight source categories covered 

under four of the MACT standards 

addressed in this proposal, we 

previously performed an RTR review 

and proposed that no revisions of the 

MACT standards were necessary to 

address residual risk and that it was not 

necessary to revise the existing 

standards under CAA section 112(d)(6). 

See 73 FR 60423, October 10, 2008. The 

MACT standards addressed in this 

proposal included Marine Tank Vessel 

Loading Operations (MTVLO), Printing 

and Publishing Industry, 

Pharmaceuticals Production, and five of 

the source categories covered under 

Group I Polymers and Resins 

(Epichlorohydrin Elastomers, 

HypalonTM Production, Nitrile 

Butadiene Rubber Production, 

Polybutadiene Rubber Production, and 

Styrene Butadiene Rubber and Latex 

Production).5 Comments were received 

on that proposal, but no final action has 

been taken. This proposal presents 

additional analyses we have performed 

since the proposal, for each of these 

source categories with regard to the 

RTR. In addition, we are proposing 

revisions to the SSM provisions in the 

existing standards for these source 

categories, and, for several of the source 

categories, we are proposing MACT 

standards under CAA sections 112(d)(2) 

and (3) for emission points that were not 

previously regulated. 

3. Categories for Which RTR Decisions 

Have Not Been Proposed 

We have not previously proposed any 

RTR actions for the four source 

categories (Hard and Decorative 

Chromium Electroplating, Chromium 

Anodizing Tanks, and Steel Pickling— 

HCl Process Facilities and Hydrochloric 

Acid Regeneration Plants) covered by 

the Chromium Electroplating and Steel 

Pickling MACT standards. Therefore, 

this is our initial proposed action for 

these two MACT standards to address 

the RTR requirement. In addition, we 

identified significant advances in the 

housekeeping requirements in the 

chromium source categories for which 

we are proposing MACT standards. We 

are also proposing revisions to the 

provisions addressing SSM to ensure 

they are consistent with the Court 

decision in Sierra Club v. EPA, 551 F.3d 

1019, and we are proposing changes to 

correct editorial errors, make 

clarifications, or address issues with 

implementation or determining 

compliance. 

IV. Analyses Performed 

As discussed above, in this notice, we 

are taking the following actions: (1) We 

are newly proposing action or 

supplementing our previous proposal to 

address the RTR requirements of CAA 

sections 112(d)(6) and (f)(2) for 16 

source categories covered by six 

different MACT standards; (2) for eight 

of the source categories, we are 

proposing MACT standards for 

significant emission sources that are not 

currently subject to emission standards 

under the MACT standards; (3) we are 

proposing to revise the provisions in 

each of these six MACT standards to 

address SSM to ensure that the SSM 

provisions are consistent with the Court 

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65076 Federal Register / Vol. 75, No. 203 / Thursday, October 21, 2010 / Proposed Rules 

6See EPA–HQ–OAR–2010–0600, Model Plant 

Data Used to Estimate Risk from Chromium 

Electroplating Sources. 

decision in Sierra Club v. EPA, 551 F. 

3d 1019; and (4) for two of the MACT 

standards, we are proposing 

amendments to correct editorial errors, 

to make clarifications, and to address 

issues with implementation or 

determining compliance. 

A. How did we estimate risk posed by 

the source categories? 

To support the proposed decision 

under the RTR for each source category, 

EPA conducted risk assessments that 

provided estimates of the MIR posed by 

the HAP emissions from each source in 

a category and by each source category, 

the distribution of cancer risks within 

the exposed populations, cancer 

incidence, HI for chronic exposures to 

HAP with non-cancer health effects, 

hazard quotients (HQ) for acute 

exposures to HAP with non-cancer 

health effects, and an evaluation of the 

potential for adverse environmental 

effects. The risk assessments consisted 

of seven primary steps, as discussed 

below. 

The docket for this rulemaking 

contains the following documents 

which provide more information on the 

risk assessment inputs and models, 

Draft Residual Risk Assessment for 9 

Source Categories, Draft Residual Risk 

Assessment for Steel Pickling, and Draft 

Residual Risk Assessment for Chromium 

Electroplating, as well as the 

memoranda for the Printing and 

Publishing Industry, MTVLO, 

Epichlorohydrin Elastomers Production, 

Polybutadiene Rubber Production, 

Styrene Butadiene Rubber Production, 

Nitrile Butadiene Production, and 

Pharmaceuticals Production source 

categories. 

1. Establishing the Nature and 

Magnitude of Actual Emissions and 

Identifying the Emissions Release 

Characteristics 

For the source categories included in 

the October 10, 2008, proposal, we 

compiled preliminary data sets using 

readily-available information, reviewed 

the data, and made changes where 

necessary, and shared these data with 

the public via an Advanced Notice of 

Proposed Rulemaking (ANPRM). 72 FR 

29287, March 29, 2007. The data sets 

were then updated based on comments 

received on the ANPRM and, in some 

cases, with additional information 

gathered by EPA. For the five Group I 

Polymers and Resins I Production 

source categories included in the 

October 2008 proposal (Epichlorohydrin 

Elastomers Production, HypalonTM

Production, Nitrile Butadiene Rubber 

Production, Polybutadiene Rubber 

Production, and Styrene Butadiene 

Rubber and Latex Production), the 

preliminary data sets were based on 

information we collected directly from 

industry on emissions data and 

emissions release characteristics. For 

the MTVLO, Pharmaceuticals 

Production, and the Printing and 

Publishing Industry source categories, 

we created the preliminary data sets 

using data in the 2002 National 

Emissions Inventory (NEI) Final 

Inventory, Version 1 (made publicly 

available on February 26, 2006), 

supplemented by data collected directly 

from industry when available. The NEI 

is a database that contains information 

about sources that emit criteria air 

pollutants and their precursors, and 

HAP. The database includes estimates of 

annual air pollutant emissions from 

point, nonpoint, and mobile sources in 

the 50 States, the District of Columbia, 

Puerto Rico, and the Virgin Islands. The 

EPA collects this information and 

releases an updated version of the NEI 

database every 3 years. 

In the March 29, 2007, ANPRM, we 

specifically requested comment on, and 

updates to, these preliminary data sets. 

We received comments on emissions 

data and emissions release 

characteristics data for facilities in these 

source categories. These comments were 

reviewed, considered, and the emissions 

information was adjusted where we 

concluded the comments supported 

such adjustment. After incorporation of 

changes to the data sets from this public 

data review process, data sets were 

created that were used to conduct the 

risk assessments and other analyses that 

formed the basis for the proposed 

actions included in the October 10, 

2008, proposal. 

Since the proposal, we have 

continued to scrutinize the data sets for 

these source categories and to review 

additional data that has become 

available since the October 10, 2008, 

proposal. For the Printing and 

Publishing Industry source category, we 

became aware that some facilities had 

closed. We also reviewed the emissions 

data and had questions about the 

emissions of certain HAP. After contact 

with industry, it was determined that 

those emissions did not occur from 

those facilities. We updated the Printing 

and Publishing Industry data set to 

reflect these changes in operating 

facilities and emissions. For the MTVLO 

data set, we had concerns that several 

emission points in our existing data set 

were mislabeled, and, thus, we 

extracted more recent data from the NEI. 

For this source category, the data set is 

based on the 2005 NEI. For the 

Pharmaceuticals Production source 

category data set, no changes are 

necessary to the data set used for the 

proposal. For the Polymers and Resins 

I MACT standard source categories 

included in the October 10, 2008, 

proposal, updates have been made 

based on information received in 

response to an industry information 

collection survey. Documentation for 

industry contacts, surveys, and other 

information gathered to support these 

changes is available in the docket for 

this action. 

For the four source categories not 

included in the December 10, 2008, 

proposal, we compiled preliminary data 

sets using the best available 

information, reviewed the data, and 

made changes where necessary. For the 

three Chromium Electroplating MACT 

standard source categories (Chromium 

Anodizing Tanks, Decorative Chromium 

Electroplating, and Hard Chromium 

Electroplating) and the Steel Pickling 

source category, we compiled the 

preliminary data sets using data in the 

2005 NEI. Then, for the Steel Pickling 

source category, seven facilities were 

contacted to verify their emissions and 

emissions release characteristic data, 

and we updated the data set based on 

the information collected. This updated 

data set was used to conduct the risk 

assessments and other analyses that 

form the bases for the proposed actions. 

For the Chromium Electroplating 

source categories, a review of the 2005 

NEI data indicated that not all 

chromium electroplating facilities were 

included in the data set. To develop an 

emissions inventory for the entire 

industry that could be used for 

modeling, an additional data set was 

developed based on facilities with 

known addresses—a total of 1,629 

facilities compared to 122 facilities in 

the NEI. Emissions for each type of 

plant were estimated based on the 

model plants developed for the original 

Chromium Electroplating MACT 

standard,6 with hard chromium model 

plants having the highest emissions, 

followed by decorative chromium 

electroplating, and then chromium 

anodizing. If the type of electroplating 

performed at a specific plant was 

unknown, we assumed these facilities 

were hard chrome electroplating when 

we estimated emissions and risks for 

those facilities. Although we knew that, 

by doing so, we would be 

overestimating emissions of chromium, 

and, therefore, also of risk, we made this 

conservative assumption because we 

did not have complete information, and 

we chose to overestimate to preserve an 

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7U.S. EPA. Revision to the Guideline on Air 

Quality Models: Adoption of a Preferred General 

Purpose (Flat and Complex Terrain) Dispersion 

Model and Other Revisions (70 FR 68218, 

November 9, 2005). 

8A census block is generally the smallest 

geographic area for which census statistics are 

tabulated. 

9The IRIS information is available at http:// 

www.epa.gov/IRIS. 

ample margin of safety in the risk 

assessment upon which our risk 

modeling would be based. This analysis 

and a supplemental assessment are fully 

described in section V.A. 

2. Establishing the Relationship 

Between Actual Emissions and MACTAllowable Emissions Levels 

The available emissions data in the 

NEI and from other sources typically 

represent the mass of emissions actually 

emitted during the specified annual 

time period. These ‘‘actual’’ emission 

levels are often lower than the level of 

emissions that a facility might be 

allowed to emit and still comply with 

the MACT standard. The emissions 

level allowed to be emitted by the 

MACT standard is referred to as the 

‘‘MACT-allowable’’ emissions level. This 

represents the highest emission level 

that could be emitted by the facility 

without violating the MACT standard. 

We discussed the use of both MACTallowable and actual emissions in the 

final Coke Oven Batteries residual risk 

rule (70 FR 19998–19999, April 15, 

2005) and in the proposed and final 

Hazardous Organic NESHAP (HON) 

residual risk rules (71 FR 34428, June 

14, 2006, and 71 FR 76609, December 

21, 2006, respectively). In those 

previous actions, we noted that 

assessing the risks at the MACTallowable level is inherently reasonable 

since these risks reflect the maximum 

level sources could emit and still 

comply with national emission 

standards. But we also explained that it 

is reasonable to consider actual 

emissions, where such data are 

available, in both steps of the risk 

analysis, in accordance with the 

Benzene NESHAP. (54 FR 38044, 

September 14, 1989.) It is reasonable to 

consider actual emissions because 

sources typically seek to perform better 

than required by emission standards to 

provide an operational cushion to 

accommodate the variability in 

manufacturing processes and control 

device performance. 

As described above, the actual 

emissions data were compiled based on 

the NEI, information gathered from 

facilities and States, and information 

received in response to the ANPRM for 

several of the source categories. To 

estimate emissions at the MACTallowable level, we developed a ratio of 

MACT-allowable to actual emissions for 

each emissions source type in each 

source category, based on the level of 

control required by the MACT standard 

compared to the level of reported actual 

emissions and available information on 

the level of control achieved by the 

emissions controls in use. For example, 

if there was information to suggest 

several facilities in a source category 

were controlling storage tank emissions 

by 98 percent while the MACT 

standards required only 92-percent 

control, we would estimate that MACTallowable emissions from these 

emission points could be as much as 

four times higher (8-percent allowable 

emissions compared with 2-percent 

actually emitted), and the ratio of 

MACT-allowable to actual would be 4:1 

for this emission point type at the 

facilities in this source category. After 

developing these ratios for each 

emission point type in each source 

category, we next applied these ratios 

on a facility-by-facility basis to the 

maximum chronic risk values from the 

inhalation risk assessment to obtain 

facility-specific maximum risk values 

based on MACT-allowable emissions. 

3. Conducting Dispersion Modeling, 

Determining Inhalation Exposures, and 

Estimating Individual and Population 

Inhalation Risks 

Both long-term and short-term 

inhalation exposure concentrations and 

health risks from each of the source 

categories addressed in this proposal 

were estimated using the Human 

Exposure Model (Community and 

Sector HEM–3 version 1.1.0). The HEM– 

3 performs three of the primary risk 

assessment activities listed above: (1) 

Conducting dispersion modeling to 

estimate the concentrations of HAP in 

ambient air, (2) estimating long-term 

and short-term inhalation exposures to 

individuals residing within 50 km of the 

modeled sources, and (3) estimating 

individual and population-level 

inhalation risks using the exposure 

estimates and quantitative doseresponse information. 

The dispersion model used by HEM– 

3 is AERMOD, which is one of EPA’s 

preferred models for assessing pollutant 

concentrations from industrial 

facilities.7 To perform the dispersion 

modeling and to develop the 

preliminary risk estimates, HEM–3 

draws on three data libraries. The first 

is a library of meteorological data, 

which is used for dispersion 

calculations. This library includes 1 

year of hourly surface and upper air 

observations for 130 meteorological 

stations, selected to provide coverage of 

the United States and Puerto Rico. A 

second library of United States Census 

Bureau census block 8 internal point 

locations and populations provides the 

basis of human exposure calculations 

(Census, 2000). In addition, the census 

library includes the elevation and 

controlling hill height for each census 

block, which are also used in dispersion 

calculations. A third library of pollutant 

unit risk factors and other health 

benchmarks is used to estimate health 

risks. These risk factors and health 

benchmarks are the latest values 

recommended by EPA for HAP and 

other toxic air pollutants. These values 

are available at http://www.epa.gov/ttn/ 

atw/toxsource/summary.html and are 

discussed in more detail later in this 

section. 

In developing the risk assessment for 

chronic exposures, we used the 

estimated annual average ambient air 

concentration of each of the HAP 

emitted by each source for which we 

have emissions data in the source 

category. The air concentrations at each 

nearby census block centroid were used 

as a surrogate for the chronic inhalation 

exposure concentration for all the 

people who reside in that census block. 

We calculated the MIR for each facility 

as the cancer risk associated with a 

lifetime (70-year period) of exposure to 

the maximum concentration at the 

centroid of an inhabited census block. 

Individual cancer risks were calculated 

as the lifetime exposure to the ambient 

concentration of each of the HAP 

multiplied by its Unit Risk Estimate 

(URE), which is an upper bound 

estimate of an individual’s probability 

of contracting cancer over a lifetime of 

exposure to a concentration of 1 

microgram of the pollutant per cubic 

meter of air. For residual risk 

assessments, we generally use URE 

values from EPA’s Integrated Risk 

Information System (IRIS).9 For 

carcinogenic pollutants without EPA 

IRIS values, we look to other reputable 

sources of cancer dose-response values, 

often using California Environmental 

Protection Agency (CalEPA) URE 

values, where available. In cases where 

new, scientifically credible dose 

response values have been developed in 

a manner consistent with EPA 

guidelines and have undergone a peer 

review process similar to that used by 

EPA, we may use such dose-response 

values in place of, or in addition to, 

other values. 

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10U.S. EPA, 2006. Performing risk assessments 

that include carcinogens described in the 

Supplemental Guidance as having a mutagenic 

mode of action. Science Policy Council Cancer 

Guidelines Implementation Workgroup 

Communication II: Memo from W.H. Farland dated 

June 14, 2006. http://epa.gov/osa/spc/pdfs/ 

CGIWGCommunication_II.pdf. 

11U.S. EPA, 2005. Supplemental Guidance for 

Assessing Early-Life Exposure to Carcinogens. EPA/ 

630/R–03/003F. http://www.epa.gov/ttn/atw/ 

childrens_supplement_final.pdf. 

12Only one of these mutagenic compounds, 

benzo[a]pyrene, is emitted by any of the sources 

covered by this proposal. 

13U.S. EPA, 2005. Science Policy Council Cancer 

Guidelines Implementation Workgroup 

Communication I: Memo from W.H. Farland dated 

October 4, 2005, to Science Policy Council. 

http://www.epa.gov/osa/spc/pdfs/canguid1.pdf. 

14These classifications also coincide with the 

terms ‘‘known carcinogen, probable carcinogen, and 

possible carcinogen,’’ respectively, which are the 

terms advocated in the EPA’s previous Guidelines 

for Carcinogen Risk Assessment, published in 1986 

(51 FR 33992, September 24, 1986). Summing the 

risks of these individual compounds to obtain the 

cumulative cancer risks is an approach that was 

recommended by the EPA’s SAB in their 2002 peer 

review of EPA’s NATA entitled, NATA—Evaluating 

the National-scale Air Toxics Assessment 1996 

Data—an SAB Advisory, available at: http:// 

yosemite.epa.gov/sab/sabproduct.nsf/ 

214C6E915BB04E14852570CA007A682C/$File/ 

ecadv02001.pdf. 

15NAS, 2001. Standing Operating Procedures for 

Developing Acute Exposure Levels for Hazardous 

Chemicals, page 2. 

We note here that several carcinogens 

have a mutagenic mode of action.10 For 

these compounds, the age-dependent 

adjustment factors described in EPA’s 

Supplemental Guidance for Assessing 

Susceptibility from Early-Life Exposure 

to Carcinogens 11 were applied. This 

adjustment has the effect of increasing 

the estimated lifetime risks for these 

pollutants by a factor of 1.6.12 In 

addition, although only a small fraction 

of the total polycyclic organic matter 

(POM) emissions were reported as 

individual compounds, EPA expresses 

carcinogenic potency for compounds in 

this group in terms of benzo[a]pyrene 

equivalence, based on evidence that 

carcinogenic POM have the same 

mutagenic mechanism of action as does 

benzo[a]pyrene. For this reason, EPA’s 

Science Policy Council 13 recommends 

applying the Supplemental Guidance to 

all carcinogenic polycyclic aromatic 

hydrocarbons for which risk estimates 

are based on relative potency. 

Accordingly, we have applied the 

Supplemental Guidance to all 

unspeciated POM mixtures. 

Incremental individual lifetime 

cancer risks associated with emissions 

from the source category were estimated 

as the sum of the risks for each of the 

carcinogenic HAP (including those 

classified as carcinogenic to humans, 

likely to be carcinogenic to humans, and 

suggestive evidence of carcinogenic 

potential 14) emitted by the modeled 

source. Cancer incidence and the 

distribution of individual cancer risks 

for the population within 50 km of any 

source were also estimated for the 

source category as part of these 

assessments by summing individual 

risks. A distance of 50 km is consistent 

with both the analysis supporting the 

1989 Benzene NESHAP (54 FR 38044) 

and the limitations of Gaussian 

dispersion modeling. 

To assess risk of non-cancer health 

effects from chronic exposures, we 

summed the HQ for each of the HAP 

that affects a common target organ 

system to obtain the HI for that target 

organ system (or target organ-specific 

HI, TOSHI). The HQ is the estimated 

exposure divided by the chronic 

reference level, which is either the U.S. 

EPA RfC, defined as ‘‘an estimate (with 

uncertainty spanning perhaps an order 

of magnitude) of a continuous 

inhalation exposure to the human 

population (including sensitive 

subgroups) that is likely to be without 

an appreciable risk of deleterious effects 

during a lifetime,’’ or, in cases where an 

RfC is not available, the CalEPA Chronic 

Reference Exposure Level (REL), 

defined as ‘‘the concentration level at or 

below which no adverse health effects 

are anticipated for a specified exposure 

duration.’’ As noted above, in cases 

where new, scientifically credible doseresponse values have been developed in 

a manner consistent with EPA 

guidelines and have undergone a peer 

review process similar to that used by 

EPA, we may use those dose-response 

values in place of, or in addition to, 

other values. 

Screening estimates of acute 

exposures and risks were also evaluated 

for each of the HAP at the point of 

highest off-site exposure for each facility 

(i.e., not just the census block centroids) 

assuming that a person is located at this 

spot at a time when both the peak 

(hourly) emission rate and hourly 

dispersion conditions (1991 calendar 

year data) occur. In each case, acute HQ 

values were calculated using best 

available, short-term health threshold 

values. These acute threshold values 

include REL, Acute Exposure Guideline 

Levels (AEGL), and Emergency 

Response Planning Guidelines (ERPG) 

for 1-hour exposure durations. As 

discussed below, we used conservative 

assumptions for emission rates, 

meteorology, and exposure location for 

our acute analysis. 

As described in the CalEPA’s Air 

Toxics Hot Spots Program Risk 

Assessment Guidelines, Part I, The 

Determination of Acute Reference 

Exposure Levels for Airborne Toxicants, 

an acute REL value (http:// 

www.oehha.ca.gov/air/pdf/acuterel.pdf) 

is defined as ‘‘the concentration level at 

or below which no adverse health 

effects are anticipated for a specified 

exposure duration is termed the REL. 

REL values are based on the most 

sensitive, relevant, adverse health effect 

reported in the medical and 

toxicological literature. REL values are 

designed to protect the most sensitive 

individuals in the population by the 

inclusion of margins of safety. Since 

margins of safety are incorporated to 

address data gaps and uncertainties, 

exceeding the REL value does not 

automatically indicate an adverse health 

impact.’’ 

AEGL values were derived in 

response to recommendations from the 

National Research Council (NRC). As 

described in ‘‘Standing Operating 

Procedures (SOP) of the National 

Advisory Committee on Acute Exposure 

Guideline Levels for Hazardous 

Substances’’ (http://www.epa.gov/ 

opptintr/aegl/pubs/sop.pdf),15 ‘‘the 

NRC’s previous name for acute exposure 

levels—community emergency exposure 

levels (CEEL)— was replaced by the 

term AEGL to reflect the broad 

application of these values to planning, 

response, and prevention in the 

community, the workplace, 

transportation, the military, and the 

remediation of Superfund sites.’’ This 

document also states that AEGL values 

‘‘represent threshold exposure limits for 

the general public and are applicable to 

emergency exposures ranging from 10 

minutes to 8 hours.’’ The document lays 

out the purpose and objectives of AEGL 

by stating (page 21) that ‘‘the primary 

purpose of the AEGL program and the 

NAC/AEGL Committee is to develop 

guideline levels for once-in-a-lifetime, 

short-term exposures to airborne 

concentrations of acutely toxic, highpriority chemicals.’’ In detailing the 

intended application of AEGL values, 

the document states (page 31) that ’’[i]t 

is anticipated that the AEGL values will 

be used for regulatory and 

nonregulatory purposes by United 

States Federal and State agencies, and 

possibly the international community in 

conjunction with chemical emergency 

response, planning, and prevention 

programs. More specifically, the AEGL 

values will be used for conducting 

various risk assessments to aid in the 

development of emergency 

preparedness and prevention plans, as 

well as real-time emergency response 

actions, for accidental chemical releases 

at fixed facilities and from transport 

carriers.’’ 

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16ERP Committee Procedures and 

Responsibilities. 1 November 2006. American 

Industrial Hygiene Association. 

17See http://www.tceq.state.tx.us/compliance/ 

field_ops/eer/index.html or docket to access the 

source of these data. 

The AEGL–1 value is then specifically 

defined as ‘‘the airborne concentration 

of a substance above which it is 

predicted that the general population, 

including susceptible individuals, could 

experience notable discomfort, 

irritation, or certain asymptomatic 

nonsensory effects. However, the effects 

are not disabling and are transient and 

reversible upon cessation of exposure.’’ 

The document also notes (page 3) that, 

‘‘Airborne concentrations below AEGL– 

1 represent exposure levels that can 

produce mild and progressively 

increasing but transient and 

nondisabling odor, taste, and sensory 

irritation or certain asymptomatic, 

nonsensory effects.’’ Similarly, the 

document defines AEGL–2 values as 

‘‘the airborne concentration (expressed 

as ppm or mg/m3) of a substance above 

which it is predicted that the general 

population, including susceptible 

individuals, could experience 

irreversible or other serious, long-lasting 

adverse health effects or an impaired 

ability to escape.’’ 

ERPG values are derived for use in 

emergency response, as described in the 

American Industrial Hygiene 

Association’s document entitled, 

Emergency Response Planning 

Guidelines (ERPG) Procedures and 

Responsibilities (http://www.aiha.org/ 

1documents/committees/ 

ERPSOPs2006.pdf), which states that, 

‘‘Emergency Response Planning 

Guidelines were developed for 

emergency planning and are intended as 

health-based guideline concentrations 

for single exposures to chemicals.’’ 16

The ERPG–1 value is defined as ‘‘the 

maximum airborne concentration below 

which it is believed that nearly all 

individuals could be exposed for up to 

1 hour without experiencing other than 

mild transient adverse health effects or 

without perceiving a clearly defined, 

objectionable odor.’’ Similarly, the 

ERPG–2 value is defined as ‘‘the 

maximum airborne concentration below 

which it is believed that nearly all 

individuals could be exposed for up to 

1 hour without experiencing or 

developing irreversible or other serious 

health effects or symptoms which could 

impair an individual’s ability to take 

protective action.’’ 

As can be seen from the definitions 

above, the AEGL and ERPG values 

include the similarly-defined severity 

levels 1 and 2. For many chemicals, a 

severity level 1 value AEGL or ERPG has 

not been developed; in these instances, 

higher severity level AEGL–2 or ERPG– 

2 values are compared to our modeled 

exposure levels to screen for potential 

acute concerns. 

Acute REL values for 1-hour exposure 

durations are typically lower than their 

corresponding AEGL–1 and ERPG–1 

values. Even though their definitions are 

slightly different, AEGL–1 values are 

often the same as the corresponding 

ERPG–1 values, and AEGL–2 values are 

often equal to ERPG–2 values. 

Maximum HQ values from our acute 

screening risk assessments typically 

result when basing them on the acute 

REL value for a particular pollutant. In 

cases where our maximum acute HQ 

value exceeds 1, we also report the HQ 

value based on the next highest acute 

threshold (usually the AEGL–1 and/or 

the ERPG–1 value). 

To develop screening estimates of 

acute exposures, we developed 

estimates of maximum hourly emission 

rates by multiplying the average actual 

annual hourly emission rates by a factor 

to cover routinely variable emissions. 

We chose the factor to use based on 

process knowledge and engineering 

judgment and with awareness of a Texas 

study of short-term emissions 

variability, which showed that most 

peak emission events, in a heavilyindustrialized 4-county area (Harris, 

Galveston, Chambers, and Brazoria 

Counties, Texas), were less than twice 

the annual average hourly emission rate, 

and the highest peak emission event 

was 8.5 times the annual average hourly 

emission rate.17 This analysis is 

provided in Appendix 4 of the Draft 

Residual Risk Assessment for Source 

Categories Report and is available in the 

docket for this action. Considering this 

analysis, unless specific process 

knowledge provided an alternate value, 

a conservative screening multiplication 

factor of 10 was applied to the average 

annual hourly emission rate in these 

acute exposure screening assessments. 

In cases where all acute HQ values 

from the screening step were less than 

or equal to 1, acute impacts were 

deemed negligible and no further 

analysis was performed. In the cases 

where an acute HQ from the screening 

step was greater than 1, additional sitespecific data were considered to 

develop a more refined estimate of the 

potential for acute impacts of concern. 

The data refinements considered 

included using a peak-to-mean hourly 

emissions ratio based on source 

category-specific knowledge or data 

(rather than the default factor of 10) and 

using the site-specific facility layout to 

distinguish facility property from an 

area where the public could be exposed. 

Ideally, we would prefer to have 

continuous measurements over time to 

see how the emissions vary by each 

hour over an entire year. Having a 

frequency distribution of hourly 

emission rates over a year would allow 

us to perform a probabilistic analysis to 

estimate potential threshold 

exceedances and their frequency of 

occurrence. Such an evaluation could 

include a more complete statistical 

treatment of the key parameters and 

elements adopted in this screening 

analysis. However, we recognize that 

having this level of data is rare, hence 

our use of the multiplier approach. 

4. Conducting Multipathway Exposure 

and Risk Modeling 

The potential for significant human 

health risks due to exposures via routes 

other than inhalation (i.e., 

multipathway exposures) and the 

potential for adverse environmental 

impacts were evaluated in a three-step 

process. In the first step, we determined 

whether any facilities emitted any HAP 

known to be persistent and bioaccumulative in the environment (PB– 

HAP). There are 14 PB–HAP 

compounds or compound classes 

identified for this screening in EPA’s 

Air Toxics Risk Assessment Library 

(available at http://www.epa.gov/ttn/ 

fera/risk_atra_vol1.html). They are 

cadmium compounds, chlordane, 

chlorinated dibenzodioxins and furans, 

dichlorodiphenyldichloroethylene, 

heptachlor, hexachlorobenzene, 

hexachlorocyclohexane, lead 

compounds, mercury compounds, 

methoxychlor, polychlorinated 

biphenyls, POM, toxaphene, and 

trifluralin. 

In the second step of the screening 

process, we determined whether the 

facility-specific emission rates of each of 

the emitted PB–HAP were large enough 

to create the potential for significant 

non-inhalation risks. To facilitate this 

step, we have developed emission rate 

thresholds for each PB–HAP using a 

hypothetical screening exposure 

scenario developed for use in 

conjunction with the TRIM.FaTE model. 

The hypothetical screening scenario was 

subjected to a sensitivity analysis to 

ensure that its key design parameters 

were established such that 

environmental media concentrations 

were not underestimated (i.e., to 

minimize the occurrence of false 

negatives, or results that suggest that 

risks might be acceptable when, in fact, 

actual risks are high), and to also 

minimize the occurrence of false 

positives for human health endpoints. 

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18 Generally, we have found that using a 5 km 

radius in the analysis will capture more than 90 

percent of all the individuals with cancer risks 

above 1-in-1 million. In the future, we plan to 

extend these analyses to cover the entire modeled 

domain for a facility (50 km radius) to capture all 

individuals with risks above 1-in-1 million from the 

affected facilities. 

19For example, the report pertaining to the Hard 

Chromium Electroplating source category is entitled 

Risk and Technology Review—Analysis of SocioEconomic Factors for Populations Living Near Hard 

Chromium Electroplating Facilities. 

We call this application of the 

TRIM.FaTE model TRIM–Screen. The 

facility-specific emission rates of each of 

the PB–HAP in each source category 

were compared to the emission 

threshold values for each of the PB– 

HAP identified in the source category 

data sets. 

For all of the facilities in the source 

categories addressed in this proposal, all 

of the PB–HAP emission rates were less 

than the emission threshold values. As 

a result of this, multi-pathway 

exposures and environmental risks were 

deemed negligible and no further 

analysis was performed. If the emission 

rates of the PB–HAP had been above the 

emission threshold values, the source 

categories would have been further 

evaluated for potential non-inhalation 

risks and adverse environmental effects 

in a third step through site-specific 

refined assessments using EPA’s 

TRIM.FaTE model. 

For further information on the multipathway analysis approach, see the 

residual risk documentation as 

referenced in section IV.A of this 

preamble. 

5. Assessing Risks Considering 

Emissions Control Options 

In addition to assessing baseline 

inhalation risks and screening for 

potential multi-pathway risks, for some 

source categories, where appropriate, 

we also estimated risks considering the 

potential emission reductions that 

would be achieved by the particular 

control options under consideration. 

The inhalation and multi-pathway risks 

estimated, as described above, at the 

actual and MACT-allowable levels 

represent the actual and maximum 

allowable operating conditions of the 

facilities in the source categories 

analyzed. For source categories where 

emission reduction options were 

available, we estimated risk based on 

the expected emissions reductions that 

would be realized with those additional 

emissions controls. In these cases, the 

expected emissions reductions were 

applied to the specific HAP and 

emissions sources in the source category 

data set. The results of the risk analyses 

considering the application of emissions 

controls are included in the residual 

risk documentation as referenced in 

section IV.A of this preamble, which is 

available in the docket for this action. 

6. Conducting Other Risk-Related 

Analyses, Including Facility-Wide 

Assessments and Demographic Analyses 

a. Facility-Wide Risk 

To put the source category risks in 

context, we also examined the risks 

from the entire ‘‘facility,’’ where the 

facility includes all HAP-emitting 

operations within a contiguous area and 

under common control. In other words, 

for each facility that includes one or 

more sources from one of the source 

categories under review, we examined 

the HAP emissions not only from the 

source category of interest, but also 

emissions of HAP from all other 

emission sources at the facility. The 

emissions data for generating these 

‘‘facility-wide’’ risks were obtained from 

the 2005 NEI (available at http:// 

www.epa.gov/chief/net/ 

2005inventory.html). We analyzed risks 

due to the inhalation of HAP that are 

emitted ‘‘facility-wide’’ for the 

populations residing within 50 km of 

each facility, consistent with the 

methods used for the source category 

analysis described above. For these 

facility-wide risk analyses, the modeled 

source category risks were compared to 

the facility-wide risks to determine the 

portion of facility-wide risks that could 

be attributed to each of the six source 

categories being addressed in this 

proposal, we specifically examined the 

facility that was associated with the 

highest estimate of risk and determined 

the percentage of that risk attributable to 

the source category of interest. The risk 

documentation available through the 

docket for this action provides all the 

facility-wide risks and the percentage of 

source category contribution for all 

source categories assessed. 

The methodology and the results of 

the facility-wide analyses for each 

source category are included in the 

residual risk documentation as 

referenced in section IV.A of this 

preamble, which is available in the 

docket for this action. 

b. Demographic Analysis 

To examine the potential for any 

environmental justice issues that might 

be associated with each source category, 

we evaluated the distributions of HAPrelated cancer and non-cancer risks 

across different social, demographic, 

and economic groups within the 

populations living near the facilities 

where these source categories are 

located. The development of 

demographic analyses to inform the 

consideration of environmental justice 

issues in EPA rulemakings is an 

evolving science. The EPA offers the 

demographic analyses in this 

rulemaking as examples of how such 

analyses might be developed to inform 

such consideration, and invites public 

comment on the approaches used and 

the interpretations made from the 

results, with the hope that this will 

support the refinement and improve 

utility of such analyses for future 

rulemakings. 

For this analysis, we analyzed risks 

due to the inhalation of HAP in two 

separate ways. In the first approach, we 

focus the analysis on the total 

populations residing within 5 km of 

each facility (source category and 

facility-wide), regardless of their 

estimated risks, and examine the 

distributions of estimated risk across the 

various demographic groups within 

those 5 km circles. The distance of 5 km 

was chosen for the first approach to be 

consistent with previous demographic 

analyses performed at EPA, such as the 

one which was performed in support of 

the recent proposal for the Boilers 

NESHAP. In the second approach, we 

focus the analysis only on the 

populations within 5 km 18 of any 

facility estimated to have exposures to 

HAP which result in cancer risks of 1- 

in-1 million or greater or non-cancer 

hazard indices of 1 or greater (based on 

the emissions of the source category or 

the facility, respectively). Once again, 

we examine the distributions of those 

risks across various demographic 

groups. In each approach, we compare 

the percentages of particular 

demographic groups to the total number 

of people in those demographic groups 

nationwide. In this preamble, we only 

present the results of the second 

approach since it focuses on the 

significant risks from either the source 

category or the facility-wide emissions. 

The results of both approaches 

including other risk metrics such as 

average risks for the exposed 

populations are documented in source 

category-specific technical reports in the 

docket for each of the source categories 

covered in this proposal.19

The basis for the risk values used in 

these analyses were the modeling 

results obtained from the HEM–3 model 

described above. The risk values for 

each census block were linked to a 

database of information from the 2000 

Decennial census that includes data on 

race and ethnicity, age distributions, 

poverty status, household incomes, and 

education level. The Census Department 

Landview ® database was the source of 

the data on race and ethnicity, and the 

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20Short-term mobility is movement from one 

microenvironment to another over the course of 

hours or days. Long-term mobility is movement 

from one residence to another over the course of a 

lifetime. 

data on age distributions, poverty status, 

household incomes, and education level 

was obtained from the 2000 Census of 

Population and Housing Summary File 

3 (SF3) Long Form. While race and 

ethnicity census data are available at the 

block group level, the age and income 

census data are only available at the 

census block level (which includes an 

average of 26 blocks or an average of 

1,350 people). Where census data are 

available at the block group level but 

not the block level, we assumed that all 

blocks within the block group have the 

same distribution of ages and incomes 

as the block group. 

For each source category, the analysis 

results include the distribution of 

estimated lifetime inhalation cancer and 

chronic non-cancer risks for different 

racial and ethnic groups, different age 

groups, adults with and without a high 

school diploma, people living in 

households below the national median 

income, and for people living below the 

poverty line among the population 

living near these facilities. The specific 

census population categories studied 

include: 

• Total population. 

• White. 

• African American (or Black). 

• Native Americans. 

• Other races and multiracial. 

• Hispanic or Latino. 

• Children 18 years of age and under. 

• Adults 19 to 64 years of age. 

• Adults 65 years of age and over. 

• Adults without a high school 

diploma. 

• Households earning under the 

national median income. 

• People living below the poverty 

line. 

It should be noted that these 

categories overlap in some instances, 

resulting in some populations being 

counted in more than one category (e.g., 

other races and multiracial and 

Hispanic). In addition, while not a 

specific census population category, we 

also examined risks to the category 

‘‘Minorities,’’ which is defined as all race 

population categories except white. 

Since these demographic analysis 

methods are still evolving, EPA 

specifically solicits comment on the 

inclusion of other demographic 

categories (e.g., ‘‘Hispanic and Nonwhite’’) in our future analyses. 

For further information about risks to 

the populations local to the facilities in 

these source categories, we also 

evaluated the estimated distribution of 

inhalation cancer and chronic noncancer risks associated with the HAP 

emissions from all the emissions 

sources at the facility (i.e., facilitywide). This analysis used the facilitywide RTR modeling results and the 

census data described above. 

The methodology and the results of 

the demographic analyses for each 

source category are included in the 

residual risk documentation as 

referenced in section IV.A of this 

preamble, which is available in the 

docket for this action. 

7. Considering Uncertainties in Risk 

Assessment 

Uncertainty and the potential for bias 

are inherent in all risk assessments, 

including those performed for the 

source categories addressed in this 

proposal. Although uncertainty exists, 

we believe the approach that we took, 

which used conservative tools and 

assumptions, ensures that our decisions 

are health-protective. A brief discussion 

of the uncertainties in the emissions 

data sets, dispersion modeling, 

inhalation exposure estimates, and 

dose-response relationships follows 

below. A more thorough discussion of 

these uncertainties is included in the 

Draft Residual Risk Assessment for the 

Steel Pickling Source Category (July 

2010), Draft Residual Risk Assessment 

for the Chromium Electroplating Source 

Category (July 2010), Draft Residual 

Risk Assessment for 9 Source Categories 

(August 2008), and the Risk and 

Technology Review (RTR) Assessment 

Plan (November 2006), each of which 

are available in the docket for this 

action. 

a. Uncertainties in the Emissions Data 

Sets 

Although the development of the RTR 

data sets involved quality assurance/ 

quality control processes, the accuracy 

of emissions values will vary depending 

on the source of the data, the degree to 

which data is incomplete or missing, the 

degree to which assumptions made to 

complete the data sets are inaccurate, 

errors in estimating emissions values, 

and other factors. The emission values 

considered in this analysis generally are 

annual totals that do not reflect shortterm fluctuations during the course of a 

year or variations from year to year. In 

contrast, the estimates of peak hourly 

emission rates for the acute effects 

screening assessment were based on 

multiplication factors applied to the 

average annual hourly emission rates 

(the default factor is 10), which are 

intended to account for emission 

fluctuations due to normal facility 

operations. In some cases, more refined 

estimates were used for source 

categories where the screening estimates 

did not ‘‘screen out’’ all sources and 

more specific information was available. 

Additionally, for some source categories 

our estimate of the number of facilities 

may not represent the number of 

facilities that we have in our notice of 

proposed rulemaking data set. There is 

also significant uncertainty for some 

source categories in the identification of 

sources as major or area in the NEI. 

b. Uncertainties in Dispersion Modeling 

While the analysis employed EPA’s 

recommended regulatory dispersion 

model, AERMOD, we recognize that 

there is uncertainty in ambient 

concentration estimates associated with 

any model, including AERMOD. Where 

possible, model options (e.g., rural/ 

urban, plume depletion, chemistry) 

were selected to provide an 

overestimate of ambient air 

concentrations of the HAP. However, 

because of practicality and data 

limitation reasons, some factors (e.g., 

meteorology, building downwash) have 

the potential in some situations to 

overestimate or underestimate ambient 

impacts. For example, meteorological 

data were taken from a single year 

(1991), and facility locations can be a 

significant distance from the site where 

these data were taken. Despite these 

uncertainties, we believe that at off-site 

locations and census block centroids, 

the approach considered in the 

dispersion modeling analysis should 

generally yield overestimates of ambient 

HAP concentrations. 

c. Uncertainties in Inhalation Exposure 

The effects of human mobility on 

exposures were not included in the 

assessment. Specifically, short-term 

mobility and long-term mobility 

between census blocks in the modeling 

domain were not considered.20 As a 

result, this simplification will likely 

bias the assessment toward 

overestimating the highest exposures. In 

addition, the assessment predicted the 

chronic exposures at the centroid of 

each populated census block as 

surrogates for the exposure 

concentrations for all people living in 

that block. Using the census block 

centroid to predict chronic exposures 

tends to over-predict exposures for 

people in the census block who live 

further from the facility and underpredict exposures for people in the 

census block who live closer to the 

facility. Thus, using the census block 

centroid to predict chronic exposures 

may lead to a potential understatement 

or overstatement of the true maximum 

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21U.S. EPA. National-Scale Air Toxics 

Assessment for 1996. (EPA 453/R–01–003; January 

2001; page 85.) 

22 IRIS glossary (http://www.epa.gov/NCEA/iris/ 

help_gloss.htm). 

23An exception to this is the URE for benzene, 

which is considered to cover a range of values, each 

end of which is considered to be equally plausible, 

and which is based on maximum likelihood 

estimates. 

24According to the NRC report, Science and 

Judgment in Risk Assessment (NRC, 1994) ‘‘[Default] 

options are generic approaches, based on general 

scientific knowledge and policy judgment, that are 

applied to various elements of the risk assessment 

process when the correct scientific model is 

unknown or uncertain.’’ The 1983 NRC report, Risk 

Assessment in the Federal Government: Managing 

the Process, defined default option as ‘‘the option 

chosen on the basis of risk assessment policy that 

appears to be the best choice in the absence of data 

to the contrary’’ (NRC, 1983a, p. 63). Therefore, 

default options are not rules that bind the Agency; 

rather, the Agency may depart from them in 

evaluating the risks posed by a specific substance 

when it believes this to be appropriate. In keeping 

with EPA’s goal of protecting public health and the 

environment, default assumptions are used to 

ensure that risk to chemicals is not underestimated 

(although defaults are not intended to overtly 

overestimate risk). See EPA 2004, An examination 

of EPA Risk Assessment Principles and Practices, 

EPA/100/B–04/001 available at: http:// 

www.epa.gov/osa/pdfs/ratf-final.pdf. 

impact, but is an unbiased estimate of 

average risk and incidence. 

The assessments evaluate the cancer 

inhalation risks associated with 

pollutant exposures over a 70-year 

period, which is the assumed lifetime of 

an individual. In reality, both the length 

of time that modeled emissions sources 

at facilities actually operate (i.e., more 

or less than 70 years), and the domestic 

growth or decline of the modeled 

industry (i.e., the increase or decrease in 

the number or size of United States 

facilities), will influence the risks posed 

by a given source category. Depending 

on the characteristics of the industry, 

these factors will likely result in an 

overestimate (or possibly an 

underestimate in the extreme case 

where a facility maintains or increases 

its emission levels beyond 70 years and 

residents live beyond 70 years at the 

same location) both in individual risk 

levels and in the total estimated number 

of cancer cases. Annual cancer 

incidence estimates from exposures to 

emissions from these sources would not 

be affected by uncertainty in the length 

of time emissions sources operate. 

The exposure estimates used in these 

analyses assume chronic exposures to 

ambient levels of pollutants. Because 

most people spend the majority of their 

time indoors, actual exposures may not 

be as high, depending on the 

characteristics of the pollutants 

modeled. For many HAP, indoor levels 

are roughly equivalent to ambient 

levels, but for very reactive pollutants or 

larger particles, these levels are 

typically lower. This factor has the 

potential to result in an overstatement of 

25 to 30 percent of exposures.21

In addition to the uncertainties 

highlighted above, there are several 

factors specific to the acute exposure 

assessment that should be highlighted. 

The accuracy of an acute inhalation 

exposure assessment depends on the 

simultaneous occurrence of 

independent factors that may vary 

greatly, such as hourly emissions rates, 

meteorology, and human activity 

patterns. In this assessment, we assume 

that individuals remain for 1 hour at the 

point of maximum ambient 

concentration as determined by the cooccurrence of peak emissions and worstcase meteorological conditions. These 

assumptions would tend to overestimate 

actual exposures since it is unlikely that 

a person would be located at the point 

of maximum exposure during the time 

of worst-case impact. 

d. Uncertainties in Dose-Response 

Relationships 

There are uncertainties inherent in 

the development of the reference values 

used in our risk assessments for cancer 

effects from chronic exposures and noncancer effects from both chronic and 

acute exposures. Some uncertainties 

may be considered quantitatively, and 

others generally are expressed in 

qualitative terms. We note as a preface 

to this discussion a point on doseresponse uncertainty that is brought out 

in EPA’s 2005 Cancer Guidelines; 

namely, that ‘‘the primary goal of EPA 

actions is protection of human health; 

accordingly, as an Agency policy, risk 

assessment procedures, including 

default options that are used in the 

absence of scientific data to the 

contrary, should be health protective.’’ 

(EPA 2005 Cancer Guidelines, pages 

1–7.) This is the approach followed here 

as summarized in the next several 

paragraphs. A complete detailed 

discussion of uncertainties and 

variabilities in dose-response 

relationships is given in the residual 

risk documentation as referenced in 

section IV.A of this preamble, which is 

available in the docket for this action. 

Cancer URE values used in our risk 

assessments are those that have been 

developed to generally provide an upper 

bound estimate of risk. That is, they 

represent a ‘‘plausible upper limit to the 

true value of a quantity’’ (although this 

is usually not a true statistical 

confidence limit).22 In some 

circumstances, the true risk could be as 

low as zero; however, in other 

circumstances the risk could also be 

greater.23 When developing an upper 

bound estimate of risk and to provide 

risk values that do not underestimate 

risk, health-protective default 

approaches are generally used. To err on 

the side of ensuring adequate healthprotection, EPA typically uses the upper 

bound estimates rather than lower 

bound or central tendency estimates in 

our risk assessments, an approach that 

may have limitations for other uses (e.g., 

priority-setting or expected benefits 

analysis). 

Chronic non-cancer reference (RfC 

and RfD) values represent chronic 

exposure levels that are intended to be 

health-protective levels. Specifically, 

these values provide an estimate (with 

uncertainty spanning perhaps an order 

of magnitude) of daily oral exposure 

(RfD) or of a continuous inhalation 

exposure (RfC) to the human population 

(including sensitive subgroups) that is 

likely to be without an appreciable risk 

of deleterious effects during a lifetime. 

To derive values that are intended to be 

‘‘without appreciable risk,’’ the 

methodology relies upon an uncertainty 

factor (UF) approach (U.S. EPA, 1993, 

1994) which includes consideration of 

both uncertainty and variability. When 

there are gaps in the available 

information, UF are applied to derive 

reference values that are intended to 

protect against appreciable risk of 

deleterious effects. UF are commonly 

default values,24 e.g., factors of 10 or 3, 

used in the absence of compoundspecific data; where data are available, 

UF may also be developed using 

compound-specific information. When 

data are limited, more assumptions are 

needed and more UF are used. Thus, 

there may be a greater tendency to 

overestimate risk in the sense that 

further study might support 

development of reference values that are 

higher (i.e., less potent) because fewer 

default assumptions are needed. 

However, for some pollutants it is 

possible that risks may be 

underestimated. 

While collectively termed ‘‘UF,’’ these 

factors account for a number of different 

quantitative considerations when using 

observed animal (usually rodent) or 

human toxicity data in the development 

of the RfC. The UF are intended to 

account for: (1) Variation in 

susceptibility among the members of the 

human population (i.e., inter-individual 

variability); (2) uncertainty in 

extrapolating from experimental animal 

data to humans (i.e., interspecies 

differences); (3) uncertainty in 

extrapolating from data obtained in a 

study with less-than-lifetime exposure 

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(i.e., extrapolating from sub-chronic to 

chronic exposure); (4) uncertainty in 

extrapolating the observed data to 

obtain an estimate of the exposure 

associated with no adverse effects; and 

(5) uncertainty when the database is 

incomplete or there are problems with 

the applicability of available studies. 

Many of the UF used to account for 

variability and uncertainty in the 

development of acute reference values 

are quite similar to those developed for 

chronic durations, but they more often 

use individual UF values that may be 

less than 10. UF are applied based on 

chemical-specific or health effectspecific information (e.g., simple 

irritation effects do not vary appreciably 

between human individuals, hence a 

value of 3 is typically used), or based on 

the purpose for the reference value (see 

the following paragraph). The UF 

applied in acute reference value 

derivation include: (1) Heterogeneity 

among humans; (2) uncertainty in 

extrapolating from animals to humans; 

(3) uncertainty in lowest observable 

adverse effect (exposure) level to no 

observable effect (exposure) level 

adjustments; and (4) uncertainty in 

accounting for an incomplete database 

on toxic effects of potential concern. 

Additional adjustments are often 

applied to account for uncertainty in 

extrapolation from observations at one 

exposure duration (e.g., 4 hours) to 

derive an acute reference value at 

another exposure duration (e.g., 1 hour). 

Not all acute reference values are 

developed for the same purpose and 

care must be taken when interpreting 

the results of an acute assessment of 

human health effects relative to the 

reference value or values being 

exceeded. Where relevant to the 

estimated exposures, the lack of 

threshold values at different levels of 

severity should be factored into the risk 

characterization as potential 

uncertainties. 

Although every effort is made to 

identify peer-reviewed reference values 

for cancer and non-cancer effects for all 

pollutants emitted by the sources 

included in this assessment, some 

pollutants have no peer-reviewed 

reference values for cancer or chronic 

non-cancer or acute effects. Since 

exposures to these pollutants cannot be 

included in a quantitative risk estimate, 

an understatement of risk for these 

pollutants at environmental exposure 

levels is possible. 

Additionally, chronic reference values 

for several of the compounds included 

in this assessment are currently under 

EPA IRIS review and revised 

assessments may determine that these 

pollutants are more or less potent than 

the current value. We may re-evaluate 

residual risks for the final rulemaking if, 

as a result of these reviews, a doseresponse metric changes enough to 

indicate that the risk assessment 

supporting this notice may significantly 

understate human health risk. 

e. Uncertainties in the Multipathway 

and Environmental Effects Assessment 

We generally assume that when 

exposure levels are not anticipated to 

adversely affect human health, they also 

are not anticipated to adversely affect 

the environment. We generally rely on 

the facility-specific levels of PB–HAP 

emissions to determine whether a full 

assessment of the multi-pathway and 

environmental effects is necessary. 

Because facility-specific PB–HAP 

emission levels were so far below levels 

which would trigger a refined 

assessment of multi-pathway impacts, 

we are confident that these types of 

impacts are insignificant for these 

source categories. 

f. Uncertainties in the Facility-Wide 

Risk Assessment 

The same uncertainties discussed 

above exist with regard to the facilitywide risk assessments. Additionally, the 

degree of uncertainty associated with 

facility-wide emissions and risks is 

generally greater because we have not 

completed our review of emissions data 

for source categories not currently 

undergoing an RTR review. 

g. Uncertainties in the Demographic 

Analysis 

Our analysis of the distribution of 

risks across various demographic groups 

is subject to the typical uncertainties 

associated with census data (e.g., errors 

in filling out and transcribing census 

forms), as well as the additional 

uncertainties associated with the 

extrapolation of census-block group data 

(e.g., income level and education level) 

down to the census block level. 

B. How did we perform the technology 

review? 

Our technology review is focused on 

the identification and evaluation of 

‘‘developments in practices, processes, 

and control technologies.’’ If a review of 

available information identifies such 

developments, then we conduct an 

analysis of the technical feasibility of 

requiring the implementation of these 

developments, along with the impacts 

(costs, emission reductions, risk 

reductions, etc.). We then make a 

decision on whether it is necessary to 

amend the regulation to require these 

developments. 

Based on specific knowledge of each 

source category, we began by identifying 

known developments in practices, 

processes, and control technologies. For 

the purpose of this exercise, we 

considered any of the following to be a 

‘‘development’’: 

• Any add-on control technology or 

other equipment that was not identified 

and considered during MACT 

development; 

• Any improvements in add-on 

control technology or other equipment 

(that was identified and considered 

during MACT development) that could 

result in significant additional emission 

reduction; 

• Any work practice or operational 

procedure that was not identified and 

considered during MACT development; 

and 

• Any process change or pollution 

prevention alternative that could be 

broadly applied that was not identified 

and considered during MACT 

development. 

In addition to looking back at 

practices, processes, or control 

technologies reviewed at the time we 

developed the MACT standard, we 

reviewed a variety of sources of data to 

aid in our evaluation of whether there 

were additional practices, processes, or 

controls to consider. One of these 

sources of data was subsequent air 

toxics rules. Since the promulgation of 

the MACT standards for the source 

categories addressed in this proposal, 

EPA has developed air toxics 

regulations for a number of additional 

source categories. In these subsequent 

air toxic regulatory actions, we 

consistently evaluated any new 

practices, processes, and control 

technologies. We reviewed the 

regulatory requirements and/or 

technical analyses associated with these 

subsequent regulatory actions to 

identify any practices, processes, and 

control technologies considered in these 

efforts that could possibly be applied to 

emission sources in the source 

categories under this current RTR 

review. 

We also consulted EPA’s RACT/ 

BACT/LAER Clearinghouse (RBLC). The 

terms ‘‘RACT,’’ ‘‘BACT,’’ and ‘‘LAER’’ are 

acronyms for different program 

requirements under the CAA provisions 

addressing the national ambient air 

quality standards. Control technologies, 

classified as RACT (Reasonably 

Available Control Technology), BACT 

(Best Available Control Technology), or 

LAER (Lowest Achievable Emission 

Rate) apply to stationary sources 

depending on whether the sources are 

existing or new, and on the size, age, 

and location of the facility. BACT and 

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LAER (and sometimes RACT) are 

determined on a case-by-case basis, 

usually by State or local permitting 

agencies. EPA established the RBLC to 

provide a central data base of air 

pollution technology information 

(including technologies required in 

source-specific permits) to promote the 

sharing of information among 

permitting agencies and to aid in 

identifying future possible control 

technology options that might apply 

broadly to numerous sources within a 

category or apply only on a source-bysource basis. The RBLC contains over 

5,000 air pollution control permit 

determinations that can help identify 

appropriate technologies to mitigate 

many air pollutant emission streams. 

We searched this database to determine 

whether any practices, processes, or 

control technologies are included for the 

types of processes used for emission 

sources (e.g., tanks or vents) in the 

source categories under consideration in 

this proposal. 

We also requested information from 

industry regarding developments in 

practices, processes, or control 

technology. Finally, we reviewed other 

information sources, such as State or 

local permitting agency databases and 

industry-supported databases. 

C. How did we perform the analyses for 

the other actions being proposed? 

For several of the source categories 

considered in this proposal, we 

identified significant emission points 

that were not previously regulated 

under MACT. For these emission points, 

consistent with the requirements of 

CAA sections 112(d)(2) and (3), we 

identified the MACT floor for existing 

and new sources and considered 

beyond-the-floor options. 

We also reviewed the SSM provisions 

of each of the six MACT standards in 

light of Sierra Club v. EPA, 551 F.3d 

1019. As part of this review, we 

evaluated available information and 

engaged industry concerning the type of 

activities and emissions that occur 

during periods of startup or shutdown. 

Finally, we identified potential 

revisions to these MACT standards to 

correct or clarify regulatory 

requirements. In the years since 

promulgation and compliance with the 

MACT standards, EPA has received 

comments and suggestions for 

improving the clarity of the MACT 

standards in general, as well as rulespecific comments for some individual 

MACT standards. These comments 

include such things as identification of 

editorial errors in the rule, clarification 

of existing rule text, regulatory obstacles 

to effective implementation of or 

compliance with the rule provisions. 

EPA has also independently identified 

these types of issues. We are proposing 

rule changes where appropriate. 

V. Analyses Results and Proposed 

Decisions 

This section of the preamble provides 

background information on the MACT 

standards and source categories, the 

results of our RTR for each source 

category, our proposed actions to 

address significant unregulated 

emission points for a number of source 

categories, our proposed decisions 

concerning the SSM provisions in each 

of the six MACT standards, and the 

specific clarifications we are proposing 

for selected MACT standards. 

A. What are the results and proposed 

decisions for the Chromium 

Electroplating source categories? 

1. Overview of the Source Categories 

and MACT Standard 

National Emission Standards for 

Chromium Emissions from Hard and 

Decorative Chromium Electroplating 

and Chromium Anodizing Tanks 

(Chromium Electroplating MACT 

standards) were promulgated on January 

25, 1995 (60 FR 4963), and codified at 

40 CFR part 63, subpart N. The 

Chromium Electroplating MACT 

standards regulate emissions of 

chromium compounds from three 

related source categories: Hard 

Chromium Electroplating, Decorative 

Chromium Electroplating, and 

Chromium Anodizing. Within these 

source categories, the MACT standards 

apply to all plants, both major and area 

sources, regardless of size. 

The Hard Chromium Electroplating 

source category consists of facilities that 

plate base metals with a relatively thick 

layer of chromium using an electrolytic 

process. Hard chromium electroplating 

provides a finish that is resistant to 

wear, abrasion, heat, and corrosion. 

These facilities plate large cylinders and 

industrial rolls used in construction 

equipment and printing presses, 

hydraulic cylinders and rods, zinc die 

castings, plastic molds, engine 

components, and marine hardware. 

The Decorative Chromium 

Electroplating source category consists 

of facilities that plate base materials 

such as brass, steel, aluminum, or 

plastic with layers of copper and nickel, 

followed by a relatively thin layer of 

chromium to provide a bright, tarnishand wear-resistant surface. Decorative 

chromium electroplating is used for 

items such as automotive trim, metal 

furniture, bicycles, hand tools, and 

plumbing fixtures. 

The Chromium Anodizing source 

category consists of facilities that use 

chromic acid to form an oxide layer on 

aluminum to provide resistance to 

corrosion. The chromium anodizing 

process is used to coat aircraft parts 

(such as wings and landing gears), as 

well as architectural structures that are 

subject to high stress and corrosive 

conditions. 

The HAP emission sources subject to 

the Chromium Electroplating NESHAP 

are the tanks in which the chromium 

deposition takes place. For hard 

chromium and decorative chromium 

electroplating facilities, the emission 

sources are electroplating tanks. For the 

Chromium Anodizing source category, 

the emission sources are anodizing 

tanks. 

The primary emission controls used 

by the facilities in these source 

categories include packed bed 

scrubbers, mesh pad mist eliminators, 

composite mesh pad (CMP) systems, 

high efficiency particulate air (HEPA) 

filters, and wetting agent/fume 

suppressants (WAFS). Most decorative 

chromium electroplating plants comply 

with the MACT standards by using 

WAFS in the tank bath to control 

surface tension, which in turn reduces 

emissions. Some plants use a 

combination of WAFS and add-on 

control to meet the MACT emission 

limits. If a facility controls emissions 

using an add-on control device, the tank 

is generally equipped with a hood and 

duct work to exhaust emissions through 

the control device and out the stack. 

However, when WAFS are used as the 

only means of emission control, the 

tanks often are not equipped with 

exhaust hoods. In such cases, emissions 

from the tank are fugitive and are 

exhausted to the outside using wallmounted exhaust fans. 

We estimate that there are 

approximately 1,770 plants that are 

currently subject to the Chromium 

Electroplating MACT standards. Of 

these, we estimate that there are 790 

hard chromium electroplating plants, 

740 decorative chromium electroplating 

plants, and 240 chromium anodizing 

plants. A detailed description of how 

the number of each type of plant was 

estimated can be found in the Estimated 

Number of Chromium Electroplating 

Plants document available in the docket 

for this action. Some facilities perform 

more than one type of chromium 

electroplating or anodizing. For 

purposes of our estimates, we classified 

facilities as hard chromium, decorative 

chromium, or chromium anodizing 

based on the primary type of 

electroplating operation performed at 

the facility. Some chromium 

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25The National Association of Surface Finishers 

provided OMB with data for 15 plants. We have 

placed this information in the docket for this 

rulemaking. 

26The Occupational Safety and Health 

Administration adopted a lower permissible 

exposure limit for hexavalent chromium in 2006. 

27There is some overlap between the 1,629 

facilities with known addresses and the 166 

facilities for which we have emissions data based 

on the NEI and the data collection request. 

electroplating facilities electroplate 

items that are used internally in the 

manufacturing process at the same 

facility or within the same company. 

For example, some large printing 

facilities electroplate their printing 

rollers in house, and the chromium 

electroplating processes are located at 

the same site as the printing and 

publishing processes. 

2. What data were used in our risk 

analyses? 

For the Chromium Electroplating 

source categories, we compiled a 

preliminary data set using data in the 

2005 NEI. A review of the NEI resulted 

in the identification of data for 122 

chromium electroplating facilities. 

These data were reviewed and the data 

for eight hard chromium and six 

decorative chromium electroplating 

plants were revised based on 

information in the facilities’ permits or 

permit applications. Additional data 

were available for 44 facilities through 

responses to a CAA section 114 

information request that was sent to 

facilities for the Plating and Polishing 

Area Source rule. The data for these 

facilities were added to the NEI data set, 

and, as with the original data, represent 

actual emission levels for these 

electroplating and anodizing facilities. 

Most of these facilities have low 

emissions, which are generally less than 

2 pounds per year (lbs/yr). These 166 

facilities now included in the 2005 NEI 

comprise approximately 9 percent of the 

estimated 1,770 facilities covered by the 

MACT standards, and include 63 hard 

chromium electroplating, 96 decorative 

chromium electroplating, and 7 

chromium anodizing facilities.25 This 

data set of 166 facilities was modeled to 

determine the maximum individual 

cancer risk, the population cancer risk, 

the cancer incidence, and the maximum 

chronic non-cancer risk for the three 

source categories based on actual 

emissions. The maximum individual 

cancer risk and the maximum chronic 

non-cancer risk estimated from this data 

set were also compared to the maximum 

individual cancer risk and the 

maximum chronic non-cancer risk 

estimated from MACT-allowable 

emissions for the three source 

categories.26

To address the possibility that the 

small number of facilities included in 

the 166-facility data set might not be 

fully representative of the source 

categories and their risks, we developed 

an additional data set. In the 

development of this data set, we used 

‘‘model plants’’ developed for the 

original MACT standard to represent the 

individual facilities. For hard and 

decorative chromium electroplating, we 

used three model plants (large, medium, 

and small) that represent average 

characteristics for each of these groups. 

For each of these plant sizes, there is an 

annual emissions rate (lbs/yr) that is 

derived from the design and operating 

parameters, and is specific to the size 

and type of model plant. For chromium 

anodizing, we have two model plants 

(large and small). The model plants 

were based on data collected during 

development of the original MACT 

standards from 1988 to 1993 from more 

than 100 facilities that responded to an 

Information Collection Request (ICR) for 

the chromium electroplating and 

anodizing industry. Data from site visits 

and other information also were used in 

developing the model plants. A 

complete description of the model 

plants developed for the MACT 

standard is provided in the Background 

Information Document (BID) for the 

original MACT standard (Chromium 

Electroplating BID). 

The basis for this additional data set 

is 1,629 chromium electroplating 

facilities with known addresses.27 For 

about half of these facilities, the type of 

electroplating performed is known, but 

the size of the facility is not known. For 

the remaining facilities, neither the type 

of chromium electroplating process or 

processes, nor the facility size is known. 

For use in the risk analysis, the 

limited available data were used to 

divide these facilities into six groups. 

Facilities in three of the six groups were 

assigned to be hard chromium 

electroplating facilities. Those groups 

include: hard chromium facilities; 

facilities with combined hard chromium 

operations and other electroplating or 

anodizing; and facilities with unknown 

processes. Together, these three groups 

yielded a total of 1,219 plants, all of 

which we modeled as hard chromium 

electroplating facilities. This total, in 

addition to the 63 hard chromium 

electroplating facilities in the 2005 NEI 

data set, yields a total of 1,282 facilities, 

which is substantially higher than the 

790 hard chromium facilities that we 

estimate exist in the United States. 

However, because hard chromium 

facilities have the highest emissions 

among the three source categories, we 

made these selections as a conservative 

or health-protective assumption. 

To represent the decorative chromium 

electroplating facilities, we combined 

two of the six groups of facilities; 

decorative chromium facilities and 

facilities that perform both decorative 

chromium and chromium anodizing. 

This results in 319 decorative chromium 

facilities in this data set, which, even 

when combined with the 96 decorative 

chromium electroplating facilities in the 

2005 NEI data set, is less than the 740 

facilities that we believe exist in the 

industry. Because we modeled all of the 

unknown electroplating type facilities 

as the highest-emitting hard chromium 

electroplating facilities, we consider this 

assessment to be conservative, even 

though it appears to under-represent 

decorative chromium facilities. 

Similarly, the last of the six groups 

are all known chromium anodizing 

facilities. This group includes 73 

facilities, and, when combined with the 

7 chromium anodizing facilities in the 

2005 NEI data set, still represents only 

about a third of the 240 facilities 

chromium anodizing facilities. Again, 

we believe this is conservative because 

those facilities not modeled as 

chromium anodizing plants were 

modeled as the higher emitting hard 

chromium facilities in the analysis. 

To estimate the risks for this 

assessment, we needed to establish 

estimated emissions for each of the 

electroplating and anodizing types. To 

ensure that we did not underestimate 

cancer risk to the most exposed 

individual, we originally planned to use 

the large plant emission factors that we 

had developed for the original MACT 

standard to represent all model plants 

for each type of chromium 

electroplating processing. In reviewing 

available emissions data, we found that, 

while the large plant emission factors 

adequately represent the average 

chromium emissions from known large 

decorative chromium electroplating and 

large chromium anodizing facilities, 

they are not representative of the 

average chromium emissions from large 

hard chromium electroplating facilities. 

The emission factor for large hard 

chromium electroplating developed for 

the original MACT standard was 35.3 

lbs/yr. However, in comparing this 

emission factor to available emissions 

data for individual facilities, we find 

that this emissions factor is 

unrealistically high and does not 

represent the average level of emissions 

for large facilities as we would expect to 

see under the current MACT standard. 

As explained more fully in the Model 

Plant Data Used to Estimate Risk from 

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Chromium Electroplating Sources 

document available in the docket for 

this action, based on the large model 

plant design flow rate and operating 

hours, a large hard chromium model 

plant operating at the MACT emission 

limit of 0.015 milligrams per dry 

standard cubic meter (mg/dscm) would 

emit a maximum of only 23.6 lbs/yr of 

chromium compounds. Moreover, the 

available data on actual emissions for 

hard chromium electroplating plants 

indicate there are only 4 plants with 

annual emissions greater than 10 lbs/yr. 

As a result, we determined that the large 

size model plant emissions factor, as 

defined for the original MACT standard, 

is not representative of existing large 

hard chromium electroplating facilities 

on a nationwide basis. On the other 

hand, the emission factor associated 

with a medium size hard chromium 

electroplating model plant (9.26 lbs/yr) 

falls between the 90th percentile (8.04 

lbs/yr) and the 95th percentile (11.6 lbs/ 

yr) of the available emissions data for 

hard chromium electroplating facilities. 

Because this emission factor, which was 

originally developed for medium sized 

facilities at the time the MACT standard 

was developed, is representative of the 

emissions from large facilities, the 

emissions factor of 9.26 lbs/yr was used 

to represent current large hard 

chromium electroplating facilities. 

Thus, for purposes of this residual risk 

review, we refer to 9.26 lbs/yr as the 

emissions factor for a ‘‘large’’ hard 

chromium electroplating facility. 

We believe the approach of using the 

‘‘large’’ facility emissions factor to 

represent all facility sizes is reasonable 

to ensure that we did not underestimate 

maximum individual cancer risk. 

Although we believe that only a small 

percentage of the facilities are large, we 

recognize that we do not have emissions 

data for approximately 90 percent of the 

sources. Thus, by assuming all sources 

are large, we have ensured that we will 

not underestimate the maximum 

individual risk. 

For hard chromium electroplating, the 

model plant emission factors for small, 

medium, and large facilities range from 

0.55 to 9.26 lbs/yr. While we expect 

only 10 percent of the facilities to be 

large, based on the distribution of model 

plant sizes developed for the MACT 

standard, we used the emissions factor 

for a large facility (9.26 lbs/yr) for all of 

the 1,219 facilities that we considered as 

hard chromium electroplating facilities. 

Similarly, for decorative chromium 

electroplating, the emission factors for 

small, medium, and large facilities are 

0.065, 0.27, and 2.65 lbs/yr, 

respectively, and the large facility 

emissions factor was used in the risk 

assessment for decorative chromium. 

For the Decorative Chromium category, 

we estimate that only 5 percent of the 

facilities are large, based upon the 

distribution of decorative chromium 

plants nationwide when the original 

NESHAP were developed. Finally, for 

chromium anodizing, the emission 

factor for small facilities is 0.036 lb/yr, 

and for large facilities, is 0.44 lb/yr. The 

large facility emissions factor (0.44 lb/ 

yr) was used in the conservative 

analysis for all of the anodizing facilities 

even though we estimate that only 25 

percent are large. 

Population risk indicators can be 

greatly overstated when highly 

conservative emission estimates are 

applied to every facility in the source 

category. Recognizing this fact, we 

performed a supplemental analysis to 

better address nationwide average 

emission levels and assess the 

sensitivity of our population risk 

estimates. Thus, as described further 

below, the supplemental analysis was 

performed to understand the degree to 

which the risk might be overstated, and, 

thus, how much weight to attach to the 

conservative analysis. The conservatism 

of this risk assessment is one factor that 

we consider in determining whether the 

risk is acceptable within the meaning of 

the Benzene NESHAP. 

For the supplemental analysis, we 

assigned unique emission factors to 

each of the 6 groups of facilities in our 

1,629 facility data set. These emission 

factors were developed to better 

estimate the average emissions for all of 

the sources within each group. The new 

emission factors are: 

• 2.24 lbs/yr for known hard 

chromium electroplating facilities, 

• 0.225 lb/yr for known decorative 

chromium electroplating facilities, 

• 0.137 lb/yr for known chromium 

anodizing facilities, 

• 1.23 lbs/yr for facilities with 

combinations of hard chromium 

electroplating and either decorative 

electroplating or anodizing, 

• 0.181 lb/yr for facilities with 

combinations of decorative 

electroplating and anodizing, and 

• 1.11 lbs/yr for facilities where the 

type of process (electroplating or 

anodizing) is unknown. 

A detailed explanation for how these 

emission factors were derived can be 

found in the Model Plant Data Used to 

Estimate Risk from Chromium 

Electroplating Sources available in the 

docket for this action. These weighted 

average emission factors account for the 

plant type (hard chromium 

electroplating, decorative chromium 

electroplating, or chromium anodizing) 

and the distribution of plant sizes (large, 

medium, or small). For example, the 

average emissions factor for hard 

chromium electroplating (2.24 lbs/yr) is 

the weighted average of the model plant 

emission factors for large plants (10 

percent of plants at 9.26 lbs/yr per 

plant), medium plants (20 percent of 

plants at 4.63 lbs/yr per plant, and small 

plants (70 percent of plants at 0.55 lb/ 

yr per plant). This distribution of plant 

sizes is based on actual data collected 

during development of the original 

MACT rule. We have no reason to 

believe the distribution of facility sizes 

has changed significantly since then. 

The uncertainties associated with 

both the conservative analysis and the 

supplemental analysis include the 

estimated distribution of plant types 

and sizes as well as the facility 

emissions factors. Although the type of 

plants used in the NEI analysis is based 

on a variety of reliable sources, 

including ICR responses for the Plating 

and Polishing NESHAP, trade 

association data, data from State 

agencies, and information from Web 

sites, we were unable to identify the 

plant type for nearly half of the data set. 

For those plants of unknown type, we 

used the highest emissions factor, which 

corresponds to a large hard chromium 

plant, in the conservative analysis. For 

the supplemental analysis, we 

developed an emissions factor using a 

weighted average across all plant types 

and sizes. For all plants that were 

modeled, we are soliciting additional 

information on actual and MACTallowable emissions, plant type, and 

plant size. More information about the 

development of the model plants can be 

found in the Model Plant Data Used to 

Estimate Risk from Chromium 

Electroplating Sources document 

available in the docket for this action. 

In all the data sets, chromium 

compounds account for all the HAP 

emissions from the Chromium 

Electroplating and Chromium 

Anodizing source categories. For the 

Hard Chromium Electroplating source 

category, in the NEI-based data set, 

chromium VI compounds account for 98 

percent of the emissions, with 

chromium III and chromium trioxide 

compounds comprising the remaining 

HAP. In both the NEI and model plant 

emission estimates, we made the 

conservative assumption that 100 

percent of the emissions are chromium 

VI compounds. For the Decorative 

Chromium Electroplating source 

category, in the NEI-based data set, 

chromium VI compounds account for 94 

percent of the emissions, with 

chromium III and chromium trioxide 

compounds comprising the remaining 

HAP. In both emission estimates, we 

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made the conservative assumption that 

100 percent of the emissions are 

chromium VI compounds. For the 

Chromium Anodizing source category, 

in the NEI-based data set, chromium VI 

compounds account for 99 percent of 

the emissions with chromium III 

compounds comprising the remaining 

HAP. In both emission estimates, we 

made the conservative assumption that 

100 percent of the emissions are 

chromium VI compounds. 

3. What are the results of the risk 

assessments and analyses? 

We conducted an inhalation risk 

assessment for each of the three source 

categories: Hard Chromium 

Electroplating, Decorative Chromium 

Electroplating, and Chromium 

Anodizing. Also, for each source 

category, we conducted an assessment 

of facility-wide risk, and performed a 

demographic analysis of population 

risks. As noted above, we developed 

two data sets for these source categories, 

one based primarily on NEI data for 166 

sources, and one based on model plant 

data for 1,629 sources. 

The following tables present the 

combined results from the data sets. 

Table A.1 provides an overall summary 

of the maximum individual inhalation 

risk assessment results, and Table A.2 

provides population risk assessment 

results for the Hard Chromium 

Electroplating, Decorative Chromium 

Electroplating, and Chromium 

Anodizing source categories. 

TABLE A.1—CHROMIUM ELECTROPLATING AND ANODIZING MAXIMUM INDIVIDUAL INHALATION RISK ASSESSMENT RESULTS* 

Source category 

Number of 

facilities 

(NEI/model 

plant) 1

Maximum individual 

cancer risk 

(in 1 million) 2

Maximum 

chronic non-cancer 

TOSHI 3 Maximum off-site 

acute non-cancer 

Actual HQ 4

emissions 

level 

Allowable 

emissions 

level 

Actual 

emissions 

level 

Allowable 

emissions 

level 

Hard Chromium Electroplating ..................... 63/1,219 70 90 0 .06 0 .09 Not applicable 5. 

Decorative Chromium Electroplating ........... 96/337 70 70 0 .06 0 .06 Not applicable 5. 

Chromium Anodizing .................................... 7/73 5 5 0 .004 0 .004 Not applicable 5. 

* All results are for impacts out to 50 km from each source in the categories. 

1 Number of facilities evaluated in the risk analysis: the first number refers to the NEI data set, and the second number applies to the conservative emission estimate. 2 Maximum individual excess lifetime cancer risk. 

3 Maximum TOSHI. The target organ with the highest TOSHI for the Hard Chromium Electroplating, Decorative Chromium Electroplating, and 

Chromium Anodizing source categories is the respiratory system. 4The maximum estimated acute exposure concentration was divided by available short-term threshold values to develop an array of HQ values. HQ values shown use the lowest available acute threshold value, which, in most cases, is the REL. When HQ values exceed 1, we also 

show HQ values using the next lowest available acute threshold. See section IV.A. of this preamble for explanation of acute threshold values. 5 NA = not applicable. There are no HAP with acute dose-response benchmark values, so no acute HQ were calculated for these source categories. See section IV.A of this preamble for an explanation of acute threshold values. 

TABLE A.2—CHROMIUM ELECTROPLATING AND ANODIZING POPULATION RISK INHALATION RISK ASSESSMENT RESULTS

Source category 

Number of 

facilities 

(NEI/model 

plant) 

Conservative assessment 

population at risk 

Conservative 

annual 

cancer 

incidence 

(cases per 

year) 

Supplemental assessment 

population at risk Supplemental 

annual 

cancer 

incidence 

(case per year) ≥ 1-in-1 million ≥ 10-in-1 million ≥ 1-in-1 million ≥ 10-in-1 million 

Hard Chromium 

Electroplating ........ 63/1,219 14,200,000 71,000 0 .8 360,000 5,100 0 .1 

Decorative Chromium Electroplating ................... 96/337 390,000 4,000 0 .08 30,000 1,300 0 .01 

Chromium Anodizing 7/73 2,700 0 0 .003 540 0 0 .001 

As shown in Table A.1, the results of 

the inhalation risk assessment for the 

Hard Chromium Electroplating source 

category indicate the maximum lifetime 

individual cancer risk could be as high 

as 70-in-1 million, based on actual 

emissions, and as high as 90-in-1 

million based on allowable emissions. 

This maximum individual cancer risk is 

based on the highest risk facility out of 

the 63 actual facilities and the 1,219 

model plants. The highest risk facility is 

one for which we have design and 

operating data, and we believe it is also 

both the largest and highest emitting 

hard chromium electroplating facility in 

the United States. Thus, we believe this 

level accurately reflects the maximum 

individual exposure. The maximum 

chronic non-cancer TOSHI value could 

be 0.06, based on the actual emissions 

level, and up to 0.09 based on 

allowables. This value is also based on 

known emission levels from the largest 

facility in the nation. A non-cancer 

TOSHI of one or less is not of human 

health concern. 

The total estimated national cancer 

incidence from hard chromium 

electroplating facilities based on actual 

emission levels is 0.8 excess cancer 

cases per year, or one case in every 1.25 

years for the conservative assessment. 

Our risk assessment shows 14.2 million 

people exposed to a cancer risk greater 

than 1-in-1 million and 71,000 people 

exposed to a cancer risk of at least 

10-in-1 million. 

As noted above, we conducted a 

supplemental analysis to determine the 

weight to give to the conservative risk 

analysis. That supplemental analysis 

estimates 0.1 excess cancer cases per 

year, or one case in every 10 years. 

Additionally, it estimates a population 

exposure of 360,000 people at 1-in-1 

million cancer risk. For a cancer risk of 

at least 10-in-1 million, the population 

exposed decreases to 5,100. 

Based on the 2005 NEI data set for the 

Decorative Chromium Electroplating 

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28There is uncertainty regarding the operating 

status of the facility (reported to be closed) 

associated with the maximum lifetime individual 

cancer risk. Prior to any final rulemaking action, we 

will investigate this situation and revise the risk 

analysis and results accordingly. 

29Based on our conservative risk assessment, we 

believe the risks are low, and, as explained further 

below, are proposing that the risks are acceptable 

for the Decorative Chromium source category. 

Although we did not need to consider the 

supplemental analysis that we conducted for 

Decorative Chromium to help guide our conclusion 

about the uncertainty of the risk assessment results, 

we note that the supplemental assessment shows 

30,000 people exposed to a cancer risk greater than 

1-in-1 million and 0.01 excess cancer case per year, 

or one case in every 100 years. 30Based on our conservative risk assessment, we 

believe the risks are low, and, as explained further 

below, are proposing that the risks are acceptable 

for the Chromium Anodizing source category. 

Although we did not need to consider the 

supplemental analysis that we conducted for 

Chromium Anodizing to help guide our conclusion 

about the uncertainty of the risk assessment results, 

we note that the supplemental assessment shows 

540 people exposed to a cancer risk greater than 1- 

in-1 million and 0.001 excess cancer case per year, 

or one case in every 1,000 years. 

31This is one of several projects EPA is 

undertaking to establish and implement national 

emission-control measures for specific sectors of the 

economy by taking an integrated multipollutant 

approach to assessing and implementing additional 

emission controls using our existing regulatory 

frameworks. 

source category, the maximum lifetime 

individual cancer risk could be as high 

as 70-in-1 million, and the maximum 

chronic non-cancer TOSHI value could 

be up to 0.06, based on the actual 

emissions level.28 We do not believe the 

maximum lifetime individual cancer 

risk and the maximum chronic noncancer TOSHI value would be any 

higher than this based on allowable 

emissions. The total estimated 

population risks from the conservative 

risk assessment of the decorative 

chromium electroplating facilities based 

on actual emission levels is 390,000 

people exposed to a cancer risk greater 

than 1-in-1 million and 0.08 excess 

cancer cases per year, or one case in 

every 12 years.29

Based on the 2005 NEI data set for the 

Chromium Anodizing source category, 

the maximum lifetime individual cancer 

risk could be as high as 5-in-1 million 

and the maximum chronic non-cancer 

TOSHI value could be up to 0.004, 

based on the actual emissions level. The 

total estimated population risks from 

the conservative assessment of the 

chromium anodizing facilities based on 

actual emission levels is 2,700 people 

exposed to a cancer risk greater than 1- 

in-1 million and 0.003 excess cancer 

cases per year, or one case in every 333 

years.30

Also, as there were no reported 

emissions of PB–HAP for these three 

source categories, we do not expect the 

potential for human health 

multipathway risks or adverse 

environmental impacts. 

Our analyses of potential differences 

between actual emission levels and 

emissions allowable under the MACT 

standards are based on emissions test 

data from specific facilities. A 

comparison of these test results to 

allowable emissions at these facilities 

indicates that the ratio of MACTallowable to actual emissions varies 

considerably from facility to facility. As 

a result, a uniform factor was not 

available to apply to all facilities. 

However, for the Hard Chromium 

Electroplating source category, we did 

evaluate the facility that was modeled as 

having the highest maximum individual 

lifetime cancer risk (70-in-1 million) 

based on actual emissions. Our analysis 

indicates that this facility, if operated at 

the allowable emissions limit, could 

have a maximum individual lifetime 

cancer risk as high as 90-in-1 million. 

Furthermore, the available data indicate 

that no other hard chromium 

electroplating facility would have a 

cancer risk that high if operated at the 

allowable emissions limit. 

For the Decorative Chromium 

Electroplating source category, we 

performed a similar analysis of the 

available data and concluded that the 

maximum individual lifetime cancer 

risk would not exceed 70-in-1 million 

for any facility that operated at the 

allowable emissions limit. As stated 

earlier, because most chromium 

anodizing facilities use WAFS, we 

believe actual emissions are essentially 

the same as allowable emissions. Thus, 

we believe that the MIR based on 

allowable emissions would be the same 

as that based on actual emissions, i.e., 

5-in-1 million. 

Table A.3 displays the results of the 

facility-wide risk assessment for actual 

emissions of all sources at the facility as 

reported in the NEI. We did not perform 

a facility-wide risk assessment based on 

allowable emissions, as explained in the 

documentation referenced in section 

IV.A of this preamble, which is 

available in the docket for this action. 

TABLE A.3—CHROMIUM ELECTROPLATING AND ANODIZING FACILITY-WIDE RISK ASSESSMENT RESULTS

Source category 

Maximum 

facility-wide 

individual 

cancer risk 

(in 1 million) 

Source 

category 

contribution 

to this 

maximum 

facility-wide 

individual 

cancer risk 1

Maximum 

facility-wide 

chronic noncancer TOSHI 

Source 

category 

contribution 

to this 

maximum 

facility-wide 

chronic 

non-cancer 

TOSHI 1

Hard Chromium Electroplating ....................................................................... 90 < 1% 2 < 1% 

Decorative Chromium Electroplating ............................................................. 90 7% 0 .8 < 1% 

Chromium Anodizing ..................................................................................... 20 75% 0 .2 < 1% 

1Percentage shown reflects source category contribution to the maximum facility-wide risks at the facility with the maximum risk value shown. 

As shown in Table A.3, the maximum 

individual cancer risks from all HAP 

emissions at facilities that perform hard 

chromium electroplating, decorative 

chromium electroplating, and 

chromium anodizing are estimated to be 

90-in-1 million, 90-in-1 million, and 

20-in-1 million, respectively. For the 

facilities where these maximum risk 

values occur, the estimated proportion 

of the cancer risk attributable to the 

hard chromium electroplating, 

decorative chromium electroplating, 

and chromium anodizing processes is 

less than 1 percent, 7 percent, and 75 

percent, respectively. The highest 

facility-wide cancer risk for a facility 

that includes a hard chromium 

electroplating source is primarily driven 

by chemical production processes. We 

are currently developing a chemical 

manufacturing sector project 31 and plan 

to address risk from these chemical 

production processes as part of that 

action. The highest facility-wide cancer 

risk for a facility that includes a 

decorative chromium electroplating 

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source is primarily driven by aerospace 

processes that will be addressed in a 

future residual risk review for the 

Aerospace Manufacturing and Rework 

Facilities source category. The highest 

facility-wide cancer risk for a facility 

that includes a chromium anodizing 

source is primarily driven by the 

chromium anodizing processes. The 

facility-wide maximum chronic noncancer TOSHI values for facilities that 

include Hard Chromium Electroplating, 

Decorative Chromium Electroplating, 

and Chromium Anodizing source 

category processes are estimated to be 2, 

0.8, and 0.2, respectively. At the 

facilities where these maximum risk 

values occur, the estimated proportion 

of the non-cancer risk attributable to the 

Hard Chromium Electroplating, 

Decorative Chromium Electroplating, 

and Chromium Anodizing source 

category processes is less than 1 percent 

for each source category. 

The results of the demographic 

analyses performed to investigate the 

distribution of risks above 1-in-1 

million, based on actual emissions 

levels for the population living within 

5 km of the facilities, among various 

demographic groups are provided in a 

report available in the docket for this 

action and summarized in Tables A.4, 

A.5, and A.6 below. These estimates of 

total population with risk exceeding 

1-in-1 million differ from the risk 

estimates presented above because the 

demographic analysis uses a 5 km 

radius and the risk assessment results 

provided above reflect use of a 50 km 

radius around all chromium 

electroplating facilities. 

TABLE A.4—HARD CHROME ELECTROPLATING DEMOGRAPHIC RISK ANALYSIS RESULTS

Emissions 

basis 

Maximum 

risk 

(in 1 million) 

Population with risk greater than 1-in-1 million 

Total 

(millions) 

Minority 

% 

African 

American 

% 

Other and 

multiracial 

% 

Hispanic 

or Latino 

% 

Native 

American 

% 

Below the 

poverty 

level 

% 

Over 25 

w/o a 

HS diploma 

% 

Nationwide n/a 285 25 12 12 14 0.9 13 13 

Source 

Category 70 13.1 52 23 29 34 0.6 22 20 

Facilitywide ...... 90 13.1 52 23 29 34 0.6 22 20 

TABLE A.5—DECORATIVE CHROMIUM ELECTROPLATING DEMOGRAPHIC RISK ANALYSIS RESULTS

Emissions 

basis 

Maximum 

risk 

(in 1 million) 

Population with risk greater than 1-in-1 million 

Total 

(millions) 

Minority 

% 

African 

American 

% 

Other and 

multiracial 

% 

Hispanic 

or Latino 

% 

Native 

American 

% 

Below the 

poverty 

level 

% 

Over 25 

w/o a 

HS diploma 

% 

Nationwide n/a 285 25 12 12 14 0.9 13 13 

Source 

Category 70 0.35 50 18 32 47 0.8 24 23 

Facilitywide ...... 90 0.43 54 21 32 48 0.7 24 25 

TABLE A.6—CHROMIUM ANODIZING DEMOGRAPHIC RISK ANALYSIS RESULTS

Emissions 

basis 

Maximum 

risk 

(in 1 million) 

Population with risk greater than 1-in-1 million 

Total 

(millions) 

Minority 

% 

African 

American 

% 

Other and 

multiracial 

% 

Hispanic 

or Latino 

% 

Native 

American 

% 

Below the 

poverty 

level 

% 

Over 25 

w/o a 

HS diploma 

% 

Nationwide n/a 285 25 12 12 14 0.9 13 13 

Source 

Category 5 0.0027 36 16 0 0 0.4 25 19 

Facilitywide ...... 20 0.0079 22 10 12 13 0.8 19 16 

The results of the demographic 

analysis show that, for the population 

located within 5 km of Hard Chromium 

Electroplating source category, there are 

about 13.1 million people with cancer 

risks greater than 1-in-1 million for both 

the source category and facility-wide. Of 

this population at risk, 52 percent could 

be classified as a ‘‘Minority,’’ 34 percent 

are included in the ‘‘Hispanic or Latino’’ 

demographic group, 29 percent are 

included in the ‘‘Other and Multiracial’’ 

demographic group, 23 percent are 

included in the ‘‘African-American’’ 

demographic group, 22 percent are 

included in the ‘‘Below Poverty Level’’ 

demographic group, and 20 percent are 

included in the ‘‘Over 25 Without a High 

School Diploma’’ demographic group. 

The percentage of the population within 

5 km of a hard chromium electroplating 

facility and with a cancer risk greater 

than 1-in-1 million is higher than the 

typical distribution of these 

demographic groups across the United 

States. These demographic analyses are 

based on the conservative assessment 

results. 

For the Decorative Chromium 

Electroplating source category, there are 

about 350,000 people with cancer risks 

greater than 1-in-1 million for the source 

category and 430,000 people with 

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32Using census data on race and ethnicity, we 

estimated the percentage of people in the United 

States that are minority. We also estimated the 

percentage of people that live within 5 km of each 

facility and have cancer risks greater than 1-in-1 

million that are minority. Where the percentage of 

people at risk is higher than the percentage 

nationwide, those minorities face disproportionate 

risks. 

cancer risks greater than 1-in-1 million 

facility-wide. Of this population at risk, 

50 percent could be classified as a 

‘‘Minority,’’ 47 percent are included in 

the ‘‘Hispanic or Latino’’ demographic 

group, 32 percent are included in the 

‘‘Other and Multiracial,’’ demographic 

group, 18 percent are included in the 

‘‘African-American’’ demographic group, 

24 percent are included in the ‘‘Below 

Poverty Level’’ demographic group, and 

23 percent are included in the ‘‘Over 25 

Without a High School Diploma’’ 

demographic group. The percentage of 

the population within 5 km of a 

decorative chromium electroplating 

facility and with a cancer risks greater 

than 1-in-1 million is higher than the 

typical distribution of these 

demographic groups across the United 

States. The results of the demographic 

analysis for facility-wide emissions are 

similar to the results for the source 

category. 

For the Chromium Anodizing source 

category, there are about 2,700 people 

with cancer risks greater than 1-in-1 

million and 7,900 people with cancer 

risks greater than 1-in-1 million facilitywide. Of the population with cancer 

risks greater than 1-in-1 million, 36 

percent could be classified as a 

‘‘Minority,’’ 16 percent are included in 

the ‘‘African-American’’ demographic 

group, 25 percent are included in the 

‘‘Below Poverty Level’’ demographic 

group, and 19 percent are included in 

the ‘‘Over 25 Without a High School 

Diploma’’ demographic group. The 

percentage of the population within 5 

km of a chromium anodizing facility 

and with a cancer risk greater than 1-in1 million is higher than the typical 

distribution of these demographic 

groups across the United States. The 

results of the facility-wide demographic 

analysis are higher than the typical 

distribution of risks to the demographic 

groups across the United States, for the 

‘‘Below Poverty Level’’ and the ‘‘Over 25 

Without a High School Diploma’’ 

demographic groups, but are lower than 

these levels for the other demographic 

groups. 

Details of these assessments and 

analyses can be found in the residual 

risk documentation as referenced in 

section IV.A of this preamble, which is 

available in the docket for this action. 

4. What are our proposed decisions on 

risk acceptability and ample margin of 

safety? 

a. Risk Acceptability 

The risk analysis we performed for 

this proposal indicates that for the Hard 

Chromium Electroplating source 

category, the cancer risks to the 

individual most exposed is 70-in-1 

million based on actual emissions and 

90-in-1 million based on MACTallowable emissions. The maximum 

non-cancer risk level, which is low, is 

a TOSHI of 0.06 based on actual 

emissions and 0.09 based on allowable 

emissions. These risks are due to 

estimated emissions of hexavalent 

chromium, which EPA describes as a 

known human carcinogen by the 

inhalation route of exposure. As 

explained above, both the MIR and the 

maximum non-cancer risk levels are 

based on emissions from what we 

believe is the highest risk hard 

chromium facility operating in the 

United States. 

We further estimate that the excess 

cancer incidence could be as high as 0.8 

cases per year, and that over 14 million 

people could be exposed to a cancer risk 

of 1-in-1 million or greater. These risk 

levels are based on a highly 

conservative risk assessment as 

described above. In summary, in this 

assessment we used (1) actual emissions 

data for 63 facilities and (2) emissions 

estimates that are reflective of average 

emissions for the highest emitting 

facilities for each one of an additional 

1,219 facilities not in the original 

dataset. Because there are only 790 hard 

chromium facilities, and because only 

ten percent of the facilities would have 

this high an emissions rate, we believe 

that these conservative risk assessment 

results overstate cancer incidence and 

population exposure. 

As noted above, we performed a 

supplemental analysis to assess the 

degree to which the conservative risk 

assessment may overstate risks, and, 

thus, to determine how heavily to weigh 

those risks in determining whether to 

find the risks acceptable. In this 

supplemental analysis we assessed 

these risks based on (1) the emissions 

data used in the conservative 

assessment for the 63 facilities for 

which we have actual facility emission 

information, and (2) revised emission 

data that better represent nationwide 

average emission levels for the 1,219 

facilities. The supplemental assessment 

indicates that the excess cancer risks 

from hard chromium electroplating 

facilities is 0.1 cancer cases per year and 

360,000 people exposed to a cancer risk 

of 1-in-1 million or more, which is 

substantially less than we found with 

the conservative assessment. These 

results indicate that the estimated risks 

are uncertain and are highly sensitive to 

input assumptions and that the 

conservative assessment may 

substantially overstate risks. 

The results of our demographic 

analysis indicate that minorities face 

disproportionate risks 32 from exposure 

to emissions from this category (Tables 

A.4–A.6). Although the demographic 

analysis was based on our conservative 

risk assessment modeling, we have no 

reason to believe that the results would 

be substantially different were we to rerun that analysis using the assumptions 

underlying the supplemental 

assessment. This is because the 

disparate impacts identified through our 

demographic analysis are reflective of 

the fact that many chrome facilities are 

located in inner city urban areas, and in 

or near residential neighborhoods more 

likely to be inhabited by minority and 

low income persons. We are concerned 

about the potential disproportionate 

health risks from these urban facilities 

on minorities and those below the 

poverty level. We solicit comment on 

whether there may be pollution 

prevention efforts or other HAP 

emission reduction approaches that 

could mitigate the impacts that these 

facilities have on their immediate 

surroundings. We also recognize that, in 

addition to whatever controls are 

required in the final rulemaking for the 

Hard Chromium Electroplating source 

category, there may be other 

approaches, such as facility-specific 

compliance assistance, that could 

mitigate the impacts that these facilities 

have on their immediate surroundings. 

We solicit comment and supporting 

information to assist EPA in identifying 

measures to mitigate these 

disproportionate risks. 

In accordance with the approach 

established in the Benzene NESHAP, 

EPA weighed all health risk measures 

and information, including the 

maximum individual cancer risk, the 

cancer incidence, the number of people 

exposed to a risk greater than 1-in-1 

million, the distribution of risks in the 

exposed population, and the uncertainty 

of our risk calculations in determining 

whether the risk posed by emissions 

from hard chromium facilities is 

acceptable. 

As an initial matter, we note that the 

90-in-1 million risk based on allowable 

emissions is approaching the 

‘‘presumptive limit on maximum 

individual lifetime risk of 

approximately 1-in-10 thousand [100-in1 million]’’ recognized in the Benzene 

NESHAP (54 FR 38045). We also note 

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33These comparisons refer to estimates of 

incidence and populations from risk assessments 

performed for other source categories previously 

covered by RTR risk assessments. 

that, based on our conservative analysis, 

there is a high level of cancer incidence 

of 0.8 excess cancer cases per year 

nationwide, and a very large number 

(14.2 million) of people potentially 

exposed to a cancer risk greater than 1- 

in-1 million.33 However, we also 

recognize that our supplemental 

assessment based on alternative input 

assumptions concerning emissions (that 

better represent nationwide average 

emissions) indicate that the results of 

the conservative assessments are 

substantially overstated. Thus, there is 

great uncertainty about both the cancer 

incidence and the number of people 

exposed. 

On the one hand, we acknowledge 

that the cancer incidence and number of 

people exposed to cancer risks of 1-in1 million or greater are high based on 

our conservative analysis. On the other 

hand, we recognize the significant 

uncertainty of these risk estimates and 

the likelihood that they are overstated, 

based on the conservative nature of the 

assessment. The supplemental analysis 

highlights the sensitivity of our risk 

analysis to highly uncertain input 

assumptions and supports a 

determination that the population 

exposure and cancer incidence risk 

numbers are overstated. It shows 

substantially lower cancer incidence 

(0.1 excess cases per year nationwide as 

opposed to 0.8) and number of people 

potentially exposed to a cancer risk of 

1-in-1 million or more (360 thousand as 

opposed to 14.2 million). In addition, 

the distribution of risks in the exposed 

population shows the number of people 

exposed to a cancer risk greater than 10- 

in-1 million is 71,000 for the 

conservative assessment and 5,100 for 

the supplemental analysis. 

In determining whether risk is 

acceptable, we focus on the results of all 

aspects of the risk assessment. Because 

the MIR is less than 100-in-1 million, 

and because of the significant 

uncertainty of the cancer incidence and 

number of people exposed, which we 

believe are overstated based on the fact 

that our risk analysis was highly 

conservative, at this time, we are 

proposing that the risks from the Hard 

Chromium Electroplating source 

category are acceptable. We are 

proposing that the risks are acceptable, 

in large part, because we believe that the 

assumptions underlying the 

supplemental analysis may present a 

more realistic estimate of the emissions 

from hard chromium facilities. 

However, we are very concerned by 

the results of our conservative risk 

analysis, especially the large number of 

people (including disproportionately 

affected populations) estimated to be 

exposed at a cancer risk above 1-in-1 

million. We are also concerned about 

the level of uncertainty with our 

analysis given that we have very limited 

information as to the number (and size) 

of the facilities. While our current 

proposal is supported by recognizing 

the uncertainty associated with the high 

risk levels from our conservative 

assessment and, as explained above, 

that uncertainty (as demonstrated by the 

supplemental analysis) points in the 

direction of an overstatement of risk, we 

would prefer to base a final rule on 

more complete and reliable information. 

The purpose of the residual risk 

standards under CAA section 112(f) is to 

ensure protection of public health and 

the environment. Thus, we believe it is 

important to develop a conservative risk 

analysis and err on the side of potential 

overestimation of risk analyses where 

we are missing data. In this case, we 

recognize that the assessment may be 

overly conservative, and we are 

considering additional methods for 

performing a conservative analysis. 

However, we believe additional 

information and data regarding the 

location, type and size of facilities will 

be important to performing any 

additional analysis that would err on 

the side of protectiveness without being 

overly conservative. At this time, we are 

not certain that we would take final 

action finding the risk to be acceptable 

based on the limited information 

currently available to the Agency. 

The comments and information that 

we receive on this proposal will be 

critical in making a final decision on 

acceptability. We are soliciting 

comment and data to help the Agency 

make an informed decision as it moves 

forward with this rulemaking. 

Specifically, with regard to each of the 

facilities listed in Appendix A to this 

preamble, we are seeking to identify (1) 

the actual annual emissions, if known; 

(2) which of the three source categories 

it falls within; and (3) whether, for hard 

chromium, it is a ‘‘large’’ or ‘‘small’’ 

facility within the definitions in 40 CFR 

63.341(a). In particular, we are 

encouraging the States to provide EPA 

with better inventory data for sources 

within their States. Moreover, we are 

encouraging States to help identify 

sources that may be located near 

sensitive populations or other 

populations of concern, such as located 

near schools or that may be located in 

communities with a significant minority 

population. To feel comfortable with a 

final decision finding the risk 

acceptable, we believe it is important to 

reduce the level of uncertainty 

associated with our current analyses. 

Thus, in light of the comments and any 

additional data (or lack thereof) that we 

receive during the comment period, we 

may determine that it is appropriate to 

issue a supplemental proposal in which 

we propose to find the risk 

unacceptable. If we issue a 

supplemental proposal in which we 

propose to find the risk unacceptable, 

we would be required to propose 

emissions standards or work practices 

that reduce risk to a level that is 

acceptable and provides an ample 

margin of safety. 

For the Decorative Chromium 

Electroplating source category, the 

cancer risks to the individual most 

exposed is 70-in-1 million, based on 

both actual and MACT-allowable 

emissions. Based on this cancer risk 

level and in consideration of other 

health measures and factors, including 

the cancer incidence (one case in every 

12.5 years) and the low maximum noncancer risk level (TOSHI of 0.06 based 

on both actual and MACT-allowable 

emissions), we propose that the risks 

from the Decorative Chromium 

Electroplating source category are 

acceptable. 

For the Chromium Anodizing source 

category, the cancer risks to the 

individual most exposed is 5-in-1 

million, based on both actual and 

allowable emissions. Based on this low 

cancer risk level and in consideration of 

other health measures and factors, 

including the cancer incidence (one 

case in every 250 years) and the low 

maximum non-cancer risk level (TOSHI 

of 0.004 based on actual emissions), we 

propose that the risks from the 

Chromium Anodizing source category 

are acceptable. 

b. Ample Margin of Safety 

Although we are proposing that the 

risks from these source categories are 

acceptable, risk estimates for 

individuals in the exposed population 

are above 1-in-1 million. Consequently, 

we considered whether the MACT 

standard provides an ample margin of 

safety. As part of this analysis, we 

investigated available emissions control 

options that might reduce the risk 

associated with chromium compound 

emissions from the nationwide 

estimated 1,770 hard chromium 

electroplating, decorative chromium 

electroplating, and chromium anodizing 

operations. Once we identified the 

available emissions control options, we 

estimated the cost of these options and 

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estimated the emission reduction 

associated with each control option. To 

determine controlled baseline emissions 

nationwide, assumptions were made 

about the numbers and types of 

emission control technologies in use, 

and the control efficiencies achieved by 

those technologies. The distribution of 

emission control methods among the 

various types of chromium 

electroplating plants and plant sizes was 

estimated based on general knowledge 

of the industry. Table A.7 summarizes 

the nationwide costs and costeffectiveness of these regulatory control 

options. 

TABLE A.7—COSTS OF CONTROL OPTIONS FOR CHROMIUM ELECTROPLATING

Type of facility Control option 

Number of 

affected 

facilities 

Emission 

reduction 

(TPY) 

Capital 

costs 

($million) 

Annualized 

costs 

($million/yr) 

Cost-effectiveness 

($million/ 

ton) 

MIR after 

control 

(in-1-million) 

Large hard chromium electroplating.HEPA filter retrofit 132 1.0 35.1 18.4 36.3 6 

Small hard chromium electroplating.HEPA filter retrofit 658 0.4 66.0 33.9 59.3 6 

CMP retrofit ........... 392 0.2 36.6 11.1 33.1 10 

Decorative chromium electroplating.HEPA filter retrofit 740 0.1 109.0 47.8 486 4 

CMP retrofit ........... 644 1 0.05 63.1 17.1 367 10 

Chromium anodizing ..................... HEPA filter retrofit 240 0.02 43.9 17.9 895 < 1 

CMP retrofit ........... 198 1 0.009 22.9 5.6 649 2 

1Based on an estimated control efficiency of 99.9 percent. 

For large hard chromium 

electroplating facilities, we evaluated 

the costs and emissions reductions 

associated with retrofitting existing 

tanks with HEPA filters. For small hard 

chromium electroplating facilities, we 

evaluated the same HEPA filter retrofit 

option, and also the option of 

retrofitting CMP systems on all tanks 

currently controlled with packed bed 

scrubbers. Retrofitting HEPA filters on 

existing tanks at large hard chromium 

electroplating plants would reduce 

nationwide emissions of chromium 

compounds by an estimated 1.0 TPY 

from the estimated baseline level of 1.10 

TPY. The estimated capital and 

annualized costs for this option would 

be $35,100,000 and $18,430,000, 

respectively. The cost-effectiveness 

would be $36,300,000 per ton of HAP 

emissions reduced. Retrofitting HEPA 

filters on existing tanks at small hard 

chromium electroplating plants would 

reduce nationwide emissions of 

chromium compounds by an estimated 

0.40 TPY from the estimated baseline 

level of 0.42 TPY. The estimated capital 

and annualized costs for this option 

would be $65,980,000 and $33,860,000, 

respectively. The cost-effectiveness 

would be $59,300,000 per ton of HAP 

emissions reduced. Retrofitting CMP 

systems on all tanks currently 

controlled with packed bed scrubbers at 

small hard chromium electroplating 

plants would reduce nationwide 

emissions of chromium compounds by 

an estimated 0.19 TPY from the 

estimated baseline level of 0.37 TPY. 

The estimated capital and annualized 

costs for this option would be 

$36,640,000 and $11,050,000, 

respectively. The cost-effectiveness 

would be $33,100,000 per ton of HAP 

emissions reduced. The Benzene 

NESHAP emphasize the need to 

consider ‘‘costs and the economic 

impacts of control,’’ which implies some 

knowledge of affordability (54 FR 

38046). The cost of the control options 

for hard chromium electroplating would 

impact over half of these facilities with 

estimated cost to sales ratios ranging 

from 8 percent to 22 percent. A cost to 

sales ratio greater than 3 percent may 

have a significant impact, including 

plant closure for many of these 

facilities. 

These additional control requirements 

would reduce the maximum lifetime 

individual cancer risk from the Hard 

Chromium Electroplating source 

category to approximately 4-in-1 

million, based on actual emissions. We 

estimate that, considering MACTallowable emissions levels, the 

maximum lifetime individual cancer 

risk from the Hard Chromium 

Electroplating source category would be 

reduced to approximately 6-in-1 

million. The cancer incidence would be 

reduced to approximately 0.05 and the 

estimated number of people exposed 

higher than 1-in-1 million would be 

about 1 million. 

For decorative chromium 

electroplating, we evaluated the options 

of retrofitting HEPA filters on all 

existing tanks and the option of 

retrofitting CMP systems on the existing 

tanks that currently are not equipped 

with add-on control devices. Retrofitting 

HEPA filters on all existing decorative 

chromium electroplating tanks would 

reduce nationwide emissions of 

chromium compounds by an estimated 

0.098 TPY from the estimated baseline 

level of 0.10 TPY. The estimated capital 

and annualized costs for this option 

would be $108,970,000 and 

$47,800,000, respectively. The costeffectiveness would be $486,000,000 per 

ton of HAP emissions reduced. 

Retrofitting CMP systems on all 

decorative chromium electroplating 

tanks that currently do not have add-on 

controls would reduce nationwide 

emissions of chromium compounds by 

an estimated 0.05 TPY from the 

estimated baseline level of 0.10 TPY. 

The estimated capital and annualized 

costs for this option would be 

$63,100,000 and $17,100,000, 

respectively. The cost-effectiveness for 

this option would be $367 million per 

ton of HAP emissions reduced. The 

additional control requirements for 

HEPA filters would reduce the 

maximum lifetime individual cancer 

risk from the Decorative Chromium 

Electroplating source category to 

approximately 4-in-1 million, based on 

actual emissions. Because we believe 

the actual emissions are essentially the 

same as the MACT-allowable emissions 

for the Decorative Chromium 

Electroplating source category, we 

estimate no difference between the risks 

from the allowable emission level and 

the actual emission level. 

For chromium anodizing, we 

evaluated the options of retrofitting 

HEPA filters on all existing tanks and 

the option of retrofitting CMP systems 

on the existing tanks that currently are 

not equipped with add-on control 

devices. Retrofitting HEPA filters on all 

existing chromium anodizing tanks 

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would reduce nationwide emissions of 

chromium compounds by an estimated 

0.020 TPY from the estimated baseline 

level of 0.021 TPY. The estimated 

capital and annualized costs for this 

option would be $43,860,000 and 

$17,900,000, respectively. The costeffectiveness would be $895,000,000 per 

ton of HAP emissions reduced. 

Retrofitting CMP systems on all 

chromium anodizing tanks that 

currently do not have add-on controls 

would not significantly reduce 

emissions. The estimated capital and 

annualized costs for this option would 

be $22,900,000 and $5,600,000, 

respectively. The cost-effectiveness for 

this option would be $649 million per 

ton of HAP emissions reduced. The 

additional control requirements for 

HEPA filters would reduce the 

maximum lifetime individual cancer 

risk from the Chromium Anodizing 

source category to less than 1-in-1 

million, based on actual emissions. 

Because we believe the actual emissions 

are essentially the same as the MACTallowable emissions for the Chromium 

Anodizing source category, we estimate 

the risk reduction based on allowable 

emissions to be the same as that for the 

actual emissions. 

Our risk analysis results show cancer 

risks to the individual most exposed of 

70-in-1 million and 5-in-1 million based 

on actual and MACT-allowable 

emissions, respectively, for the 

Decorative Chromium Electroplating 

and Chromium Anodizing source 

categories. For both of these categories, 

the cancer incidence is less than 0.01 

cases per year. For decorative chromium 

electroplating, the number of people 

exposed to a cancer risk of 1-in-1 

million or more is approximately 

390,000. For chromium anodizing, the 

number of people exposed to a cancer 

risk of 1-in-1 million or more is 

approximately 2,700. 

For the Hard Chromium 

Electroplating source category, our risk 

analysis shows cancer risks to the 

individual most exposed are 70-in-1 

million based on actual emissions levels 

and 90-in-1 million based on MACTallowable emissions. The cancer 

incidence for this source category could 

be as high as 0.8 cases per year, and 

could be over 14 million people 

exposed to cancer risks of 1-in-1 million 

or greater due to emissions from hard 

chromium electroplating sources using 

highly conservative assumptions. As we 

stated previously, we believe we 

overestimated hard chromium 

electroplating emissions, the number of 

plants that perform hard chromium 

electroplating, and, therefore, that the 

risks from the resulting analyses are also 

overstated. Our supplemental risk 

analysis for this source category 

indicates a cancer incidence of 0.1 cases 

per year and 360,000 people exposed to 

cancer risks of greater than 1-in-1- 

million. This analysis indicates that the 

risk levels in the assessment are highly 

uncertain and err on the side of being 

conservative. 

Our analyses also show that, for these 

source categories, there is no potential 

for an adverse environmental effect or 

human health multipathway effects, and 

that acute and chronic non-cancer 

health impacts are unlikely. Our 

additional analysis of facility-wide risks 

showed that the maximum facility-wide 

cancer risk is 90-in-1 million, and that 

the maximum chronic non-cancer risks 

are unlikely to cause health impacts. 

Our additional analysis of the 

demographics of the exposed 

population shows that minorities face 

disproportionate risk from exposure to 

emissions from this category 

We do not believe there is a 

significant risk reduction from the 

housekeeping measures we are 

proposing under CAA section 112(d)(6). 

However, we are requesting information 

on any risk reductions from these 

housekeeping practices and whether we 

should consider adopting these 

practices under CAA section 112(f)(2). 

We considered all these factors in our 

ample margin of safety decision, and 

concluded that the costs of the options 

analyzed are not reasonable considering 

the emissions reductions and cancer 

health benefits potentially achievable 

with the controls. As a result, we 

propose that the existing MACT 

standard provides an ample margin of 

safety (considering cost, technical 

feasibility, and other factors) to protect 

public health for all three of these 

source categories. Thus, we are 

proposing to re-adopt the existing 

MACT standard to satisfy section 112(f) 

of the CAA. 

While we propose that the existing 

MACT standard for the Hard Chromium 

Electroplating source category is 

acceptable and provides an ample 

margin of safety, we are proposing 

additional requirements under CAA 

section 112(d)(6), as discussed below. 

Notwithstanding our proposal that the 

risks are acceptable, we remain 

concerned that up to 14.2 million 

people may be exposed to cancer risks 

of 1-in-1 million or greater, and that 

there are disparities in risks for some 

demographic groups. While we are 

rejecting the option of adding HEPA 

filters or CMP as not cost-effective, we 

are specifically requesting comment on 

whether there are any cost-effective 

controls that may be able to reduce 

these risks. In particular, we are 

requesting States to identify any 

controls they have already required for 

these facilities, any controls they are 

currently considering, or any other 

controls of which they may be aware. 

We are also soliciting comment on 

whether our cost estimates for these 

options are accurate and whether these 

controls may be more cost-effective. 

In summary, we propose that the risks 

posed by these source categories are 

acceptable. We are also proposing that 

the current MACT standard provides an 

ample margin of safety to protect public 

health based on our conclusion that the 

controls available are not cost-effective 

in light of the additional health 

protection the controls would provide. 

Thus, we are proposing to re-adopt the 

existing MACT standard to satisfy 

section 112(f) of the CAA. 

5. What is our proposed decision on the 

technology review? 

To evaluate developments in 

practices, processes, and control 

technologies for the chromium 

electroplating source categories, several 

activities were performed. Public 

comments received on the proposed 

2002 amendments to the Chromium 

Electroplating MACT standards (67 FR 

38810, June 5, 2002) were reviewed to 

determine whether they identified any 

developments in practices, processes, or 

control technologies that warrant further 

consideration. A review was performed 

of the supporting documentation for the 

2007 amendments to California’s 

Airborne Toxic Control Measure 

(ATCM) for Chromium Plating and 

Chromium Anodizing Facilities. Finally, 

searches of the RBLC and the Internet 

were conducted to identify other 

practices, processes, or control 

technologies that could be applied to 

chromium electroplating. 

The 2004 amendments to the 

Chromium Electroplating MACT 

standards addressed three specific 

technology developments that occurred 

following promulgation of the original 

MACT standard: The use of WAFS for 

hard chromium electroplating emission 

control; instrumental differences in 

surface tension measurements for 

demonstrating compliance with 

electroplating bath surface tension 

limits; and enclosing hoods for 

electroplating tanks. Because those 

technology developments have already 

been addressed and we are not aware of 

any improvements to them, they are not 

discussed further. The following 

paragraphs describe all developments in 

practices, processes, and control 

technologies that we identified and that 

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34This report is available at http:// 

www.oehha.org/prop65/CRNR_notices/pdf_zip/ 

070910_PFOS_CIC.pdf. 

were thus considered for the technology 

review, along with our conclusions. 

a. Emission Elimination Device 

An emission elimination device 

(EED), which is also referred to as a 

‘‘Merlin cover,’’ consists of a tank cover 

that includes a porous membrane that 

allows gases to escape, but captures 

droplets and mist emanating from the 

electroplating tank. While these tank 

covers are available, we do not believe 

any chromium electroplating or 

anodizing facilities are currently using 

an EED due to the impracticality of 

covering the electroplating tank while 

plating is underway. Because these 

devices are not known to be used in this 

industry and because it is unclear that 

they are feasible for these operations, we 

concluded that it is not necessary to 

revise the MACT standard to require 

this control under section 112(d)(6). 

However, we request comment on tanks 

or processes in which an EED could 

practicably be used by chromium 

electroplating or anodizing facilities. 

b. HEPA Filters 

Although HEPA filters have been on 

the market for decades, they were not 

considered to be a practical control 

method for electroplating tank 

emissions when the MACT standards 

were developed due to potential 

problems with clogging and the 

availability of several other types of mist 

eliminator technologies that had been 

proven to be effective in reducing 

emissions from electroplating tanks. 

However, in the past decade, facilities 

in California have increasingly used 

HEPA filters to meet the emission limits 

of the State’s ATCM for Chromium 

Plating and Chromic Acid Anodizing 

Facilities. In October 2007, the 

California Air Resources Board (CARB) 

amended the ATCM to further tighten 

emission limits and to require HEPA 

filters on all new chromium 

electroplating and anodizing tanks. In 

those applications, HEPA filters act as a 

second stage of control, with the first 

stage generally consisting of a mesh pad 

mist eliminator or other device that 

removes large particles from the exhaust 

stream prior to the HEPA filter. 

Discussions with State and local agency 

staff in California indicate no 

technological problems with using 

HEPA filters for chromium 

electroplating emissions control. As part 

of this technology review, HEPA filters 

have been considered as a possible 

control option for sources subject to the 

Chromium Electroplating MACT 

standards. The costs of requiring HEPA 

filters were estimated, and are discussed 

above in section V.A.4.b of this 

preamble. In light of the high cost of this 

option as compared with the risk 

reductions it would achieve, we are 

proposing that it is not necessary to 

revise the MACT standard under section 

112(d)(6) to require HEPA filters. 

However, we request comment on 

whether we should require HEPA filters 

for new source MACT. 

c. Wetting Agent Fume Suppressants 

(WAFS) 

The MACT standard allows the use of 

WAFS as a compliance alternative for 

meeting the applicable emission limit. 

WAFS are used in most decorative 

chromium electroplating and chromium 

anodizing tanks and in many hard 

chromium electroplating tanks for 

emission control. Historically, the most 

effective types of WAFS have been 

based on perfluorooctyl sulfonate 

(PFOS). The PFOS-based WAFS used in 

the chromium electroplating industry 

are part of a family of chemical 

compounds categorized as long-chain 

perfluorinated chemicals (PFC). As 

noted in a 2010 California Office of 

Health Hazard Assessment report, 

Perfluorooctane sulfonate (PFOS) and 

Its Salts and Transformation and 

Degradation Precursors,34 these 

compounds have persistent, 

bioaccumulative, and toxic 

characteristics and are a particular 

concern for children’s health. 

Over the last several years there have 

been developments associated with the 

use of WAFS as a compliance 

alternative. There are now several types 

of WAFS on the market that do not 

include PFOS chemicals and have been 

proven effective for use in hard 

chromium and decorative chromium 

electroplating baths that we believe are 

cost-effective. Furthermore, these nonPFOS WAFS are not associated with any 

known adverse health effects. Although 

the non-PFOS WAFS have not been 

used extensively in the chromium 

anodizing industry, we are not aware of 

any technical reasons to preclude their 

use and effectiveness for chromium 

anodizing baths. However, we seek 

comment on this, as well as on our 

assessment that their use is costeffective. Because of the adverse non-air 

quality health and environmental 

impacts associated with using PFOSbased WAFS (i.e., the increasing 

concern over the presence of long-chain 

PFC in the environment), we are 

proposing under CAA section 112(d)(6) 

to revise the scope of the compliance 

alternative to no longer allow the 

addition of PFOS-based WAFS to tanks 

as a control method for these source 

categories. We solicit comment on all 

aspects of this change, including the 

non-air quality health and 

environmental impacts associated with 

using PFOS based WAFS. 

For new sources, we are proposing 

that no PFOS-based WAFS could be 

used upon startup. For existing sources, 

we are proposing that no PFOS-based 

WAFS could be added to the 

electroplating or anodizing tanks 

beginning 3 years after promulgation of 

the final amendments; however, the 

tanks may continue operating with the 

remaining PFOS-based WAFS in them 

after that date until it is depleted. Under 

these amendments, these requirements 

would be specified in 40 CFR 

63.342(c)(1)(iv) and (2)(vi) for hard 

chromium electroplating tanks, 40 CFR 

63.342(d)(3) for decorative chromium 

electroplating and chromium anodizing 

tanks, and 40 CFR 63.342(e)(2) for 

decorative chromium electroplating 

tanks that use a trivalent chromium 

bath. A definition of PFOS-based fume 

suppressants also would be added to 40 

CFR 63.341. 

d. Housekeeping Procedures 

We are also proposing under CAA 

section 112 (d)(6) to incorporate several 

housekeeping requirements into 40 CFR 

63.342(f). In our review of the 2007 

amendments to California’s ATCM for 

Chromium Plating and Chromic Acid 

Anodizing Facilities, we found this rule 

required several housekeeping 

procedures that were not included in 

the housekeeping procedures required 

by the Chromium Electroplating MACT 

standards. These measures would 

potentially reduce fugitive chromium 

emissions from chromium electroplating 

and anodizing operations. In view of the 

implementation of these procedures in 

California and the potential for fugitive 

emissions reductions, we are proposing 

to add these procedures to the 

Chromium Electroplating MACT 

standards. The proposed housekeeping 

procedures would include storage 

requirements for any substance that 

contains hexavalent chromium as a 

primary ingredient; controls for the 

dripping of bath solution resulting from 

dragout; splash guards to minimize 

overspray and return bath solution to 

the electroplating or anodizing tank; a 

requirement to promptly clean up or 

contain all spills of any substance 

containing hexavalent chromium; 

requirements for the routine cleaning or 

stabilizing of storage and work surfaces, 

walkways, and other surfaces 

potentially contaminated with 

hexavalent chromium; a requirement to 

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install a barrier between all buffing, 

grinding, or polishing operations and 

electroplating or anodizing operations; 

and requirements for the storage, 

disposal, recovery, or recycling of 

chromium-containing wastes. The 

proposed housekeeping procedures 

would be listed in a new Table 2 to 40 

CFR 63.342. In addition, this proposed 

action would require owners and 

operators to incorporate these 

housekeeping procedures in the facility 

Operation and Maintenance Plan 

specified in section 40 CFR 63.342(f)(3) 

and implement them, and a new 

definition would be added to 40 CFR 

63.341(a) to clarify what is meant by the 

term ‘‘contains hexavalent chromium as 

a primary ingredient.’’ The proposed 

compliance date for implementing the 

housekeeping procedures would be 6 

months after promulgation of the final 

amendments. 

6. What are the other actions we are 

proposing? 

a. SSM Provisions 

Consistent with Sierra Club v. EPA, 

EPA is proposing that standards in this 

rule would apply at all times. The 

existing MACT standards for these three 

source categories already specifies that 

the emission limitations apply ‘‘during 

periods of startup and shutdown’’ but 

not during malfunctions. We are 

proposing to revise this paragraph to 

remove the sentence indicating that the 

emission limitations do not apply 

during malfunctions. We are 

maintaining the malfunction-associated 

reporting and recordkeeping 

requirements in 40 CFR 63.346 and 40 

CFR 63.347 with minor revisions. We 

are proposing to add language to 40 CFR 

63.344(a) to clarify the conditions 

during which performance tests shall be 

conducted and to specify in Table 1 that 

the performance test specifications in 40 

CFR 63.7(e)(1) of the General Provisions 

do not apply. We are also proposing to 

add a general duty provision to 

minimize emissions into 40 CFR 

63.342(a)(1). In addition, we are 

proposing to promulgate an affirmative 

defense against civil penalties for 

exceedances of emission standards 

caused by malfunctions, as well as 

criteria for establishing the affirmative 

defense. EPA has attempted to ensure 

that we have not incorporated into the 

proposed regulatory language any 

provisions that are inappropriate, 

unnecessary, or redundant in the 

absence of the SSM exemption. We are 

specifically seeking comment on 

whether there are any such provisions 

that we have inadvertently incorporated 

or overlooked. 

b. Rule Improvements 

In addition, we identified the need for 

revisions of the standards to correct 

editorial errors, make clarifications, or 

address issues with implementation or 

determining compliance with the rule 

provisions. 

Monitoring and Testing Requirements. 

We are proposing to revise 40 CFR 

63.344(e), which addresses compliance 

provisions for multiple sources 

controlled by a common add-on air 

pollution control device. This section of 

the MACT standard references testing 

by Method 306, without any mention of 

Method 306A. Since Method 306A is an 

alternative to Method 306, we are 

proposing to revise section 40 CFR 

63.344(e) to clarify that testing can be 

performed by either Method 306 or 

Method 306A. 

To correct inconsistencies between 

the amendments made to 40 CFR part 

63, subpart N in 2004 (69 FR 42885) and 

Method 306B, we are proposing to 

revise Method 306B, which specifies 

procedures for measuring the surface 

tension of chromium electroplating and 

anodizing baths. In addition, the 

proposed amendments would help to 

ensure that surface tension 

measurements made using 

stalagmometers are accurate. Under the 

proposed amendments, section 1.2 of 

Method 306B would be revised to 

clarify that the method also applies to 

hard chromium electroplating tanks. 

Section 11.1 would be revised to 

include procedures for checking the 

accuracy of, and cleaning, a 

stalagmometer before using the 

stalagmometer to measure surface 

tension. The proposed revisions to 

section 11.1 are consistent with the 

CARB ATCM for Hexavalent Chromium 

for Decorative and Hard Chrome plating 

and Chromic Acid Anodizing Facilities. 

Maintaining surface tension measuring 

devices is critical for obtaining accurate 

measurements. Method 306B currently 

references standard procedures for the 

use of tensiometers (ASTM Method D 

1331–89), but not for the use of 

stalagmometers. The proposed 

amendment to section 11.1 would help 

to ensure that stalagmometers used to 

demonstrate compliance with surface 

tension limits are maintained and used 

properly. Finally, section 11.2 would be 

revised to account for the differences in 

surface tension limits, depending on the 

type of instrument used (tensiometer or 

stalagmometer). 

Rule Corrections. To eliminate a 

discrepancy between the Chromium 

Electroplating MACT standards in 

subpart N of part 63 and the General 

Provisions in subpart A of part 63, this 

proposed action would also revise the 

trigger for semiannual compliance 

reports specified in 40 CFR 

63.347(h)(2)(A) to be consistent with the 

trigger specified in the General 

Provisions. Subpart N currently 

provides that a semiannual report must 

be submitted if both the duration of 

excess emissions exceeds 1 percent of 

the source operating time and the 

duration of air pollution control device 

malfunctions exceeds 5 percent of the 

source operating time during the 

reporting period; however, 40 CFR 

63.10(e)(3)(viii) of the General 

Provisions requires submitting a 

semiannual report if either condition 

occurs. We are proposing to revise 40 

CFR part 63, subpart N to require 

semiannual reports to be submitted if 

either condition occurs. 

B. What are the results and proposed 

decisions for the Group I Polymers and 

Resins Production source categories? 

The National Emission Standards for 

Hazardous Air Pollutant Emissions: 

Group I Polymers and Resins were 

promulgated on September 5, 1996 (62 

FR 46925), and codified at 40 CFR part 

63, subpart U. The Polymers and Resins 

I MACT standard applies to major 

sources and regulates HAP emissions 

from nine source categories: Butyl 

Rubber Production, Epichlorohydrin 

Elastomers Production, Ethylene 

Propylene Rubber Production, 

HypalonTM Production, Neoprene 

Production, Nitrile Butadiene Rubber 

Production, Polybutadiene Rubber 

Production, Polysulfide Rubber 

Production, and Styrene Butadiene 

Rubber and Latex Production. 

The Polymers and Resins I MACT 

standards regulate HAP emissions 

resulting from the production of 

elastomers (i.e., synthetic rubber). An 

elastomer is a synthetic polymeric 

material that can stretch to at least twice 

its original length and then return 

rapidly to approximately its original 

length when released. Elastomers are 

produced via a polymerization/ 

copolymerization process, in which 

monomers undergo intermolecular 

chemical bond formation to form a very 

large polymer molecule. Generally, the 

production of elastomers entails four 

processes: (1) Raw material (i.e., 

solvent) storage and refining; (2) 

polymer formation in a reactor (either 

via the solution process, where 

monomers are dissolved in an organic 

solvent, or the emulsion process, where 

monomers are dispersed in water using 

a soap solution); (3) stripping and 

material recovery; and (4) finishing (i.e., 

blending, aging, coagulation, washing, 

and drying). 

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Sources of HAP emissions from 

elastomers production include raw 

material storage vessels, front-end 

process vents, back-end process 

operations, wastewater operations, and 

equipment leaks. The ‘‘front-end’’ 

processes include pre-polymerization, 

reaction, stripping, and material 

recovery operations; and the ‘‘back-end’’ 

process includes all operations after 

stripping (predominately drying and 

finishing). Typical control devices used 

to reduce organic HAP emissions from 

front-end process vents include flares, 

incinerators, absorbers, carbon 

adsorbers, and condensers. In addition, 

hydrochloric acid formed when 

chlorinated organic compounds are 

combusted are controlled using 

scrubbers. Emissions from storage 

vessels are controlled by floating roofs 

or by routing them to a control device. 

While emissions from back-end 

process operations can be controlled 

with control devices such as 

incinerators, the most common method 

of reducing these emissions is the 

pollution prevention method of 

reducing the amount of residual HAP 

that is contained in the raw product 

going to the back-end operations. 

Emissions from wastewater are 

controlled by a variety of methods, 

including equipment modifications 

(e.g., fixed roofs on storage vessels and 

oil water separators; covers on surface 

impoundments, containers, and drain 

systems), treatment to remove the HAP 

(steam stripping, biological treatment), 

control devices, and work practices. 

Emissions from equipment leaks are 

typically reduced by leak detection and 

repair work practice programs, and in 

some cases, by equipment 

modifications. Each of the seven Group 

I Polymers and Resins Production 

source categories addressed in this 

proposal are discussed further below. 

1. Epichlorohydrin Elastomers 

Production 

Epichlorohydrin Elastomers 

Production is one of the source 

categories for which we proposed RTR 

decisions on October 10, 2008. 

a. Overview of the Source Category 

Epichlorohydrin elastomers are 

prepared from the polymerization or 

copolymerization of epichlorohydrin or 

other monomers. Epichlorohydrin 

elastomers are produced by a solution 

polymerization process, typically using 

toluene as the solvent in the reaction. 

The main epichlorohydrin elastomers 

are polyepichlorohydrin, epi-ethylene 

oxide (EO) copolymer, epi-allyl glycidyl 

ether (AGE) copolymer, and epi-EOAGE 

terpolymer. Epichlorohydrin elastomers 

are widely used in the automotive 

industry. 

We identified one currently operating 

epichlorohydrin elastomers production 

facility subject to the Polymers and 

Resins I MACT standard. Toluene 

accounts for the majority of the HAP 

emissions from the epichlorohydrin 

elastomers production processes at this 

facility (approximately 44 TPY and 99 

percent of the total HAP emissions by 

mass). This facility also reported 

relatively small emissions of 

epichlorohydrin and ethylene oxide. 

The majority of HAP emissions are from 

back-end process vents (approximately 

82 percent of the total HAP by mass). 

We estimate that the MACT-allowable 

emissions (i.e., the maximum emission 

levels allowed if in compliance with the 

MACT standard) from this source 

category are approximately equal to the 

reported, actual emissions. For more 

detail about this estimate of the ratio of 

actual to MACT-allowable emissions, 

see the memo in the docket for this 

action describing the estimation of 

MACT-allowable emission levels and 

associated risks and impacts. 

b. What data were used in our risk 

analyses? 

We initially created a preliminary 

data set for the Epichlorohydrin 

Elastomers Production source category 

using information we collected directly 

from industry on emissions data and 

emissions release characteristics. We 

also reviewed the emissions and other 

data to identify data anomalies that 

could affect risk estimates. On March 

29, 2007, we published an ANPRM (72 

FR 29287) for the express purpose of 

requesting comments on and updates to 

this data set, as well as to the data sets 

for the other source categories addressed 

in that ANPRM. Comments received in 

response to the ANPRM were reviewed 

and considered, and we made 

adjustments to the data set where we 

concluded the comments supported 

such adjustment. After making 

appropriate changes to the data set 

based on this public data review 

process, the data set on which we based 

the initial proposal was created. This 

data set was used to conduct the risk 

assessment and other analyses for the 

Epichlorohydrin Elastomers Production 

source category that formed the basis for 

the proposed RTR included in the 

October 10, 2008, proposal. 

We have continued to scrutinize the 

existing data set and have evaluated any 

additional data that became available 

subsequent to the October 10, 2008, 

proposal. Specific questions we had 

concerning current operations led us to 

develop a questionnaire and ask for 

updated emissions and emissions 

release characteristics information. This 

information was requested from the 

facility in May 2010 using the authority 

of section 114 of the CAA. We updated 

our data set for this source category 

based on the information received 

through this request. 

c. What are the results of the risk 

assessments and analyses? 

We have conducted a revised 

inhalation risk assessment for the 

Epichlorohydrin Elastomers Production 

source category. We have also 

conducted an assessment of facilitywide risk, and performed a demographic 

analysis of population risks. Table B.1.1 

provides an overall summary of the 

results of the revised inhalation risk 

assessment. 

TABLE B.1.1—EPICHLOROHYDRIN ELASTOMERS PRODUCTION REVISED INHALATION RISK ASSESSMENT RESULTS * 

Number of facilities1

Maximum 

individual 

cancer risk 

(in 1 million) 2 Population 

at risk ≥ 1- 

in-1 million 

Annual 

cancer 

incidence 

(cases per 

year) 

Maximum 

chronic non-cancer 

TOSHI 3

Maximum off-site acute noncancer HQ 4

Actual 

emissions 

level 

Allowable 

emissions 

level 

Actual 

emissions 

level 

Allowable 

emissions 

level 

1 ................................. 10 10 800 0.0001 0.1 0.1 HQREL = 0.2 epichlorohydrin 

* All results are for impacts out to 50 km from every source in the category. 

1 Number of facilities evaluated in the risk analysis. 

2 Maximum individual excess lifetime cancer risk. 

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3 Maximum TOSHI. The target organ with the highest TOSHI for the Epichlorohydrin Elastomer Production source category is the respiratory 

system. 4The maximum estimated acute exposure concentration was divided by available short-term threshold values to develop an array of HQ values. HQ values shown use the lowest available acute threshold value, which, in most cases, is the REL. When HQ values exceed 1, we also 

show HQ values using the next lowest available acute threshold. See section IV.A. of this preamble for explanation of acute threshold values. 

The inhalation risk modeling was 

performed using actual emissions level 

data. As shown in Table B.1.1, the 

results of the revised inhalation risk 

assessment indicated the maximum 

lifetime individual cancer risk could be 

as high as 10-in-1 million, the maximum 

chronic non-cancer TOSHI value could 

be as high as 0.1, and the maximum offfacility-site acute HQ value could be as 

high as 0.2, based on the actual 

emissions level and the REL value for 

epichlorohydrin. The total estimated 

national cancer incidence from these 

facilities based on actual emission levels 

is 0.0001 excess cancer cases per year, 

or one case in every 10,000 years. 

Based on our analysis, we believe that 

actual emissions approximate emissions 

allowable under the MACT standard. 

Therefore, the risk results for MACTallowable emissions are approximately 

equal to those for actual emissions. For 

more detail about the estimate of the 

ratio of actual to MACT-allowable 

emissions, see the memo in the docket 

for this action describing the estimation 

of MACT-allowable emission levels and 

associated risks and impacts. 

There were no reported emissions of 

PB–HAP; therefore, we do not expect 

potential for human health 

multipathway risks or adverse 

environmental impacts. 

Table B.1.2 displays the results of the 

facility-wide risk assessment. This 

assessment was conducted based on 

actual emission levels. 

TABLE B.1.2—EPICHLOROHYDRIN ELASTOMERS PRODUCTION FACILITY-WIDE RISK ASSESSMENT RESULTS

Maximum facility-wide individual cancer risk (in 1 million) ............................................................................................................ 10 

Epichlorohydrin Elastomer Production source category contribution to this maximum facility-wide individual cancer risk 1 100% 

Maximum facility-wide chronic non-cancer TOSHI ....................................................................................................................... 0.1 

Epichlorohydrin Elastomer Production source category contribution to this maximum facility-wide non-cancer TOSHI 1 ... 100% 

1Percentage shown reflects Epichlorohydrin Elastomer Production source category contribution to the maximum facility-wide risks at the facility 

with the maximum risk value shown. 

As shown in Table B.1.2, the 

maximum individual cancer risk from 

all HAP emissions at the one facility 

that contains epichlorohydrin 

elastomers production processes subject 

to the Group I Polymers and Resins 

MACT standard is estimated to be 10-in1 million, and the maximum chronic 

non-cancer TOSHI value is estimated to 

be 0.1. The estimated proportion of the 

risk attributable to Epichlorohydrin 

Elastomers Production source category 

processes at this facility is 

approximately 100 percent for cancer 

risks and 100 percent for chronic noncancer risk. 

The results of the demographic 

analyses performed to investigate the 

distribution of risks above 1-in-1 

million, based on actual emissions 

levels for the population living within 5 

km of the facilities, among various 

demographic groups are provided in a 

report available in the docket for this 

action and summarized in Table B.1.3 

below. 

TABLE B.1.3—EPICHLOROHYDRIN ELASTOMERS DEMOGRAPHIC RISK ANALYSIS RESULTS

Emissions basis 

Maximum 

risk 

(in 1 million) 

Population with risk greater than 1-in-1 million 

Total 

(millions) 

Minority 

% 

African 

American 

% 

Other and 

multiracial 

% 

Hispanic 

or Latino 

% 

Native 

American 

% 

Below the 

poverty 

level 

% 

Over 25 

W/O a HS 

diploma 

% 

Nationwide ................ n/a 285 25 12 12 14 0.9 13 13 

Source Category ...... 10 0.0008 54 53 1 1 0.4 20 11 

Facility-wide .............. 10 0.01 52 50 2 1 0.2 23 14 

The results of the demographic 

analysis show that, for the 

Epichlorohydrin Elastomers Production 

source category, of the population of 

800 people with cancer risk greater than 

1-in-1 million, 54 percent could be 

classified as a ‘‘Minority,’’ 53 percent are 

included the ‘‘African-American’’ 

demographic group, and 20 percent are 

included the ‘‘Below Poverty Level,’’ 

demographic group. The percentage of 

the population within 5 km of a 

epichlorohydrin elastomers production 

facility and with a cancer risk greater 

than 1-in-1 million is higher than 

expected for these demographic 

categories based on the typical 

distribution of these demographic 

groups across the United States. The 

table also shows that the results of the 

demographic analysis for the facilitywide emissions are similar to the results 

for the source category. 

Details of these assessments and 

analyses can be found in the residual 

risk documentation as referenced in 

section IV.A. of this preamble, which is 

available in the docket for this action. 

d. What are our proposed decisions on 

risk acceptability and ample margin of 

safety? 

October 2008 Proposed Decision. In 

our October 10, 2008, proposal, we 

proposed that the risks 0f 30-in-1 

million were acceptable because the 

risks results indicated that cancer risks 

to the individual most exposed to 

emissions from the category were 

greater than 1-in-1 million, but less than 

100-in-1 million. We then analyzed 

other risk factors in the ample margin of 

safety determination. In this analysis, 

we proposed that emissions from the 

source category posed no potential for 

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35Note that these uncontrolled emissions were 

included in the baseline risk assessment. 

an adverse environmental effect, did not 

pose potential for human health 

multipathway risks, and were unlikely 

to cause acute or chronic non-cancer 

health impacts. We also identified one 

emissions control option that would 

reduce risks. We proposed that such 

control was not necessary to protect 

public health with an ample margin of 

safety in light of the high cost and 

limited addition health protection it 

would provide. Therefore, we proposed 

that the existing standard provided an 

ample margin of safety and proposed to 

re-adopt the existing MACT standard to 

satisfy section 112(f) of the CAA. 

Risk Acceptability. The revised risk 

analysis we performed for this proposal 

indicates that the cancer risks to the 

individual most exposed is 10-in-1 

million based on both actual and 

MACT-allowable emissions. The cancer 

incidence and the number of people 

exposed to cancer risks of 1-in-1 million 

or greater are not significantly changed 

from the risk identified in the October 

2008 proposal. Similarly, the risk 

analysis continued to show no potential 

for an adverse environmental effect or 

human health multipathway effects, and 

that acute or chronic non-cancer health 

impacts are unlikely. Our additional 

analysis of facility-wide risks showed 

that the maximum facility-wide cancer 

risk is 10-in-1 million and that the 

maximum chronic non-cancer risks are 

unlikely to cause health impacts. Our 

additional analysis of the demographics 

of the exposed population shows 

disparities in risks between 

demographic groups for the 800 people 

exposed at risks of 1-in-1 million. Based 

on this low cancer risk level and in 

consideration of other health measures 

and factors, including the low cancer 

incidence (one case in every 10,000 

years) and the low maximum noncancer risk level (TOSHI of 0.1), we 

propose that the risks from the 

Epichlorohydrin Elastomers Production 

are acceptable. 

Ample Margin of Safety. Because we 

are proposing that the risks are 

acceptable, but still above 1-in-1 

million, we then reconsidered our 2008 

ample margin of safety decision. We 

have not identified any additional 

control options or any changes to the 

previously analyzed control option. Our 

analysis does not indicate a change in 

the emissions reductions that could be 

achieved or the cost of control for the 

control option considered in the 

October 2008 proposal. Therefore, we 

continue to propose that the current 

MACT standard provides an ample 

margin of safety to protect public health 

and the environment, and we are 

proposing to re-adopt the existing 

MACT standard to satisfy section 112(f) 

of the CAA. 

e. What are our proposed decisions on 

the technology review? 

In the October 10, 2008 proposal, we 

identified no advancements in practices, 

processes, and control technologies 

applicable to the emission sources in 

the Group I Polymers and Resins 

Production source categories in our 

technology review, and we proposed to 

re-adopt the existing MACT standard to 

satisfy section 112(d)(6) of the CAA. In 

that review, we examined the regulatory 

requirements and/or technical analyses 

for subsequently promulgated air toxics 

regulations with similar types of 

emissions sources as those in the Group 

I Polymers and Resins Production 

source categories, and we conducted a 

search of the RBLC for controls for VOCand HAP-emitting processes in the 

Group I Polymers and Resins 

Production source categories. We have 

not identified any additional 

developments in practices, processes, 

and control technologies since the 

proposal date for the Epichlorohydrin 

Elastomers Production source category. 

Thus, we are proposing that it is not 

necessary to revise the MACT standard 

pursuant to section 112(d)(6) of the 

CAA. 

f. What other actions are we proposing? 

SSM Provisions. We are proposing to 

eliminate the SSM exemption in the 

Group 1 Polymers and Resins MACT 

standard. Consistent with Sierra Club v. 

EPA, EPA is proposing that standards in 

this rule would apply at all times. We 

are proposing several revisions to 40 

CFR part 63, subpart U. Specifically, we 

are proposing to revise Table 1 to 

indicate that the requirements of 40 CFR 

63.6(e) of the General Provisions do not 

apply. The 40 CFR 63.6(e) requires 

owner or operators to act according to 

the general duty to ‘‘operate and 

maintain any affected source, including 

associated air pollution control 

equipment and monitoring equipment, 

in a manner consistent with safety and 

good air pollution control practices for 

minimizing emissions.’’ We are 

separately proposing to incorporate this 

general duty to minimize into 40 CFR 

63.483(a). The 40 CFR 63.6(e) also 

requires the owner or operator of an 

affected source to develop a written 

SSM plan. We are proposing to remove 

the SSM plan requirement. We are 

proposing to remove the explanation of 

applicability of emissions standards 

during periods SSM in 40 CFR 63.480(j); 

remove the malfunction plan from 40 

CFR 63.482 and revise the definition of 

initial start-up to remove references to 

malfunctions in this section; clarify that 

representative conditions do not include 

periods of SSM throughout the rule; 

remove references to periods of SSM in 

monitoring; and revise the SSMassociated recordkeeping and reporting 

requirements in 40 CFR 63.506 to 

require reporting and recordkeeping for 

periods of malfunction. We are also 

proposing to revise Table 1 to indicate 

that SSM-related provisions in 40 CFR 

63.6(f)(1), 40 CFR 63.7(e)(1), and 40 CFR 

63.10(d)(5)(i) of the General Provisions 

do not apply. In addition, we are 

proposing to promulgate an affirmative 

defense against civil penalties for 

exceedances of emission standards 

caused by malfunctions, as well as 

criteria for establishing the affirmative 

defense. 

EPA has attempted to ensure that we 

have not incorporated into proposed 

regulatory language any provisions that 

are inappropriate, unnecessary, or 

redundant in the absence of the SSM 

exemption. We are specifically seeking 

comment on whether there are any such 

provisions that we have inadvertently 

incorporated or overlooked. 

Significant Emission Points Not 

Previously Regulated Review. We 

identified the absence of a limit for a 

significant emissions source within the 

provisions of the Group I Polymers and 

Resins MACT standard that apply to the 

Epichlorohydrin Elastomers Production 

source category. Specifically, there are 

no back-end process operation emission 

limits for this source category.35 As 

these processes are major sources of 

emissions for the one facility in the 

source category, we are proposing to set 

standards for back-end process 

operations under CAA section 112(d)(2) 

and (d)(3) in this action. 

As there is only one facility in the 

source category, the emissions level 

currently being achieved by this facility 

represents the MACT floor. The annual 

HAP emissions from the back-end 

process operations at this facility are 

approximately 36 TPY of toluene. There 

are two separate dryer vents, one 

emitting around 24 TPY of toluene, and 

the other emitting around 12 TPY of 

toluene. Neither of these vents is 

controlled. Therefore, we have 

determined that the MACT floor for 

these processes is 36 TPY based on the 

current level of HAP stripping and 

recovery, given current production 

levels, but which would fluctuate 

proportionally with an increase or 

decrease in production levels. 

As part of our beyond-the-floor 

analysis, we considered alternatives 

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more stringent than the MACT floor 

option. We identified one option using 

add-on emission controls that would 

require the ducting of emissions from 

the back-end process operations to a 

control device, such as an incinerator. 

This option would also require an initial 

performance test of the incinerator and 

continuous parameter monitoring 

averaged daily. The capital costs of this 

option are estimated to be 

approximately $600,000 and the total 

annual costs are estimated to be 

approximately $1,100,000. We estimate 

that an incinerator would achieve an 

emissions reduction of 98 percent, 

resulting in a HAP decrease of 

approximately 35 TPY, with a costeffectiveness of approximately $31,000/ 

ton. Table B.2.4 summarizes the cost 

and emission reduction impacts of the 

proposed options. Because the 

reduction in HAP would be due to 

toluene, no reduction of cancer risk 

would result from this control option. 

TABLE B.1.4—EPICHLOROHYDRIN ELASTOMER PRODUCTION FACILITY BACK-END OPTIONS IMPACTS

Regulatory alternatives HAP emissions 

(TPY HAP) 

Capital cost 

($million) 

Annual cost 

($million/yr) 

Costeffectiveness 

as compared to 

baseline 

$/Ton HAP 

Removed 

Baseline ........................................................................................... 36 ............................ ............................ ............................

1 (MACT floor) ............................................................................... 36 0 0 ............................

2 (Beyond-the-floor) ...................................................................... 1 0.6 1.1 31,000 

In addition to the cost and emission 

reduction impacts shown in Table B.1.4, 

we estimate that the beyond-the-floor 

option would result in increases in 

criteria pollutant and carbon dioxide 

emissions (PM¥0.2 TPY, SO2¥0.03 

TPY, NOX¥12 TPY, CO¥2 TPY, and 

CO2¥7,000 TPY), and an increase in 

energy use of approximately 117,000 

million British thermal units (BTU)/year 

at a cost of approximately $33,000/year. 

We believe that the costs and other 

impacts of this beyond-the-floor option 

are not reasonable, given the level of 

emission reduction. Therefore, we are 

proposing an emission standard that 

reflects the MACT floor option. We are 

requesting comment on this analysis 

and these options. 

As noted above, we are proposing that 

the MACT standard, prior to the 

implementation of the proposed 

emission limitation to the back-end 

process operations discussed in this 

section, provides an ample margin of 

safety to protect public health. 

Therefore, we maintain that after the 

new standard’s implementation, the rule 

will continue to provide an ample 

margin of safety to protect public health. 

Consequently, we do not believe it will 

be necessary to conduct another 

residual risk review under CAA section 

112(f) for this source category 8 years 

following promulgation of new backend process limitations, merely due to 

the addition of this new MACT 

requirement. 

2. Polybutadiene Rubber Production 

Polybutadiene Rubber Production is 

one of the source categories for which 

we proposed RTR decisions on October 

10, 2008. 

a. Overview of the Source Category 

Polybutadiene rubber is a 

homopolymer of 1,3-butadiene (i.e., 1,3- 

butadiene is the only monomer used in 

the production of this polymer). While 

both the solution and emulsion 

polymerization processes can be used to 

produce polybutadiene rubber, all 

currently operating facilities in the 

United States use a solution process. In 

the solution process, the reaction is 

conducted in an organic solvent 

(hexane, toluene, or a non-HAP organic 

solvent), which helps to dissipate heat 

generated by the reaction and control 

the reaction rate. While polybutadiene 

rubber is the primary product at these 

facilities, styrene-butadiene rubber can 

also be produced as a minor product by 

adding styrene as a monomer. Most of 

the polybutadiene rubber manufactured 

in the United States is used in the 

production of tires in the construction 

of the tread and sidewalls. 

Polybutadiene rubber is also used as a 

modifier in the production of other 

polymers and resins (e.g., polystyrene). 

We identified five currently operating 

polybutadiene rubber production 

facilities subject to the Polymers and 

Resins I MACT standard. Some of these 

facilities are located at plant sites that 

also have other HAP-emitting sources 

regulated under separate MACT 

standards, which have been or will be 

addressed in separate regulatory actions. 

Three of the polybutadiene rubber 

production facilities use hexane as the 

solvent in their solution process, one 

facility uses toluene as its solvent, and 

the fifth uses a non-HAP organic 

solvent. Overall, hexane and toluene 

account for the majority of the HAP 

emissions from this source category 

(approximately 1,600 TPY hexane, 

which represents 70 percent of the total 

HAP emissions by mass, and 500 TPY 

toluene, which represents 23 percent). 

The facilities in this source category 

also reported emissions of styrene, 1,3- 

butadiene, ethylbenzene, and relatively 

minor quantities of other HAP. The 

majority of HAP emissions are from 

back-end process operations 

(approximately 70 percent of the total 

HAP by mass). For all emission sources 

except the back-end process operations, 

the actual emissions level is 

representative of the MACT-allowable 

level. For back-end process operations, 

we estimate that MACT-allowable 

emissions from this source category 

could be as high as seven times the 

actual emissions. Because these backend limitations are production-based, 

this estimate was made by comparing 

the actual emissions levels to the 

emissions calculated using the 

limitations and production levels. For 

more detail about the estimate of the 

ratio of actual to MACT-allowable 

emissions, see the memo in the docket 

for this action describing the estimation 

of MACT-allowable emission levels and 

associated risks and impacts. 

b. What data were used in our risk 

analyses? 

We initially created a preliminary 

data set for the Polybutadiene Rubber 

Production source category using 

information we collected directly from 

industry on emissions data and 

emissions release characteristics. We 

also reviewed the emissions and other 

data to identify data anomalies that 

could affect risk estimates. On March 

29, 2007, we published an ANPRM (72 

FR 29287) for the express purpose of 

requesting comments on, and updates 

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to, this data set, as well as to the data 

sets for the other source categories 

addressed in that ANPRM. Comments 

received in response to the ANPRM 

were reviewed and considered. We 

made adjustments to the data set where 

we concluded the comments supported 

such adjustment. After making 

appropriate changes to the data set 

based on this public data review 

process, the data set on which we based 

the initial proposal was created. This 

data set was used to conduct the risk 

assessment and other analyses for the 

Polybutadiene Rubber Production 

source category that formed the basis for 

the proposed actions included in the 

October 10, 2008, proposal. We have 

continued to scrutinize the data set and 

any additional data that have become 

available since the October 10, 2008, 

proposal. 

c. What are the results of the risk 

assessments and analyses? 

We have conducted a revised 

inhalation risk assessment for the 

Polybutadiene Rubber Production 

source category. We have also 

conducted an assessment of facilitywide risk and performed a demographic 

analysis of population risks. Table B.2.1 

provides an overall summary of the 

results of the revised inhalation risk 

assessment. 

TABLE B.2.1—POLYBUTADIENE RUBBER REVISED INHALATION RISK ASSESSMENT RESULTS * 

Number of 

facilities1

Maximum individual cancer risk 

(in 1 million) 2

Population at 

risk ≥ 1-in-1 

million 

Annual cancer 

incidence 

(cases per 

year) 

Maximum chronic non-cancer 

TOSHI 3

Maximum off-site 

acute Actual non-cancer HQ 4

emissions 

level 

Allowable 

emissions 

level 

Actual 

emissions 

level 

Allowable 

emissions 

level 

5 ........................... 30 30 24,000 0.003 0.3 0.3 HQREL = 1 toluene 

* All results are for impacts out to 50 km from every source in the category. 

1 Number of facilities evaluated in the risk analysis. 

2 Maximum individual excess lifetime cancer risk. 

3 Maximum TOSHI. The target organ with the highest TOSHI for the Polybutadiene Rubber Production source category is the reproductive 

system. 4The maximum estimated acute exposure concentration was divided by available short-term threshold values to develop an array of HQ values. HQ values shown use the lowest available acute threshold value, which, in most cases, is the REL. When HQ values exceed 1, we also 

show HQ values using the next lowest available acute threshold. See section IV.A. of this preamble for explanation of acute threshold values. 

The inhalation risk modeling was 

performed using actual emissions level 

data. As shown in Table B.2.1, the 

results of the revised inhalation risk 

assessment indicated the maximum 

lifetime individual cancer risk could be 

as high as 30-in-1 million, the maximum 

chronic non-cancer TOSHI value could 

be up to 0.3, and the maximum offfacility-site acute HQ value could be as 

high as 1, based on the actual emissions 

level and the REL value for toluene. The 

total estimated national cancer 

incidence from these facilities based on 

actual emission levels is 0.003 excess 

cancer cases per year, or one case in 

every 333 years. 

Our analysis of potential differences 

between actual emission levels and 

emissions allowable under the MACT 

standard indicated that MACTallowable emission levels are equal to 

actual emissions for all emissions 

sources other than back-end process 

operations and may be up to seven 

times greater than actual emission levels 

for back-end process operations. When 

these ratios of actual to MACTallowable emissions are applied to each 

emission source type, the result is that 

the cancer risks at the MACT-allowable 

level are equal to those at the actual 

level shown in Table B.2.1. 

There were no reported emissions of 

PB–HAP; therefore, we do not expect 

potential for human health 

multipathway risks or adverse 

environmental impacts. 

Table B.2.2 displays the results of the 

facility-wide risk assessment. This 

assessment was conducted based on 

actual emission levels. 

TABLE B.2.2—POLYBUTADIENE RUBBER PRODUCTION FACILITY-WIDE RISK ASSESSMENT RESULTS

Maximum facility-wide individual cancer risk (in 1 million) .......................................................................................................................... 30 

Polybutadiene Rubber Production source category contribution to this maximum facility-wide individual cancer risk) 1 ................... 100% 

Maximum facility-wide chronic non-cancer TOSHI ..................................................................................................................................... 0.3 

Polybutadiene Rubber Production source category contribution to this maximum facility-wide non-cancer TOSHI 1 ........................ 100% 

1 Percentage shown reflects Polybutadiene Rubber Production source category contribution to the maximum facility-wide risks at the facility 

with the maximum risk value shown. 

The maximum individual cancer risk 

from all HAP emissions at a facility that 

contains polybutadiene rubber 

production processes subject to the 

Group I Polymers and Resins MACT 

standard is estimated to be 30-in-1 

million, and the maximum chronic noncancer TOSHI value is estimated to be 

0.3. At the facilities where these 

maximum risk values occur, the 

estimated proportion of the risk 

attributable to the Polybutadiene Rubber 

Production source category processes is 

100 percent for both cancer and noncancer risk. 

The results of the demographic 

analyses performed to investigate the 

distribution of risks above 1-in-1 

million, based on actual emissions 

levels for the population living within 

5 km of the facilities, among various 

demographic groups are provided in a 

report available in the docket for this 

action and summarized in Table B.2.3 

below. 

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TABLE B.2.3—POLYBUTADIENE RUBBER DEMOGRAPHIC RISK ANALYSIS RESULTS

Emissions basis 

Maximum 

risk 

(in 1 million) 

Population with risk greater than 1-in-1 million 

Total 

(millions) 

Minority 

% 

African 

American 

% 

Other and 

multiracial 

% 

Hispanic or 

Latino 

% 

Native 

American 

% 

Below the 

poverty 

level 

% 

Over 25 

W/O a HS 

diploma 

% 

Nationwide ................ n/a 285 25 12 12 14 0.9 13 13 

Source Category ...... 30 0.017 11 6 4 4 0.5 11 13 

Facility-wide .............. 30 0.02 12 7 5 4 0.5 12 14 

The results of the Polybutadiene 

Rubber Production source category 

demographic analysis show that the 

percentage of the population within 5 

km of a polybutadiene rubber 

production facility and with a cancer 

risk greater than 1-in-1 million is less 

than the distribution of these 

demographic groups across the United 

States as displayed in Table B.2.3, with 

the exception of those ‘‘Over 25 Without 

a High School Diploma’’, where the 

levels are equal to the distribution of 

these demographic groups across the 

United States. The table also shows that 

the facility-wide emissions demographic 

analysis shows similar results. 

Details of these assessments and 

analyses can be found in the residual 

risk documentation as referenced in 

section IV.A of this preamble, which is 

available in the docket for this action. 

d. What are our proposed decisions on 

risk acceptability and ample margin of 

safety? 

October 2008 Proposed Decision. In 

our October 10, 2008 proposal, we 

proposed that the risks were acceptable 

because the risks results indicated that 

cancer risks to the individual most 

exposed to emissions from the category 

were 10-in-1 million which is greater 

than 1-in-1 million but less than 100-in1 million. We then analyzed other risk 

factors in the ample margin of safety 

determination. In this analysis, we 

proposed that emissions from the source 

category posed no potential for an 

adverse environmental effect, did not 

pose potential for human health 

multipathway risks, and were unlikely 

to cause acute or chronic non-cancer 

health impacts. We also identified two 

emissions control options that would 

reduce risks. We proposed that these 

controls were not necessary to protect 

public health with an ample margin of 

safety in light of the high cost and 

limited addition health protection they 

would provide. Therefore, we proposed 

that the existing standard provided an 

ample margin of safety and proposed to 

re-adopt the existing MACT standard to 

satisfy section 112(f) of the CAA. 

Risk Acceptability. The revised risk 

analysis we performed for this proposal 

indicates that the cancer risks to the 

individual most exposed is 30-in-1 

million based on both actual and 

MACT-allowable emissions. The cancer 

incidence and the number of people 

exposed to cancer risks of 1-in-1 million 

or greater are not significantly changed 

from the risk identified in the October 

2008 proposal. Similarly, the risk 

analysis continued to show no potential 

for an adverse environmental effect or 

human health multipathway effects, and 

that chronic non-cancer health impacts 

are unlikely. The revised assessment did 

indicate that an acute non-cancer HQ as 

high as 1 could occur, based on the REL 

value at an area adjacent to the facility 

fenceline. Our additional analysis of 

facility-wide risks showed that the 

maximum facility-wide cancer risk is 

30-in-1 million and that the maximum 

chronic non-cancer risks are unlikely to 

cause health impacts. Our additional 

analysis of the demographics of the 

exposed population suggests there are 

no disparities in risks for the various 

demographic groups. Based on this low 

cancer risk level and in consideration of 

other health measures and factors, 

including the low cancer incidence (one 

case in every 333 years) and the low 

maximum non-cancer risk level (TOSHI 

of 0.3), we propose that the risks from 

the Polybutadiene Rubber Production 

source category are acceptable. 

Ample Margin of Safety. Because we 

are proposing that the risks are 

acceptable, but still above 1-in-1 

million, we then re-considered our 2008 

ample margin of safety decision. We 

have not identified any additional 

control options or any changes to the 

previously analyzed control option. Our 

analysis does not indicate a change in 

the emissions reductions that could be 

achieved or the cost of control for the 

control option considered in the 

October 2008 proposal. Therefore, we 

continue to propose that the current 

MACT standard provides an ample 

margin of safety to protect public health 

and the environment, and we are 

proposing to re-adopt the existing 

MACT standard to satisfy section 112(f) 

of the CAA. 

e. What are our proposed decisions on 

the technology review? 

In the October 10, 2008 proposal, we 

identified no advancements in practices, 

processes, and control technologies 

applicable to the emission sources in 

the Group I Polymers and Resins 

Production source categories in our 

technology review, and we proposed to 

re-adopt the existing MACT standard to 

satisfy section 112(d)(6) of the CAA. In 

that review we examined the regulatory 

requirements and/or technical analyses 

for subsequently promulgated air toxics 

regulations with similar types of 

emissions sources as those in the Group 

I Polymers and Resins Production 

source categories, and we conducted a 

search of the RBLC for controls for VOCand HAP-emitting processes in the 

Group I Polymers and Resins 

Production source categories. We have 

not identified any additional 

developments in practices, processes, 

and control technologies since the 

proposal date for the Polybutadiene 

Rubber Production source category. In 

addition, we have not identified the 

need for revisions of the standards to 

correct editorial errors, make 

clarifications, or address issues with 

implementation or determining 

compliance with the rule provisions. 

Thus, we are continuing to propose to 

re-adopt the existing MACT standard to 

satisfy section 112(d)(6) of the CAA. 

f. What other actions are we proposing? 

The proposed changes to the SSM 

provisions for the Group I Polymers and 

Resins MACT, which apply to the 

Polybutadiene Rubber Production 

source category, are discussed above in 

section V.B.1.f. 

3. Styrene Butadiene Rubber and Latex 

Production 

Styrene Butadiene Rubber and Latex 

Production is one of the source 

categories for which we proposed RTR 

decisions on October 10, 2008. 

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a. Overview of the Source Category 

Styrene butadiene rubber and latex 

are elastomers prepared from styrene 

and butadiene monomer units. The 

source category is divided into three 

subcategories due to technical process 

and HAP emission differences: (1) The 

production of styrene butadiene rubber 

by emulsion, (2) the production of 

styrene butadiene rubber by solution, 

and (3) the production of styrene 

butadiene latex. Styrene butadiene 

rubber is coagulated and dried to 

produce a solid product, while latex is 

a liquid product. For both styrene 

butadiene rubber processes, the 

monomers used are styrene and 

butadiene; either process can be 

conducted as a batch or a continuous 

process. These elastomers are 

commonly used in tires and tire-related 

products. We identified three currently 

operating styrene butadiene rubber 

production facilities using the emulsion 

process and three styrene butadiene 

rubber latex production facilities subject 

to the Polymers and Resins I MACT 

standard. Other than the polybutadiene 

plants that produce styrene butadiene 

rubber as a minor product, we did not 

identify any styrene butadiene rubber 

produced in a solution process. Some of 

these facilities are located at plant sites 

that also have other HAP-emitting 

sources regulated under separate MACT 

standards, for which we have addressed 

or will address in future rulemaking 

actions. Overall, styrene accounts for 

the majority of the HAP emissions from 

these facilities (approximately 276 TPY 

and 90 percent of the total HAP 

emissions by mass). These facilities also 

reported relatively small emissions of 

other HAP. The majority of HAP 

emissions are from back-end process 

operations (approximately 78 percent of 

the total HAP by mass). For all emission 

sources except the back-end process 

operations, the actual emissions level is 

representative of the MACT-allowable 

level. For back-end process operations, 

we estimate that MACT-allowable 

emissions from this source category 

could be as high as four times the actual 

emissions. Since these back-end 

limitations are production-based, this 

estimate was made by comparing the 

actual emissions levels to the emissions 

calculated using the limitations and 

production levels. For more detail about 

the estimate of the ratio of actual to 

MACT-allowable emissions, see the 

memo in the docket for this action 

describing the estimation of MACTallowable emission levels and 

associated risks and impacts. 

b. What data were used in our risk 

analyses? 

We initially created a preliminary 

data set for the Styrene Butadiene 

Rubber and Latex Production source 

category using information we collected 

directly from industry on emissions data 

and emissions release characteristics. 

We also reviewed the emissions and 

other data to identify data anomalies 

that could affect risk estimates. On 

March 29, 2007, we published an 

ANPRM (72 FR 29287) for the express 

purpose of requesting comments on and 

updates to this data set, as well as to the 

data sets for the other source categories 

addressed in that ANPRM. Comments 

received in response to the ANPRM 

were reviewed and considered, and we 

made adjustments to the data set where 

we concluded the comments supported 

such adjustment. After making 

appropriate changes to the data set 

based on this public data review 

process, the data set on which we based 

the initial proposal was created. This 

data set was used to conduct the risk 

assessment and other analyses for the 

Styrene Butadiene Rubber and Latex 

Production source category, which 

formed the basis for the proposed RTR 

actions included in the October 10, 2008 

proposal. 

We have continued to scrutinize the 

existing data set and have evaluated any 

additional data that became available 

subsequent to the October 2008 

proposal. Specific questions we had 

concerning current operations led us to 

develop a questionnaire and ask for 

updated emissions and emissions 

release characteristics information. This 

information was requested from the 

facilities in May 2010 using the 

authority of section 114 of the CAA. We 

updated our data set for this source 

category based on the information 

received through this request. 

c. What are the results of the risk 

assessments and analyses? 

We have conducted a revised 

inhalation risk assessment for the 

Styrene Butadiene Rubber and Latex 

Production source category. We have 

also conducted an assessment of 

facility-wide risk and performed a 

demographic analysis of population 

risks. Table B.3.1 provides an overall 

summary of the results of the revised 

inhalation risk assessment. 

TABLE B.3.1—STYRENE BUTADIENE RUBBER AND LATEX PRODUCTION REVISED INHALATION RISK ASSESSMENT RESULTS * 

Number of facilities 1

Maximum individual cancer risk 

(in 1 million) 2

Population at 

risk ≥ 1-in-1 

million 

Annual cancer 

incidence 

(cases per 

year) 

Maximum chronic non-cancer 

TOSHI 3

Maximum off-site 

acute non-cancer Actual HQ 4

emissions 

level 

Allowable 

emissions 

level 

Actual 

emissions 

level 

Allowable 

emissions 

level 

6 ....................... 10 10 25,000 0.004 0.2 0.2 HQREL = 0.4 styrene. 

* All results are for impacts out to 50 km from every source in the category. 

1 Number of facilities evaluated in the risk analysis. 

2 Maximum individual excess lifetime cancer risk. 

3 Maximum TOSHI. The target organ with the highest TOSHI for the Styrene Butadiene Rubber and Latex Production source category is the 

reproductive system. 4The maximum estimated acute exposure concentration was divided by available short-term threshold values to develop an array of HQ values. HQ values shown use the lowest available acute threshold value, which, in most cases, is the REL. When HQ values exceed 1, we also 

show HQ values using the next lowest available acute threshold. See section IV.A. of this preamble for explanation of acute threshold values. 

The inhalation risk modeling was 

performed using actual emissions level 

data. As shown in Table B.3.1, the 

results of the revised inhalation risk 

assessment indicated the maximum 

lifetime individual cancer risk could be 

as high as 10-in-1 million, the maximum 

chronic non-cancer TOSHI value could 

be up to 0.2, and the maximum offfacility-site acute HQ value could be as 

high as 0.4, based on the actual 

emissions level and the REL value for 

styrene. The total estimated national 

cancer incidence from these facilities 

based on actual emission levels is 0.004 

excess cancer cases per year, or one case 

in every 250 years. 

Our analysis of potential differences 

between actual emission levels and 

emissions allowable under the MACT 

standard indicated that MACTmstockstill on DSKH9S0YB1PROD with PROPOSALS2

Federal Register / Vol. 75, No. 203 / Thursday, October 21, 2010 / Proposed Rules 65103 

allowable emission levels are equal to 

actual emissions for all emissions 

sources other than back-end process 

operations. While the emissions may be 

up to four times greater than actual 

emission levels for back-end process 

operations, the compounds emitted do 

not have cancer potency values so this 

potential increase in emissions does not 

effect risk. When these ratios of actual 

to MACT-allowable emissions are 

applied to each emission source type, 

the result is that the cancer risks at the 

MACT-allowable level are equal to those 

at the actual level shown in Table B.3.1. 

There were no reported emissions of 

PB–HAP; therefore, we do not expect 

potential for human health 

multipathway risks or adverse 

environmental impacts. 

Table B.3.2 displays the results of the 

facility-wide risk assessment. This 

assessment was conducted based on 

actual emission levels. 

TABLE B.3.2—STYRENE BUTADIENE RUBBER AND LATEX PRODUCTION FACILITY-WIDE RISK ASSESSMENT RESULTS

Maximum facility-wide individual cancer risk (in 1 million) .............................................................................................................. 70 

Styrene Butadiene Rubber and Latex Production source category contribution to this maximum facility-wide individual 

cancer risk 1 .......................................................................................................................................................................... 5% 

Maximum facility-wide chronic non-cancer TOSHI ......................................................................................................................... 1 

Styrene Butadiene Rubber and Latex Production source category contribution to this maximum facility-wide non-cancer 

TOSHI 1 ................................................................................................................................................................................. 10% 

1Percentage shown reflects the Styrene Butadiene Rubber Production source category contribution to the maximum facility-wide risks at the 

facility with the maximum risk value shown. 

As shown in Table B.3.2, the 

maximum individual cancer risk from 

all HAP emissions at a facility that 

contains styrene butadiene rubber and 

latex production processes subject to the 

Group I Polymers and Resins MACT 

standard is estimated to be 70-in-1 

million, and the maximum chronic noncancer TOSHI value is estimated to be 

1. At the facilities where these 

maximum risk values occur, the 

estimated proportion of the risk 

attributable to Styrene Butadiene 

Rubber and Latex Production source 

category processes is approximately 5 

percent for cancer risks and 10 percent 

for chronic non-cancer risk. Both the 

cancer and non-cancer risks at this 

facility are primarily due to a nitrile 

butadiene rubber process, which has 

recently closed. 

The results of the demographic 

analyses performed to investigate the 

distribution of risks above 1-in-1 

million, based on actual emissions 

levels for the population living within 5 

km of the facilities, among various 

demographic groups are provided in a 

report available in the docket for this 

action and summarized in Table B.3.3 

below. 

TABLE B.3.3—STYRENE BUTADIENE RUBBER AND LATEX PRODUCTION DEMOGRAPHIC RISK ANALYSIS RESULTS

Emissions basis 

Maximum 

risk 

(in 1 million) 

Population with risk greater than 1-in-1 million 

Total 

(millions) 

Minority 

% 

African 

American 

% 

Other and 

multiracial 

% 

Hispanic 

or Latino 

% 

Native 

American 

% 

Below the 

poverty 

level 

% 

Over 25 

W/O a HS 

diploma 

% 

Nationwide ................ n/a 285 25 12 12 14 0.9 13 13 

Source Category ...... 10 0.02 40 3 36 54 0.6 18 24 

Facility-wide .............. 70 0.1 50 29 20 32 0.5 23 20 

The results of the Styrene Butadiene 

Rubber and Latex Production source 

category demographic analysis show 

that of the population with cancer risk 

greater than 1-in-1 million, 40 percent 

could be classified as a ‘‘Minority,’’ 54 

percent are included in the ‘‘Hispanic or 

Latino’’ demographic group, 36 percent 

are included in the ‘‘Other and 

Multiracial,’’ demographic group, 18 

percent are included in the ‘‘Below 

Poverty Level,’’ and 24 percent are 

included in the ‘‘Over 25 Without a High 

School Diploma’’ demographic group. 

These percentages of the population 

within 5 km of a styrene butadiene 

rubber and latex production facility and 

with a cancer risk greater than 1-in-1 

million is higher than the percentages 

for these demographic categories based 

on the distribution of these 

demographic groups across the United 

States. The table also shows that the 

results of the facility-wide demographic 

analysis are higher than the national 

percentages for the those that could be 

classified as a ‘‘Minority’’ and for those 

included in the ‘‘Hispanic or Latino,’’ 

‘‘African American,’’ ‘‘Other and 

Multiracial,’’ ‘‘Below Poverty Level,’’ and 

the ‘‘Over 25 Without a High School 

Diploma’’ demographic groups. 

Details of these assessments and 

analyses can be found in the residual 

risk documentation as referenced in 

section IV.A of this preamble, which is 

available in the docket for this action. 

d. What are our proposed decisions on 

risk acceptability and ample margin of 

safety? 

October 2008 Proposed Decision. In 

our October 10, 2008 proposal, we 

proposed that the risks were acceptable 

because the risks results of 7-in-1 

million indicated that cancer risks to the 

individual most exposed to emissions 

from the category were greater than 1- 

in-1 million but less than 100-in-1 

million. We then analyzed other risk 

factors in the ample margin of safety 

determination. In this analysis, we 

proposed that emissions from the source 

category posed no potential for an 

adverse environmental effect, did not 

pose potential for human health 

multipathway risks, and were unlikely 

to cause acute or chronic non-cancer 

health impacts. We also identified one 

emissions control option that would 

reduce risks. We proposed that such 

control was not necessary to protect 

public health with an ample margin of 

safety in light of the high cost and 

limited addition health protection it 

would provide. Therefore, we proposed 

that the existing standard provided an 

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ample margin of safety and proposed to 

re-adopt the existing MACT standard to 

satisfy section 112(f) of the CAA. 

Risk Acceptability. The revised risk 

analysis we performed for this proposal 

indicates that the cancer risks to the 

individual most exposed is 10-in-1 

million based on both actual and 

MACT-allowable emissions. The cancer 

incidence and the number of people 

exposed to cancer risks of 1-in-1 million 

or greater are not significantly changed 

from the risk identified in the October 

2008 proposal. Similarly, the risk 

analysis continued to show no potential 

for an adverse environmental effect or 

human health multipathway effects, and 

that chronic non-cancer health impacts 

are unlikely. The revised assessment 

indicated that an acute non-cancer HQ 

as high as 0.4 could occur, based on the 

REL value. Our additional analysis of 

facility-wide risks showed that the 

maximum facility-wide cancer risk is 

70-in-1 million and the maximum 

facility-wide non-cancer TOSHI is 1. It 

also showed that the styrene butadiene 

rubber production processes located at 

the facilities with these maximum risk 

values contribute approximately 5 and 

10 percent to such risks, respectively. 

Our additional analysis of the 

demographics of the exposed 

population may show disparities in 

risks between demographic groups. 

Based on this low cancer risk level and 

in consideration of other health 

measures and factors, including the low 

cancer incidence (one case in every 250 

years) and the low maximum noncancer risk level (TOSHI of 0.2), we 

propose that the risks from the Styrene 

Butadiene Rubber and Latex Production 

source category are acceptable. 

Ample Margin of Safety. Because we 

are proposing that the risks are 

acceptable, but still above 1-in-1 

million, we then re-considered our 2008 

ample margin of safety decision. 

We have not identified any additional 

control options or any changes to the 

previously analyzed control option to 

reduce risks. Our analysis does not 

indicate a change in the emissions 

reductions that could be achieved or the 

cost of control for the control option 

considered in the October 2008 

proposal. Therefore, we continue to 

propose that the current MACT standard 

provides an ample margin of safety to 

protect public health and the 

environment, and we are proposing to 

re-adopt the existing MACT standard to 

satisfy section 112(f) of the CAA. 

e. What are our proposed decisions on 

the technology review? 

In the October 10, 2008 proposal, we 

identified no advancements in practices, 

processes, and control technologies 

applicable to the emission sources in 

the Group I Polymers and Resins 

Production source categories in our 

technology review, and we proposed to 

re-adopt the existing MACT standard to 

satisfy section 112(d)(6) of the CAA. In 

that review we examined the regulatory 

requirements and/or technical analyses 

for subsequently promulgated air toxics 

regulations with similar types of 

emissions sources as those in the Group 

I Polymers and Resins I Production 

source categories, and we conducted a 

search of the RBLC for controls for VOCand HAP-emitting processes in the 

Group I Polymers and Resins 

Production source categories. We have 

not identified any additional 

developments in practices, processes, 

and control technologies since the 

proposal date for the Styrene Butadiene 

Rubber and Latex Production source 

category. Thus, we are continuing to 

propose to re-adopt the existing MACT 

standard to satisfy section 112(d)(6) of 

the CAA. 

f. What other actions are we proposing? 

The proposed changes to the SSM 

provisions for the Group I Polymers and 

Resins MACT, which apply to the 

Styrene Butadiene Rubber and Latex 

Production source category, are 

discussed above in section V.B.1.f. 

4. Nitrile Butadiene Rubber Production 

Nitrile Butadiene Rubber Production 

is one of the source categories for which 

we proposed RTR decisions on October 

10, 2008. 

a. Overview of the Source Category 

Nitrile butadiene rubber is a 

copolymer of 1,3-butadiene and 

acrylonitrile, and the Nitrile Butadiene 

Rubber Production source category 

includes any facility that polymerizes 

1,3-butadiene and acrylonitrile. While 

nitrile butadiene rubber is the primary 

product at these facilities, styrenebutadiene rubber can also be produced 

as a minor product by substituting 

styrene for acrylonitrile as a monomer. 

Depending on its specific composition, 

nitrile butadiene rubber can be resistant 

to oil and chemicals, a property that 

facilitates its use in disposable gloves, 

hoses, seals, and a variety of automotive 

applications. 

We identified one nitrile butadiene 

rubber production facility currently 

subject to the Polymers and Resins I 

MACT standard. This facility is at a 

plant site that also has other HAPemitting sources that are regulated 

under separate MACT standards, for 

which we have addressed or will 

address in future rulemaking actions. 

Acrylonitrile and 1,3-butadiene account 

for the HAP emissions from this source 

category (approximately 2 TPY). The 

majority of HAP emissions are from 

back-end process operations 

(approximately 97 percent of the total 

HAP by mass) for this source category. 

We estimate that MACT-allowable 

emissions from this source category are 

approximately equal to reported, actual 

emissions. For more detail about this 

estimate of the ratio of actual to MACTallowable emissions, see the memo in 

the docket for this action describing the 

estimation of MACT-allowable emission 

levels and associated risks and impacts. 

b. What data were used in our risk 

analyses? 

We initially created a preliminary 

data set for the Nitrile Butadiene Rubber 

Production source category using 

information we collected directly from 

industry on emissions data and 

emissions release characteristics. We 

also reviewed the emissions and other 

data to identify data anomalies that 

could affect risk estimates. On March 

29, 2007, we published an ANPRM (72 

FR 29287) for the express purpose of 

requesting comments and updates to 

this data set, as well as to the data sets 

for the other source categories addressed 

in that ANPRM. Comments received in 

response to the ANPRM were reviewed 

and considered, and we made 

adjustments to the data set where we 

concluded the comments supported 

such adjustment. After making 

appropriate changes to the data set 

based on this public data review 

process, the data set on which we based 

the initial proposal was created. This 

data set was used to conduct the risk 

assessment and other analyses for the 

Nitrile Butadiene Rubber Production 

source category, which formed the basis 

for the proposed RTR actions included 

in the October 10, 2008 proposal. 

Since the proposal, we have 

continued to scrutinize the existing data 

set and have evaluated any additional 

data that became available subsequent 

to the October 10, 2008 proposal. 

Specific questions we had concerning 

current operations led us to develop a 

questionnaire and ask for updated 

emissions and emissions release 

characteristics information. This 

information was requested from the 

facility in May 2010 using the authority 

of section 114 of the CAA. We updated 

our data set for this source category 

based on the information received 

through this request. 

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c. What are the results of the risk 

assessments and analyses? 

We have conducted a revised 

inhalation risk assessment for the Nitrile 

Butadiene Rubber Production source 

category. We have also conducted an 

assessment of facility-wide risk and 

performed a demographic analysis of 

population risks. Table B.4.1 provides 

an overall summary of the results of the 

revised inhalation risk assessment. 

TABLE B.4.1—NITRILE BUTADIENE RUBBER PRODUCTION REVISED INHALATION RISK ASSESSMENT RESULTS * 

Number of facilities 1

Maximum individual cancer risk 

(in 1 million) 2

Population at 

risk ≥ 1-in-1 

million 

Annual cancer 

incidence 

(cases per 

year) 

Maximum chronic non-cancer 

TOSHI 3

Maximum off-site 

acute non-cancer Actual HQ 4

emissions 

level 

Allowable 

emissions 

level 

Actual 

emissions 

level 

Allowable 

emissions 

level 

1 ....................... 2 2 70 0.0004 0.009 0.009 HQAEGL–1 = 0.002 acrylonitrile 

* All results are for impacts out to 50 km from every source in the category. 

1 Number of facilities evaluated in the risk analysis. 

2 Maximum individual excess lifetime cancer risk. 

3 Maximum TOSHI. The target organ with the highest TOSHI for the Nitrile Butadiene Rubber Production source category is the reproductive 

system. 4The maximum estimated acute exposure concentration was divided by available short-term threshold values to develop an array of HQ values. HQ values shown use the lowest available acute threshold value, which in most cases, is the REL. When HQ values exceed 1, we also 

show HQ values using the next lowest available acute threshold. See section III.A of this preamble for explanation of acute threshold values. 

The inhalation risk modeling was 

performed using actual emissions level 

data. As shown in Table B.4.1, the 

results of the revised inhalation risk 

assessment indicated the maximum 

lifetime individual cancer risk could be 

as high as 2-in-1 million, the maximum 

chronic non-cancer TOSHI value could 

be up to 0.009, and the maximum offfacility-site acute HQ value could be as 

high as 0.002, based on the actual 

emissions level and the AEGL–1 value 

for acrylonitrile. The total estimated 

national cancer incidence from these 

facilities based on actual emission levels 

is 0.0004 excess cancer cases per year, 

or one case in every 2,500 years. 

Our analysis of potential differences 

between actual emission levels and 

emissions allowable under the MACT 

standard indicate that actual and 

allowable emissions are approximately 

the same. Therefore, the risk results for 

MACT-allowable emissions are equal to 

those for actual emissions. 

There were no reported emissions of 

PB–HAP; therefore, we do not expect 

potential for human health 

multipathway risks or adverse 

environmental impacts. 

Table B.4.2 displays the results of the 

facility-wide risk assessment. This 

assessment was conducted based on 

actual emission levels. 

TABLE B.4.2—NITRILE BUTADIENE RUBBER PRODUCTION FACILITY-WIDE RISK ASSESSMENT RESULTS

Maximum facility-wide individual cancer risk (in 1 million) .............................................................................................................. 5 

Nitrile Butadiene Rubber Production source category contribution to this maximum facility-wide individual cancer risk 1 .... 33% 

Maximum facility-wide chronic non-cancer TOSHI ......................................................................................................................... 0.03 

Nitrile Butadiene Rubber Production source category contribution to this maximum facility-wide non-cancer TOSHI 1 ........ 30% 

1 Percentage shown reflects Nitrile Butadiene Rubber Production source category contribution to the maximum facility-wide risks at the facility 

with the maximum risk value shown. 

The maximum individual cancer risk 

from all HAP emissions at a facility that 

contains nitrile butadiene rubber 

production processes subject to the 

Group I Polymers and Resins MACT 

standard is estimated to be 5-in-1 

million, and the maximum chronic noncancer TOSHI value is estimated to be 

0.03. The estimated proportion of the 

risk attributable to Nitrile Butadiene 

Rubber Production source category 

processes at this facility is 

approximately 33 percent for cancer 

risks and 30 percent for chronic noncancer risk. This facility also has 

processes subject to the Group IV 

Polymers and Resins MACT standard, 

40 CFR part 63, subpart JJJ. 

The results of the demographic 

analyses performed to investigate the 

distribution of risks above 1-in-1 

million, based on actual emissions 

levels for the population living within 

5 km of the facilities, among various 

demographic groups are provided in a 

report available in the docket for this 

action and summarized in Table B.4.3 

below. 

TABLE B.4.3—NITRILE BUTADIENE RUBBER PRODUCTION DEMOGRAPHIC RISK ANALYSIS RESULTS

Emissions 

basis 

Maximum 

risk 

(in 1 million) 

Population with risk greater than 1-in-1 million 

Total 

(millions) 

Minority 

% 

African 

American 

% 

Other and 

multiracial 

% 

Hispanic or 

Latino 

% 

Native 

American 

% 

Below the 

poverty 

level 

% 

Over 25 

W/O a HS 

diploma 

% 

Nationwide ................ n/a 285 25 12 12 14 0.9 13 13 

Source Category ...... 2 0.00007 94 94 0 0 0 33 14 

Facility-wide .............. 5 0.006 95 93 2 0.4 0.1 23 17 

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36Note that these uncontrolled emissions were 

included in the baseline risk assessment. 

The results of the demographic 

analysis show that, for the Nitrile 

Butadiene Rubber Production source 

category, of the population of 70 people 

with cancer risk greater than 1-in-1 

million, 94 percent could be classified 

as a ‘‘Minority,’’ 94 percent are included 

in the ‘‘African-American’’ demographic 

group, 33 percent are included in the 

‘‘Below Poverty Level’’ demographic 

group, and 14 percent are included in 

the ‘‘Over 25 Without a High School 

Diploma’’ demographic group. The 

percentage of the population for these 

demographic categories within 5 km of 

a nitrile butadiene rubber production 

facility and with a cancer risk greater 

than 1-in-1 million is higher than 

distribution of these demographic 

groups across the United States. The 

table also shows that the results of the 

demographic analysis for the 6,000 

people at cancer risk greater than 1-in1 million from facility-wide emissions 

are similar to the results for the source 

category. 

Details of these assessments and 

analyses can be found in the residual 

risk documentation as referenced in 

section IV.A of this preamble, which is 

available in the docket for this action. 

d. What are our proposed decisions on 

risk acceptability and ample margin of 

safety? 

October 2008 Proposed Decision. In 

our October 2008 proposal, we proposed 

that the risks were acceptable because 

the risks results indicated that cancer 

risks to the individual most exposed to 

emissions from the category of 60-in-1 

million were greater than 1-in-1 million 

but less than 100-in-1 million. We then 

analyzed other risk factors in the ample 

margin of safety determination. In this 

analysis, we proposed that emissions 

from the source category posed no 

potential for an adverse environmental 

effect, did not pose potential for human 

health multipathway risks, and were 

unlikely to cause acute or chronic noncancer health impacts. We also 

identified one emissions control option 

that would reduce risks. We proposed 

that such control was not necessary to 

protect public health with an ample 

margin of safety in light of the high cost 

and limited addition health protection it 

would provide. Therefore, we proposed 

that the existing standard provided an 

ample margin of safety and proposed to 

re-adopt the existing MACT standard to 

satisfy section 112(f) of the CAA. 

Risk Acceptability. The revised risk 

analysis we performed for this proposal 

indicates that the cancer risks to the 

individual most exposed is 2-in-1 

million based on both actual and 

MACT-allowable emissions. The cancer 

incidence and the number of people 

exposed to cancer risks of 1-in-1 million 

or greater are much less than the risk 

identified in the October 2008 proposal. 

Similarly, the risk analysis continued to 

show no potential for an adverse 

environmental effect or human health 

multipathway effects, and that acute or 

chronic non-cancer health impacts are 

unlikely. Our additional analysis of 

facility-wide risks showed that the 

maximum facility-wide cancer risk is 

5-in-1 million and that the maximum 

chronic non-cancer risks are unlikely to 

cause health impacts. Our additional 

analysis of the demographics of the 

exposed population may show 

disparities in risks between 

demographic groups, but only for the 60 

people at cancer risk greater than 1-in1 million. Based on this low cancer risk 

level and in consideration of other 

health measures and factors, including 

the low cancer incidence (one case in 

every 2,500 years) and the low 

maximum non-cancer risk level (TOSHI 

of 0.009), we propose that the risks from 

the Nitrile Butadiene Rubber Production 

source category are acceptable. 

Ample Margin of Safety. Because we 

are proposing that the risks are 

acceptable, but still above 1-in-1 

million, we then re-considered our 

October 2008 ample margin of safety 

decision. 

We have not identified any additional 

control options or any changes to the 

previously analyzed control option. Our 

analysis does not indicate a change in 

the emissions reductions that could be 

achieved or the cost of control for the 

control option considered in the 

October 2008 proposal. Therefore, we 

continue to propose that the current 

MACT standard provides an ample 

margin of safety to protect public health 

and the environment, and we are 

proposing to re-adopt the existing 

MACT standard to satisfy section 112(f) 

of the CAA. 

e. What are our proposed decisions on 

the technology review? 

In the October 10, 2008 proposal, we 

identified no advancements in practices, 

processes, and control technologies 

applicable to the emission sources in 

the Group I Polymers and Resins 

Production source categories in our 

technology review, and we proposed to 

re-adopt the existing MACT standard to 

satisfy section 112(d)(6) of the CAA. In 

that review we examined the regulatory 

requirements and/or technical analyses 

for subsequently promulgated air toxics 

regulations with similar types of 

emissions sources as those in the Group 

I Polymers and Resins Production 

source categories, and we conducted a 

search of the RBLC for controls for VOCand HAP-emitting processes in the 

Group I Polymers and Resins 

Production source categories. We have 

not identified any additional 

developments in practices, processes, 

and control technologies since the 

proposal date for the Nitrile Butadiene 

Rubber Production source category. 

Thus, we are continuing to propose to 

re-adopt the existing MACT standard to 

satisfy section 112(d)(6) of the CAA. 

f. What other actions are we proposing? 

SSM Provisions. The proposed 

changes to the Group I Polymers and 

Resins MACT, which apply to the 

Nitrile Butadiene Rubber Production 

source category, are discussed above in 

section V.B.1.f. 

Significant Emission Points Not 

Previously Regulated. We identified the 

absence of a standard for a significant 

emissions source in the category in the 

provisions of the Group I Polymers and 

Resins MACT standard that apply to the 

Nitrile Butadiene Rubber Production 

source category. Specifically, there are 

no back-end process operation emission 

limits for this source category.36 As 

these processes are major sources of 

emissions for the one facility in the 

source category, we are proposing to set 

standards for back-end process 

operations under CAA section 112(d)(2) 

and (d)(3) in this action. 

The emission limit we are proposing 

today represents the MACT floor level 

of control. As there is only one facility 

in the source category, the emissions 

limitation achieved by this facility is the 

MACT floor. The annual emissions from 

the back-end process operations at this 

facility are approximately 2 TPY. There 

are 11 separate dryer vents; one is 

controlled, while the others are 

uncontrolled. The controlled vent emits 

around 0.003 TPY of 1,3-butadiene and 

0.002 TPY of acrylonitrile. The 

regenerative thermal oxidizer used on 

this vent achieves approximately 96 

percent control of the acrylonitrile 

emissions, but no control of 1,3- 

butadiene. The collection of 10 

uncontrolled vents emit around 0.8 TPY 

of 1,3-butadiene and 0.9 TPY of 

acrylonitrile. 

As part of our beyond-the-floor 

analysis, we considered alternatives 

more stringent than the MACT floor 

option. We identified one option using 

add-on emission controls that would 

require the ducting of emissions from 

the currently uncontrolled back-end 

process operations emission source to a 

control device, such as an incinerator. 

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This option would also require an initial 

performance test of the incinerator and 

continuous parameter monitoring 

averaged daily. The capital costs of this 

option are estimated to be 

approximately $1,600,000 and the total 

annual costs are estimated to be 

approximately $11,400,000/year. We 

estimate that an incinerator would 

achieve an emissions reduction of 98 

percent, resulting in a HAP decrease of 

approximately 1.7 TPY, with a costeffectiveness of approximately 

$6,700,000/ton. Table B.4.4 summarizes 

the cost and emission reduction impacts 

of the proposed options. 

TABLE B.4.4—NITRILE BUTADIENE RUBBER PRODUCTION FACILITY BACK-END OPTION IMPACTS

Regulatory alternatives HAP emissions 

(TPY) 

Capital cost 

(million $) 

Annual cost 

(million $/yr) 

Cost-effectiveness as compared to baseline 

(million $/ton 

HAP removed) 

Baseline ........................................................................................... 1.7 ............................ ............................ ............................

1 (MACT floor) ............................................................................... 1.7 0 0 ............................

2 (Beyond-the-floor) ...................................................................... 0.04 1.6 11.4 6.7 

In addition to the cost and emission 

reduction impacts shown in Table B.4.4, 

we estimate that the beyond-the-floor 

option will result in increases in criteria 

pollutant and carbon dioxide emissions 

(PM¥2 TPY, SO2¥0.4 TPY, NOX¥133 

TPY, CO¥23 TPY, and CO2¥80,000 

TPY) and an increase in energy use of 

approximately 1,400,000 BTU/year at a 

cost of approximately $385,000/year. 

We believe that the costs and other 

impacts of this beyond-the-floor option 

are not reasonable, given the level of 

emission reduction. Therefore, we are 

proposing Option 1, the MACT floor 

option. We are requesting comment on 

this analysis and these options. 

As noted above, we are proposing that 

the MACT standard, prior to the 

implementation of the proposed 

emission limitation to the back-end 

process operations discussed in this 

section, provides an ample margin of 

safety to protect public health. Since the 

proposed emission limitation represents 

the existing level of control for the 

single plant in the source category, this 

proposed emission limitation will not 

have an impact on risk. Therefore, we 

maintain that after its implementation, 

the rule will continue to provide an 

ample margin of safety to protect public 

health. Consequently, we do not believe 

it will be necessary to conduct another 

residual risk review under CAA section 

112(f) for this source category 8 years 

following promulgation of new backend process limitations, merely due to 

the addition of this new MACT 

requirement. 

5. Neoprene Rubber Production 

Neoprene Rubber Production is one of 

the source categories for which we 

proposed and finalized RTR decisions 

on December 12, 2007 (72 FR 70543) 

and December 16, 2008 (73 FR 76220), 

respectively. 

a. Overview of the Source Category 

Neoprene is a polymer of chloroprene. 

Neoprene was originally developed as 

an oil-resistant substitute for natural 

rubber, and its properties allow its use 

in a wide variety of applications, 

including wetsuits, gaskets and seals, 

hoses and tubing, plumbing fixtures, 

adhesives, and other products. We have 

identified one neoprene rubber 

production facility currently subject to 

the Polymers and Resins I MACT 

standards. 

For the Neoprene Rubber Production 

source category, we have proposed and 

finalized a decision not to revise the 

standards for those source categories 

based on our RTR. As noted above, this 

decision was proposed on December 12, 

2007 and finalized on December 16, 

2008. Since the Neoprene Production 

source category was determined to be 

‘‘low risk’’ (maximum lifetime cancer 

risk less than 1-in-1 million), we did not 

believe it was necessary to conduct a 

facility-wide or demographic risk 

analysis. Therefore, we are not 

addressing the RTR in today’s notice for 

this source category. 

b. What other actions are we proposing? 

SSM Provisions. The proposed 

changes to the Group I Polymers and 

Resins MACT, which apply to the 

Neoprene Rubber Production source 

category, are discussed above in section 

V.B.1.f. 

Significant Emission Points Not 

Previously Regulated. We identified in 

the provisions of the Group I Polymers 

and Resins MACT standard that apply 

to the Neoprene Rubber Production 

source category the absence of a 

standard for a significant emissions 

source in the category. Specifically, 

there are no back-end process operation 

emission limits for this source category. 

As these processes are major sources of 

emissions for the one facility in the 

source category, we are proposing to set 

standards for back-end process 

operations under CAA sections 

112(d)(2) and (3) in this action. 

As there is only one facility in the 

source category, the emissions level 

currently being achieved by this facility 

represents the MACT floor. The annual 

emissions from the back-end process 

operations at this facility are 

approximately 14 TPY. There are 11 

separate dryer vents collectively 

emitting around 14 TPY of toluene. 

None of the vents are controlled. 

Therefore, we have determined that the 

MACT floor for the back-end process is 

14 TPY based on stripping and HAP 

recovery, given current production 

levels, but which would fluctuate 

proportionally with an increase or 

decrease in production levels. 

As part of our beyond-the-floor 

analysis, we considered alternatives 

more stringent than the MACT floor 

option. We identified one option using 

add-on emission controls that would 

require the ducting of emissions from 

the back-end process operations to a 

control device, such as an incinerator. 

This option would also require an initial 

performance test of the incinerator and 

continuous parameter monitoring 

averaged daily. The capital costs of this 

option are estimated to be 

approximately $1,300,000 and the total 

annual costs are estimated 

approximately $4,800,000 per year. We 

estimate that an incinerator would 

achieve an emissions reduction of 98 

percent, resulting in a HAP decrease of 

approximately 22.6 TPY, with a costeffectiveness of approximately $213,000 

per ton. Table B.5.1 summarizes the 

impacts of the proposed options. 

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TABLE B.5.1—NEOPRENE RUBBER PRODUCTION FACILITY BACK-END OPTION IMPACTS

Regulatory alternatives 

HAP 

emissions 

(TPY) 

Capital cost 

(million $) 

Annual cost 

(million$/yr) 

Cost-effectiveness as 

compared to 

baseline ($/ton 

HAP removed) 

Baseline ........................................................................................... 23 ............................ ............................ ............................

1 (MACT floor) ............................................................................... 23 0 0 ............................

2 (Beyond-the-floor) ...................................................................... 0.5 1.3 4.8 213,000 

In addition to the cost and emission 

reduction impacts shown in Table B.5.1, 

we estimate that the beyond-the-floor 

option will result in increases in criteria 

pollutant and carbon dioxide emissions 

(PM ¥ 0.8, SO2 ¥ 0.2 TPY, NOX ¥ 55 

TPY, CO ¥ 10 TPY, and CO2 ¥ 33,000 

TPY) and an increase in energy use of 

approximately 560,000 million BTU/ 

year at a cost of approximately 

$159,000/year. 

We believe that the costs and other 

impacts of this beyond-the-floor option 

are not reasonable, given the level of 

emission reduction. Therefore, we are 

proposing Option 1, the MACT floor 

option. We are requesting comment on 

this analysis and these options. 

As noted above, we have proposed 

and finalized a decision that the MACT 

standard for neoprene rubber 

production, prior to the implementation 

of the proposed emission limitation to 

the back-end process operations 

discussed in this section, provides an 

ample margin of safety to protect public 

health. Since this source category was 

‘‘low risk’’ prior to this proposed 

emission limitation, we maintain that 

after their implementation, the rule will 

continue to provide an ample margin of 

safety to protect public health. 

Consequently, we do not believe it will 

be necessary to conduct another 

residual risk review under CAA section 

112(f) for this source category 8 years 

following promulgation of new backend process limitations, merely due to 

the addition of this new MACT 

requirement. 

6. Ethylene Propylene Rubber 

Production 

Ethylene Propylene Rubber 

Production is one of the source 

categories for which we proposed and 

finalized RTR decisions on December 

12, 2007 (72 FR 70543) and December 

16, 2008 (73 FR 76220), respectively. 

a. Overview of the Source Category 

Ethylene propylene rubber is an 

elastomer prepared from ethylene and 

propylene monomers. Common uses for 

these elastomers include radiator and 

heater hoses, weather stripping, door 

and window seals for cars, construction 

plastics blending, wire and cable 

insulation and jackets, and single-ply 

roofing membranes. 

For the Ethylene Propylene Rubber 

Production source category, we have 

proposed and finalized a decision not to 

revise the standards for this source 

category based on our RTR. As noted 

above, this decision was proposed on 

December 12, 2007 and finalized on 

December 16, 2008. Since the Ethylene 

Propylene Rubber Production source 

category was determined to be ‘‘low 

risk’’ (maximum lifetime cancer risk less 

than 1-in-1 million), we did not believe 

it was necessary to conduct a facilitywide or demographic risk analysis. 

Therefore, we are not addressing the 

RTR in this notice for this source 

category. 

b. What other actions are we proposing? 

SSM Provisions. The proposed 

changes to the SSM provisions for the 

Group I Polymers and Resins MACT, 

which apply to the Ethylene Propylene 

Rubber Production source category, are 

discussed above in section V.B.1.f. 

Significant Emission Points Not 

Previously Regulated. We identified in 

the provisions of the Group I Polymers 

and Resins MACT standard that apply 

to the Ethylene Propylene Rubber 

Production source category the absence 

of a standard for a significant emissions 

source in the category. Specifically, the 

rule requires that emissions from Group 

1 front-end process vents be routed to a 

control device that achieves 98 percent 

reduction in organic HAP emissions but 

does not require the control of hydrogen 

halides and halogens from the outlet of 

combustion devices. All three currentlyoperating facilities in this source 

category control the organic HAP 

emissions in accordance with the 

requirements in the rule (i.e., reduce 

organic HAP emissions by 98 percent). 

This represents the MACT floor for this 

source category. However, one facility 

routes a chlorinated organic compound 

to a flare, which results in emissions of 

HCl that are not regulated by the current 

MACT requirements. When chlorinate 

organics are burned in a flare, there are 

variations in the combustion which 

likely results in the formation of 

combustion by-products. These 

combustion by-products could include 

trace chlorinated compounds such as 

dioxins and furans. Due to the level of 

HCl emissions resulting from the 

combustion of chlorinated organic 

compounds in Group 1 streams, we are 

proposing to require control of these 

HCl emissions for the Ethylene 

Propylene Rubber Production source 

category. 

As part of our beyond-the-floor 

analysis, we considered alternatives to 

reduce these HCl emissions, which are 

more stringent than the MACT floor 

option. We identified the option of 

eliminating the exemption from the 

requirement to control hydrogen halides 

and halogens from the outlet of 

combustion devices. The one facility 

reports around 20 TPY of HCl emissions 

resulting from the combustion of 

chlorinated organic compounds in a 

flare. The other two facilities indicated 

that they do not emit any HCl emissions 

resulting from the combustion of 

chlorinated organic compounds. We 

estimated that the capital costs for the 

facility to replace the flare with an 

incinerator followed by a scrubber to 

reduce the HCl would be approximately 

$985,000 and the total annual costs are 

estimated to be approximately $446,000 

per year. While there would be no 

additional reduction in organic HAP 

from this requirement, the HCl 

emissions would be reduced by 99 

percent, or 19.6 TPY. The costeffectiveness of this option would be 

approximately $21,000 per ton. 

However, this ethylene propylene 

rubber process is co-located with the 

halobutyl rubber process, which also 

vents a vent stream containing 

chlorinated organic compounds to a 

flare, resulting in HCl emissions. We 

estimated the costs of a single 

incinerator and scrubber to control the 

streams containing chlorinated organics 

from both the ethylene propylene rubber 

and halobutyl rubber processes. The 

estimated capital cost of this control 

scenario is $1,100,000 and the annual 

cost is $640,000 per year. This would 

still achieve the same HCl emission 

reduction from the ethylene propylene 

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rubber process (19.6 TPY), and the 

overall cost-effectiveness considering 

the reductions from the ethylene 

propylene rubber and halobutyl rubber 

would be around $6,700 per ton. Table 

B.6.1 summarizes the impacts of the 

proposed options. 

TABLE B.6.1—ETHYLENE PROPYLENE RUBBER PRODUCTION FACILITY FRONT-END OPTIONS IMPACTS

Regulatory alternatives 

HAP 

emissions 

(TPY HAP) 

Capital cost 

($million) 

Annual cost 

($million/yr) 

Costeffectiveness 

as compared 

to baseline 

($/ton HAP 

removed) 

Baseline ........................................................................................... 20 ............................ ............................ ............................

1 (MACT floor) ............................................................................... 20 0 0 ............................

2 (Beyond-the-floor) ...................................................................... 0.2 * 1.1 * 0.6 * 6,700 

* Assuming a shared control incinerator/scrubber combination is used for both the ethylene propylene rubber and halobutyl rubber processes. 

In addition to the cost and emission 

reduction impacts shown in Table B.6.1, 

we estimate that the beyond-the-floor 

option will result in increases in criteria 

pollutant and carbon dioxide emissions 

(PM ¥ 0.03 TPY, SO2 ¥ 0.006 TPY, 

NOX ¥ 2 TPY, CO ¥ 0.4 TPY, and CO2

¥ 1,200 TPY), the generation of 

approximately 29 million gallons/year 

of wastewater, and an increase in energy 

use of approximately 21,000 million 

BTU/year at a cost of approximately 

$7,000/year. 

We believe that the costs and other 

impacts of this beyond-the-floor option 

are reasonable, given the level of 

emission reduction. Therefore, we are 

proposing Option 2, the beyond-thefloor option. We are requesting 

comment on this analysis and these 

options. 

As noted above, we have proposed 

and finalized a decision that the MACT 

standard for ethylene propylene rubber 

production, prior to the implementation 

of the proposed emission limitation 

discussed in this section, provides an 

ample margin of safety to protect public 

health. Since this source category was 

‘‘low risk’’ prior to this proposed 

emission limitation, we maintain that 

after its implementation, which will 

only further reduce HAP emissions, the 

rule will continue to provide an ample 

margin of safety to protect public health. 

Consequently, we do not believe it will 

be necessary to conduct another 

residual risk review under CAA section 

112(f) for this source category 8 years 

following promulgation of new 

limitations, merely due to the addition 

of this new MACT requirement. 

7. Butyl Rubber Production 

Butyl Rubber Production is one of the 

source categories for which we 

proposed and finalized RTR decisions 

on December 12, 2007 (72 FR 70543) 

and December 16, 2008 (73 FR 76220), 

respectively. 

a. Overview of the Source Category 

The Butyl Rubber Production source 

category includes any facility that 

manufactures copolymers of isobutylene 

and isoprene. A typical composition of 

butyl rubber is approximately 97 

percent isobutylene and 3 percent 

isoprene. Modified, derivative, and 

halogenated copolymers and latexes are 

also included in this source category. 

Butyl rubber is typically made by a 

precipitation (slurry) polymerization 

process in which isobutylene and 

isoprene are copolymerized in methyl 

chloride solvent. Butyl rubber is very 

impermeable to common gases and 

resists oxidation. Uses for butyl rubber 

include tires, tubes, and tire products; 

automotive mechanical goods; 

adhesives, caulks, and sealants; and 

pharmaceutical uses. A specialty group 

of butyl rubbers are halogenated butyl 

rubbers, which are produced 

commercially by dissolving butyl rubber 

in hydrocarbon solvent and contacting 

the solution with gaseous or liquid 

elemental halogens such as chlorine or 

bromine. For the purpose of the MACT 

standards, this source category is 

divided into two subcategories: butyl 

rubber and halobutyl rubber. 

For the Butyl Rubber Production 

source category, we have proposed and 

finalized a decision not to revise the 

standards for this source category based 

on our RTR. As noted above, this 

decision was proposed on December 12, 

2007 and finalized on December 16, 

2008. Since the Butyl Rubber 

Production source category was 

determined to be ‘‘low risk’’ (maximum 

lifetime cancer risk less than 1-in-1 

million), we did not believe it was 

necessary to conduct a facility-wide or 

demographic risk analysis. Therefore, 

we are not addressing the RTR in this 

notice for this source category. 

b. What other actions are we proposing? 

SSM Provisions. The proposed SSM 

changes to the Group I Polymers and 

Resins MACT, which apply to the Butyl 

Rubber Production source category, are 

discussed above in section V.B.1.f. 

Significant Emission Points Not 

Previously Regulated. We identified in 

the provisions of the Group I Polymers 

and Resins MACT standard that apply 

to both Butyl Rubber Production 

subcategories the absence of standards 

for two significant emissions sources in 

each of the Butyl Rubber Production 

subcategories. Specifically, these 

situations are HCl emissions from frontend process vents and emissions from 

back-end process operations. 

The rule requires that emissions from 

Group 1 front-end process vents be 

routed to a control device that achieves 

98 percent reduction in organic HAP 

emissions but does not require the 

control of hydrogen halides and 

halogens from the outlet of combustion 

devices. Both facilities in these 

subcategories control the organic HAP 

emissions in accordance with the 

requirements in the rule (i.e., reduce 

organic HAP emissions by 98 percent). 

This represents the MACT floor for 

these subcategories. However, these 

facilities route a chlorinated organic 

compound to a flare, which results in 

emissions of HCl that are exempted 

from the current MACT requirements. 

Due to the level of HCl emissions 

resulting from the combustion of 

chlorinated organic compounds in 

Group 1 streams, we are proposing to 

require control of these HCl emissions 

for both the Butyl Rubber Production 

and Halobutyl Rubber Production 

subcategories. 

As there is only one facility in each 

subcategory, the existing level of control 

for organic HAP emissions represents 

the MACT floor. As part of our beyondthe-floor analysis, we considered 

alternatives to reduce the HCl 

emissions, which are more stringent 

than the MACT floor option. For frontend process vents, we identified the 

option of eliminating the exemption 

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65110 Federal Register / Vol. 75, No. 203 / Thursday, October 21, 2010 / Proposed Rules 

from the requirement to control 

hydrogen halides and halogens from the 

outlet of combustion devices. The butyl 

rubber facility reported HCl emissions 

of 30.1 TPY, while the halobutyl rubber 

facility reported 76.8 TPY. Since 

scrubbers could not be installed on the 

outlet of these combustion devices to 

reduce the HCl emissions by 99 percent, 

the butyl rubber facility and the 

halobutyl rubber facility would need to 

install new incinerators followed by 

scrubbers to comply with this beyondthe-floor requirement. We estimate that 

the capital costs for this would be 

$669,000 for the butyl rubber facility 

and $984,000 for the halobutyl rubber 

facility. The total annual costs would be 

around $235,000 per year for the butyl 

rubber facility and $424,000 per year for 

the halobutyl rubber facility. Since there 

would be no additional reduction in 

organic HAP emissions from what is 

being achieved by the current controls, 

the only emission reduction would a 99 

percent reduction in HCl emissions, or 

29.8 TPY for the butyl rubber facility 

and 76 TPY for the halobutyl rubber 

facility. Thus, the cost-effectiveness of 

these beyond-the-floor options would be 

approximately $7,900 per ton for butyl 

rubber and $6,000 per ton for halobutyl 

rubber. However, this halobutyl rubber 

process is co-located with an ethylene 

propylene rubber process, which also 

vents a vent stream containing 

chlorinated organic compounds to a 

flare, resulting in HCl emissions. As 

these streams could be controlled using 

the same equipment at this facility, we 

estimated the costs of a single 

incinerator and scrubber to control the 

streams containing chlorinated organics 

from both the ethylene propylene rubber 

and halobutyl rubber processes. The 

estimated capital cost of this control 

scenario is $1,100,000 and the annual 

cost is $640,000 per year. This would 

still achieve the same HCl emission 

reduction from the halobutyl rubber 

process (76 TPY), and the overall costeffectiveness considering the reductions 

from the ethylene propylene rubber and 

halobutyl rubber would be around 

$6,700 per ton. Tables B.7.1 and B.7.2 

summarize the impacts of the proposed 

options. 

TABLE B.7.1—BUTYL RUBBER PRODUCTION FACILITY FRONT-END OPTIONS IMPACTS

Regulatory alternatives 

HAP 

emissions 

(TPY HAP) 

Capital cost 

($million) 

Annual cost 

($million/yr) 

Costeffectiveness 

as compared to 

baseline 

($/ton HAP 

removed) 

Baseline ....................................................................................................... 30.1 ........................ ............................ ............................

1 (MACT floor) ........................................................................................... 30.1 0 0 ............................

2 (Beyond-the-floor) .................................................................................. 0.3 0.6 0.2 $7,900 

TABLE B.7.2—HALOBUTYL RUBBER PRODUCTION FACILITY FRONT-END OPTIONS IMPACTS

Regulatory alternatives 

HAP 

emissions 

(TPY HAP) 

Capital cost 

($million) 

Annual cost 

($million/yr) 

Costeffectiveness 

as compared to 

baseline 

($/ton HAP 

removed) 

Baseline ........................................................................................... 76.8 ............................ ............................ ............................

1 (MACT floor) ............................................................................... 76.8 0 0 ............................

2 (Beyond-the-floor) ...................................................................... 0.8 * 1.1 * 0.6 * $6,700 

* Assuming a shared control incinerator/scrubber combination is used for both the ethylene propylene rubber and halobutyl rubber processes. 

In addition to the cost and emission 

reduction impacts shown in Table B.7.1 

for butyl rubber production, we estimate 

that the beyond-the-floor option will 

result in increases in criteria pollutant 

and carbon dioxide emissions (PM ¥ 

0.004 TPY, SO2 ¥ 0.001 TPY, NOX ¥ 

2 TPY, CO ¥ 0.05 TPY, and CO2 ¥ 160 

TPY), the generation of approximately 

31 million gallons/year of wastewater, 

and an increase in energy use of around 

3,000 million BTU/year at a cost of 

approximately $3,000/year. 

In addition to the cost and emission 

reduction impacts shown in Table B.6.2 

for halobutyl rubber production, we 

estimate that the beyond-the-floor 

option will result in increases in criteria 

pollutant and carbon dioxide emissions 

(PM ¥ 0.03 TPY, SO2 ¥ 0.006 TPY, 

NOX ¥ 2 TPY, CO ¥ 0.4 TPY, and CO2

¥ 1,200 TPY), the generation of 

approximately 29 million gallons/year 

of wastewater, and an increase in energy 

use of around 21,000 million BTU/year 

at a cost of approximately $7,000/year. 

We believe that the costs and other 

impacts of these beyond-the-floor 

options are reasonable, given the level 

of emission reduction. Therefore, we are 

proposing Option 2, the beyond-thefloor option, for both the Butyl Rubber 

Production and Halobutyl Rubber 

Production subcategories. We are 

requesting comment on this analysis 

and these options. 

We also noted that there are no backend process operation emission limits 

for either the Butyl Rubber Production 

or Halobutyl Rubber Production 

subcategories. As there is only one 

facility in each subcategory, the backend process operations emissions level 

currently being achieved by these 

facilities represents the MACT floor. 

The annual emissions from the 

uncontrolled back-end process 

operations at the butyl rubber facility 

are approximately 26 TPY, and 35 TPY 

at the halobutyl facility. There are two 

separate dryer vent streams at the butyl 

rubber facility, with one stream 

controlled. The controlled stream emits 

around 28 TPY of hexane. The 

regenerative thermal oxidizer used to 

control emissions achieves 

approximately 98-percent control. There 

are four separate dryer vents at the 

halobutyl facility and one vent is 

controlled. The controlled vent emits 

around 18 TPY of hexane. The 

regenerative thermal oxidizer used to 

control emissions achieves 

approximately 97-percent control of the 

hexane emissions. The four 

uncontrolled vents collectively emit 

around 35 TPY of hexane. Therefore, we 

have determined that the MACT floors 

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for these processes are these emission 

levels, given current production levels, 

but which would fluctuate 

proportionally with an increase or 

decrease in production levels. 

As part of our beyond-the-floor 

analysis, we considered alternatives 

more stringent than the MACT floor 

option. We identified one option using 

add-on emission controls that would 

require the ducting of emissions from 

the uncontrolled back-end process 

operations to a control device, such as 

an incinerator. This option would also 

require an initial performance test of the 

incinerator and continuous parameter 

monitoring averaged daily. For the Butyl 

Rubber Production subcategory, the 

capital costs of this option are estimated 

to be approximately $235,000 and the 

total annual costs are estimated to be 

approximately $181,000. For the 

Halobutyl Rubber Production 

subcategory, the capital costs of this 

option are estimated to be 

approximately $950,000 and the total 

annual costs are estimated to be 

approximately $1,600,000 per year. We 

estimate that an incinerator would 

achieve an emissions reduction of 98 

percent, resulting in a HAP decrease of 

approximately 26 TPY for the Butyl 

Rubber Production subcategory and 34 

for Halobutyl Rubber Production 

subcategory. The associated costeffectiveness values would be 

approximately $7,000 per ton for Butyl 

Rubber Production subcategory and 

$47,000/ton for Halobutyl Rubber 

Production subcategory. Tables B.7.3 

and B.7.4 summarize the impacts of the 

proposed options. 

TABLE B.7.3—BUTYL RUBBER PRODUCTION SUBCATEGORY FACILITY BACK-END OPTION IMPACTS

Regulatory alternatives 

HAP 

emissions 

(TPY HAP) 

Capital cost 

($million) 

Annual cost 

($million/yr) 

Costeffectiveness 

as compared to 

baseline 

($/ton HAP 

removed) 

Baseline ....................................................................................... 54 .............................. .............................. ............................

1 (MACT floor) ........................................................................... 54 0 0 ............................

2 (Beyond-the-floor) .................................................................. 28 0 .2 0 .2 $7,000 

TABLE B.7.4—HALOBUTYL RUBBER PRODUCTION SUBCATEGORY FACILITY BACK-END OPTION IMPACTS

Regulatory alternatives 

HAP 

Emissions 

(TPY HAP) 

Capital cost 

($million) 

Annual cost 

($million/yr) 

Costeffectiveness 

as compared to 

baseline 

($/ton HAP 

removed) 

Baseline ....................................................................................................... 53 ........................ ............................ ............................

1 (MACT floor) ........................................................................................... 53 0 0 ............................

2 (Beyond-the-floor) .................................................................................. 19 1 1.6 $47,000 

In addition to the cost and emission 

reduction impacts shown in Table B.7.3 

for Butyl Rubber Production 

subcategory, we estimate that the 

beyond-the-floor option will result in 

increases in criteria pollutant and 

carbon dioxide emissions (PM ¥ 0.01, 

SO2 ¥ 0.003 TPY, NOX ¥ 8 TPY, CO 

¥ 0.2 TPY, and CO2 ¥ 600 TPY) and 

an increase in energy use of 

approximately 10,000 million BTU/year 

at a cost of approximately $6,000/year. 

In addition to the cost and emission 

reduction impacts shown in Table B.7.4 

for Halobutyl Rubber Production 

subcategory, we estimate that the 

beyond-the-floor option will result in 

increases in criteria pollutant and 

carbon dioxide emissions (PM ¥0.25, 

SO2 ¥0.05 TPY, NOX ¥17 TPY, CO ¥3 

TPY, and CO2 ¥10,500 TPY) and an 

increase in energy use of approximately 

170,000 million BTU/year at a cost of 

approximately $49,000/year. 

We believe that the costs and other 

impacts of the beyond-the-floor option 

for back-end process operations for the 

Butyl Rubber Production subcategory 

are reasonable, given the level of 

emission reduction. Therefore, we are 

proposing Option 2 for the Butyl Rubber 

Production subcategory, the beyond-thefloor option. We are requesting 

comment on this analysis and these 

options. 

We believe that the costs and other 

impacts of the beyond-the-floor option 

for the Halobutyl Rubber Production 

subcategory back-end process 

operations are not reasonable, given the 

level of emission reduction. Therefore, 

we are proposing Option 1, the MACT 

floor option. We are requesting 

comment on this analysis and these 

options. 

As noted above, we have proposed 

and finalized a decision that the MACT 

standard for the Butyl Rubber 

Production source category, prior to the 

implementation of the proposed 

emission limitations to the front-end 

process vent and back-end process 

operations discussed in this section, 

provides an ample margin of safety to 

protect public health. Since both 

subcategories of this source category 

were ‘‘low risk’’ prior to these proposed 

emission limitations, we maintain that 

after their implementation, which will 

only further reduce HAP emissions, the 

rule will continue to provide an ample 

margin of safety to protect public health. 

Consequently, we do not believe it will 

be necessary to conduct another 

residual risk review under CAA section 

112(f) for this source category 8 years 

following promulgation of new frontend process vent and back-end process 

limitations, merely due to the addition 

of these new MACT requirements. 

C. What are the results and proposed 

decisions for the Marine Tank Vessel 

Loading Operations source category? 

1. Overview of the Source Category and 

MACT Standards 

The NESHAP for MTVLO were 

promulgated on September 19, 1995 (60 

FR 48388), and codified at 40 CFR part 

63, subpart Y. The MTVLO MACTbased standards apply to major sources 

and regulate HAP emissions from: Landbased terminals, off-shore terminals, 

and the Alyeska Pipeline Service 

Company’s Valdez Marine Terminal. 

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65112 Federal Register / Vol. 75, No. 203 / Thursday, October 21, 2010 / Proposed Rules 

MTVLO are conducted at terminals 

that load liquid commodities in bulk, 

such as crude oil, gasoline, and other 

fuels, and some chemicals and solvent 

mixtures. The cargo is pumped from the 

terminal’s large, above-ground storage 

tanks through a network of pipes into a 

storage compartment (tank) on the 

vessel. Emissions occur as vapors are 

displaced from the tank as it is being 

filled. Most MTVLO facilities are either 

independent terminals or are associated 

with petroleum refineries or synthetic 

organic chemical manufacturers. 

For purposes of the MTVLO analysis, 

we considered only emissions from 

those sources that are part of the 

MTVLO source category. We recognize 

that there are additional sources of 

emissions at these facilities that are not 

part of the MTVLO source category. 

Those emission sources include 

emissions from hatch leaks or J tubes 

during transit, lightering operations, 

ballasting wastewater from nonsegregated ballasting, cleaning of the 

cargo tank (especially when changing 

products), and ventilating the cargo tank 

prior to loading. We are investigating 

these sources to understand their 

emissions and any controls used to 

reduce those emissions and request 

information about these sources that are 

currently not part of the MTVLO source 

category. 

The primary emission sources of 

displaced vapors associated with 

MTVLO activities include open tank 

hatches and overhead vent systems. 

Other possible emission points are 

hatch covers or domes, pressure or 

vacuum relief valves, seals, and vents. 

The MACT standards require control of 

all displaced vapors that result from 

product loading at affected sources 

irrespective of the point from which 

those vapors are emitted. Typical 

control devices used to reduce HAP 

emissions at affected facilities include 

vapor collection systems routed to 

either combustion or recovery devices, 

such as flares, incinerators, absorbers, 

carbon adsorbers, and condensers. 

When we developed the MTVLO 

MACT, we estimated that approximately 

300 major source facilities with MTVLO 

would be subject to the MACT 

standards. However, data in the 2005 

NEI were only available for 152 facilities 

subject to the MACT standards and the 

analyses discussed in this section are 

based on these 152 facilities. We believe 

the 152 facilities emit HAP that are 

representative of HAP emissions within 

the source category because, based on 

available information, we expect that 

the rest of the facilities in the source 

category generally emit the same HAP as 

do the 152 modeled facilities. In 

addition, we expect that these 152 

terminals represent the larger-emitting 

terminals, based on the specific 

terminals included in the 2005 NEI and 

the average reported emissions from 

these terminals (2.8 TPY of HAP on 

average). 

Marine terminals with MTVLO 

located at petroleum refineries are not 

part of the MTVLO source category, but 

are subject to the MTVLO MACT-based 

standards because the Refinery 

NESHAP, 40 CFR part 63, subpart CC, 

incorporate those requirements by 

reference. However, marine terminals 

that are part of the Petroleum Refineries 

source category were not included in 

this risk assessment because they are 

not in the MTVLO source category. For 

these reasons, we are proposing to 

exclude refineries from the additional 

control requirements that are being 

proposed in this action. Loading 

operations at marine terminals that are 

part of the Petroleum Refineries source 

category will be addressed in a separate 

RTR rulemaking action. 

2. What data were used in our risk 

analyses? 

We initially created a preliminary 

data set for the source category using 

data in the 2002 NEI Final Inventory, 

Version 1 (made publicly available on 

February 26, 2006), which we reviewed 

and changed where necessary to ensure 

that the proper facilities were included 

and that emissions from the proper 

processes were allocated to the MTVLO 

source category. We also reviewed the 

emissions and other data to identify 

data anomalies that could affect risk 

estimates. On March 29, 2007, we 

published an ANPRM (72 FR 29287) 

requesting comments on and updates to 

this data set, as well as the data sets for 

the other source categories included in 

the notice. Comments received in 

response to the ANPRM were reviewed 

and considered, and adjustments were 

made to the data set where we 

concluded the comments supported 

such adjustment. After making 

appropriate changes to the data set 

based on this public data review 

process, we created the data set on 

which we based the initial proposal. 

This data set was used to conduct the 

risk assessment and other analyses for 

the MTVLO source category that formed 

the basis for the actions included in the 

October 2008, proposal. 

Since the initial October 2008 

proposal, we have continued to 

scrutinize the existing data set and have 

evaluated all additional data that 

became available subsequent to the 

proposal. Uncertainty about possible 

changes in the industry led us to extract 

more recent data from the NEI and, 

ultimately, to replace the entire 2002 

NEI–based MTVLO data set with a data 

set based on the 2005 NEI. Additionally, 

we continue to work with industry 

representatives to resolve data issues 

found with facilities modeled with a 

MIR above 1-in-1 million (discussed in 

the next section) using the 2005 NEI 

data. The industry’s review to date is 

provided in the docket for public review 

and comment. 

The 2005 NEI-based data set shows 

420 TPY of total HAP emissions from 

the 152 modeled facilities in the data 

set. Hexane, methyl tertiary butyl ether, 

toluene, methanol, benzene, and 

xylenes account for the majority of the 

HAP emissions from loading operations 

included in the MTVLO source category 

at the 152 facilities in the data set 

(approximately 350 TPY, or 79 percent 

of the total HAP emissions by mass). 

These facilities also reported relatively 

small emissions of 56 other HAP. 

3. What are the results of the risk 

assessments and analyses? 

We have conducted a revised 

inhalation risk assessment for the 

MTVLO source category. We have also 

conducted an assessment of facilitywide risks and performed a 

demographic analysis of population 

risks. Table C.1 provides an overall 

summary of the results of the revised 

inhalation risk assessment. 

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Federal Register / Vol. 75, No. 203 / Thursday, October 21, 2010 / Proposed Rules 65113 

TABLE C.1—MARINE TANK VESSEL LOADING OPERATIONS REVISED INHALATION RISK ASSESSMENT RESULTS * 

Number of facilities 1

Maximum 

individual 

cancer risk 

(in 1 million) 2

Population 

at risk 

≥ 1-in-1 

million 

Annual 

cancer 

incidence 

(cases per 

year) 

Maximum 

chronic non-cancer 

TOSHI 3

Maximum off-site 

acute non-cancer 

HQ 4

Actual 

emissions 

level 

Allowable 

emissions 

level 

Actual 

emissions 

level 

Allowable 

emissions 

level 

152 Modeled Facilities ........... 20 60 71,000 0.01 0.3 0.9 HQREL = 1 benzene 

300 Major Source Facilities 

Subject to the MTVLO 

MACT Standard.

20 60 140,000 0.02 0.3 0.9 HQREL = 1 benzene 

* All results are for impacts out to 50 km from every source in the category. 

1There were 152 facilities in the data set that were modeled. We believe that these facilities are representative of the entire source category 

and that the maximum risks arising from any individual facility in the source category are properly characterized. The population risks were 

scaled up based on a linear relationship. 2 Maximum individual excess lifetime cancer risk. 

3 Maximum TOSHI. The target organ with the highest TOSHI for the MTVLO source category is the reproductive system. 

4The maximum estimated acute exposure concentration was divided by available short-term threshold values to develop an array of HQ values. HQ values shown use the lowest available acute threshold value, which, in most cases, is the REL. When HQ values exceed 1, we also 

show HQ values using the next lowest available acute threshold. See section IV.A of this preamble for explanation of acute threshold values. 

The inhalation risk modeling was 

performed using actual emissions level 

data. As shown in Table C.1, the results 

of the revised inhalation risk assessment 

indicate the maximum lifetime 

individual cancer risk could be as high 

as 20-in-1 million, the maximum 

chronic non-cancer TOSHI value could 

be up to 0.3. The total estimated 

national cancer incidence from these 

facilities based on actual emission levels 

at the 152 modeled facilities is 0.01 

excess cancer cases per year or one case 

in every 100 years. The total estimated 

cancer incidence for the MTVLO source 

category could, however, be as high as 

0.02, or one case in every 50 years, 

considering that there may be 300 

facilities in the source category. The 

maximum off-facility-site acute HQ 

value could be as high as 1, based on the 

actual emissions level and the REL 

value for benzene. 

In evaluating potential differences 

between actual emission levels and 

emissions allowable under the MACTbased standards, we investigated the 

specific controls in use at facilities 

associated with cancer risks greater than 

1-in-1 million and determined that the 

highest factor for one of these facilities 

was 3.0, based on the ability of these 

facilities to achieve 98-percent control 

of emissions where only 97-percent 

emissions control is required by the 

MACT standards for another facility, 

they could, under MACT, increase 

emissions by a factor of 3. Therefore, the 

maximum individual cancer risk based 

on MACT-allowable emissions is 

estimated to be up to 60-in-1 million, 

and the maximum chronic non-cancer 

TOSHI value is up to 0.9. 

Table C.2 displays the results of the 

facility-wide risk assessment. This 

assessment was conducted based on 

actual emission levels for the 152 

modeled facilities. 

TABLE C.2—MARINE TANK VESSEL LOADING OPERATIONS FACILITY-WIDE RISK ASSESSMENT RESULTS

Maximum facility-wide individual cancer risk (in 1 million) .......................................................................................................................... 200 

MTVLO source category contribution to this maximum facility-wide individual cancer risk 1 .............................................................. 10% 

Maximum facility-wide chronic non-cancer TOSHI ..................................................................................................................................... 4 

MTVLO source category contribution to this maximum facility-wide non-cancer TOSHI 1 ................................................................. 20% 

1Percentage shown reflects MTVLO source category contribution to the maximum facility-wide risks at the facility with the maximum risk value 

shown. 

The maximum individual cancer risk 

from all HAP emissions at a facility that 

contains sources subject to the MTVLO 

MACT standards is estimated to be 200- 

in-1 million, and the maximum chronic 

non-cancer TOSHI value is estimated to 

be 4. The highest facility-wide cancer 

risk for a facility that includes a MTVLO 

source is primarily driven by emissions 

associated with sources subject to the 

organic liquids distribution (OLD) 

NESHAP, 40 CFR part 63, subpart EEEE, 

and the highest facility-wide non-cancer 

risk is primarily driven by chemical 

manufacturing processes. The OLD and 

chemical manufacturing process 

emissions will be addressed as part of 

our effort to develop integrated 

requirements for the chemical 

manufacturing sector. We intend to 

develop integrated rules for the 

chemical manufacturing sector over the 

next 2 years. 

The results of the demographic 

analyses performed to investigate the 

distribution of risks above 1-in-1 

million, based on actual emissions 

levels for the population living within 

5 km of the facilities, among various 

demographic groups are provided in a 

report available in the docket for this 

action and summarized in Table C.3 

below. 

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65114 Federal Register / Vol. 75, No. 203 / Thursday, October 21, 2010 / Proposed Rules 

TABLE C.3—MARINE TANK VESSEL LOADING OPERATIONS DEMOGRAPHIC RISK ANALYSIS RESULTS

Emissions basis 

Maximum 

risk 

(in 1 million) 

Population with risk greater than 1-in-1 million 

Total 

(millions) 

Minority 

% 

African 

American 

% 

Other and 

multi-racial 

% 

Hispanic or 

Latino 

% 

Native 

American 

% 

Below the 

poverty 

level 

% 

Over 25 

W/O a HS 

diploma 

% 

Nationwide ................ n/a 285 25 12 12 14 0.9 13 13 

Source Category ...... 20 0.06 29 7 21 38 0.6 15 19 

Facility-wide .............. 200 0.8 38 18 39 14 0.5 18 18 

The results of the demographic 

analysis show that, for the MTVLO 

source category, of the 60,000 people 

with cancer risk greater than 1-in-1 

million, 29 percent could be classified 

as a ‘‘Minority,’’ 38 percent are included 

in the ‘‘Hispanic or Latino’’ demographic 

group, 21 percent are included in the 

‘‘Other and Multiracial’’ demographic 

group, 15 percent are included in the 

‘‘Below Poverty Level’’ demographic 

group, and 19 percent are included in 

the ‘‘Over 25 Without a High School 

Diploma’’ demographic group. The 

percentage of the population within 

5 km of the terminal and with a cancer 

risk greater than 1-in-1 million is higher 

than the typical distribution of these 

demographic groups across the United 

States. The facility-wide demographic 

analysis shows that many more people 

(800,000) are at cancer risk greater than 

1-in-1 million. As with the MTVLO 

analysis, many of the demographic 

groups have disparate impacts 

compared to the distribution across the 

United States. 

Details of these assessments and 

analyses can be found in the residual 

risk documentation referenced in 

section IV.A of this preamble, which is 

available in the docket for this action. 

4. What are our proposed decisions on 

risk acceptability and ample margin of 

safety? 

a. October 2008 Proposed Decision 

In October 2008, we proposed that the 

risks were acceptable because the risk 

results indicated that cancer risks to the 

individual most exposed to emissions 

from the category were greater than 

1-in-1 million, but less than 100-in-1 

million, and there were no other 

significant health impacts. We 

identified one emissions control option 

that would reduce risks in the ample 

margin of safety determination. We 

proposed that such control was not 

necessary to protect public health with 

an ample margin of safety in light of the 

high costs and limited additional health 

protection it would provide. We also 

proposed that emissions from the source 

category posed no potential for adverse 

environmental effects, did not pose 

potential for human health 

multipathway risks, and were unlikely 

to cause acute or chronic non-cancer 

health impacts. Therefore, we proposed 

that the existing standards provided an 

ample margin of safety and proposed to 

re-adopt the existing MACT standards to 

satisfy section 112(f) of the CAA. 

b. Risk Acceptability 

The revised risk analysis we 

performed for this proposal indicates 

that the cancer risks to the individual 

most exposed is 20-in-1 million based 

on actual emissions and 30-in-1 million 

based on MACT-allowable emissions. 

The cancer incidence and the number of 

people exposed to cancer risks of 1-in1 million or greater are relatively low, 

based on actual emissions. The analyses 

show no potential for adverse 

environmental effects or human health 

multipathway effects, and that chronic, 

non-cancer health impacts are unlikely. 

The revised assessment did indicate that 

an acute non-cancer HQ as high as 1 

could occur, based on the REL value. 

Our additional analysis of facility-wide 

risks shows that the maximum facilitywide cancer risk is 200-in-1 millions 

and the maximum facility-wide noncancer TOSHI is 4. It also shows that the 

MTVLO processes located at the 

facilities with these maximum risk 

values contribute approximately 10 and 

20 percent to such risks, respectively. 

Our additional analyses of the 

demographics of the exposed 

population show disparities in risks 

between demographic groups, but 

MTVLO represent a small portion of the 

population at risk. Based on this low 

cancer risk level and in consideration of 

other health measures and factors, 

including the low cancer incidence (one 

case in every 100 years) and the low 

maximum non-cancer risk level (TOSHI 

of 0.3 based on actual emissions and 0.5 

based on MACT-allowable emissions), 

we propose that the risks from the 

MTVLO source category are acceptable. 

c. Ample Margin of Safety 

Because we are proposing that the 

risks are acceptable, but still above 1-in1 million, we then reconsidered our 

2008 ample margin of safety decision. 

We have not identified any additional 

control options or any changes to the 

previously-analyzed control option that 

would further reduce risks from MTVLO 

that have cancer risks above 1-in-1 

million. Our analysis does not indicate 

a change in the emissions reductions 

that could be achieved or in the cost of 

control for the control option 

considered, but ultimately rejected, in 

the October 2008 proposal. Therefore, 

we continue to propose that the current 

MACT-based standards provide an 

ample margin of safety to protect public 

health and the environment, and we are 

proposing to re-adopt the existing 

MACT standards to satisfy section 112(f) 

of the CAA. 

5. What are our proposed decisions on 

the technology review? 

In the October 10, 2008 proposal, as 

part of our technology review, we stated 

that we had not identified any 

advancements in practices, processes, 

and control technologies applicable to 

the emission sources in the MTVLO 

source category that would result in 

decreased emissions, and, on that basis, 

proposed to re-adopt the existing MACT 

standards to satisfy section 112(d)(6) of 

the CAA. In that review, we examined 

the regulatory requirements and/or 

technical analyses for subsequentlypromulgated air toxics regulations 

applicable to source categories with 

emission sources similar to those in the 

MTVLO source category, and we 

searched the RBLC for controls 

applicable to VOC- and HAP-emitting 

processes in the MTVLO source 

category that might further reduce HAP 

emissions. In addition to reviewing 

subsequent regulatory actions 

applicable to similar types of emissions, 

such as those from loading racks or 

transfer operations, we also conducted a 

review for other VOC and organic HAPemitting processes that would have 

similar, technology-transferable 

controls. 

We conducted a further review in 

conjunction with this proposed 

rulemaking. The existing MACT 

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Federal Register / Vol. 75, No. 203 / Thursday, October 21, 2010 / Proposed Rules 65115 

standards require collection and control 

for MTVLO facilities that load at least 

10 million barrels per year (bbl/yr) of 

gasoline. As part of our technology 

review, we identified vapor collection 

and processors (recovery), as a possible 

control for additional gasoline loading 

MTLVO facilities. Recovery technology 

is appropriate for controlling mixtures 

of compounds and gasoline is the 

highest-quantity commodity loaded, 

based on our review of the Waterborne 

Commerce Statistics Center (WCSC) 

database for the United States. The 

WCSC database contains detailed 

information on the types and quantities 

of commodities loaded and unloaded at 

United States ports, harbors, waterways, 

and canals. 

As part of our technology review, we 

evaluated gasoline loading thresholds of 

0.5, 1.0, and 5 million bbl/yr gasoline 

loaded. Specifically, we found that 

MTVLO facilities loading 5 million bbl/ 

yr have approximately 25 tons per year 

of HAP emissions. Facilities with this 

level of HAP emissions are subject to 

the control requirements under the 

existing rule. Therefore, loading in 

excess of 5 million bbl/yr of gasoline is 

already required to be controlled under 

the current standard. 

We estimated the cost-effectiveness 

and overall impacts of the vapor 

collection and recovery options as 

shown in Table C.4. As discussed 

earlier, the 5 million bbl/yr threshold 

would not achieve any HAP or VOC 

reductions beyond those required under 

the current rule. For the 1 million bbl/ 

yr threshold, we estimate an additional 

190 TPY of HAP emissions and 2,600 

TPY of VOC emission reduction can be 

achieved. The cost-effectiveness of these 

controls is $74,000 per ton of HAP 

emission reduction and $5,500 per ton 

of VOC emission reduction. While the 

HAP cost-effectiveness is higher than 

our historical values, the VOC costeffectiveness is within the range of 

acceptability. For the 0.5 million bbl/yr 

option, the additional costs of controls 

is disproportionate to the additional 

emission reduction. As such, we are 

proposing to reduce the threshold in the 

current rule from 10 million bbl/yr to 

1 million bbl/yr. 

TABLE C.4—COST-EFFECTIVENESS AND NATIONWIDE IMPACTS FOR VAPOR COLLECTION AND RECOVERY CONTROLS FOR

SOURCES WITH GASOLINE LOADING

Gasoline loading 

threshold 

(million bbl/yr) 

Capital cost 

(million $) 

Total 

annualized 

cost 

(million $) 

Recovery 

credit 

(million $) 

Net 

annualized 

cost 

(million $) 

HAP 

emission 

reduction 

(TPY) 

HAP costeffectiveness 

($/ton) 

VOC 

emission 

reduction 

(TPY) 

VOC costeffectiveness 

($/ton) 

5 ....................... 0 0 0 0 0 ...................... 0 ......................

1 ....................... 22 16 1 14 190 74,000 2,600 5,500 

0.5 .................... 36 22 2 20 240 85,000 3,200 6,300 

The current rule requires a 97 percent 

HAP reduction for those facilities with 

a loading of 10 million bbl/yr. To foster 

the use of vapor recovery rather than 

combustion of the vapors, we 

considered additional formats for the 

standard. We looked to similar MACT 

standards for gasoline loading of tank 

trucks and rail cars. Based on our 

review of these standards, we believe 

that vapor recovery is capable of 

achieving an emission limit of less than 

or equal to 10 milligrams of total organic 

compound emissions per liter of 

gasoline loaded (mg/l). The 10 mg/l 

emission limit also approximates the 97- 

percent control that is required for the 

larger-emitting, existing MTVLO 

subcategories. Thus, we propose to 

provide facilities the option of either 

meeting the 97-percent control 

requirement or the equivalent emission 

limit of 10 mg/l. 

In summary, as a result of the 

technology review under section 

112(d)(6) of the CAA, we are proposing 

to lower the existing threshold for 

control of emissions from gasoline 

loading from 10 million bbl/yr to 1 

million bbl/yr and to provide facilities 

the option of either meeting the 

97-percent control requirement or the 

equivalent emission limit of 10 mg/l. 

6. What other actions are we proposing? 

a. SSM Provisions 

We reviewed the SSM provisions of 

the MTVLO NESHAP. The MTVLO 

NESHAP do contain an SSM exemption 

because they specify in 40 CFR 63.560, 

Table 1 that 40 CFR 63.6(f)(1) applies. 

Consistent with Sierra Club v. EPA, EPA 

is proposing that standards in this rule 

would apply at all times. We 

determined that there are currently 

several cross-references in the MTVLO 

NESHAP that could cause some 

confusion regarding periods of SSM. We 

also determined that the NESHAP do 

not specifically address recordkeeping 

and reporting requirements during 

periods of malfunction. We are, 

therefore, proposing several revisions to 

40 CFR part 63, subpart Y to address 

these issues. We are also proposing to 

add language to 40 CFR 63.563(b)(1) to 

clarify the conditions during which 

performance tests shall be conducted. 

We are further proposing to revise 40 

CFR 63.560, Table 1 to specify that the 

SSM included provisions in 40 CFR 

63.6(f)(1), 40 CFR 63.7(e)(1), and 40 CFR 

63.10(c)(10)–(11) of the General 

Provisions do not apply. Finally, we are 

proposing to promulgate an affirmative 

defense against civil penalties for 

exceedances of emission standards 

caused by malfunctions, as well as 

criteria for establishing the affirmative 

defense. 

EPA has attempted to ensure that we 

have removed any provisions in the 

regulatory text that are inappropriate, 

unnecessary, or redundant in the 

absence of the SSM exemption. We are 

specifically seeking comment on 

whether there are any such provisions 

that we have inadvertently overlooked. 

b. Significant Emission Points Not 

Previously Regulated 

We also conducted a review of the 

MTVLO NESHAP to determine whether 

there were significant emissions sources 

for which standards were not previously 

developed. In this review, we identified 

two subcategories, those facilities 

emitting less than 10/25 TPY of HAP, 

and those facilities located more than 

0.5 miles from shore, for which the 

current NESHAP do not include 

emission standards. As discussed 

below, we considered two levels of 

control (submerged fill and vapor 

recovery) for these two subcategories. 

Submerged fill reduces the amount of 

emissions generated from the loading of 

vessels by reducing turbulence and 

misting. Use of this technique results in 

a 60-percent reduction in emissions 

compared to splash loading. We have 

determined that submerged fill is 

currently used by most, if not all, of the 

facilities. We reached this conclusion 

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65116 Federal Register / Vol. 75, No. 203 / Thursday, October 21, 2010 / Proposed Rules 

based on information obtained through 

contact with industry representatives 

and the Coast Guard about submerged 

filling. Existing Coast Guard rules 

(46 CFR 153.282) require that ‘‘the 

discharge point of a cargo tank filling 

line must be not higher above the 

bottom of the cargo tank or sump than 

10 centimeters (approximately 4 inches) 

or the radius of the filling line, 

whichever is greater.’’ According to 

Coast Guard representatives, the radius 

of the fill lines can be up to 6 inches. 

We are proposing that the submerged 

fill technique is the MACT floor. 

We next undertook an evaluation of 

potential beyond-the-floor options for 

the two identified subcategories. The 

only option beyond the floor is the 

application of vapor collection and 

processors, which were the basis for the 

emissions standards applicable to other 

MTVLO, at existing facilities in two 

subcategories of the MTVLO NESHAP 

(60 FR 48388). We examined the use of 

these controls by sources in the two 

subcategories in the context of the 

original MACT standards, but rejected 

their use as a beyond the floor option 

because they were not cost effective. As 

described above under the technology 

review, we are proposing to lower the 

threshold for using vapor collection and 

processing at MTVLO facilities loading 

gasoline from 10 million bbl/yr to 1 

million bbl/yr. We are also proposing to 

provide facilities the option of either 

meeting the 97-percent control 

requirement or the equivalent emission 

limit of 10 mg/l. For the reasons set 

forth above, we are proposing these 

same requirements as a beyond the floor 

measure for these two subcategories. As 

for those facilities that do not load 1 

million bbl/yr, we are proposing no 

additional controls as part of our 

beyond the floor analysis. 

In conclusion, we are proposing in 

this action to set submerged fill as the 

floor level of control for these two 

MTVLO subcategories. Additionally, we 

are proposing vapor recovery as a 

beyond-the-floor option for those two 

MTVLO subcategories if they load 1 

million bbl/yr or more of gasoline. 

As noted above, we are proposing that 

the MACT standards, prior to the 

implementation of the proposed 

emission limitations discussed in this 

section, provide an ample margin of 

safety to protect public health. 

Therefore, we maintain that after 

implementation, which will further 

reduce HAP emissions, the rule will 

continue to provide an ample margin of 

safety to protect public health. 

Consequently, we do not believe it will 

be necessary to conduct another 

residual risk review under CAA section 

112(f) for this source category 8 years 

following promulgation of these 

limitations. 

D. What are the results and proposed 

decisions for the Pharmaceuticals 

Production source category? 

1. Overview of the Source Category and 

MACT Standard 

The National Emission Standards for 

Pharmaceuticals Production were 

promulgated on September 21, 1998 (63 

FR 50280) and codified at 40 CFR part 

63, subpart GGG. The Pharmaceuticals 

Production MACT standards apply to 

major sources of HAP. We identified 27 

facilities currently subject to the 

Pharmaceuticals Production MACT 

standards. 

The pharmaceutical manufacturing 

process consists of chemical production 

operations that produce drugs and 

medication. These operations include 

chemical synthesis (deriving a drug’s 

active ingredient) and chemical 

formulation (producing a drug in its 

final form). 

Emission sources at pharmaceutical 

production facilities include breathing 

and withdrawal losses from chemical 

storage tanks, venting of process vessels, 

leaks from piping and equipment used 

to transfer HAP compounds (equipment 

leaks), and volatilization of HAP from 

wastewater streams. 

Typical control devices used to 

reduce HAP emissions from process 

vents include flares, incinerators, 

scrubbers, carbon adsorbers, and 

condensers. Emissions from storage 

vessels are controlled by floating roofs 

or by routing them to a control device. 

Emissions from wastewater are 

controlled by a variety of methods, 

including equipment modifications 

(e.g., fixed roofs on storage vessels and 

oil water separators; covers on surface 

impoundments containers, and drain 

systems), treatment to remove the HAP 

(steam stripping, biological treatment), 

control devices, and work practices. 

Emissions from equipment leaks 

typically are reduced by leak detection 

and repair work practice programs, and 

in some cases, by equipment 

modifications. 

2. What data were used in our risk 

analyses? 

We initially created a preliminary 

data set for the source category using 

data in the 2002 NEI Final Inventory, 

Version 1 (made publicly available on 

February 26, 2006). We reviewed the 

NEI data set and made changes where 

necessary to ensure the proper facilities 

were included and to ensure the proper 

processes were allocated to the 

Pharmaceuticals Production source 

category. We also reviewed the 

emissions and other data to identify 

data anomalies that could affect risk 

estimates. On March 29, 2007, we 

published an ANPRM (72 FR 29287) for 

the express purpose of requesting 

comments and updates to this data set, 

as well as to the data sets for the other 

source categories addressed in that 

ANPRM. Comments received in 

response to the ANPRM were reviewed 

and considered, and we made 

adjustments to the data set where we 

concluded the comments supported 

such adjustment. After making 

appropriate changes to the data set 

based on this public data review 

process, the data set on which we based 

the initial proposal was created. This 

data set was used to conduct the risk 

assessment and other analyses for the 

Pharmaceuticals Production source 

category that formed the basis for the 

proposed RTR review actions included 

in the October 10, 2008 proposal. 

We have continued to scrutinize the 

existing data set and have evaluated any 

additional data that has become 

available since the October 10, 2008 

proposal. Since the time of the proposal, 

we identified an error in the latitude/ 

longitude coordinates of one emission 

point at one facility. This error has been 

corrected in the data set, and no other 

changes have been made to it since the 

proposal. 

Methylene chloride, methanol, 

acetonitrile, and toluene account for the 

majority of the HAP emissions from 

these facilities (approximately 890 TPY, 

or 85 percent of the total HAP emissions 

by mass). These facilities also reported 

relatively small emissions of 54 other 

HAP. For more detail, see the memo in 

the docket for this action describing the 

risk assessment inputs and models for 

the Pharmaceuticals Production source 

category. 

We estimate that MACT-allowable 

emissions from this source category 

could be up to 25 percent greater than 

the actual emissions, primarily from 

process vents, as it is possible that the 

control devices used at some facilities 

achieve greater emission reductions 

from these emission sources than what 

is required by the MACT standard. For 

more detail about this estimate of the 

ratio of actual to MACT-allowable 

emissions, see the memo in the docket 

for this action describing the estimation 

of MACT-allowable emission levels and 

associated risks and impacts. 

3. What are the results of the risk 

assessments and analyses? 

We have conducted a revised 

inhalation risk assessment for the 

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Federal Register / Vol. 75, No. 203 / Thursday, October 21, 2010 / Proposed Rules 65117 

Pharmaceuticals Production source 

category. We have also conducted an 

assessment of facility-wide risk and 

performed a demographic analysis of 

population risks. Table D.1 provides an 

overall summary of the results of the 

revised inhalation risk assessment. 

TABLE D.1—PHARMACEUTICALS PRODUCTION REVISED INHALATION RISK ASSESSMENT RESULTS * 

Number of 

facilities 1

Maximum 

individual cancer risk 

(in 1 million) 2 Population 

at risk ≥ 1- 

in-1 million 

Annual 

cancer 

incidence 

(cases per 

year) 

Maximum 

chronic non-cancer 

TOSHI 3

Maximum off-site acute non-cancer 

HQ 4

Actual 

emissions 

level 

Allowable 

emissions 

level 

Actual 

emissions 

level 

Allowable 

emissions 

level 

27 ...................... 3 4 2,000 0.0008 0.2 0.4 HQREL = 2 glycol ethers, chloroform 

HQAEGL–1 = 0.001 chloroform 

* All results are for impacts out to 50 km from every source in the category. 

1 Number of facilities evaluated in the risk analysis. 

2 Maximum individual excess lifetime cancer risk. 

3 Maximum TOSHI. The target organ with the highest TOSHI for the Pharmaceutical Production source category is the nervous system.

4The maximum estimated acute exposure concentration was divided by available short-term threshold values to develop an array of HQ values. HQ values shown use the lowest available acute threshold value, which, in most cases, is the REL. When HQ values exceed 1, we also 

show HQ values using the next lowest available acute threshold. See section IV.A of this preamble for explanation of acute threshold values. 

The inhalation risk modeling was 

performed using actual emissions level 

data. As shown in Table D.1, the results 

of the revised inhalation risk assessment 

indicate the maximum lifetime 

individual cancer risk could be as high 

as 3-in-1 million, the maximum chronic 

non-cancer TOSHI value could be up to 

0.2. The total estimated national cancer 

incidence from these facilities based on 

actual emission levels is 0.0008 excess 

cancer cases per year, or one case in 

every 1,250 years. The maximum offfacility-site acute HQ value could be as 

high as 2, based on the actual emissions 

level and the REL value for chloroform. 

The HQ value at this level occurs at a 

location adjacent to one facility 

fenceline for only a few (13) hours per 

year. This maximum exceedance of the 

REL value corresponds to an HQAEGL–2

equal to 0.001. We also note a possible 

exceedance of the short-term REL value 

for glycol ethers at one other facility 

(HQREL = 2). There are no other 

appropriate acute threshold values 

available for glycol ethers on which to 

base a comparison of potential risk. 

Our analysis of potential differences 

between actual emission levels and 

emissions allowable under the MACT 

standards indicated that MACTallowable emission levels may be up to 

25 percent greater than actual emission 

levels. Considering this difference, the 

risk results from the revised inhalation 

risk assessment indicate the maximum 

lifetime individual cancer risk could be 

as high as 4-in-1 million, and the 

maximum chronic non-cancer TOSHI 

value could be up to 0.4 at the MACTallowable emissions level. 

Table D.2 displays the results of the 

facility-wide risk assessment. This 

assessment was conducted based on 

actual emission levels. 

TABLE D.2—PHARMACEUTICALS PRODUCTION FACILITY-WIDE RISK ASSESSMENT RESULTS

Maximum facility-wide individual cancer risk (in 1 million) .......................................................................................................................... 40 

Pharmaceuticals Production source category contribution to this maximum facility-wide individual cancer risk 1 ............................. <1% 

Maximum facility-wide chronic non-cancer TOSHI ..................................................................................................................................... 0.8 

Pharmaceuticals Production source category contribution to this maximum facility-wide chronic non-cancer TOSHI 1 .................... <1% 

1Percentage shown reflects Pharmaceuticals Production source category contribution to the maximum facility-wide risks at the facility with the 

maximum risk value shown. 

The maximum individual cancer risk 

from all HAP emissions at a facility that 

contains sources subject to the 

Pharmaceuticals Production MACT 

standards is estimated to be 40-in-1 

million, and the maximum chronic noncancer TOSHI value is estimated to be 

0.8. At the facility where these 

maximum risk values occur, the 

estimated proportion of the risk 

attributable to the Pharmaceuticals 

Production source category processes is 

less than one percent for both cancer 

and non-cancer risk. The highest 

facility-wide cancer risk for a facility 

that includes a pharmaceuticals 

production source is primarily driven 

by acrylonitrile-butadiene-styrene (ABS) 

resin production processes, and the 

highest facility-wide non-cancer risk is 

primarily driven by pesticide 

manufacturing processes. These ABS 

resin and pesticide manufacturing 

processes will be addressed in future 

residual risk and technology reviews. 

The results of the demographic 

analyses performed to investigate the 

distribution of risks above 1-in-1 

million, based on actual emissions 

levels for the population living within 

5 km of the facilities, among various 

demographic groups are provided in a 

report available in the docket for this 

action and summarized in Table D.3 

below. 

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TABLE D.3—PHARMACEUTICALS PRODUCTION DEMOGRAPHIC RISK ANALYSIS RESULTS

Emissions basis 

Maximum 

risk 

(in 1 million) 

Population with risk greater than 1-in-1 million 

Total 

(millions) 

Minority 

% 

African 

American 

% 

Other and 

multiracial 

% 

Hispanic 

or Latino 

% 

Native 

American 

% 

Below the 

poverty 

level 

% 

Over 25 

W/O a HS 

diploma 

% 

Nationwide ................ n/a 285 25 12 12 14 0.9 13 13 

Source category ....... 3 0.002 12 4 8 34 0.5 32 25 

Facility-wide .............. 40 0.03 18 14 4 12 0.3 21 15 

The results of the demographic 

analysis show that, for the 

Pharmaceuticals Production source 

category, of the population of 2,000 

people with cancer risk greater than 1- 

in-1 million, 34 percent are included in 

the ‘‘Hispanic or Latino’’ demographic 

group, 32 percent are included in the 

‘‘Below Poverty Level’’ demographic 

group, and 25 percent are included in 

the ‘‘Over 25 Without a High School 

Diploma’’ demographic group. The 

percentage of the population within 5 

km of a pharmaceuticals production 

facility and with a cancer risk greater 

than 1-in-1 million is higher than seen 

for these demographic categories based 

on the distribution of these 

demographic groups across the United 

States. The table also shows that the 

results of the facility-wide demographic 

analysis are higher than seen across the 

U.S, for the those included in the 

‘‘African American,’’ ‘‘Below Poverty 

Level,’’ and the ‘‘Over 25 Without a High 

School Diploma’’ demographic groups, 

but the risks are lower than these levels 

for the other demographic groups. 

Details of these assessments and 

analyses can be found in the residual 

risk documentation referenced in 

section IV.A of this preamble, which is 

available in the docket for this action. 

4. What are our proposed decisions on 

risk acceptability and ample margin of 

safety? 

a. October 2008 Proposed Decision 

In our October 10, 2008 proposal, we 

stated that the risks were acceptable 

because the risk results indicated that 

cancer risks to the individual most 

exposed to emissions from the category 

of 10-in-1 million were greater than 1- 

in-1 million but less than 100-in-1 

million. We then analyzed other risk 

factors and emissions control options in 

the ample margin of safety 

determination. In this analysis, we 

found emissions from the source 

category posed no potential for an 

adverse environmental effect, did not 

pose potential for human health multipathway risks, and were unlikely to 

cause acute or chronic non-cancer 

health impacts. We also identified one 

emissions control option that would 

reduce risks. We proposed that such 

control was not necessary to protect 

public health with an ample margin of 

safety in light of the high cost and 

limited additional health protection it 

would provide. Therefore, we proposed 

that the existing standard provided an 

ample margin of safety, and we 

proposed to re-adopt the existing MACT 

standard to satisfy section 112(f) of the 

CAA. 

b. Risk Acceptability 

The revised inhalation risk analysis 

we performed for this proposal indicates 

that the cancer risks to the individual 

most exposed is 3-in-1 million based on 

actual emissions and up to 4-in-1 

million based on MACT-allowable 

emissions. The cancer incidence and the 

number of people exposed to cancer 

risks of 1-in-1 million or greater are not 

significantly changed from the risk 

identified in the October 2008 proposal. 

Similarly, the risk analysis continued to 

show no potential for an adverse 

environmental effect or human health 

multi-pathway effects, and that chronic 

non-cancer health impacts are unlikely. 

The revised assessment did indicate that 

an acute non-cancer HQ as high as 2 

could occur, based on the REL value at 

a location adjacent to the facility 

fenceline for only a few (13) hours per 

year. However, we do not believe this 

situation warrants additional control 

considering the overall health effects. 

While our additional analysis of facilitywide risks showed that the maximum 

facility-wide cancer risk is 40-in-1 

million, it also showed that 

pharmaceutical sources located at such 

facilities contributed less than 1 percent 

to such risk. The facility-wide analysis 

indicates that the maximum chronic 

non-cancer risks are unlikely to cause 

health impacts. Our additional analysis 

of the demographics of the exposed 

population may show disparities in 

risks between demographic groups. 

Based on this low cancer risk level and 

in consideration of other health 

measures and factors, including the low 

cancer incidence (one case in every 

1,250 years) and the low maximum noncancer risk level (TOSHI of 0.2 based on 

actual emissions and 0.4 based on 

MACT-allowable emissions), we 

propose that the risks from the 

Pharmaceuticals Production source 

category are acceptable. 

c. Ample Margin of Safety 

Because we are proposing that the 

risks are acceptable, but still above 1-in1 million, we then re-considered our 

2008 ample margin of safety decision. 

We have not identified any additional 

control options or any changes to the 

previously-analyzed control option that 

would affect emissions reductions or the 

costs of control. Therefore, we continue 

to propose that the current MACT 

standards provide an ample margin of 

safety to protect public health and the 

environment, and we are proposing to 

re-adopt the existing MACT standards to 

satisfy section 112(f) of the CAA. 

5. What are our proposed decisions on 

the technology review? 

In the October 10, 2008 proposal, we 

identified no developments in practices, 

processes, and control technologies 

applicable to the emission sources and 

thus we did not propose any additional 

controls as necessary under CAA 

section 112(d)(6). In that review, we 

examined the regulatory requirements 

and/or technical analyses for 

subsequently promulgated air toxics 

regulations with similar types of 

emissions sources as those in the 

Pharmaceuticals Production source 

category, and we conducted a search of 

the RBLC for controls for VOC- and 

HAP-emitting processes in the 

Pharmaceuticals Production source 

category. We have not identified any 

additional developments in practices, 

processes, and control technologies 

since the proposal date. Thus, we are 

again proposing that it is not necessary 

to revise the existing MACT standards 

pursuant to section 112(d)(6). 

6. What other actions are we proposing? 

a. SSM Provisions 

We propose to eliminate the SSM 

exemption in the Pharmaceuticals 

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Production MACT standards. Consistent 

with Sierra Club v. EPA, EPA proposes 

that standards in this rule would apply 

at all times. We are proposing several 

revisions to 40 CFR part 63, subpart 

GGG. Specifically, we are proposing to 

revise Table 1 to indicate that the 

requirements in 40 CFR 63.6(e) of the 

General Provisions do not apply. The 40 

CFR 63.6(e) requires owner or operators 

to act according to the general duty to 

‘‘operate and maintain any affected 

source, including associated air 

pollution control equipment and 

monitoring equipment, in a manner 

consistent with safety and good air 

pollution control practices for 

minimizing emissions.’’ We are 

separately proposing to incorporate this 

general duty to minimize into 40 CFR 

63.1250(g)(3). The 40 CFR 63.6(e) also 

requires the owner or operator of an 

affected source to develop a written 

SSM plan. We are proposing to remove 

the SSM plan requirement. We are 

proposing to remove the exemption 

provisions for periods of SSM in 40 CFR 

63.1250(g), require that delay of 

equipment leak repair plans be 

contained in a separate document in 40 

CFR 63.1255(g)(4), revise 40 CFR 

63.1257(a) to specify the conditions for 

performance tests, and revise the SSM 

associated monitoring, recordkeeping, 

and reporting requirements in 40 CFR 

63.1258(b)(8), 40 CFR 63.1259(a), and 40 

CFR 63.1260(i) to require reporting and 

recordkeeping for periods of 

malfunction. We are also proposing to 

revise Table 1 to specify that 40 CFR 

63.6(f)(1), 40 CFR 63.7(e)(1), the last 

sentence of 40 CFR 63.8(d)(3), 40 CFR 

63.10(c)(10), (11), and (15), and 40 CFR 

63.10(d)(5) of the General Provisions do 

not apply. In addition, we are proposing 

to promulgate an affirmative defense 

against civil penalties for exceedances 

of emission standards caused by 

malfunctions, as well as criteria for 

establishing the affirmative defense. 

EPA has attempted to ensure that we 

have not incorporated into proposed 

regulatory language any provisions that 

are inappropriate, unnecessary, or 

redundant in the absence of the SSM 

exemption. We are specifically seeking 

comment on whether there are any such 

provisions that we have inadvertently 

incorporated or overlooked. 

b. Rule Improvements Review 

We are proposing to correct an 

editorial error in 40 CFR 

63.1257(e)(2)(iii)(A)(6)(ii). That section 

specifies several criteria under which 

the inlet to the equalization tank may be 

considered as the inlet to the biological 

treatment process for the purposes of 

performance tests to show compliance 

with the standards in 40 CFR 

63.1256(a)(2)(i). This section incorrectly 

provides that only one of the listed 

criteria must be met for the inlet to the 

equalization tank to be considered the 

inlet to the biological treatment process. 

Instead, it should specify that all of the 

criteria must be met. Thus, we are 

proposing to revise this section by 

changing the ‘‘or’’ before each clause to 

‘‘and,’’ to clarify that all the criteria of 40 

CFR 63.1256(e)(2)(iii)(A)(6)(ii) must be 

met for the inlet to the equalization tank 

to be considered as the inlet to the 

biological treatment process. 

E. What are the results and proposed 

decisions for the Printing and 

Publishing Industry source category? 

1. Overview of the Source Category and 

MACT Standard 

The National Emission Standards for 

the Printing and Publishing Industry 

were promulgated on May 30, 1996 (61 

FR 27132) and codified at 40 CFR part 

63, subpart KK. The Printing and 

Publishing Industry MACT standards 

apply to major sources of HAP. We 

identified 172 facilities currently subject 

to the Printing and Publishing Industry 

MACT standards. 

Printing and publishing facilities are 

those facilities that use rotogravure, 

flexography, and other methods, such as 

lithography, letterpress, and screen 

printing, to print on a variety of 

substrates, including paper, plastic film, 

metal foil, and vinyl. The Printing and 

Publishing Industry MACT standards 

include two subcategories: (1) 

Publication rotogravure printing and (2) 

product and packaging rotogravure and 

wide-web flexographic printing. 

Emissions at printing and publishing 

facilities result from the evaporation of 

solvents in the inks and from cleaning 

solvents. The emission points include 

printing presses and associated dryers 

and ink and solvent storage. Control 

techniques include recovery devices, 

combustion devices, and the use of nonHAP/low-HAP inks and cleaning 

solvents. 

2. What data were used in our risk 

analyses? 

We initially created a preliminary 

data set for the source category using 

data in the 2002 NEI Final Inventory, 

Version 1 (made publicly available on 

February 26, 2006). We reviewed the 

NEI data and made changes where 

necessary to ensure the proper facilities 

were included and to ensure the proper 

processes were allocated to the Printing 

and Publishing Industry source 

category. We also reviewed the 

emissions and other data to identify 

data anomalies that could affect risk 

estimates. On March 29, 2007, we 

published an ANPRM (72 FR 29287) for 

the express purpose of requesting 

comments on and updates to this data 

set, as well as to the data sets for the 

other source categories addressed in that 

ANPRM. Comments received in 

response to the ANPRM were reviewed 

and considered, and we made 

adjustments to the data set where we 

concluded the comments supported 

such adjustment. After making 

appropriate changes to the data set 

based on this public data review 

process, the data set on which we based 

the initial proposal was created. This 

data set was used to conduct the risk 

assessment and other analyses for the 

Printing and Publishing Industry source 

category that formed the basis for the 

proposed RTR actions included in the 

October 2008 proposal. 

We have continued to scrutinize the 

existing data set and have evaluated any 

additional data that became available 

since the October 2008 proposal. Since 

the time of the proposal, we identified 

errors in some HAP that were reported 

to be emitted and several facilities that 

were included have permanently closed. 

The data set was updated to correct the 

errors and remove the facilities that 

have closed. 

Toluene accounts for the majority of 

the HAP emissions from these facilities 

(approximately 7,105 TPY, or 83 percent 

of the total HAP emissions by mass). 

These facilities also reported relatively 

small emissions of 58 other HAP. These 

emissions are primarily from the 

evaporation of HAP present in the inks 

and other materials applied with 

rotogravure and flexographic processes. 

We estimate that MACT-allowable 

emissions from emission points within 

this source category could be up to five 

times greater than the actual emissions 

because some capture systems and 

control devices used on printers at some 

facilities could achieve greater emission 

reductions (in the range of 98 to 

possibly 100 percent) than what is 

required by the MACT standard (92 

percent). For more detail about this 

estimate of the ratio of actual to MACTallowable emissions, see the memo in 

the docket for this action describing the 

estimation of MACT-allowable emission 

levels and associated risks and impacts. 

3. What are the results of the risk 

assessments and analyses? 

We have conducted a revised 

inhalation risk assessment for the 

Printing and Publishing Industry source 

category. We have also conducted an 

assessment of facility-wide risk, and 

performed a demographic analysis of 

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population risks. Table E.1 provides an overall summary of the results of the 

revised inhalation risk assessment. 

TABLE E.1—PRINTING AND PUBLISHING INDUSTRY REVISED INHALATION RISK ASSESSMENT RESULTS * 

Number 

of 

facilities 1

Maximum individual cancer risk 

(in 1 million) 2

Population at 

risk ≥ 1-in-1 

million 

Annual cancer 

incidence 

(cases per 

year) 

Maximum chronic 

non-cancer 

TOSHI 3

Maximum off-site acute 

Actual non-cancer HQ 4

emissions 

level 

Allowable 

emissions 

level 

Actual 

emissions 

level 

Allowable 

emissions level 

172 ...... 4 20 300 0.0006 0.08 0.4 HQREL = 10 toluene 

HQAEGL¥1 = 0.6 toluene 

* All results are for impacts out to 50 km from every source in the category. 

1 Number of facilities evaluated in the risk analysis. 

2 Maximum individual excess lifetime cancer risk. 

3 Maximum TOSHI. The target organ with the highest TOSHI for the Printing and Publishing Industry source category is the reproductive system. 4The maximum estimated acute exposure concentration was divided by available short-term threshold values to develop an array of HQ values. HQ values shown use the lowest available acute threshold value, which in most cases is the REL. When HQ values exceed 1, we also 

show HQ values using the next lowest available acute threshold. See section IV.A. of this preamble for explanation of acute threshold values. 

The inhalation risk modeling was 

performed using actual emissions level 

data. As shown in Table E.1, the risks 

based on these actual emission levels 

indicate the maximum lifetime 

individual cancer risk could be as high 

as 4-in-1 million, the maximum chronic 

non-cancer TOSHI value could be up to 

0.08. The total estimated national cancer 

incidence from these facilities based on 

the actual emission levels is 0.0006 

excess cancer cases per year, or one case 

in every 1,666 years. The maximum offfacility-site acute HQ value could be as 

high as 10, based on the actual 

emissions level and the REL value for 

toluene. The HQ value at this level 

occurs at a location adjacent to one 

facility fenceline for only a few (90) 

hours per year. This maximum 

exceedance of the REL value 

corresponds to an HQAEGL¥1 equal to 

0.6. 

Our analysis of potential differences 

between actual emission levels and 

emissions allowable under the MACT 

standard indicated that MACTallowable emission levels may be up to 

five times greater than actual emission 

levels. Assuming this worst case 

difference occurred at the highest risk 

facility, the scaled risk results from the 

revised inhalation risk assessment 

would indicate the maximum lifetime 

individual cancer risk could be as high 

as 20-in-1 million, and the maximum 

chronic non-cancer TOSHI value could 

be up to 0.4. 

Table E.2 displays the results of the 

facility-wide risk assessment. This 

assessment was conducted based on 

actual emission levels. 

TABLE E.2—PRINTING AND PUBLISHING INDUSTRY FACILITY-WIDE RISK ASSESSMENT RESULTS

Maximum facility-wide individual cancer risk (in 1 million) .......................................................................................................................... 20 

Printing and Publishing Industry source category contribution to this maximum facility-wide individual cancer risk 1 ....................... < 1% 

Maximum facility-wide chronic non-cancer TOSHI ..................................................................................................................................... 1 20 

Printing and Publishing Industry source category contribution to this maximum facility-wide chronic non-cancer TOSHI 2 .............. 3 < 1% 

1After risk modeling was complete, EPA received data that identified an error in emissions that caused this highest TOSHI value. After revising 

the emissions value, the highest facility-wide TOSHI is 2 from a different facility. 2Percentage shown reflects Printing and Publishing Industry source category contribution to the maximum facility-wide risks at the facility with 

the maximum risk value shown. 3This percentage reflects the Printing and Publishing Industry source category contribution to the highest facility-wide TOSHI of 2, as noted in 

footnote 1 to this table. 

The maximum individual cancer risk 

from all HAP emissions at a facility that 

contains sources subject to the Printing 

and Publishing Industry MACT 

standards is estimated to be 20-in-1 

million, and the maximum chronic noncancer TOSHI value is estimated to be 

20. At the facilities where these 

maximum risk values occur, the 

estimated proportion of the risk 

attributable to the Printing and 

Publishing Industry source category 

processes is less than one percent for 

both cancer and non-cancer risk. 

The results of the demographic 

analyses performed to investigate the 

distribution of risks above 1-in-1 

million, based on actual emissions 

levels for the population living within 5 

km of the facilities, among various 

demographic groups are provided in a 

report available in the docket for this 

action and summarized in Table E.3 

below. 

TABLE E.3—PRINTING AND PUBLISHING INDUSTRY DEMOGRAPHIC RISK ANALYSIS RESULTS

Emissions basis 

Maximum 

risk 

(in 1 million) 

Population with risk greater than 1-in-1 million 

Total 

(millions) 

Minority 

% 

African 

American 

% 

Other and 

multiracial 

% 

Hispanic 

or Latino 

% 

Native 

American 

% 

Below the 

poverty 

level 

% 

Over 25 

W/O a HS 

diploma 

% 

Nationwide ................ n/a 285 25 12 12 14 0.9 13 13 

Source Category ...... 4 0.00005 0 0 0 0 0 11 5 

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TABLE E.3—PRINTING AND PUBLISHING INDUSTRY DEMOGRAPHIC RISK ANALYSIS RESULTS—Continued 

Emissions basis 

Maximum 

risk 

(in 1 million) 

Population with risk greater than 1-in-1 million 

Total 

(millions) 

Minority 

% 

African 

American 

% 

Other and 

multiracial 

% 

Hispanic 

or Latino 

% 

Native 

American 

% 

Below the 

poverty 

level 

% 

Over 25 

W/O a HS 

diploma 

% 

Facility-wide .............. 20 0.05 14 8 5 5 0.3 9 11 

The results of the Printing and 

Publishing Industry source category 

demographic analysis show that for the 

50 people living within 5 km of a 

printing and publishing industry facility 

and with a cancer risk greater than 1-in1 million is less than the national 

averages for the demographic categories 

displayed in Table E.3, based on the 

typical distribution of these 

demographic groups across the United 

States. The table also shows that the 

results of the demographic analysis for 

the facility-wide emissions are similarly 

less than the national averages for these 

demographic groups. This means the 

emissions from these sources do not 

create any significant disparate risk 

impacts. 

Details of these assessments and 

analyses can be found in the residual 

risk documentation as referenced in 

section IV.A of this preamble, which is 

available in the docket for this action. 

4. What are our proposed decisions on 

risk acceptability and ample margin of 

safety? 

a. October 2008 Proposed Decision 

In our October 10, 2008 proposal, the 

risk results indicated that cancer risk to 

the individual most exposed to 

emissions from the category was 0.05- 

in-1 million, which is less than 1-in-1 

million (i.e., were ‘‘low risk’’). Therefore, 

we did not conduct an additional ample 

margin of safety analysis for the 

proposed rule. 

b. Risk Acceptability 

While at the time of the October 10, 

2008 proposal this source category 

showed low risks (cancer risks to the 

individual most exposed to emissions 

from the category were less than 1-in-1 

million), in our revised analysis we 

found that cancer risks to the individual 

most exposed to emissions from the 

category were 4-in-1 million based on 

actual emissions and as high as 20-in1 million based on MACT-allowable 

emissions. This change in risk is 

primarily the result of a cancer health 

benchmark value becoming available for 

ethyl benzene. The cancer incidence 

and the number of people exposed to 

cancer risks of 1-in-1 million or greater 

are relatively low, based on actual 

emissions. The analyses show no 

potential for an adverse environmental 

effect or human health multi-pathway 

effects, and that chronic non-cancer 

health impacts are unlikely. The revised 

assessment did indicate that an acute 

non-cancer HQ as high as 10 could 

occur, based on the REL value for 

toluene at a location adjacent to the 

facility fenceline for up to 90 hours per 

year. However, given the fact that this 

potential impact does not exceed the 

AEGL–1 value for toluene (HQAEGL–1 = 

0.6) we do not believe this situation 

warrants additional control considering 

the overall health effects. Our additional 

analysis of facility-wide risks showed 

that the maximum facility-wide cancer 

risk is 20-in-1 million and the maximum 

facility-wide non-cancer TOSHI is 20. It 

also showed that the printing and 

publishing processes located at the 

facilities with these maximum risk 

values contribute less than 1 percent to 

such risks. As previously mentioned, 

our additional analysis of the 

demographics of the exposed 

population suggests there are not large 

disparities in risks between 

demographic groups. 

Based on this low cancer risk level 

and in consideration of other health 

measures and factors, including the low 

cancer incidence (one case in every 

1,666 years), the low maximum noncancer risk level (TOSHI of 0.08 based 

on actual emissions and 0.4 based on 

MACT-allowable emissions), relatively 

low facility-wide risks which are not 

attributable to the printing and 

publishing category, and the lack of 

disparate impacts in the demographic 

analysis, we propose that the risks from 

the Printing and Publishing Industry 

source category are acceptable. 

c. Ample Margin of Safety 

Because we are proposing that the 

risks are acceptable, but still above 1-in1 million, we then re-considered our 

2008 ample margin of safety decision. 

Based on these analyses, we continue to 

propose that the current MACT 

standards provide an ample margin of 

safety to protect public health and the 

environment, and we are proposing to 

re-adopt the existing MACT standards to 

satisfy section 112(f) of the CAA. 

5. What are our proposed decisions on 

the technology review? 

In the October 2008 proposal, we 

identified no advancements in practices, 

processes, and control technologies 

applicable to the emission sources in 

the Printing and Publishing Industry 

source category in our technology 

review, and thus we proposed that it 

was not necessary to revise the existing 

MACT standards pursuant to section 

112(d)(6) of the CAA. In that review we 

examined the regulatory requirements 

and/or technical analyses for 

subsequently promulgated air toxics 

regulations with similar types of 

emissions sources as those in the 

Printing and Publishing Industry source 

category, and we conducted a search of 

the RBLC for controls for VOC- and 

HAP-emitting processes in the Printing 

and Publishing Industry source 

category. We re-examined these same 

sources of information to identify any 

new developments since the time of the 

October 2008 proposal. For the purposes 

of this proposal, we examined the 

option of retrofitting permanent total 

enclosures onto those controlled presses 

that do not already have permanent total 

enclosures. A permanent total enclosure 

improves the capture of solvent HAP 

from inks and delivers the additional 

captured solvent HAP to a control 

device. We estimate the costeffectiveness of this retrofit to be over 

$50,000 per additional ton of HAP 

controlled. We find the cost of this 

retrofit to be disproportionate to the 

emission reduction that would be 

achieved. Thus, we are proposing that it 

is not necessary to revise the existing 

MACT standards pursuant to section 

112(d)(6) of the CAA. 

6. What other actions are we proposing? 

We propose to eliminate the SSM 

exemption in the Printing and 

Publishing Industry MACT standard. 

Consistent with Sierra Club v. EPA, EPA 

proposes that standards in this rule 

would apply at all times. We are 

proposing several revisions to 40 CFR 

part 63, subpart KK regarding the 

standards that apply during periods of 

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65122 Federal Register / Vol. 75, No. 203 / Thursday, October 21, 2010 / Proposed Rules 

SSM. Specifically, we are proposing to 

revise Table 1 to indicate that the 

requirements of 40 CFR 63.6(e) of the 

General Provisions do not apply. 

Section 63.6(e) requires owners or 

operators to act according to the general 

duty to ‘‘operate and maintain any 

affected source, including associated air 

pollution control equipment and 

monitoring equipment, in a manner 

consistent with safety and good air 

pollution control practices for 

minimizing emissions.’’ We are 

separately proposing to incorporate this 

general duty to minimize emissions into 

40 CFR 63.823. The 40 CFR 63.6(e) also 

requires the owner or operator of an 

affected source to develop a written 

SSM plan. We are proposing to remove 

the SSM plan requirement. We are also 

proposing to revise 40 CFR 63.827 to 

specify the conditions for performance 

tests and to revise 40 CFR 63.829 and 

40 CFR 63.830 to require reporting and 

recordkeeping for periods of 

malfunction. We are proposing to revise 

Table 1 to specify that 40 CFR 63.6(f)(1), 

40 CFR 63.7(e)(1), the last sentence of 40 

CFR 63.8(d)(3), 40 CFR 63.10(b)(2)(i), 

(ii), (iv), and (v), 40 CFR 63.10(c)(10), 

(11), and (15), and 40 CFR 63.10(d)(5) of 

the General Provisions do not apply. In 

addition, we are proposing to 

promulgate an affirmative defense 

against civil penalties for exceedances 

of emission standards caused by 

malfunctions, as well as criteria for 

establishing the affirmative defense. 

EPA has attempted to ensure that we 

have not incorporated into proposed 

regulatory language any provisions that 

are inappropriate, unnecessary, or 

redundant in the absence of the SSM 

exemption. We are specifically seeking 

comment on whether there are any such 

provisions that we have inadvertently 

incorporated or overlooked. 

F. What are the results and proposed 

decisions for Steel Pickling—HCl 

Process Facilities and Hydrochloric 

Acid Regeneration Plants source 

category? 

1. Overview of the Source Category and 

MACT Standard 

The National Emission Standards for 

Steel Pickling—HCl Process Facilities 

and Hydrochloric Acid Regeneration 

Plants were promulgated on June 22, 

1999 (64 FR 33202) and codified at 40 

CFR part 63, subpart CCC. The Steel 

Pickling—HCl Process Facilities and 

Hydrochloric Acid Regeneration Plants 

MACT standards (i.e., Steel Pickling 

MACT standard) apply to major sources 

of HAP. We estimate that there are 

approximately 80 facilities subject to the 

MACT standards that are currently 

performing steel pickling and/or acid 

regeneration. Many of these facilities are 

located adjacent to integrated iron and 

steel manufacturing plants or electric 

arc furnace steelmaking facilities (minimills) that produce steel from scrap. 

Facilities that regenerate HCl may or 

may not be located at steel pickling 

operations. 

The Steel Pickling source category 

consists of facilities that pickle steel, 

using HCl as the pickling acid, and 

facilities that regenerate the HCl after 

use, but does not include facilities 

which pickle steel using acids other 

than HCl. 

Steel pickling is a treatment process 

in which the heavy oxide crust or mill 

scale that develops on the steel surface 

during hot forming or heat treating is 

removed chemically in a bath of 

aqueous acid solution. Pickling is a 

process applied to metallic substances 

that removes surface impurities, stains, 

or crusts to prepare the metal for 

subsequent plating (e.g., with 

chromium) or other treatment, such as 

galvanization or painting. 

The HAP emission points from the 

steel pickling and acid regeneration 

processes include spray roasters, steel 

pickling baths, steel pickling sprays, 

and tank vents. 

Typical control devices used to 

reduce HAP emissions from steel 

pickling facilities include a packed 

tower scrubber, sieve tray scrubber, or 

horizontal packed bed scrubber. Each 

type of scrubber is coupled with a 

demister. The general trend in scrubber 

installations at steel pickling facilities is 

to replace older scrubbers with sieve 

tray scrubbers, which generate less 

scrubber effluent (blowdown). For acid 

regeneration roasters, a cyclone or a 

Venturi pre-concentrator is generally 

used before the emissions are scrubbed 

in one or two counter-current packed 

tower absorbers. 

2. What data were used in our risk 

analyses? 

For the Steel Pickling source category, 

we compiled preliminary data sets using 

data in the 2005 NEI. We reviewed these 

data and made changes where 

necessary. We also contacted several 

facilities to verify the emissions and 

emissions release characteristic data, 

and we made updates to the data set 

based on the information received from 

these communications. This updated 

data set comprises the data set that was 

used to conduct the risk assessments 

and other analyses that form the basis 

for this proposed action. Hydrochloric 

acid and chlorine account for all of the 

HAP emissions from the Steel Pickling 

source category (approximately 248 and 

164 TPY, respectively). 

Our analysis of potential differences 

between actual emission levels and 

emissions allowable under the MACT 

standards indicate that actual emissions 

and allowable emissions are 

approximately the same as allowable 

emissions. The available data indicate 

that pickling processes throughout the 

industry are equipped with controls that 

achieve the HCl and chlorine emission 

limits required by the MACT standards. 

For more detail about this estimate of 

the ratio of actual to MACT-allowable 

emissions, see the memo in the docket 

for this action describing the estimation 

of MACT-allowable emission levels and 

associated risks and impacts. 

3. What are the results of the risk 

assessments and analyses? 

We have conducted an inhalation risk 

assessment for the Steel Pickling source 

category. We have also conducted an 

assessment of facility-wide risk and 

performed a demographic analysis of 

population risks. Table F.1 provides an 

overall summary of the inhalation risk 

assessment results. 

TABLE F.1—STEEL PICKLING INHALATION RISK ASSESSMENT RESULTS * 

Number of facilities 1

Maximum chronic non-cancer 

TOSHI 2

Population at 

risk from HI 

> 1 

Maximum off-site 

acute non-cancer Actual HQ 3

emissions 

level 

Allowable 

emissions 

level 

51 Modeled Facilities ......................................................................... 2 2 30 HQREL = 0.4 chlorine 

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TABLE F.1—STEEL PICKLING INHALATION RISK ASSESSMENT RESULTS *—Continued 

Number of facilities 1

Maximum chronic non-cancer 

TOSHI 2

Population at 

risk from HI 

> 1 

Maximum off-site 

acute non-cancer Actual HQ 3

emissions 

level 

Allowable 

emissions 

level 

80 Major Source Facilities Subject to the MACT Standard .............. 2 2 50 HQREL = 0.4 chlorine 

* All results are for impacts out to 50 km from every source in the category. 

1There are 51 facilities in the data set that were modeled. It is believed that these facilities are representative of the entire source category 

and that the maximum risks are characterized. The population risks were scaled up based on a linear relationship. 2 Maximum TOSHI. The target organ with the highest TOSHI for the Steel Pickling source category is the neurological system. 

3The maximum estimated acute exposure concentration was divided by available short-term threshold values to develop an array of HQ values. HQ values shown use the lowest available acute threshold value, which, in most cases, is the REL. When HQ values exceed 1, we also 

show HQ values using the next lowest available acute threshold. See section IV.A of this preamble for explanation of acute threshold values. 

The results of the inhalation risk 

assessment indicated there are no 

cancer risks or incidences attributable to 

emissions from the Steel Pickling source 

category because there were no 

emissions of any HAP with cancer doseresponse values (i.e., no known 

carcinogens are emitted from these 

sources). As shown in Table F.1, the 

maximum chronic non-cancer TOSHI 

value could be as high as 2. The 

maximum off-facility-site acute HQ 

value could be as high as 0.4, based on 

the actual emissions level and the REL 

value for chlorine. As our analysis of 

potential differences between actual 

emission levels and emissions allowable 

under the MACT standards indicate, 

actual emissions are approximately the 

same as MACT-allowable emissions, 

and the risk results for actual emissions 

are approximately the same as those for 

MACT-allowable emissions. 

Table F.2 displays the results of the 

facility-wide risk assessment. This 

assessment was conducted based on 

actual emission levels for the 51 

modeled facilities. 

TABLE F.2—STEEL PICKLING FACILITY-WIDE RISK ASSESSMENT RESULTS

Maximum Facility-Wide Individual Cancer Risk (in 1 million) ..................................................................................................................... 100 

Steel Pickling source category contribution to this maximum facility-wide individual cancer risk ....................................................... 1 NA 

Maximum Facility-Wide Chronic Non-cancer TOSHI .................................................................................................................................. 10 

Steel Pickling source category contribution to this maximum facility-wide chronic non-cancer TOSHI 2 ........................................... < 1% 

1The Steel Pickling source category does not contribute to the facility-wide cancer risks, as the facilities in this source category do not report 

emissions of any HAP with cancer dose-response values. 2Percentage shown reflects Steel Pickling source category contribution to the maximum facility-wide risks at the facility with the maximum risk 

value shown. 

The maximum individual cancer risk 

from all HAP emissions at a facility that 

contains sources subject to the Steel 

Pickling—HCl Process Facilities and 

Hydrochloric Acid Regeneration Plants 

MACT standards is estimated to be 100- 

in-1 million, and the maximum chronic 

non-cancer TOSHI value is estimated to 

be 10. As noted previously, there were 

no emissions of any HAP with cancer 

dose-response values from the Steel 

Pickling source category; therefore, this 

source category does not contribute to 

the maximum facility-wide cancer risk 

of 100-in-1 million. At the facility where 

the maximum TOSHI risk value occurs, 

the estimated proportion of the risk 

attributable to the Steel Pickling source 

category processes is less than one 

percent. The highest facility-wide 

cancer risk for a facility that includes a 

steel pickling or HCL regeneration 

source is primarily driven by iron and 

steel processes and coke oven 

emissions. The iron and steel processes 

will be addressed in a future residual 

risk review, some coke oven processes 

(charging, top side, and door leaks) have 

been addressed in a previous 

rulemaking action (70 FR 19992), and 

other coke oven processes (pushing, 

quenching, and battery stacks) will be 

addressed in a future residual risk 

review. 

The results of the demographic 

analyses performed to investigate the 

distribution of TOSHI greater than 1, 

based on actual emissions levels for the 

population living within 5 km of the 

facilities, among various demographic 

groups are provided in a report available 

in the docket for this action and 

summarized in Table F.3 below. 

TABLE F.3—STEEL PICKLING DEMOGRAPHIC RISK ANALYSIS RESULTS

Emissions basis 

Maximum 

respiratory 

hazard 

index 

Population with TOSHI greater than 1-in-1 million 

Total 

(millions) 

Minority 

% 

African 

American 

% 

Other and 

multiracial 

% 

Hispanic 

or Latino 

% 

Native 

American 

% 

Below the 

poverty 

level 

% 

Over 25 

W/O 

a HS 

diploma 

% 

Nationwide ................ n/a 175 32 16 15 16 0.6 13 13 

Source Category ...... 2 0.000045 0 0 0 9 0 6 9 

Facility-wide .............. 10 0.0017 41 34 6 1 0.2 11 13 

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65124 Federal Register / Vol. 75, No. 203 / Thursday, October 21, 2010 / Proposed Rules 

The results of the Steel Pickling 

source category demographic analysis 

show that there are 45 people exposed 

to an HI of one or greater from the 

source category and 1,700 people 

exposed to an HI of one or greater for 

the facility-wide emissions. Of this 

relatively small number of people for 

the source category, none of the groups 

shows a disparate impact compared to 

the national distribution of non-cancer 

risk. The facility-wide analysis shows a 

higher percentage population with an HI 

of one or more only for those that could 

be classified as a ‘‘Minority’’ and for 

those included in the ‘‘African 

American’’ demographic group. 

Details of these assessments and 

analyses can be found in the residual 

risk documentation as referenced in 

section IV.A of this preamble, which is 

available in the docket for this action. 

4. What are our proposed decisions on 

risk acceptability and ample margin of 

safety? 

a. Risk Acceptability 

The Steel Pickling source category 

does not emit HAP that are known, 

probable, or possible carcinogens; 

therefore, based on actual and MACTallowable emission levels, cancer risks 

are less than 1-in-1 million to the 

individual most exposed. The analyses 

we performed for this proposal show no 

potential for an adverse environmental 

effect or human health multi-pathway 

effects, and that acute non-cancer health 

impacts are unlikely. We determined 

that emissions from the Steel Pickling 

source category would result in chronic 

non-cancer TOSHI approximately equal 

to 2 for the individual most exposed 

based on either actual emissions or 

MACT-allowable emissions. This HI 

value is for one facility, which has had 

compliance issues with the MACT 

standards. The emissions data used in 

our analysis include emissions that are 

in excess of what is allowed by the 

MACT standards. Work is underway 

between this facility, OECA at EPA, and 

the State to improve compliance. The 

next highest HI from any facility in the 

source category is 0.1. Based on this, we 

do not anticipate that MACT-allowable 

emissions for the sources in this 

category, or actual emissions when a 

source is in compliance with the MACT 

standards, would result in adverse 

chronic non-cancer health effects. Our 

additional analysis of facility-wide risks 

showed that the maximum facility-wide 

cancer risk is 100-in-1 million and the 

maximum facility-wide non-cancer 

TOSHI is 10. It also showed that the 

steel pickling processes located at the 

facilities with these maximum risk 

values did not contribute to the cancer 

risk and contributed less than 1 percent 

to these non-cancer risks. Our 

additional analysis of the demographics 

of the exposed population may show 

disparities in risks between 

demographic groups. Based on this 

cancer risk level and in consideration of 

other health measures and factors, 

including the cancer incidence (no 

cases) and the low maximum noncancer risk level (TOSHI of 0.2), the lack 

of disparate impacts in the demographic 

analysis, and the small contribution to 

the facility-wide risks, we propose that 

the risks from the Steel Pickling source 

category are acceptable. 

b. Ample Margin of Safety 

We are proposing that the risks are 

acceptable, and while cancer risks were 

not above 1-in-1 million (the level at 

which we generally perform an ample 

margin of safety analysis), we decided to 

consider other factors before making a 

decision regarding the need for 

standards to reduce risks. 

Based on these analyses, we continue 

to propose that the current MACT 

standards provide an ample margin of 

safety to protect public health and the 

environment, and we are proposing to 

re-adopt the existing MACT standards to 

satisfy section 112(f) of the CAA. 

5. What are our proposed decisions on 

the technology review? 

We evaluated developments in 

practices, processes, and control 

technologies applicable to the Steel 

Pickling source category. This included 

a search of the RBLC and the internet. 

The only advancement that we 

identified was one technology that is 

being used instead of steel pickling for 

some applications which is called the 

smooth clean surface (SCS) process. The 

SCS process uses patented roller 

brushes to remove scale from steel 

sheets and coils. However, this 

technology leaves the last layer of scale, 

resulting in a product that is rustresistant, but is not conducive to in-line 

galvanizing, painting, enameling or 

electrolytic plating. Additionally, some 

types of forming, including 

hydroforming, cold reduction and deep 

draw cannot be used with SCS treated 

steel. It is therefore not a viable 

replacement for steel pickling 

operations. Another technology, eco 

pickled surface (EPS), could potentially 

become a low-emission alternative for 

steel pickling. EPS blasts steel with an 

acid-free slurry which, like steel 

pickling, removes all layers of scale. 

However, EPS only became 

commercially available in 2009 and it is 

not yet a proven technology. Thus, it is 

premature to consider it as a 

replacement for steel pickling 

operations. 

Because we determined that the only 

identified development is not 

technologically feasible at this time, we 

are proposing that it is not necessary to 

revise the MACT standards pursuant to 

section 112(d)(6). 

6. What other actions are we proposing? 

We propose to eliminate the SSM 

exemption in the Steel Pickling MACT 

standards. Consistent with Sierra Club 

v. EPA, EPA proposes that standards in 

this rule would apply at all times. We 

are proposing several revisions to 40 

CFR part 63, subpart CCC regarding the 

standards that apply during periods of 

SSM. Specifically, we are proposing to 

revise Table 1 to indicate that the 

requirements in 40 CFR 63.6(e) of the 

General Provisions do not apply. The 40 

CFR 63.6(e) requires owner or operators 

to act according to the general duty to 

‘‘operate and maintain any affected 

source, including associated air 

pollution control equipment and 

monitoring equipment, in a manner 

consistent with safety and good air 

pollution control practices for 

minimizing emissions.’’ We are 

separately proposing to incorporate this 

general duty to minimize emissions into 

40 CFR 63.1159(c). The 40 CFR 63.6(e) 

also requires the owner or operator of an 

affected source to develop a written 

SSM plan. We are proposing to remove 

the SSM plan requirement. We are also 

proposing to revise 40 CFR 63.1161 to 

specify the conditions for performance 

tests, to revise the SSM-associated 

reporting and recordkeeping 

requirements in 40 CFR 63.1164 and 40 

CFR 63.1165 to require reporting and 

recordkeeping for periods of 

malfunction, and to revise Table 1 to 

specify that 40 CFR 63.6(f)(1), 40 CFR 

63.7(e)(1), the last sentence of 40 CFR 

63.8(d)(3), 40 CFR 63.10(b)(2)(i),(ii), (vi), 

and (v), 40 CFR 63.10(c)(10), (11), and 

(15), and 40 CFR 63.10(d)(5) of the 

General Provisions do not apply. In 

addition, we are proposing to 

promulgate an affirmative defense 

against civil penalties for exceedances 

of emission standards caused by 

malfunctions, as well as criteria for 

establishing the affirmative defense. 

EPA has attempted to ensure that we 

have not incorporated into proposed 

regulatory language any provisions that 

are inappropriate, unnecessary, or 

redundant in the absence of the SSM 

exemption. We are specifically seeking 

comment on whether there are any such 

provisions that we have inadvertently 

incorporated or overlooked. 

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VI. Summary of Proposed Actions 

A. What actions are we proposing as a 

result of the technology reviews? 

For the technology review for the 

chromium electroplating and anodizing 

source categories, we are proposing to 

amend the rules to prohibit the addition 

of PFOS-based WAFS to the 

electroplating or anodizing tanks. For 

these source categories, we are also 

proposing to require several 

housekeeping requirements to minimize 

emissions of chromium-laden fugitive 

dust from chromium electroplating 

operations and for owners and operators 

to incorporate these housekeeping 

procedures in the facility operation and 

maintenance plan. For MTVLO, we are 

proposing to lower the existing 

threshold for control of emissions from 

gasoline loading from 10 million bbl/yr 

to 1 million bbl/yr. 

For the Group I Polymers and Resins, 

Pharmaceuticals Production, and 

Printing and Publishing Industry MACT 

standards, which were addressed in the 

October 10, 2008 proposal, we have 

reaffirmed our previous determinations 

that there have been no developments in 

practices, processes, or control 

technologies. Thus, we are continuing to 

propose that it is not necessary to revise 

the existing MACT requirements based 

on our CAA section 112(d)(6) review. 

For the Steel Pickling—HCl Process 

Facilities and Hydrochloric Acid 

Regeneration Plants source category, we 

have determined that there have been 

no developments in practices, 

processes, or control technologies since 

the promulgation of the MACT 

standards, and we are proposing that it 

is not necessary to revise the existing 

MACT requirements based on our CAA 

section 112(d)(6) review. 

B. What actions are we proposing as a 

result of the residual risk reviews? 

For the Epichlorohydrin Elastomers 

Production, HypalonTM Production, 

Nitrile Butadiene Rubber Production, 

Polybutadiene Rubber Production, 

Styrene-Butadiene Rubber and Latex 

Production, MTVLO, Pharmaceuticals 

Production, and Printing and Publishing 

Industry MACT standards source 

categories, which were addressed in the 

October 10, 2008 proposal, we have 

reaffirmed our proposed determinations 

that the MACT standards for these 

source categories provide an ample 

margin of safety to protect public health 

and prevent adverse environmental 

effects. Thus, we are continuing to 

propose to re-adopt each of these 

standards for purposes of meeting the 

requirements of CAA sections 112(f)(2). 

For the Hard Chromium 

Electroplating, Decorative Chromium 

Electroplating, Chromium Anodizing, 

and Steel Pickling—HCl Process 

Facilities and Hydrochloric Acid 

Regeneration Plants MACT standards 

source categories, we propose that the 

MACT standards provide an ample 

margin of safety to protect public health 

and prevent adverse environmental 

effects. Thus, we are proposing to readopt these standards for the purpose of 

meeting the requirements of CAA 

section 112(f)(2). 

C. What other actions are we proposing? 

We propose to amend the Hard and 

Decorative Chromium Electroplating 

and Chromium Anodizing Tanks, Group 

I Polymers and Resins, MTVLO, 

Pharmaceuticals Production, Printing 

and Publishing Industry, and Steel 

Pickling—HCl Process Facilities and 

Hydrochloric Acid Regeneration Plants 

MACT standards to remove the language 

that exempts facilities from the 

emissions standards that would 

otherwise be applicable during periods 

of SSM, and to add an affirmative 

defense against civil penalties for 

exceedances of emission standards 

caused by malfunctions. These changes 

are being made to ensure these rules are 

consistent with the court’s ruling in 

Sierra Club v. EPA, 551 F.3d 1019, 

which addressed similar provisions in 

the General Provisions that apply to 

many MACT standards. 

We are also proposing requirements 

for two MACT standards under the 

authority of section 112(d)(2) and (3) of 

the CAA to address emission points for 

which emission standards were 

previously not developed. For the 

MTVLO MACT standard, we are 

proposing to add the requirement to 

perform submerged fill for existing 

facilities for two subcategories, those 

emitting less than 10/25 tons of HAP, 

and those located more than 0.5 miles 

from shore. For the Group I Polymers 

and Resins MACT standard source 

categories, we propose to add MACT 

standards limiting emissions from the 

back-end process operations from the 

Butyl Rubber Production subcategory, 

the Halobutyl Rubber Production 

subcategory, the Epichlorohydrin 

Rubber Production source category, the 

Nitrile Butadiene Rubber Production 

source category, and the Neoprene 

Rubber Production source category. We 

also propose to revise the MACT 

standards for front-end process vents 

from the Butyl Rubber Production 

subcategory, the Halobutyl Rubber 

Production subcategory, and the 

Ethylene Propylene Rubber Production 

source category by requiring control of 

HCl emissions resulting from the 

combustion of chlorinated organic 

compounds. 

In addition, we are proposing minor 

changes to two MACT standards to 

improve compliance and correct errors. 

For the Chromium Electroplating MACT 

standard source categories, we are 

proposing to clarify that testing can be 

performed by either Method 306 or 

Method 306A, and we are proposing to 

revise Method 306B to correct 

inconsistencies between the 

amendments made to subpart N in 2004 

(69 FR 42885) and Method 306B. In 

addition, to eliminate a discrepancy 

between the Chromium Electroplating 

MACT standard and the General 

Provisions to part 63, we are also 

proposing to revise the trigger for 

semiannual compliance reports to be 

consistent with General Provisions to 

part 63. For the Pharmaceuticals 

Production MACT standards, we are 

proposing to correct one typographical 

error. 

VII. Request for Comments 

We are soliciting comments on all 

aspects of this proposed action. All 

comments received during the comment 

period will be considered. In addition to 

general comments on the proposed 

actions, we are also interested in any 

additional data that may help to reduce 

the uncertainties inherent in the risk 

assessments. Such data should include 

supporting documentation in sufficient 

detail to allow characterization of the 

quality and representativeness of the 

data or information. Please see the 

following section for more information 

on submitting data. 

VIII. Submitting Data Corrections 

The facility-specific data used in the 

source category risk analyses, facilitywide analyses, and demographic 

analyses for each source category 

subject to this action are available for 

download on the RTR Web page at 

http://www.epa.gov/ttn/atw/rrisk/ 

rtrpg.html. These data files include 

detailed information for each HAP 

emissions release point at each facility 

included in the source category and all 

other HAP emissions sources at these 

facilities (facility-wide emissions 

sources). However, it is important to 

note that the source category risk 

analysis included only those emissions 

tagged with the MACT code associated 

with the source category subject to the 

risk analysis. 

If you believe the data are not 

representative or are inaccurate, please 

identify the data in question, provide 

your reason for concern, and provide 

any ‘‘improved’’ data that you have, if 

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65126 Federal Register / Vol. 75, No. 203 / Thursday, October 21, 2010 / Proposed Rules 

available. When you submit data, we 

request that you provide documentation 

of the basis for the revised values to 

support your suggested changes. To 

submit comments on the data 

downloaded from the RTR Web page, 

complete the following steps: 

1. Within this downloaded file, enter 

suggested revisions to the data fields 

appropriate for that information. The 

data fields that may be revised include 

the following: 

Data element Definition 

Control Measure ................................................. Are control measures in place? (yes or no). 

Control Measure Comment ................................ Select control measure from list provided, and briefly describe the control measure. 

Delete .................................................................. Indicate here if the facility or record should be deleted. 

Delete Comment ................................................. Describes the reason for deletion. 

Emission Calculation Method Code For Revised 

Emissions.

Code description of the method used to derive emissions. For example, CEM, material balance, stack test, etc. 

Emission Process Group .................................... Enter the general type of emission process associated with the specified emission point. 

Fugitive Angle ..................................................... Enter release angle (clockwise from true North); orientation of the y-dimension relative to true 

North, measured positive for clockwise starting at 0 degrees (maximum 89 degrees). 

Fugitive Length ................................................... Enter dimension of the source in the east-west (x-) direction, commonly referred to as length 

(ft). 

Fugitive Width ..................................................... Enter dimension of the source in the north-south (y-) direction, commonly referred to as width 

(ft). 

Malfunction Emissions ........................................ Enter total annual emissions due to malfunctions (TPY). 

Malfunction Emissions Max Hourly .................... Enter maximum hourly malfunction emissions here (lb/hr). 

North American Datum ....................................... Enter datum for latitude/longitude coordinates (NAD27 or NAD83); if left blank, NAD83 is assumed. 

Process Comment .............................................. Enter general comments about process sources of emissions. 

REVISED Address .............................................. Enter revised physical street address for MACT facility here. 

REVISED City ..................................................... Enter revised city name here. 

REVISED County Name ..................................... Enter revised county name here. 

REVISED Emission Release Point Type ........... Enter revised Emission Release Point Type here. 

REVISED End Date ............................................ Enter revised End Date here. 

REVISED Exit Gas Flow Rate ............................ Enter revised Exit Gas Flowrate here (ft3/sec). 

REVISED Exit Gas Temperature ....................... Enter revised Exit Gas Temperature here (F). 

REVISED Exit Gas Velocity ............................... Enter revised Exit Gas Velocity here (ft/sec). 

REVISED Facility Category Code ...................... Enter revised Facility Category Code here, which indicates whether facility is a major or area 

source. 

REVISED Facility Name ..................................... Enter revised Facility Name here. 

REVISED Facility Registry Identifier .................. Enter revised Facility Registry Identifier here, which is an ID assigned by the EPA Facility 

Registry System. 

REVISED HAP Emissions Performance Level 

Code.

Enter revised HAP Emissions Performance Level here. 

REVISED Latitude .............................................. Enter revised Latitude here (decimal degrees). 

REVISED Longitude ........................................... Enter revised Longitude here (decimal degrees). 

REVISED MACT Code ....................................... Enter revised MACT Code here. 

REVISED Pollutant Code ................................... Enter revised Pollutant Code here. 

REVISED Routine Emissions ............................. Enter revised routine emissions value here (TPY). 

REVISED SCC Code .......................................... Enter revised SCC Code here. 

REVISED Stack Diameter .................................. Enter revised Stack Diameter here (ft). 

REVISED Stack Height ...................................... Enter revised Stack Height here (ft). 

REVISED Start Date ........................................... Enter revised Start Date here. 

REVISED State ................................................... Enter revised State here. 

REVISED Tribal Code ........................................ Enter revised Tribal Code here. 

REVISED Zip Code ............................................ Enter revised Zip Code here. 

Shutdown Emissions .......................................... Enter total annual emissions due to shutdown events (TPY). 

Shutdown Emissions Max Hourly ....................... Enter maximum hourly shutdown emissions here (lb/hr). 

Stack Comment .................................................. Enter general comments about emission release points. 

Startup Emissions ............................................... Enter total annual emissions due to startup events (TPY). 

Startup Emissions Max Hourly ........................... Enter maximum hourly startup emissions here (lb/hr). 

Year Closed ........................................................ Enter date facility stopped operations. 

2. Fill in the commenter information 

fields for each suggested revision (i.e., 

commenter name, commenter 

organization, commenter e-mail address, 

commenter phone number, and revision 

comments). 

3. Gather documentation for any 

suggested emissions revisions (e.g., 

performance test reports, material 

balance calculations, etc.). 

4. Send the entire downloaded file 

with suggested revisions in Microsoft®

Access format and all accompanying 

documentation to Docket ID No. EPA– 

HQ–OAR–2010–0600 (through one of 

the methods described in the ADDRESSES

section of this preamble). To expedite 

review of the revisions, it would also be 

helpful if you submitted a copy of your 

revisions to the EPA directly at 

RTR@epa.gov in addition to submitting 

them to the docket. 

5. If you are providing comments on 

a facility with multiple source 

categories, you need only submit one 

file for that facility, which should 

contain all suggested changes for all 

source categories at that facility. We 

request that all data revision comments 

be submitted in the form of updated 

Microsoft® Access files, which are 

provided on the http://www.epa.gov/ttn/ 

atw/rrisk/rtrpg.html Web page. 

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Federal Register / Vol. 75, No. 203 / Thursday, October 21, 2010 / Proposed Rules 65127 

IX. Statutory and Executive Order 

Reviews 

A. Executive Order 12866: Regulatory 

Planning and Review 

Under Executive Order 12866 (58 FR 

51735, October 4, 1993), this action is a 

significant regulatory action because it 

raises novel legal and policy issues. 

Accordingly, EPA submitted this action 

to OMB for review under Executive 

Order 12866 and any changes made in 

response to OMB recommendations 

have been documented in the docket for 

this action. 

B. Paperwork Reduction Act 

The information collection 

requirements in this rule have been 

submitted for approval to OMB under 

the Paperwork Reduction Act, 44 U.S.C. 

3501, et seq. 

The proposed revisions to the SSM 

provisions for all of the standards being 

amended with this proposed rule will 

reduce the reporting burden associated 

with having to prepare and submit an 

SSM report. We are not proposing any 

new paperwork requirements to the 

Pharmaceuticals Production, Printing 

and Publishing Industry, and Steel 

Pickling-–HCl Process Facilities and 

Hydrochloric Acid Regeneration Plants 

MACT standards. Revisions and burden 

associated with amendments to the 

Hard and Decorative Chromium 

Electroplating and Chromium 

Anodizing Tanks; Group I Polymers and 

Resins; and MTVLO MACT standards 

are discussed in the following 

paragraphs. The OMB has previously 

approved the information collection 

requirements contained in the existing 

regulations being amended with this 

proposed rule (i.e., 40 CFR part 63, 

subparts N, U, Y, KK, CCC, and GGG) 

under the provisions of the Paperwork 

Reduction Act, 44 U.S.C. 3501, et seq. 

The OMB control numbers for EPA’s 

regulations in 40 CFR are listed in 40 

CFR part 9. Burden is defined at 5 CFR 

1320.3(b). 

1. Hard and Decorative Chromium 

Electroplating and Chromium 

Anodizing Tanks MACT Standard 

The ICR document prepared by EPA 

for the amendments to the Hard and 

Decorative Chromium Electroplating 

and Chromium Anodizing Tanks MACT 

standards has been assigned EPA ICR 

number 1611.08. Burden changes 

associated with these amendments 

would result from new recordkeeping 

and reporting requirements associated 

with the new housekeeping 

requirements being proposed with 

today’s action. The estimated average 

burden per response is 11 hours; the 

frequency of response is annual for all 

respondents that must comply with the 

rule’s reporting requirements and the 

estimated average number of likely 

respondents per year is 590. The cost 

burden to respondents resulting from 

the collection of information includes 

the total capital cost annualized over the 

equipment’s expected useful life (about 

$171,000), a total operation and 

maintenance component (about 

$534,000 per year), and a labor cost 

component (about $500,000 per year). 

2. Group I Polymers and Resins MACT 

Standard 

The ICR document prepared by EPA 

for the amendments to the Group I 

Polymers and Resins MACT standards 

has been assigned EPA ICR number 

2410.01. Burden changes associated 

with these amendments would result 

from new recordkeeping and reporting 

requirements associated with the new 

back-end process operation emission 

limits for epichlorohydrin, neoprene, 

nitrile butadiene rubber, and butyl 

rubber and the HCl emission limits from 

the front-end process vents for ethylene 

propylene rubber and butyl rubber being 

proposed with this action. The 

estimated average burden per response 

is 237 hours; the frequency of response 

is annual for all respondents that must 

comply with the rule’s reporting 

requirements and the estimated average 

number of likely respondents per year is 

19. The cost burden to respondents 

resulting from the collection of 

information includes the total capital 

cost annualized over the equipment’s 

expected useful life (averaging $2,800), 

a total operation and maintenance 

component (averaging $1,000 per year), 

and a labor cost component (averaging 

$1.1 million per year). 

3. Marine Tank Vessel Loading 

Operations MACT Standard 

The ICR document prepared by EPA 

for the amendments to the MTVLO 

MACT standards has been assigned EPA 

ICR number 1679.08. Burden changes 

associated with these amendments 

would result from new recordkeeping 

and reporting requirements associated 

with the vapor recovery requirements 

being proposed with today’s action. The 

estimated average burden per response 

is 46 hours; the frequency of response 

is annual for all respondents that must 

comply with the rule’s reporting 

requirements and the estimated average 

number of likely respondents per year is 

18. The cost burden to respondents 

resulting from the collection of 

information includes the total capital 

cost annualized over the equipment’s 

expected useful life (averaging $3,780), 

a total operation and maintenance 

component (averaging $108 per year), 

and a labor cost component (averaging 

$165,000 per year). 

An agency may not conduct or 

sponsor, and a person is not required to 

respond to a collection of information 

unless it displays a currently valid OMB 

control number. 

To comment on the Agency’s need for 

this information, the accuracy of the 

provided burden estimates, and any 

suggested methods for minimizing 

respondent burden, EPA has established 

a public docket for this rule, which 

includes these ICR, under Docket ID 

number EPA–HQ–OAR–2010–0600. 

Submit any comments related to the ICR 

to EPA and OMB. See ADDRESSES

section at the beginning of this notice 

for where to submit comments to EPA. 

Send comments to OMB at the Office of 

Information and Regulatory Affairs, 

Office of Management and Budget, 725 

17th Street, NW., Washington, DC 

20503, Attention: Desk Office for EPA. 

Since OMB is required to make a 

decision concerning the ICR between 30 

and 60 days after October 21, 2010, a 

comment to OMB is best assured of 

having its full effect if OMB receives it 

by November 22, 2010. The final rule 

will respond to any OMB or public 

comments on the information collection 

requirements contained in this proposal. 

C. Regulatory Flexibility Act 

The Regulatory Flexibility Act (RFA) 

generally requires an agency to prepare 

a regulatory flexibility analysis of any 

rule subject to notice and comment 

rulemaking requirements under the 

Administrative Procedure Act or any 

other statute unless the agency certifies 

that the rule will not have a significant 

economic impact on a substantial 

number of small entities. Small entities 

include small businesses, small 

organizations, and small governmental 

jurisdictions. For purposes of assessing 

the impacts of this proposed rule on 

small entities, small entity is defined as: 

(1) A small business that is a small 

industrial entity as defined by the Small 

Business Administration’s regulations at 

13 CFR 121.201; (2) a small 

governmental jurisdiction that is a 

government of a city, county, town, 

school district or special district with a 

population of less than 50,000; and (3) 

a small organization that is any not-forprofit enterprise which is independently 

owned and operated and is not 

dominant in its field. 

This proposed rule will not impose 

emission measurements or reporting 

requirements on small entities beyond 

those specified in existing regulations, 

nor does it change the level of any 

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65128 Federal Register / Vol. 75, No. 203 / Thursday, October 21, 2010 / Proposed Rules 

emission standard for amendments to 

all of the MACT standards proposed 

today, with the exception of the 

proposed amendments to the hard and 

decorative chromium electroplating and 

chromium anodizing tanks MACT 

standard. The new housekeeping 

requirements and PFOS use restrictions 

proposed by these amendments to the 

hard and decorative chromium 

electroplating and chromium anodizing 

tanks MACT standard may impact small 

entities, but those impacts have been 

estimated to be nominal. 

After considering the economic 

impacts of this proposed rule on small 

entities, I certify that this action will not 

have a significant economic impact on 

a substantial number of small entities. 

We continue to be interested in the 

potential impacts of the proposed rule 

on small entities and welcome 

comments on issues related to such 

impacts. 

D. Unfunded Mandates Reform Act 

This proposed rule does not contain 

a Federal mandate under the provisions 

of Title II of the Unfunded Mandates 

Reform Act of 1995 (UMRA), 2 U.S.C. 

1531–1538 for State, local, or tribal 

governments or the private sector. The 

proposed rule would not result in 

expenditures of $100 million or more 

for State, local, and tribal governments, 

in aggregate, or the private sector in any 

1 year. The proposed rule imposes no 

enforceable duties on any State, local, or 

tribal governments or the private sector. 

Thus, this proposed rule is not subject 

to the requirements of sections 202 or 

205 of the UMRA. 

This proposed rule is also not subject 

to the requirements of section 203 of 

UMRA because it contains no regulatory 

requirements that might significantly or 

uniquely affect small governments 

because it contains no requirements that 

apply to such governments nor does it 

impose obligations upon them. 

E. Executive Order 13132: Federalism 

This proposed rule does not have 

federalism implications. It will not have 

substantial direct effects on the States, 

on the relationship between the national 

government and the States, or on the 

distribution of power and 

responsibilities among the various 

levels of government, as specified in 

Executive Order 13132. None of the 

facilities subject to this action are 

owned or operated by State 

governments, and, because no new 

requirements are being promulgated, 

nothing in this proposal will supersede 

State regulations. Thus, Executive Order 

13132 does not apply to this proposed 

rule. 

In the spirit of Executive Order 13132, 

and consistent with EPA policy to 

promote communications between EPA 

and State and local governments, EPA 

specifically solicits comment on this 

proposed rule from State and local 

officials. 

F. Executive Order 13175: Consultation 

and Coordination With Indian Tribal 

Governments 

Subject to the Executive Order 13175 

(65 FR 67249, November 9, 2000), EPA 

may not issue a regulation that has tribal 

implications, that imposes substantial 

direct compliance costs, and that is not 

required by statute, unless the Federal 

government provides the funds 

necessary to pay the direct compliance 

costs incurred by tribal governments, or 

EPA consults with tribal officials early 

in the process of developing the 

proposed regulation and develops a 

tribal summary impact statement. EPA 

has concluded that this proposed rule 

will not have tribal implications, as 

specified in Executive Order 13175. It 

will not have substantial direct effect on 

tribal governments, on the relationship 

between the Federal government and 

Indian tribes, or on the distribution of 

power and responsibilities between the 

Federal government and Indian tribes, 

as specified in Executive Order 13175. 

Thus, Executive Order 13175 does not 

apply to this action. 

EPA specifically solicits additional 

comment on this proposed action from 

tribal officials. 

G. Executive Order 13045: Protection of 

Children From Environmental Health 

Risks and Safety Risks 

This proposed rule is not subject to 

Executive Order 13045 (62 FR 19885, 

April 23, 1997) because it is not 

economically significant as defined in 

Executive Order 12866, and because the 

Agency does not believe the 

environmental health or safety risks 

addressed by this action present a 

disproportionate risk to children. This 

action would not relax the control 

measures on existing regulated sources, 

and EPA’s risk assessments (included in 

the docket for this proposed rule) 

demonstrate that the existing 

regulations are health protective. 

H. Executive Order 13211: Actions 

Concerning Regulations That 

Significantly Affect Energy Supply, 

Distribution, or Use 

This action is not a ‘‘significant energy 

action’’ as defined under EO 13211, 

‘‘Actions Concerning Regulations That 

Significantly Affect Energy Supply, 

Distribution, or Use’’ (66 FR 28355, May 

22, 2001), because it is not likely to have 

significant adverse effect on the supply, 

distribution, or use of energy. This 

action will not create any new 

requirements for sources in the energy 

supply, distribution, or use sectors. 

I. National Technology Transfer and 

Advancement Act 

Section 12(d) of the National 

Technology Transfer and Advancement 

Act of 1995 (NTTAA), Public Law 104– 

113, 12(d) (15 U.S.C. 272 note) directs 

EPA to use voluntary consensus 

standards (VCS) in its regulatory 

activities unless to do so would be 

inconsistent with applicable law or 

otherwise impractical. VCS are 

technical standards (e.g., materials 

specifications, test methods, sampling 

procedures, and business practices) that 

are developed or adopted by VCS 

bodies. The NTTAA directs EPA to 

provide Congress, through OMB, 

explanations when the Agency decides 

not to use available and applicable VCS. 

This proposed rulemaking does not 

involve technical standards. Therefore, 

EPA is not considering the use of any 

VCS. 

J. Executive Order 12898: Federal 

Actions To Address Environmental 

Justice in Minority Populations and 

Low-Income Populations 

Executive Order 12898 (59 FR 7629, 

February 16, 1994) establishes Federal 

executive policy on environmental 

justice. Its main provision directs 

Federal agencies, to the greatest extent 

practicable and permitted by law, to 

make environmental justice part of their 

mission by identifying and addressing, 

as appropriate, disproportionately high 

and adverse human health or 

environmental effects of their programs, 

policies, and activities on minority 

populations and low-income 

populations in the United States. 

To examine the potential for any 

environmental justice issues that might 

be associated with each source category, 

we evaluated the distributions of HAPrelated cancer and non-cancer risks 

across different social, demographic, 

and economic groups within the 

populations living near the facilities 

where these source categories are 

located. The methods used to conduct 

demographic analyses for this rule are 

described in section IV.A of the 

preamble for this rule. The development 

of demographic analyses to inform the 

consideration of environmental justice 

issues in EPA rulemakings is an 

evolving science. The EPA offers the 

demographic analyses in this 

rulemaking as examples of how such 

analyses might be developed to inform 

such consideration, and invites public 

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Federal Register / Vol. 75, No. 203 / Thursday, October 21, 2010 / Proposed Rules 65129 

comment on the approaches used and 

the interpretations made from the 

results, with the hope that this will 

support the refinement and improve 

utility of such analyses for future 

rulemakings. 

For this analysis, we analyzed risks 

due to the inhalation of HAP in two 

separate ways. In the first approach, we 

focus the analysis on the total 

populations residing within 5 km of 

each facility (source category and 

facility-wide), regardless of their 

estimated risks, and examine the 

distributions of estimated risk across the 

various demographic groups within 

those 5 km circles. In the other, we 

focus the analysis only on the 

populations within 5 km of any facility 

who are estimated to have HAP 

exposures which result in cancer risks 

of 1-in-1 million or greater or noncancer HI of 1 or greater (based on the 

emissions of the source category or the 

facility, respectively), once again 

examining the distributions of those 

risks across various demographic 

groups. In each approach, we compare 

the percentages of particular 

demographic groups to the total number 

of people in those demographic groups. 

In this preamble, we only present the 

results of the second approach since it 

focuses on the significant risks from 

either the source category or the facilitywide emissions. The results of both 

approaches are documented in memos 

to the docket for each of the source 

categories covered in this proposal. 

As described in the preamble, for the 

Epichlorohydrin Elastomers Production, 

Hypalon TM Production, Nitrile 

Butadiene Rubber Production, 

Polybutadiene Rubber Production, 

Styrene-Butadiene Rubber and Latex 

Production, MTVLO, Pharmaceuticals 

Production, and Printing and Publishing 

Industry MACT standard source 

categories, which were addressed in the 

October 10, 2008, proposal, we have 

reaffirmed our proposed determinations 

that the MACT standards for these 

source categories provide an ample 

margin of safety to protect public health 

and prevent adverse environmental 

effects. For the Hard Chromium 

Electroplating, Decorative Chromium 

Electroplating, Chromium Anodizing, 

and Steel Pickling—HCl Process 

Facilities and Hydrochloric Acid 

Regeneration Plants MACT standard 

source categories, we propose the 

MACT standards provide an ample 

margin of safety to protect public health 

and prevent adverse environmental 

effects. 

Our analyses also show that, for all 

the source categories evaluated, there is 

no potential for an adverse 

environmental effect or human health 

multipathway effects, and that acute 

and chronic non-cancer health impacts 

are unlikely. Our additional analysis of 

facility-wide risks showed that the 

maximum facility-wide cancer risks for 

all source categories are within the 

range of acceptable risks, and that the 

maximum chronic non-cancer risks are 

unlikely to cause health impacts. Our 

additional analysis of the demographics 

of the exposed population may show 

disparities in risks between 

demographic groups for all three 

categories; EPA has determined that, 

although there may be a disparity in 

risks between demographic groups, no 

group is exposed to unacceptable level 

of risk. The proposed rule would not 

relax the control measures on sources 

regulated by the rule, and, therefore, 

would not increase risks to any 

populations exposed to these sources. 

List of Subjects in 40 CFR Part 63 

Environmental protection, Air 

pollution control, Reporting and 

recordkeeping requirements, Volatile 

organic compounds. 

Dated: September 14, 2010. 

Lisa P. Jackson, 

Administrator. 

For the reasons stated in the 

preamble, the Environmental Protection 

Agency proposes to amend title 40, 

chapter I of the Code of Federal 

Regulations as follows: 

PART 63—[AMENDED] 

1. The authority citation for part 63 

continues to read as follows: 

Authority: 42 U.S.C. 7401, et seq. 

Subpart N—[Amended] 

2. Section 63.341 is amended by: 

a. Adding, in alphabetical order in 

paragraph (a), definitions for 

‘‘affirmative defense,’’ ‘‘contains 

hexavalent chromium,’’ and 

‘‘perfluorooctyl sulfonate (PFOS)-based 

fume suppressant’’; and 

b. Revising paragraph (b)(10) to read 

as follows: 

§ 63.341 Definitions and nomenclature. 

(a) * * * 

Affirmative defense means, in the 

context of an enforcement proceeding, a 

response or a defense put forward by a 

defendant, regarding which the 

defendant has the burden of proof, and 

the merits of which are independently 

and objectively evaluated in a judicial 

or administrative proceeding. 

* * * * * 

Contains hexavalent chromium 

means, the substance consists of, or 

contains 0.1 percent or greater by 

weight, chromium trioxide, chromium 

(VI) oxide, chromic acid, or chromic 

anhydride. 

* * * * * 

Perfluorooctyl sulfonate (PFOS)-based 

fume suppressant means a fume 

suppressant that contains 1 percent or 

greater PFOS by weight. 

* * * * * 

(b) * * * 

(10) VRtot = the average total 

ventilation rate for the three test runs as 

determined at the outlet by means of the 

Method 306 or 306A testing specified in 

appendix A of this part in dscm/min. 

3. Section 63.342 is amended by: 

a. Revising paragraph (a); 

b. Revising paragraph (b)(1); 

c. Adding paragraph (c)(1)(iv); 

d. Adding paragraph (c)(2)(vi); 

e. Adding paragraph (d)(3); 

f. Redesignating paragraphs (e)(2) and 

(e)(3) as paragraphs (e)(3) and (e)(4); 

g. Adding new paragraph (e)(2); 

h. Revising newly designated 

paragraph (e)(4); 

i. Adding paragraph (f)(3)(i)(F); and 

j. Adding Table 2 to read as follows: 

§ 63.342 Standards. 

(a)(1) At all times, each owner or 

operator must operate and maintain any 

affected source subject to the 

requirements of this subpart, including 

associated air pollution control 

equipment and monitoring equipment, 

in a manner consistent with safety and 

good air pollution control practices for 

minimizing emissions. The general duty 

to minimize emissions does not require 

the owner or operator to make any 

further efforts to reduce emissions if 

levels required by this standard have 

been achieved. Determination of 

whether such operation and 

maintenance procedures are being used 

will be based on information available 

to the Administrator which may 

include, but is not limited to, 

monitoring results, review of operation 

and maintenance procedures, review of 

operation and maintenance records, and 

inspection of the source. 

(2) Each owner or operator of an 

affected source subject to the provisions 

of this subpart shall comply with these 

requirements in this section on and after 

the compliance dates specified in 

§ 63.343(a). All affected sources are 

regulated by applying maximum 

achievable control technology. 

* * * * * 

(b) * * * 

(1) The emission limitations in this 

section apply during tank operation as 

defined in § 63.341, and during periods 

of startup and shutdown as these are 

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65130 Federal Register / Vol. 75, No. 203 / Thursday, October 21, 2010 / Proposed Rules 

routine occurrences for affected sources 

subject to this subpart. In response to an 

action to enforce the standards set forth 

in this subpart, you may assert a civil 

defense to a claim for civil penalties for 

exceedances of such standards that are 

caused by a malfunction, as defined in 

40 CFR 63.2. Appropriate penalties may 

be assessed, however, if the respondent 

fails to meet its burden of proving all 

the requirements in the affirmative 

defense. The affirmative defense shall 

not be available for claims for injunctive 

relief. 

(i) To establish the affirmative defense 

in any action to enforce such a limit, the 

owners or operators of facilities must 

timely meet the notification 

requirements of paragraph (b)(1)(ii) of 

this section, and must prove by a 

preponderance of evidence that: 

(A) The excess emissions were caused 

by a sudden, short, infrequent, and 

unavoidable failure of air pollution 

control and monitoring equipment, or of 

a process to operate in a normal an 

usual manner; and could not have been 

prevented through careful planning, 

proper design or better operation and 

maintenance practices; and did not stem 

from any activity or event that could 

have been foreseen and avoided, or 

planned for; and were not part of a 

recurring pattern indicative of 

inadequate design, operation, or 

maintenance; and 

(B) Repairs were made as 

expeditiously as possible when the 

applicable emission limitations were 

being exceeded. Off-shift and overtime 

labor were used, to the extent 

practicable to make these repairs; and 

(C) The frequency, amount and 

duration of the excess emissions 

(including any bypass) were minimized 

to the maximum extent practicable 

during periods of such emissions; and 

(D) If the excess emissions resulted 

from a bypass of control equipment or 

a process, then the bypass was 

unavoidable to prevent loss of life, 

severe personal injury, or severe 

property damage; and 

(E) All possible steps were taken to 

minimize the impact of the excess 

emissions on ambient air quality, the 

environment, and human health; and 

(F) All emissions monitoring and 

control systems were kept in operation 

if at all possible; and 

(G) Your actions in response to the 

excess emissions were documented by 

properly signed, contemporaneous 

operating logs; and 

(H) At all times, the facility was 

operated in a manner consistent with 

good practices for minimizing 

emissions; and 

(I) The owner or operator has 

prepared a written root cause analysis to 

determine, correct and eliminate the 

primary causes of the malfunction and 

the excess emissions resulting from the 

malfunction event at issue. The analysis 

shall also specify, using the best 

monitoring methods and engineering 

judgment, the amount of excess 

emissions that were the result of the 

malfunction. 

(ii) Notification. The owner or 

operator of the facility experiencing an 

exceedance of its emission limit(s) 

during a malfunction shall notify the 

Administrator by telephone or facsimile 

(FAX) transmission as soon as possible, 

but no later than two business days after 

the initial occurrence of the 

malfunction, if it wishes to avail itself 

of an affirmative defense to civil 

penalties for that malfunction. The 

owner or operator seeking to assert an 

affirmative defense shall also submit a 

written report to the Administrator 

within 30 days of the initial occurrence 

of the exceedance of the standard in this 

subpart to demonstrate, with all 

necessary supporting documentation, 

that it has met the requirements set forth 

in paragraph (b)(1)(i) of this section. 

* * * * * 

(c)(1) * * * 

(iv) After 3 years from date of 

publication of the final rule 

amendments in the Federal Register, 

the owner or operator of an affected 

open surface hard chromium 

electroplating tank shall not add PFOSbased fume suppressants to any affected 

open surface hard chromium 

electroplating tank. 

* * * * * 

(2) * * * 

(vi) After 3 years from date of 

publication of the final rule 

amendments in the Federal Register, 

the owner or operator of an affected 

enclosed hard chromium electroplating 

tank shall not add PFOS-based fume 

suppressants to any affected enclosed 

hard chromium electroplating tank. 

* * * * * 

(d) * * * 

(3) After 3 years from date of 

publication of the final rule 

amendments in the Federal Register, 

the owner or operator of an affected 

decorative chromium electroplating 

tank or an affected chromium anodizing 

tank shall not add PFOS-based fume 

suppressants to any affected decorative 

chromium electroplating tank or 

chromium anodizing tank. 

(e) * * * 

(2) After 3 years from date of 

publication of the final rule 

amendments in the Federal Register, 

the owner or operator of an affected 

decorative chromium electroplating 

tank using a trivalent chromium bath 

shall not add PFOS-based fume 

suppressants to any affected decorative 

chromium electroplating tank. 

* * * * * 

(4) Each owner or operator of an 

existing, new, or reconstructed 

decorative chromium electroplating 

tank that had been using a trivalent 

chromium bath that incorporated a 

wetting agent and ceases using this type 

of bath must fulfill the reporting 

requirements of § 63.347(i)(3) and 

comply with the applicable emission 

limitation within the timeframe 

specified in § 63.343(a)(7). 

(f) * * * 

(3) * * * 

(i) * * * 

(F) The plan shall include 

housekeeping procedures, as specified 

in Table 2 of this section. 

* * * * * 

TABLE 2 TO § 63.342—HOUSEKEEPING PRACTICES

For You must: At this minimum frequency 

1. Any substance that contains hexavalent 

chromium. 

(a) Store the substance in a closed container 

in an enclosed storage area; AND 

At all times. 

(b) Use a closed container when transporting 

the substance from the enclosed storage 

area. 

Whenever transporting substance. 

2. Each affected tank, to minimize spills of bath 

solution that result from dragout. 

(a) Install drip trays that collect and return to 

the tank any bath solution that drips or 

drains from parts as the parts are removed 

from the tank; OR 

Prior to operating the tank. 

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TABLE 2 TO § 63.342—HOUSEKEEPING PRACTICES—Continued 

For You must: At this minimum frequency 

(b) Contain and return to the tank all solution 

that drains or drips from parts as the parts 

are removed from the tank. 

Whenever removing parts from an affected 

tank. 

3. Each spraying operation for removing excess 

chromic acid from parts removed from an affected tank. 

Install a splash guard to minimize overspray 

and to ensure that any hexavalent chromium laden liquid is returned to the electroplating or anodizing tank. 

Prior to any such spraying operation. 

4. Each operation that involves the handling or 

use of any substance that contains 

hexavalent chromium. 

Clean up, or otherwise contain, all spills of the 

substance. 

Within 1 hour of the spill. 

5. All surfaces within the enclosed storage 

area, open floor area, walkways around affected tanks, or any surface potentially contaminated with hexavalent chromium that accumulates or potentially accumulates dust. 

(a) Clean the surfaces using one or more of 

the following methods: 

(i) HEPA vacuuming; 

(ii) Hand-wiping with a damp cloth; 

(iii) Wet mopping; 

(iv) Other cleaning method approved by 

the permitting agency; OR 

At least once every 7 days. 

(b) Apply a non-toxic chemical dust suppressant to the surfaces. According to manufacturer’s recommendations. 

6. All buffing, grinding, or polishing operations. Separate the operation from any affected 

electroplating or anodizing operation by installing a physical barrier; the barrier may 

take the form of plastic strip curtains. 

Prior to beginning the buffing, grinding, or 

polishing operation. 

7. All chromium or chromium-containing wastes 

generated from housekeeping activities. 

Store, dispose, recover, or recycle the wastes 

using practices that do not lead to fugitive 

dust and in accordance with hazardous 

waste requirements. 

At all times. 

4. Section 63.343 is amended by 

adding paragraph (a)(8) to read as 

follows: 

§ 63.343 Compliance provisions. 

(a) * * * 

(8) No later than 6 months from date 

of publication of the final amendments 

in the Federal Register, the owner or 

operator of an affected source that is 

subject to the standards in paragraphs 

§ 63.342(c) or (d) shall implement the 

housekeeping procedures specified in 

Table 2 of § 63.342. 

* * * * * 

5. Section 63.344 is amended by: 

a. Revising paragraph (a); 

b. Revising paragraphs (e)(3)(iii), 

(e)(3)(iv), and (e)(3)(v); and 

c. Revising paragraphs (e)(4)(ii) and 

(e)(4)(iv) to read as follows: 

§ 63.344 Performance test requirements 

and test methods. 

(a) Performance test requirements. 

Performance tests shall be conducted 

using the test methods and procedures 

in this section. Performance tests shall 

be conducted under such conditions as 

the Administrator specifies to the owner 

or operator based on representative 

performance of the affected source for 

the period being tested. Upon request, 

the owner or operator shall make 

available to the Administrator such 

records as may be necessary to 

determine the conditions of 

performance tests. Performance test 

results shall be documented in complete 

test reports that contain the information 

required by paragraphs (a)(1) through (9) 

of this section. The test plan to be 

followed shall be made available to the 

Administrator prior to the testing, if 

requested. 

* * * * * 

(e) * * * 

(3) * * * 

(iii) Perform Method 306 or 306A 

testing and calculate an outlet mass 

emission rate. 

(iv) Determine the total ventilation 

rate from the affected sources (VRinlet) by 

using equation 1: 

VR IDA

IA tot VR i

total

× = inlet ∑ ( )1

where VRtot is the average total ventilation 

rate in dscm/min for the three test runs 

as determined at the outlet by means of 

the Method 306 or 306A testing; IDAi is 

the total inlet area for all ducts 

associated with affected sources; èIAtotal

is the sum of all inlet duct areas from 

both affected and nonaffected sources; 

and VRinlet is the total ventilation rate 

from all inlet ducts associated with 

affected sources. 

(v) Establish the allowable mass 

emission rate of the system (AMRsys) in 

milligrams of total chromium per hour 

(mg/hr) using equation 2: 

∑VR EL inlet × × = AMRsys 60 minutes/hour ( ) 2

where è VRinlet is the total ventilation rate in 

dscm/min from the affected sources, and 

EL is the applicable emission limitation 

from § 63.342 in mg/dscm. The allowable 

mass emission rate (AMRsys) calculated 

from equation 2 should be equal to or 


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more than the outlet three-run average 

mass emission rate determined from 

Method 306 or 306A testing in order for 

the source to be in compliance with the 

standard. 

(4) * * * 

(ii) Determine the total ventilation 

rate for each type of affected source 

(VRinlet,a) using equation 3: 

VR

IDA

IA tot VR i a

total

× = inlet a ∑

,

, ( ) 3

where VRtot is the average total ventilation 

rate in dscm/min for the three test runs 

as determined at the outlet by means of 

the Method 306 or 306A testing; IDAi,a is 

the total inlet duct area for all ducts 

conveying chromic acid from each type 

of affected source performing the same 

operation, or each type of affected source 

subject to the same emission limitation; 

èIAtotal is the sum of all duct areas from 

both affected and nonaffected sources; 

and VRinlet,a is the total ventilation rate 

from all inlet ducts conveying chromic 

acid from each type of affected source 

performing the same operation, or each 

type of affected source subject to the 

same emission limitation. 

* * * * * 

(iv) Establish the allowable mass 

emission rate of the system (AMRsys) in 

milligrams of total chromium per hour 

(mg/hr) using equation 8, including 

each type of affected source as 

appropriate: 

AMR AMR AMR AMR AMR hcl hc dc ca sys + ++= 2 ( ) 8

The allowable mass emission rate 

calculated from equation 8 should be 

equal to or more than the outlet threerun average mass emission rate 

determined from Method 306 or 306A 

testing in order for the source to be in 

compliance with the standards. 

* * * * * 

6. Section 63.346 is amended by 

revising paragraphs (b)(4) and (b)(13) to 

read as follows: 

§ 63.346 Recordkeeping requirements. 

* * * * * 

(b) * * * 

(4) Records of actions taken during 

periods of malfunction to minimize 

emissions in accordance with 

§ 63.342(a)(1), including corrective 

actions to restore malfunctioning 

process and air pollution control and 

monitoring equipment to its normal or 

usual manner of operation; 

* * * * * 

(13) For sources using fume 

suppressants to comply with the 

standards, records of the date and time 

that fume suppressants are added to the 

electroplating or anodizing bath and 

records of the fume suppressant 

manufacturer and product name; 

* * * * * 

7. Section 63.347 is amended by: 

a. Redesignating paragraphs (g)(3)(xii) 

and (g)(3)(xiii) as (g)(3)(xiii) and 

(g)(3)(xiv), respectively, and adding a 

new paragraph (g)(3)(xii); 

c. Revising paragraphs (h)(2)(i) 

introductory text and (h)(2)(i)(A) to read 

as follows: 

§ 63.347 Reporting requirements. 

* * * * * 

(g) * * * 

(3) * * * 

(xii) The number, duration, and a 

brief description for each type of 

malfunction which occurred during the 

reporting period and which caused or 

may have caused any applicable 

emission limitation to be exceeded. The 

report must also include a description of 

actions taken by an owner or operator 

during a malfunction of an affected 

source to minimize emissions in 

accordance with § 63.342(a)(1), 

including actions taken to correct a 

malfunction. 

* * * * * 

(h) * * * 

(2) * * * 

(i) If either of the following conditions 

is met, semiannual reports shall be 

prepared and submitted to the 

Administrator: 

(A) The total duration of excess 

emissions (as indicated by the 

monitoring data collected by the owner 

or operator of the affected source in 

accordance with § 63.343(c)) is 1 

percent or greater of the total operating 

time for the reporting period; or 

* * * * * 

8. Table 1 to Subpart N is amended 

by: 

a. Removing entry 63.7(e); 

b. Adding entries 63.7(e)(1) and 

63.7(e)(2)–(4) to read as follows: 

TABLE 1 TO SUBPART N OF PART 63—GENERAL PROVISIONS APPLICABILITY TO SUBPART N 

General provisions 

reference Applies to Subpart N Comment 

*******

63.7(e)(1) .......................................................... No ................................ See § 63.344(a). Any cross reference to § 63.7(e)(1) in any other general provision incorporated by reference shall be treated as a crossreference to § 63.344(a). 

63.7(e)(2)–(4) .................................................... Yes .............................. Subpart N also contains test methods specific to affected sources 

covered by that subpart. 

* * * * * * * 

Subpart U—[Amended] 

9. Section 63.480 is amended by 

revising paragraph (j) to read as follows: 

§ 63.480 Applicability and designation of 

affected sources. 

* * * * * 

(j) Applicability of this subpart. 

Paragraphs (j)(1) through (4) of this 

section shall be followed during periods 

of non-operation of the affected source 

or any part thereof. 

(1) The emission limitations set forth 

in this subpart and the emission 

limitations referred to in this subpart 

shall apply at all times except during 

periods of non-operation of the affected 

source (or specific portion thereof) 

resulting in cessation of the emissions to 

which this subpart applies. However, if 

a period of non-operation of one portion 

of an affected source does not affect the 

ability of a particular emission point to 

comply with the emission limitations to 

which it is subject, then that emission 


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point shall still be required to comply 

with the applicable emission limitations 

of this subpart during period of nonoperation. 

(2) The emission limitations set forth 

in subpart H of this part, as referred to 

in § 63.502, shall apply at all times 

except during periods of non-operation 

of the affected source (or specific 

portion thereof) in which the lines are 

drained and depressurized resulting in 

cessation of the emissions to which 

§ 63.502 applies. 

(3) The owner or operator shall not 

shut down items of equipment that are 

required or utilized for compliance with 

this subpart during times when 

emissions (or, where applicable, 

wastewater streams or residuals) are 

being routed to such items of equipment 

if the shutdown would contravene 

requirements of this subpart applicable 

to such items of equipment. 

(4) In response to an action to enforce 

the standards set forth in this subpart, 

you may assert a civil defense to a claim 

for civil penalties for exceedances of 

such standards that are caused by a 

malfunction, as defined in 40 CFR 63.2. 

Appropriate penalties may be assessed, 

however, if the respondent fails to meet 

its burden of proving all the 

requirements in the affirmative defense. 

The affirmative defense shall not be 

available for claims for injunctive relief. 

(i) To establish the affirmative defense 

in any action to enforce such a limit, the 

owners or operators of facilities must 

timely meet the notification 

requirements of paragraph (j)(4)(ii) of 

this section, and must prove by a 

preponderance of evidence that: 

(A) The excess emissions were caused 

by a sudden, short, infrequent, and 

unavoidable failure of air pollution 

control and monitoring equipment, or a 

process to operate in a normal and usual 

manner; and could not have been 

prevented through careful planning, 

proper design, or better operation and 

maintenance practices; and did not stem 

from any activity or event that could 

have been foreseen and avoided, or 

planned for; and were not part of a 

recurring pattern indicative of 

inadequate design, operation, or 

maintenance; and 

(B) Repairs were made as 

expeditiously as possible when the 

applicable emission limitations were 

being exceeded. Off-shift and overtime 

labor were used, to the extent 

practicable to make these repairs; and 

(C) The frequency, amount, and 

duration of the excess emissions 

(including any bypass) were minimized 

to the maximum extent practicable 

during periods of such emissions; and 

(D) If the excess emissions resulted 

from a bypass of control equipment or 

a process, then the bypass was 

unavoidable to prevent loss of life, 

severe personal injury, or severe 

property damage; and 

(E) All possible steps were taken to 

minimize the impact of the excess 

emissions on ambient air quality, the 

environment, and human health; and 

(F) All emissions monitoring and 

control systems were kept in operation 

if at all possible; and 

(G) Your actions in response to the 

excess emissions were documented by 

properly signed, contemporaneous 

operating logs; and 

(H) At all times, the facility was 

operated in a manner consistent with 

good practices for minimizing 

emissions; and 

(I) The owner or operator has 

prepared a written root cause analysis to 

determine, correct, and eliminate the 

primary causes of the malfunction and 

the excess emissions resulting from the 

malfunction event at issue. The analysis 

shall also specify, using the best 

monitoring methods and engineering 

judgment, the amount of excess 

emissions that were the result of the 

malfunction. 

(ii) Notification. The owner or 

operator of the facility experiencing an 

exceedance of its emission limit(s) 

during a malfunction shall notify the 

Administrator by telephone or facsimile 

(FAX) transmission as soon as possible, 

but no later than 2 business days after 

the initial occurrence of the 

malfunction, if it wishes to avail itself 

of an affirmative defense to civil 

penalties for that malfunction. The 

owner or operator seeking to assert an 

affirmative defense shall also submit a 

written report to the Administrator 

within 30 days of the initial occurrence 

of the exceedance of the standard in this 

subpart to demonstrate, with all 

necessary supporting documentation, 

that it has met the requirements set forth 

in paragraph (j)(4)(i) of this section. 

10. Section 63.481 is amended by 

revising paragraph (c) to read as follows: 

§ 63.481 Compliance dates and 

relationship of this subpart to existing 

applicable rules. 

* * * * * 

(c) With the exceptions provided in 

paragraphs (c)(1) through (4) of this 

section, existing affected sources shall 

be in compliance with this subpart no 

later than June 19, 2001, as provided in 

§ 63.6(c), unless an extension has been 

granted as specified in paragraph (e) of 

this section. 

(1) Existing affected sources 

producing epichlorohydrin elastomer, 

halobutyl rubber, neoprene rubber, and 

nitrile butadiene rubber shall be in 

compliance with the applicable 

emission limitation in § 63.494(a)(4) no 

later than 1 year from date of 

publication of the final rule 

amendments in the Federal Register. 

(2) Existing affected sources 

producing butyl rubber shall be in 

compliance with § 63.494(a)(4)(i) no 

later than 3 years from date of 

publication of the final rule 

amendments in the Federal Register. 

(3) Existing affected sources 

producing butyl rubber, halobutyl 

rubber, and ethylene propylene rubber 

shall be in compliance with 

§ 63.485(q)(1) no later than 3 years from 

date of publication of the final rule 

amendments in the Federal Register. 

(4) Compliance with § 63.502 is 

covered by paragraph (d) of this section. 

* * * * * 

11. Section 63.482 is amended by 

adding in alphabetical order a definition 

for ‘‘affirmative defense,’’ and revising 

the definition of ‘‘initial start-up’’ in 

paragraph (b) to read as follows: 

§ 63.482 Definitions. 

* * * * * 

(b) * * * 

Affirmative defense means, in the 

context of an enforcement proceeding, a 

response or a defense put forward by a 

defendant, regarding which the 

defendant has the burden of proof, and 

the merits of which are independently 

and objectively evaluated in a judicial 

or administrative proceeding. 

* * * * * 

Initial start-up means the first time a 

new or reconstructed affected source 

begins production of an elastomer 

product, or, for equipment added or 

changed as described in § 63.480(i), the 

first time the equipment is put into 

operation to produce an elastomer 

product. Initial start-up does not 

include operation solely for testing 

equipment. Initial start-up does not 

include subsequent start-ups of an 

affected source or portion thereof 

following shutdowns or following 

changes in product for flexible 

operation units or following recharging 

of equipment in batch operation. 

* * * * * 

12. Section 63.483 is amended by 

revising paragraph (a) to read as follows: 

§ 63.483 Emission standards. 

(a) At all times, each owner or 

operator must operate and maintain any 

affected source subject to the 

requirements of this subpart, including 

associated air pollution control 

equipment and monitoring equipment, 

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in a manner consistent with safety and 

good air pollution control practices for 

minimizing emissions. The general duty 

to minimize emissions does not require 

the owner or operator to make any 

further efforts to reduce emissions if 

levels required by this standard have 

been achieved. Determination of 

whether such operation and 

maintenance procedures are being used 

will be based on information available 

to the Administrator which may 

include, but is not limited to, 

monitoring results, review of operation 

and maintenance procedures, review of 

operation and maintenance records, and 

inspection of the source. Except as 

allowed under paragraphs (b) through 

(d) of this section, the owner or operator 

of an existing or new affected source 

shall comply with the provisions in: 

(1) Section 63.484 for storage vessels; 

(2) Section 63.485 for continuous 

front-end process vents; 

(3) Sections 63.486 through 63.492 for 

batch front-end process vents; 

(4) Sections 63.493 through 63.500 for 

back-end process operations; 

(5) Section 63.501 for wastewater; 

(6) Section 63.502 for equipment 

leaks; 

(7) Section 63.504 for additional test 

methods and procedures; 

(8) Section 63.505 for monitoring 

levels and excursions; and 

(9) Section 63.506 for general 

reporting and recordkeeping 

requirements. 

* * * * * 

13. Section 63.484 is amended by 

revising paragraph (b)(4) to read as 

follows: 

§ 63.484 Storage vessel provisions. 

* * * * * 

(b) * * * 

(4) Storage vessels located 

downstream of the stripping operations 

at affected sources subject to the backend residual organic HAP limitation 

located in § 63.494(a)(1) through (3), 

that are complying through the use of 

stripping technology, as specified in 

§ 63.495; 

* * * * * 

14. Section 63.485 is amended by 

revising paragraphs (q) introductory text 

and (q)(1) introductory text to read as 

follows: 

§ 63.485 Continuous front-end process 

vent provisions. 

* * * * * 

(q) Group 1 halogenated continuous 

front-end process vents must comply 

with the provisions of § 63.113(a)(1)(ii) 

and § 63.113(c), with the exceptions 

noted in paragraphs (q)(1) and (2) of this 

section. 

(1) All Group 1 and Group 2 

halogenated continuous front-end 

process vents at existing affected 

sources producing butyl rubber, 

halobutyl rubber, or ethylene propylene 

rubber using a solution process, must 

comply with § 63.113(a)(1)(ii) and 

§ 63.113(c). 

* * * * * 

15. Section 63.489 is amended by 

revising paragraph (b)(4)(ii)(C) to read as 

follows: 

§ 63.489 Batch front-end process vents— 

monitoring equipment. 

* * * * * 

(b) * * * 

(4) * * * 

(ii) * * * 

(C) The owner or operator may 

prepare and implement a gas stream 

flow determination plan that documents 

an appropriate method which will be 

used to determine the gas stream flow. 

The plan shall require determination of 

gas stream flow by a method which will 

at least provide a value for either a 

representative or the highest gas stream 

flow anticipated in the scrubber during 

representative operating conditions. The 

plan shall include a description of the 

methodology to be followed and an 

explanation of how the selected 

methodology will reliably determine the 

gas stream flow, and a description of the 

records that will be maintained to 

document the determination of gas 

stream flow. The owner or operator 

shall maintain the plan as specified in 

§ 63.506(a). 

* * * * * 

16. Section 63.491 is amended by 

revising paragraph (e)(2)(ii) to read as 

follows: 

§ 63.491 Batch front-end process vents— 

recordkeeping requirements. 

* * * * * 

(e) * * * 

(2) * * * 

(ii) Monitoring data recorded during 

periods of monitoring system 

breakdowns, repairs, calibration checks, 

and zero (low-level) and high-level 

adjustments shall not be included in 

computing the batch cycle daily 

averages. In addition, monitoring data 

recorded during periods of nonoperation of the EPPU (or specific 

portion thereof) resulting in cessation of 

organic HAP emissions shall not be 

included in computing the batch cycle 

daily averages. 

* * * * * 

17. Section 63.493 is revised to read 

as follows: 

§ 63.493 Back-end process provisions. 

Owners and operators of new and 

existing affected sources shall comply 

with the requirements in §§ 63.494 

through 63.500. Owners and operators 

of affected sources whose only 

elastomer products are latex products, 

liquid rubber products, or products 

produced in a gas-phased reaction 

process are not subject to the provisions 

of §§ 63.494 through 63.500. If latex or 

liquid rubber products are produced in 

an affected source that also produces 

another elastomer product, the 

provisions of §§ 63.494 through 63.500 

do not apply to the back-end operations 

dedicated to the production of one or 

more latex products or to the back-end 

operations during the production of a 

latex product. 

18. Section 63.494 is amended by: 

a. Revising the section heading; 

b. Revising paragraph (a) introductory 

text; 

c. Revising paragraph (a)(4) and the 

introductory text of paragraph (a)(5); 

d. Adding paragraph (a)(6); 

e. Revising paragraph (b); 

f. Revising paragraph (c); and 

g. Revising paragraph (d) to read as 

follows: 

§ 63.494 Back-end process provisions— 

residual organic HAP and emission 

limitations. 

(a) The monthly weighted average 

residual organic HAP content of all 

grades of styrene butadiene rubber 

produced by the emulsion process, 

polybutadiene rubber and styrene 

butadiene rubber produced by the 

solution process, and ethylenepropylene rubber produced by the 

solution process that is processed, shall 

be measured after the stripping 

operation [or the reactor(s), if the plant 

has no stripper(s)] as specified in 

§ 63.495(d), and shall not exceed the 

limits provided in paragraphs (a)(1) 

through (3) of this section, as applicable. 

Owners or operators of these affected 

sources shall comply with the 

requirements of paragraphs (a)(1) 

through (3) of this section using either 

stripping technology or control or 

recovery devices. The organic HAP 

emissions from all back-end process 

operations at affected sources producing 

butyl rubber, epichlorohydrin 

elastomer, halobutyl rubber, neoprene, 

and nitrile butadiene rubber shall not 

exceed the limits determined in 

accordance with paragraph (a)(4) of this 

section, as applicable. 

* * * * * 

(4) The organic HAP emissions from 

back-end processes at affected sources 

producing butyl rubber, 

epichlorohydrin elastomer, halobutyl 

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rubber, neoprene, and nitrile butadiene 

rubber shall not exceed the limits 

determined in accordance with 

paragraphs (a)(4)(i) through (v) of this 

section for any consecutive 12-month 

period. The specific limitation for each 

elastomer type shall be determined 

based on the emissions level provided 

in paragraphs (a)(4)(i) through (v) of this 

section divided by the base year 

production level. The limitation shall be 

calculated and submitted in accordance 

with § 63.499(f)(1). 

(i) For butyl rubber, the organic HAP 

emission limitation, in units of Mg 

organic HAP emissions per Mg of butyl 

rubber produced, shall be calculated by 

dividing 28 Mg/yr by the mass of butyl 

rubber produced in 2009, in Mg. 

(ii) For epichlorohydrin elastomer, the 

organic HAP emission limitation, in 

units of Mg organic HAP emissions per 

Mg of epichlorohydrin elastomer 

produced, shall be calculated by 

dividing 36 Mg/yr by the mass of 

epichlorohydrin elastomer produced in 

2009, in Mg. 

(iii) For halobutyl rubber, the organic 

HAP emission limitation, in units of Mg 

organic HAP emissions per Mg of 

halobutyl rubber produced, shall be 

calculated by dividing 53 Mg/yr by the 

mass of halobutyl rubber produced in 

2006, in Mg. 

(iv) For neoprene, the organic HAP 

emission limitation, in units of Mg 

organic HAP emissions per Mg of 

neoprene produced, shall be calculated 

by dividing 23 Mg/yr by the mass of 

neoprene produced in 2009, in Mg. 

(v) For nitrile butadiene rubber, the 

organic HAP emission limitation, in 

units of Mg organic HAP emissions per 

Mg of nitrile butadiene rubber 

produced, shall be calculated by 

dividing 1.7 Mg/yr by the mass of nitrile 

butadiene rubber produced in 2009, in 

Mg. 

(5) For EPPU that produce both an 

elastomer product with a residual 

organic HAP limitation listed in 

paragraphs (a)(1) through (3) of this 

section, and a product listed in 

paragraphs (a)(5)(i) through (iv) of this 

section, only the residual HAP content 

of the elastomer product with a residual 

organic HAP limitation shall be used in 

determining the monthly average 

residual organic HAP content. 

* * * * * 

(6) There are no back-end process 

operation residual organic HAP or 

emission limitations for HypalonTM and 

polysulfide rubber production. There 

are also no back-end process operation 

residual organic HAP limitations for 

latex products, liquid rubber products, 

products produced in a gas-phased 

reaction process, styrene butadiene 

rubber produced by any process other 

than a solution or emulsion process, 

polybutadiene rubber produced by any 

process other than a solution process, or 

ethylene-propylene rubber produced by 

any process other than a solution 

process. 

(b) If an owner or operator complies 

with the residual organic HAP 

limitations in paragraph (a)(1) through 

(3) of this section using stripping 

technology, compliance shall be 

demonstrated in accordance with 

§ 63.495. The owner or operator shall 

also comply with the recordkeeping 

provisions in § 63.498, and the reporting 

provisions in § 63.499. 

(c) If an owner or operator complies 

with the residual organic HAP 

limitations in paragraph (a)(1) through 

(3) of this section using control or 

recovery devices, compliance shall be 

demonstrated using the procedures in 

§ 63.496. The owner or operator shall 

also comply with the monitoring 

provisions in § 63.497, the 

recordkeeping provisions in § 63.498, 

and the reporting provisions in § 63.499. 

(d) If the owner or operator complies 

with the residual organic HAP 

limitations in paragraph (a)(1) through 

(3) of this section using a flare, the 

owner or operator of an affected source 

shall comply with the requirements in 

§ 63.504(c). 

19. Section 63.495 is amended by: 

a. Revising the section heading; 

b. Revising paragraph (a); 

c. Revising paragraph (b)(5); and 

d. Adding paragraph (g) to read as 

follows: 

§ 63.495 Back-end process provisions— 

procedures to determine compliance with 

residual organic HAP limitations using 

stripping technology and organic HAP 

emissions limitations. 

(a) If an owner or operator complies 

with the residual organic HAP 

limitations in § 63.494(a)(1) through (3) 

using stripping technology, compliance 

shall be demonstrated using the 

periodic sampling procedures in 

paragraph (b) of this section, or using 

the stripper parameter monitoring 

procedures in paragraph (c) of this 

section. The owner or operator shall 

determine the monthly weighted 

average residual organic HAP content 

for each month in which any portion of 

the back-end of an elastomer production 

process is in operation. A single 

monthly weighted average shall be 

determined for all back-end process 

operations at the affected source. 

(b) * * * 

(5) The monthly weighted average 

shall be determined using the equation 

in paragraph (f) of this section. All 

representative samples taken and 

analyzed during the month shall be 

used in the determination of the 

monthly weighted average. 

* * * * * 

(g) Compliance with the organic HAP 

emission limitations determined in 

accordance with § 63.494(a)(4) shall be 

demonstrated in accordance with 

paragraphs (g)(1) through (5) of this 

section. 

(1) Calculate your organic HAP 

emission limitation in accordance with 

§ 63.494(a)(4)(i) through (v), as 

applicable, record it, and submit it in 

accordance with § 63.499(f)(1). 

(2) Each month, calculate and record 

the organic HAP emissions from all back 

end process operations using 

engineering assessment. Engineering 

assessment includes, but is not limited 

to, the following: 

(i) Previous test results, provided the 

test was representative of current 

operating practices. 

(ii) Bench-scale or pilot-scale test data 

obtained under conditions 

representative of current process 

operating conditions. 

(iii) Design analysis based on 

accepted chemical engineering 

principles, measurable process 

parameters, or physical or chemical 

laws or properties. Examples of 

analytical methods include, but are not 

limited to: 

(A) Use of material balances; 

(B) Estimation of flow rate based on 

physical equipment design, such as 

pump or blower capacities; 

(C) Estimation of organic HAP 

concentrations based on saturation 

conditions; and 

(D) Estimation of organic HAP 

concentrations based on grab samples of 

the liquid or vapor. 

(3) Each month, record the mass of 

elastomer product produced. 

(4) Each month, calculate and record 

the sums of the organic HAP emissions 

and the mass of elastomer produced for 

the month and the previous 11 months. 

(5) Each month, divide the total mass 

of organic HAP emitted for the 12- 

month period by the total mass of 

elastomer produced during the 12- 

month period. This value must be 

recorded in accordance with § 63.498(e) 

and reported in accordance with 

§ 63.499(f)(2). 

20. Section 63.496 is amended by: 

a. Revising the section heading; 

b. Revising paragraph (a); 

c. Revising paragraph (c)(2); and 

d. Revising paragraph (d) to read as 

follows: 

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65136 Federal Register / Vol. 75, No. 203 / Thursday, October 21, 2010 / Proposed Rules 

§ 63.496 Back-end process provisions— 

procedures to determine compliance with 

residual organic HAP limitations using 

control or recovery devices. 

(a) If an owner or operator complies 

with the residual organic HAP 

limitations in § 63.494(a)(1) through (3) 

using control or recovery devices, 

compliance shall be demonstrated using 

the procedures in paragraphs (b) and (c) 

of this section. Previous test results 

conducted in accordance with 

paragraphs (b)(1) through (6) of this 

section may be used to determine 

compliance in accordance with 

paragraph (c) of this section. 

* * * * * 

(c) * * * 

(2) A facility is in compliance if the 

average of the organic HAP contents 

calculated for all three test runs is below 

the residual organic HAP limitations in 

§ 63.494(a)(1) through (3). 

(d) An owner or operator complying 

with the residual organic HAP 

limitations in § 63.494(a)(1) through (3) 

using a control or recovery device, shall 

redetermine the compliance status 

through the requirements described in 

paragraph (b) of this section whenever 

process changes are made. The owner or 

operator shall report the results of the 

redetermination in accordance with 

§ 63.499(d). For the purposes of this 

section, a process change is any action 

that would reasonably be expected to 

impair the performance of the control or 

recovery device. For the purposes of this 

section, the production of an elastomer 

with a residual organic HAP content 

greater than the residual organic HAP 

content of the elastomer used in the 

compliance demonstration constitutes a 

process change, unless the overall effect 

of the change is to reduce organic HAP 

emissions from the source as a whole. 

Other examples of process changes may 

include changes in production capacity 

or production rate, or removal or 

addition of equipment. For the purposes 

of this paragraph, process changes do 

not include: Process upsets; 

unintentional, temporary process 

changes; or changes that reduce the 

residual organic HAP content of the 

elastomer. 

21. Section 63.497 is amended by: 

a. Revising the section heading to 

§ 63.497; 

b. Revising paragraph (a) introductory 

text; and 

c. Revising paragraph (d) introductory 

text to read as follows: 

§ 63.497 Back-end process provisions— 

monitoring provisions for control and 

recovery devices used to comply with 

residual organic HAP limitations. 

(a) An owner or operator complying 

with the residual organic HAP 

limitations in § 63.494(a)(1) through (3) 

using control or recovery devices, or a 

combination of stripping and control or 

recovery devices, shall install the 

monitoring equipment specified in 

paragraphs (a)(1) through (6) of this 

section, as appropriate. 

* * * * * 

(d) The owner or operator of an 

affected source with a controlled backend process vent using a vent system 

that contains bypass lines that could 

divert a vent stream away from the 

control or recovery device used to 

comply with § 63.494(a)(1) through (3) 

shall comply with paragraph (d)(1) or 

(2) of this section. Equipment such as 

low leg drains, high point bleeds, 

analyzer vents, open-ended valves or 

lines, and pressure relief valves needed 

for safety purposes are not subject to 

this paragraph. 

* * * * * 

22. Section 63.498 is amended by: 

a. Revising paragraph (a) introductory 

text; 

b. Revising paragraph (a)(3); 

c. Adding paragraph (a)(4); 

d. Revising paragraph (b) introductory 

text; 

e. Revising paragraph (b)(3); 

f. Revising paragraph (c) introductory 

text; 

g. Revising paragraph (d) introductory 

text; 

h. Revising paragraph (d)(5)(ii)(B); 

i. Revising paragraph (d)(5)(ii)(E); and 

j. Adding paragraph (e) to read as 

follows: 

§ 63.498 Back-end process provisions— 

recordkeeping. 

(a) Each owner or operator shall 

maintain the records specified in 

paragraphs (a)(1) through (3), and 

paragraphs (b) through (d) of this 

section, as appropriate. 

* * * * * 

(3) If the back-end process operation 

is subject to a residual organic HAP 

limitation in § 63.494(a)(1) through (3), 

whether compliance will be achieved by 

stripping technology, or by control or 

recovery devices. 

(4) If the back-end process operation 

is subject to an emission limitation in 

§ 63.494(a)(4), the organic HAP emission 

limitation calculated in accordance with 

§ 63.494(a)(4)(i) through (v), as 

applicable. 

(b) Each owner or operator of a backend process operation using stripping 

technology to comply with a residual 

organic HAP limitation in § 63.494(a)(1) 

through (3), and demonstrating 

compliance using the periodic sampling 

procedures in § 63.495(b), shall 

maintain the records specified in 

paragraph (b)(1), and in paragraph (b)(2) 

or paragraph (b)(3) of this section, as 

appropriate. 

* * * * * 

(3) If the organic HAP contents for all 

samples analyzed during a month are 

below the appropriate level in 

§ 63.494(a), the owner or operator may 

record that all samples were in 

accordance with the residual organic 

HAP limitations in § 63.494(a)(1) 

through (3), rather than calculating and 

recording a monthly weighted average. 

(c) Each owner or operator of a backend process operation using stripping 

technology to comply with a residual 

organic HAP limitation in § 63.494(a)(1) 

through (3), and demonstrating 

compliance using the stripper parameter 

monitoring procedures in § 63.495(c), 

shall maintain the records specified in 

paragraphs (c)(1) through (3) of this 

section. 

* * * * * 

(d) Each owner or operator of a backend process operation using control or 

recovery devices to comply with a 

residual organic HAP limitation in 

§ 63.494(a)(1) through (3) shall maintain 

the records specified in paragraphs 

(d)(1) through (5) of this section. The 

recordkeeping requirements contained 

in paragraphs (d)(1) through (4) pertain 

to the results of the testing required by 

§ 63.496(b), for each of the three 

required test runs. 

* * * * * 

(5) * * * 

(ii) * * * 

(B) Monitoring data recorded during 

periods of monitoring system 

breakdowns, repairs, calibration checks, 

and zero (low-level) and high-level 

adjustments shall not be included in 

computing the hourly or daily averages. 

In addition, monitoring data recorded 

during periods of non-operation of the 

EPPU (or specific portion thereof) 

resulting in cessation of organic HAP 

emissions shall not be included in 

computing the hourly or daily averages. 

Records shall be kept of the times and 

durations of all such periods and any 

other periods of process or control 

device operation when monitors are not 

operating. 

* * * * * 

(E) For flares, records of the times and 

duration of all periods during which the 

pilot flame is absent shall be kept rather 

than daily averages. The records 

specified in this paragraph are not 

required during periods when emissions 

are not routed to the flare. 

* * * * * 

(e) If the back-end process operation 

is subject to an organic HAP emission 

limitation in § 63.494(a)(4), the records 

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Federal Register / Vol. 75, No. 203 / Thursday, October 21, 2010 / Proposed Rules 65137 

specified in paragraphs (e)(1) through 

(4) of this section. 

(1) The applicable organic HAP 

emission limitation determined in 

accordance with § 63.494(a)(4)(i) 

through (v). 

(2) The organic HAP emissions from 

all back-end process operations for each 

month, along with documentation of all 

calculations and other information used 

in the engineering assessment to 

estimate these emissions. 

(3) The mass of elastomer product 

produced each month. 

(4) The total mass of organic HAP 

emitted for each 12-month period 

divided by the total mass of elastomer 

produced during the 12-month period, 

determined in accordance with 

§ 63.495(g)(5). 

23. Section 63.499 is amended by: 

a. Revising paragraph (a)(3); 

b. Revising paragraph (b) introductory 

text; 

c. Revising paragraph (c) introductory 

text; 

d. Revising paragraph (d) introductory 

text; and 

e. Adding paragraph (f) to read as 

follows: 

§ 63.499 Back-end process provisions— 

reporting. 

(a) * * * 

(3) If the back-end process operation 

is subject to a residual organic HAP 

limitation in § 63.494(a)(1) through (3), 

whether compliance will be achieved by 

stripping technology, or by control or 

recovery devices. 

(b) Each owner or operator of a backend process operation using stripping to 

comply with a residual organic HAP 

limitation in § 63.494(a)(1) through (3), 

and demonstrating compliance by 

stripper parameter monitoring, shall 

submit reports as specified in 

paragraphs (b)(1) and (2) of this section. 

* * * * * 

(c) Each owner or operator of an 

affected source with a back-end process 

operation control or recovery device 

that shall comply with a residual 

organic HAP limitation in § 63.494(a)(1) 

through (3) shall submit the information 

specified in paragraphs (c)(1) through 

(3) of this section as part of the 

Notification of Compliance Status 

specified in § 63.506(e)(5). 

* * * * * 

(d) Whenever a process change, as 

defined in § 63.496(d), is made that 

causes the redetermination of the 

compliance status for the back-end 

process operations subject to a residual 

organic HAP limitation in § 63.494(a)(1) 

through (3), the owner or operator shall 

submit a report within 180 days after 

the process change, as specified in 

§ 63.506(e)(7)(iii). The report shall 

include: 

* * * * * 

(f) If the back-end process operation is 

subject to an organic HAP emission 

limitation in § 63.494(a)(4), the owner 

and operator must submit the 

information specified in paragraphs 

(f)(1) and (2) of this section. 

(1) The applicable organic HAP 

emission limitation determined in 

accordance with § 63.494(a)(4)(i) 

through (v) shall be submitted no later 

than 180 days from the date of 

publication of the final rule 

amendments in the Federal Register. 

(2) In the periodic report required to 

be submitted by § 63.506(e)(6), the total 

mass of organic HAP emitted for each of 

the rolling 12-month periods in the 

reporting period divided by the total 

mass of elastomer produced during the 

corresponding 12-month period, 

determined in accordance with 

§ 63.495(g)(5). 

24. Section 63.501 is amended by 

revising paragraph (c)(2) to read as 

follows: 

§ 63.501 Wastewater provisions. 

* * * * * 

(c) * * * 

(2) Back-end streams at affected 

sources that are subject to a residual 

organic HAP limitation in § 63.494(a)(1) 

through (3) and that are complying with 

these limitations through the use of 

stripping technology. 

25. Section 63.502 is amended by 

revising paragraph (b)(4) to read as 

follows: 

§ 63.502 Equipment leak and heat 

exchange system provisions. 

* * * * * 

(b) * * * 

(4) Surge control vessels and bottoms 

receivers located downstream of the 

stripping operations at affected sources 

subject to the back-end residual organic 

HAP limitation located in § 63.494(a)(1) 

through (3), that are complying through 

the use of stripping technology, as 

specified in § 63.495; 

* * * * * 

§ 63.503 [Amended] 

26. Section 63.503 is amended by 

removing and reserving paragraph (f)(1). 

27. Section 63.504 is amended by 

revising paragraph (a)(1) introductory 

text to read as follows: 

§ 63.504 Additional requirements for 

performance testing. 

(a) * * * 

(1) Performance tests shall be 

conducted at maximum representative 

operating conditions achievable during 

one of the time periods described in 

paragraph (a)(1)(i) of this section, 

without causing any of the situations 

described in paragraph (a)(1)(ii) of this 

section to occur. Upon request, the 

owner or operator shall make available 

to the Administrator such records as 

may be necessary to determine the 

conditions of performance tests. 

* * * * * 

28. Section 63.505 is amended by: 

a. Revising paragraph (e)(4); 

b. Revising paragraph (g)(1)(v)(A); 

c. Revising paragraph (g)(1)(v)(B); 

d. Removing paragraphs (g)(1)(v)(C) 

through (g)(1)(v)(E); 

e. Revising paragraph (g)(2)(ii)(B); and 

f. Adding paragraph (j) to read as 

follows: 

§ 63.505 Parameter monitoring levels and 

excursions. 

* * * * * 

(e) * * * 

(4) An owner or operator complying 

with the residual organic HAP 

limitations in paragraphs (a)(1) through 

(3) of § 63.494 using stripping, and 

demonstrating compliance by stripper 

parameter monitoring, shall redetermine 

the residual organic HAP content for all 

affected grades whenever process 

changes are made. For the purposes of 

this section, a process change is any 

action that would reasonably be 

expected to impair the performance of 

the stripping operation. For the 

purposes of this section, examples of 

process changes may include changes in 

production capacity or production rate, 

or removal or addition of equipment. 

For purposes of this paragraph, process 

changes do not include: Process upsets; 

unintentional, temporary process 

changes; or changes that reduce the 

residual organic HAP content of the 

elastomer. 

* * * * * 

(g) * * * 

(1) * * * 

(v) * * * 

(A) Monitoring system breakdowns, 

repairs, calibration checks, and zero 

(low-level) and high-level adjustments; 

or 

(B) Periods of non-operation of the 

affected source (or portion thereof), 

resulting in cessation of the emissions to 

which the monitoring applies. 

(2) * * * 

(ii) * * * 

(B) Subtract the time during the 

periods of monitoring system 

breakdowns, repairs, calibration checks, 

and zero (low-level) and high-level 

adjustments from the total amount of 

time determined in paragraph 

(g)(2)(ii)(A) of this section, to obtain the 

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65138 Federal Register / Vol. 75, No. 203 / Thursday, October 21, 2010 / Proposed Rules 

operating time used to determine if 

monitoring data are insufficient. 

* * * * * 

(j) Excursion definition for back-end 

operations subject to § 63.494(a)(4). An 

excursion means when the total mass of 

organic HAP emitted for any 

consecutive 12-month period divided by 

the total mass of elastomer produced 

during the 12-month period, determined 

in accordance with § 63.495(g), is 

greater than the applicable emission 

limitation, determined in accordance 

with § 63.494(a)(4)(i) through (v) and 

submitted in accordance with 

§ 63.499(f)(1). 

29. Section 63.506 is amended by: 

a. Revising paragraph (b)(1); 

b. Revising paragraph (d)(7); 

c. Revising paragraph (e)(3) 

introductory text; 

d. Removing and reserving paragraph 

(e)(3)(viii); 

e. Revising paragraph (e)(3)(ix)(B); 

f. Revising paragraph (e)(6)(iii)(E); 

g. Revising paragraph (h)(1)(i); 

h. Revising paragraph (h)(1)(ii)(C); 

i. Revising paragraph (h)(1)(iii); 

j. Revising paragraph (h)(2)(iii); and 

k. Removing and reserving paragraph 

(h)(2)(iv)(A) to read as follows: 

§ 63.506 General recordkeeping and 

reporting provisions. 

* * * * * 

(b) * * * 

(1) Malfunction records. Each owner 

or operator of an affected source subject 

to this subpart shall maintain records of 

the occurrence and duration of each 

malfunction of operation (i.e., process 

equipment), air pollution control 

equipment, or monitoring equipment. 

Each owner or operator shall maintain 

records of actions taken during periods 

of malfunction to minimize emissions in 

accordance with § 63.483(a)(1), 

including corrective actions to restore 

malfunctioning process and air 

pollution control and monitoring 

equipment to its normal or usual 

manner of operation. 

* * * * * 

(d) * * * 

(7) Monitoring data recorded during 

periods identified in paragraphs (d)(7)(i) 

and (ii) of this section shall not be 

included in any average computed 

under this subpart. Records shall be 

kept of the times and durations of all 

such periods and any other periods 

during process or control device or 

recovery device operation when 

monitors are not operating. 

(i) Monitoring system breakdowns, 

repairs, calibration checks, and zero 

(low-level) and high-level adjustments; 

or 

(ii) Periods of non-operation of the 

affected source (or portion thereof), 

resulting in cessation of the emissions to 

which the monitoring applies. 

* * * * * 

(e) * * * 

(3) Precompliance Report. Owners or 

operators of affected sources requesting 

an extension for compliance; requesting 

approval to use alternative monitoring 

parameters, alternative continuous 

monitoring and recordkeeping, or 

alternative controls; requesting approval 

to use engineering assessment to 

estimate emissions from a batch 

emissions episode, as described in 

§ 63.488(b)(6)(i); wishing to establish 

parameter monitoring levels according 

to the procedures contained in 

§ 63.505(c) or (d); shall submit a 

Precompliance Report according to the 

schedule described in paragraph (e)(3)(i) 

of this section. The Precompliance 

Report shall contain the information 

specified in paragraphs (e)(3)(ii) through 

(vii) of this section, as appropriate. 

* * * * * 

(viii) [Reserved] 

(ix) * * * 

(B) Supplements to the Precompliance 

Report may be submitted to request 

approval to use alternative monitoring 

parameters, as specified in paragraph 

(e)(3)(iii) of this section; to use 

alternative continuous monitoring and 

recordkeeping, as specified in paragraph 

(e)(3)(iv) of this section; to use 

alternative controls, as specified in 

paragraph (e)(3)(v) of this section; to use 

engineering assessment to estimate 

emissions from a batch emissions 

episode, as specified in paragraph 

(e)(3)(vi) of this section; or to establish 

parameter monitoring levels according 

to the procedures contained in 

§ 63.505(c) or (d), as specified in 

paragraph (e)(3)(vii) of this section. 

* * * * * 

(6) * * * 

(iii) * * * 

(E) The number, duration, and a brief 

description for each type of malfunction 

which occurred during the reporting 

period and which caused or may have 

caused any applicable emission 

limitation to be exceeded. The report 

must also include a description of 

actions taken by an owner or operator 

during a malfunction of an affected 

source to minimize emissions in 

accordance with § 63.483(a)(1), 

including actions taken to correct a 

malfunction. 

* * * * * 

(h) * * * 

(1) * * * 

(i) The monitoring system is capable 

of detecting unrealistic or impossible 

data during periods of normal operation 

(e.g., a temperature reading of ¥200 °C 

on a boiler), and will alert the operator 

by alarm or other means. The owner or 

operator shall record the occurrence. All 

instances of the alarm or other alert in 

an operating day constitute a single 

occurrence. 

(ii) * * * 

(C) The running average reflects a 

period of normal operation. 

(iii) The monitoring system is capable 

of detecting unchanging data during 

periods of normal operation, except in 

circumstances where the presence of 

unchanging data is the expected 

operating condition based on past 

experience (e.g., pH in some scrubbers), 

and will alert the operator by alarm or 

other means. The owner or operator 

shall record the occurrence. All 

instances of the alarm or other alert in 

an operating day constitute a single 

occurrence. 

* * * * * 

(2) * * * 

(iii) The owner or operator shall retain 

the records specified in paragraphs 

(h)(1)(i) through (iii) of this section, for 

the duration specified in paragraph (h) 

of this section. For any calendar week, 

if compliance with paragraphs (h)(1)(i) 

through (iii) of this section does not 

result in retention of a record of at least 

one occurrence or measured parameter 

value, the owner or operator shall 

record and retain at least one parameter 

value during a period of normal 

operation. 

(iv) * * * 

(A) [Reserved] 

* * * * * 

30. Table 1 to Subpart U of part 63 is 

amended by: 

a. Removing entry 63.6(e); 

b. Revising entries 63.6(e)(1)(i) and 

63.6(e)(1)(ii); 

c. Revising entry 63.6(e)(2); 

d. Adding entry 63.6(e)(3); 

e. Removing entries 63.6(e)(3)(i) 

through 63.6(e)(3)(ix); 

f. Revising entry 63.6(f)(1); and 

e. Revising entries 63.7(e)(1) and 

63.10(d)(5)(i) to read as follows: 

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Federal Register / Vol. 75, No. 203 / Thursday, October 21, 2010 / Proposed Rules 65139 

TABLE 1 TO SUBPART U OF PART 63—APPLICABILITY OF GENERAL PROVISIONS TO SUBPART U AFFECTED SOURCES

Reference Applies to Subpart U Explanation 

*******

§ 63.6(e)(1)(i) ...................... No ................................................ See § 63.483(a)(1) for general duty requirement. Any cross reference to 

§ 63.6(e)(1)(i) in any other general provision incorporated by reference shall 

be treated as a cross reference to § 63.483(a)(1). 

§ 63.6(e)(1)(ii) ..................... No.

* * * * * * * 

§ 63.6(e)(2) ......................... No ................................................ [Reserved.] 

§ 63.6(e)(3) ......................... No.

§ 63.6(f)(1) .......................... No.

* * * * * * * 

§ 63.7(e)(1) ......................... No ................................................ See § 63.504(a)(1). Any cross-reference to § 63.7(e)(1) in any other general 

provision incorporated by reference shall be treated as a cross-reference to 

§ 63.504(a)(1). 

*******

63.10(d)(5)(i) ....................... No.

*******

Subpart Y—[Amended] 

31–32. Section 63.560 is amended by: 

a. Revising paragraphs (a)(1), (a)(2), 

and (a)(3); 

b. Revising paragraph (d)(6); 

c. Adding paragraph (e)(1)(iv); 

d. Amending Table 1 to § 63.560 as 

follows: 

i. Revising entry 63.6(f)(1); 

ii. Removing entry 63.7(e); 

iii. Adding entries 63.7(e)(1) and 

63.7(e)(2)–(4); 

iv. Removing entries 63.10(b)(2)(i) and 

(b)(2)(ii)–(iii); 

v. Adding entries 63.10(b)(2)(i)–(ii) 

and (b)(2)(iii); 

vi. Removing entry 63.10(c)(10)–(13); 

and 

vii. Adding entries 63.10(c)(10)–(11) 

and 63.10(c)(12)–(13) to read as follows: 

§ 63.560 Applicability and designation of 

affected source. 

(a) * * * 

(1) The provisions of this subpart 

pertaining to the MACT standards in 

§ 63.562(b) and (d) of this subpart are 

applicable to existing and new sources 

with emissions of 10 or 25 tons, as that 

term is defined in § 63.561, except as 

specified in paragraph (d) of this 

section, and are applicable to new 

sources with emissions less than 10 and 

25 tons, as that term is defined in 

§ 63.561, except as specified in 

paragraphs (d) and (f) of this section. 

(2) Existing sources with emissions 

less than 10 and 25 tons are not subject 

to the emissions standards in § 63.562(b) 

and (d), except as specified in paragraph 

(f) of this section. 

(3) The recordkeeping requirements of 

§ 63.567(j)(4) and the emission 

estimation requirements of § 63.565(l) 

apply to existing sources with emissions 

less than 10 and 25 tons, except as 

specified in paragraph (f) of this section. 

* * * * * 

(d) * * * 

(6) The provisions of this subpart do 

not apply to marine tank vessel loading 

operations at existing offshore loading 

terminals, as that term is defined in 

§ 63.561, except existing offshore 

loading terminals must meet paragraphs 

(d)(6)(i) and (ii) of this section. 

(i) The submerged fill standards of 46 

CFR 153.282, and 

(ii) The provisions of § 63.562(f)(1) or 

§ 63.562(f)(2), if the terminal loads more 

than 1 million barrels (M barrels) of 

gasoline. 

* * * * * 

(e) * * * 

(1) * * * 

(iv) New and existing sources with 

emissions less than 10 or 25 tons, that 

load more than 1 M barrels of gasoline 

shall comply with the provisions of 

§ 63.562(f) by [DATE 3 YEARS FROM 

DATE OF PUBLICATION OF THE 

FINAL RULE IN THE FEDERAL 

REGISTER]. 

* * * * * 

TABLE 1 OF § 63.560—GENERAL PROVISIONS APPLICABILITY TO SUBPART Y 

Reference Applies to affected sources in 

subpart Y Comment 

*******

63.6(f)(1) ............................. No. 

*******

63.7(e)(1) ............................ No. See 63.563(b)(1). Any cross reference to 63.7(e)(1) in any other general provision incorporated by reference shall be treated as a cross-reference to 

63.563(b)(1). 

63.7(e)(2)–(4) ..................... Yes. 

*******

63.10 (b)(2)(i)–(ii) ............... No. 

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65140 Federal Register / Vol. 75, No. 203 / Thursday, October 21, 2010 / Proposed Rules 

TABLE 1 OF § 63.560—GENERAL PROVISIONS APPLICABILITY TO SUBPART Y—Continued 

Reference Applies to affected sources in 

subpart Y Comment 

*******

63.10(b)(2)(iii) ..................... Yes. 

*******

63.10(c)(10)–(11) ................ No. See 63.567(m)(1) for reporting malfunctions. Any cross-reference to 

63.10(c)(10) or 63.10(c)(11) in any other general provision incorporated by 

reference shall be treated as a cross-reference to 63.567(m)(1). 

63.10(c)(12)–(13) ................ Yes. 

*******

33. Section 63.561 is amended by 

adding in alphabetical order a definition 

for ‘‘affirmative defense’’ to read as 

follows: 

§ 63.561 Definitions. 

* * * * * 

Affirmative defense means, in the 

context of an enforcement proceeding, a 

response or a defense put forward by a 

defendant, regarding which the 

defendant has the burden of proof, and 

the merits of which are independently 

and objectively evaluated in a judicial 

or administrative proceeding. 

* * * * * 

34. Section 63.562 is amended by: 

a. Revising paragraph (a); 

b. Revising paragraph (b)(1); 

c. Revising paragraph (e) introductory 

text; 

d. Adding paragraph (e)(7); and 

e. Adding paragraph (f) to read as 

follows: 

§ 63.562 Standards. 

(a) The emissions limitations in 

paragraphs (b), (c), (d) and (f) of this 

section apply during marine tank vessel 

loading operations. 

(b) MACT standards, except for the 

VMT source—(1)(i) Vapor collection 

system of the terminal. The owner or 

operator of a new source with emissions 

less than 10 and 25 tons, an existing or 

new source with emissions of 10 or 25 

tons, and an existing source with 

emissions less than 10 and 25 tons that 

loads more than 1 M barrels of gasoline 

shall equip each terminal with a vapor 

collection system that is designed to 

collect HAP vapors displaced from 

marine tank vessels during marine tank 

vessel loading operations and to prevent 

HAP vapors collected at one loading 

berth from passing through another 

loading berth to the atmosphere, except 

for those commodities exempted under 

§ 63.560(d). 

(ii) Ship-to-shore compatibility. The 

owner or operator of a new source with 

emissions less than 10 and 25 tons, an 

existing or new source with emissions 

of 10 or 25 tons, and an existing source 

with emissions less than 10 and 25 tons 

that loads more than 1 million bbl/yr of 

gasoline shall limit marine tank vessel 

loading operations to those vessels that 

are equipped with vapor collection 

equipment that is compatible with the 

terminal’s vapor collection system, 

except for those commodities exempted 

under § 63.560(d). 

(iii) Vapor tightness of marine vessels. 

The owner or operator of a new source 

with emissions less than 10 and 25 tons, 

an existing or new source with 

emissions of 10 or 25 tons, and an 

existing source with emissions less than 

10 and 25 tons that loads more than 1 

million bbl/yr of gasoline shall limit 

marine tank vessel loading operations to 

those vessels that are vapor tight and to 

those vessels that are connected to the 

vapor collection system, except for 

those commodities exempted under 

§ 63.560(d). 

* * * * * 

(e) Operation and maintenance 

requirements for air pollution control 

equipment and monitoring equipment 

for affected sources. At all times, owners 

or operators of affected sources shall 

operate and maintain a source, 

including associated air pollution 

control equipment, in a manner 

consistent with safety and good air 

pollution control practices for 

minimizing emissions. Determination of 

whether acceptable operation and 

maintenance procedures are being used 

will be based on information available 

to the Administrator which may 

include, but is not limited to, 

monitoring results, review of operation 

and maintenance procedures, review of 

operation and maintenance records, and 

inspection of the source. 

* * * * * 

(7) In response to an action to enforce 

the standards set forth in this subpart, 

you may assert a civil defense to a claim 

for civil penalties for exceedances of 

such standards that are caused by a 

malfunction, as defined in § 63.2. 

Appropriate penalties may be assessed, 

however, if the respondent fails to meet 

its burden of proving all the 

requirements in the affirmative defense. 

The affirmative defense shall not be 

available for claims for injunctive relief. 

(i) To establish the affirmative defense 

in any action to enforce such a limit, the 

owners or operators of facilities must 

timely meet the notification 

requirements of paragraph (e)(7)(ii) of 

this section, and must prove by a 

preponderance of evidence that: 

(A) The excess emissions were caused 

by a sudden, short, infrequent, and 

unavoidable failure of air pollution 

control and monitoring equipment, or a 

process to operate in a normal and usual 

manner; and could not have been 

prevented through careful planning, 

proper design or better operation and 

maintenance practices; and did not stem 

from any activity or event that could 

have been foreseen and avoided, or 

planned for; and were not part of a 

recurring pattern indicative of 

inadequate design, operation, or 

maintenance; and 

(B) Repairs were made as 

expeditiously as possible when the 

applicable emission limitations were 

being exceeded. Off-shift and overtime 

labor were used, to the extent 

practicable to make these repairs; and 

(C) The frequency, amount and 

duration of the excess emissions 

(including any bypass) were minimized 

to the maximum extent practicable 

during periods of such emissions; and 

(D) If the excess emissions resulted 

from a bypass of control equipment or 

a process, then the bypass was 

unavoidable to prevent loss of life, 

severe personal injury, or severe 

property damage; and 

(E) All possible steps were taken to 

minimize the impact of the excess 

emissions on ambient air quality, the 

environment, and human health; and 

(F) All emissions monitoring and 

control systems were kept in operation 

if at all possible; and 

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Federal Register / Vol. 75, No. 203 / Thursday, October 21, 2010 / Proposed Rules 65141 

(G) Your actions in response to the 

excess emissions were documented by 

properly signed, contemporaneous 

operating logs; and 

(H) At all times, the facility was 

operated in a manner consistent with 

good practices for minimizing 

emissions; and 

(I) The owner or operator has 

prepared a written root cause analysis to 

determine, correct and eliminate the 

primary causes of the malfunction and 

the excess emissions resulting from the 

malfunction event at issue. The analysis 

shall also specify, using the best 

monitoring methods and engineering 

judgment, the amount of excess 

emissions that were the result of the 

malfunction. 

(ii) Notification. The owner or 

operator of the facility experiencing an 

exceedance of its emission limit(s) 

during a malfunction shall notify the 

Administrator by telephone or facsimile 

(FAX) transmission as soon as possible, 

but no later 2 business days after the 

initial occurrence of the malfunction, if 

it wishes to avail itself of an affirmative 

defense to civil penalties for that 

malfunction. The owner or operator 

seeking to assert an affirmative defense 

shall also submit a written report to the 

Administrator within 30 days of the 

initial occurrence of the exceedance of 

the standard in this subpart to 

demonstrate, with all necessary 

supporting documentation, that it has 

met the requirements set forth in 

paragraph (e)(7)(i) of this section. 

(f) The owner or operator of an 

existing source, that is not located at a 

petroleum refinery, with emissions less 

than 10 and 25 tons that loads more 

than 1 million bbl/yr of gasoline shall: 

(1) Limit emissions to not more than 

10 mg of total organic compounds per 

liter of gasoline loaded; or 

(2) Reduce captured emissions by at 

least 97 percent by weight. 

35. Section 63.563 is amended by 

revising paragraphs (a) introductory text 

and (b)(1) to read as follows: 

§ 63.563 Compliance and performance 

testing. 

(a) The following procedures shall be 

used to determine compliance with the 

emissions limits under § 63.562(b)(1), 

(c)(2), (d)(1), and (f): 

* * * * * 

(b) * * * 

(1) Initial performance test. An initial 

performance test shall be conducted 

using the procedures listed in § 63.7 of 

subpart A of this part according to the 

applicability in Table 1 of § 63.560, the 

procedures listed in this section, and 

the test methods listed in § 63.565. The 

initial performance test shall be 

conducted within 180 days after the 

compliance date for the specific affected 

source. During this performance test, 

sources subject to MACT standards 

under § 63.562(b)(2), (3), (4), and (5), 

and (d)(2) shall determine the reduction 

of HAP emissions, as VOC, for all 

combustion or recovery devices other 

than flares. Performance tests shall be 

conducted under such conditions as the 

Administrator specifies to the owner or 

operator based on representative 

performance of the affected source for 

the period being tested. Upon request, 

the owner or operator shall make 

available to the Administrator such 

records as may be necessary to 

determine the conditions of 

performance tests. Sources subject to 

RACT standards under § 63.562(c)(3), 

(4), and (5), and (d)(2) shall determine 

the reduction of VOC emissions for all 

combustion or recovery devices other 

than flares. 

* * * * * 

Subpart KK—[Amended] 

36. Section 63.820 is amended by 

adding paragraph (c) to read as follows: 

§ 63.820 Applicability. 

* * * * * 

(c) In response to an action to enforce 

the standards set forth in this subpart, 

you may assert a civil defense to a claim 

for civil penalties for exceedances of 

such standards that are caused by a 

malfunction, as defined in § 63.2. 

Appropriate penalties may be assessed, 

however, if the respondent fails to meet 

its burden of proving all the 

requirements in the affirmative defense. 

The affirmative defense shall not be 

available for claims for injunctive relief. 

(1) To establish the affirmative 

defense in any action to enforce such a 

limit, the owners or operators of 

facilities must timely meet the 

notification requirements of paragraph 

(c)(2) of this section, and must prove by 

a preponderance of evidence that: 

(i) The excess emissions were caused 

by a sudden, short, infrequent, and 

unavoidable failure of air pollution 

control and monitoring equipment, or a 

process to operate in a normal an usual 

manner; and could not have been 

prevented through careful planning, 

proper design or better operation and 

maintenance practices; and did not stem 

from any activity or event that could 

have been foreseen and avoided, or 

planned for; and were not part of a 

recurring pattern indicative of 

inadequate design, operation, or 

maintenance; and 

(ii) Repairs were made as 

expeditiously as possible when the 

applicable emission limitations were 

being exceeded. Off-shift and overtime 

labor were used, to the extent 

practicable to make these repairs; and 

(iii) The frequency, amount, and 

duration of the excess emissions 

(including any bypass) were minimized 

to the maximum extent practicable 

during periods of such emissions; and 

(iv) If the excess emissions resulted 

from a bypass of control equipment or 

a process, then the bypass was 

unavoidable to prevent loss of life, 

severe personal injury, or severe 

property damage; and 

(v) All possible steps were taken to 

minimize the impact of the excess 

emissions on ambient air quality, the 

environment, and human health; and 

(vi) All emissions monitoring and 

control systems were kept in operation 

if at all possible; and 

(vii) Your actions in response to the 

excess emissions were documented by 

properly signed, contemporaneous 

operating logs; and 

(viii) At all times, the facility was 

operated in a manner consistent with 

good practices for minimizing 

emissions; and 

(ix) The owner or operator has 

prepared a written root cause analysis to 

determine, correct and eliminate the 

primary causes of the malfunction and 

the excess emissions resulting from the 

malfunction event at issue. The analysis 

shall also specify, using the best 

monitoring methods and engineering 

judgment, the amount of excess 

emissions that were the result of the 

malfunction. 

(2) Notification. The owner or 

operator of the facility experiencing an 

exceedance of its emission limit(s) 

during a malfunction shall notify the 

Administrator by telephone or facsimile 

(FAX) transmission as soon as possible, 

but no later 2 business days after the 

initial occurrence of the malfunction, if 

it wishes to avail itself of an affirmative 

defense to civil penalties for that 

malfunction. The owner or operator 

seeking to assert an affirmative defense 

shall also submit a written report to the 

Administrator within 30 days of the 

initial occurrence of the exceedance of 

the standard in this subpart to 

demonstrate, with all necessary 

supporting documentation, that it has 

met the requirements set forth in 

paragraph (c)(1) of this section. 

37. Section 63.822 is amended by 

adding in alphabetical order a definition 

for ‘‘affirmative defense’’ to paragraph (a) 

to read as follows: 

§ 63.822 Definitions. 

(a) * * * 

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65142 Federal Register / Vol. 75, No. 203 / Thursday, October 21, 2010 / Proposed Rules 

Affirmative defense means, in the 

context of an enforcement proceeding, a 

response or a defense put forward by a 

defendant, regarding which the 

defendant has the burden of proof, and 

the merits of which are independently 

and objectively evaluated in a judicial 

or administrative proceeding. 

* * * * * 

38. Section 63.823 is revised to read 

as follows: 

§ 63.823 Standards: General. 

(a) Table 1 to this subpart provides 

cross references to the 40 CFR part 63, 

subpart A, general provisions, 

indicating the applicability of the 

general provisions requirements to this 

subpart KK. 

(b) Each owner or operator of an 

affected source subject to this subpart 

must at all times operate and maintain 

that affected source, including 

associated air pollution control 

equipment and monitoring equipment, 

in a manner consistent with safety and 

good air pollution control practices for 

minimizing emissions. Determination of 

whether such operation and 

maintenance procedures are being used 

will be based on information available 

to the Administrator, which may 

include, but is not limited to, 

monitoring results, review of operation 

and maintenance procedures, review of 

operation and maintenance records, and 

inspection of the source. 

39. Section 63.827 is amended by 

adding introductory text to read as 

follows: 

§ 63.827 Performance test methods. 

Performance tests shall be conducted 

under such conditions as the 

Administrator specifies to the owner or 

operator based on representative 

performance of the affected source for 

the period being tested. Upon request, 

the owner or operator shall make 

available to the Administrator such 

records as may be necessary to 

determine the conditions of 

performance tests. 

* * * * * 

40. Section 63.829 is amended by 

adding paragraphs (g) and (h) to read as 

follows: 

§ 63.829 Recordkeeping requirements. 

* * * * * 

(g) Each owner or operator of an 

affected source subject to this subpart 

shall maintain records of the occurrence 

and duration of each malfunction of 

operation (i.e., process equipment), air 

pollution control equipment, or 

monitoring equipment. 

(h) Each owner or operator of an 

affected source subject to this subpart 

shall maintain records of actions taken 

during periods of malfunction to 

minimize emissions in accordance with 

§ 63.823(b), including corrective actions 

to restore malfunctioning process and 

air pollution control and monitoring 

equipment to its normal or usual 

manner of operation. 

41. Section 63.830 is amended by: 

a. Removing and reserving paragraph 

(b)(5); and 

b. Adding paragraph (b)(6)(v) to read 

as follows: 

§ 63.830 Reporting requirements. 

* * * * * 

(b) * * * 

(5) [Reserved] 

(6) * * * 

(v) The number, duration, and a brief 

description for each type of malfunction 

which occurred during the reporting 

period and which caused or may have 

caused any applicable emission 

limitation to be exceeded. The report 

must also include a description of 

actions taken by an owner or operator 

during a malfunction of an affected 

source to minimize emissions in 

accordance with § 63.823(b), including 

actions taken to correct a malfunction. 

42. Table 1 to Subpart KK of part 63 

is amended by: 

a. Removing entry 63.6(e); 

b. Adding entries 63.6(e)(1)(i), 

63.6(e)(1)(ii); 63.6(e)(1)(iii), 63.6(e)(2), 

and 63.6(e)(3); 

c. Removing entry 63.6(f); 

d. Adding entries 63.6(f)(1) and 

63.6(f)(2)–(f)(3); 

e. Removing entry 63.7; 

f. Adding entries 63.7(a)–(d), 

63.7(e)(1), and 63.7(e)(2)–(e)(4); 

g. Removing entry 63.8(d)–(f); 

h. Adding entries 63.8(d)(1)–(2), 

63.8(d)(3), and 63.8(e)–(f); 

i. Removing entries 63.10(b)(1)–(b)(3), 

63.10(c)(10)–(c)(15), and 63.10(d)(4)– 

(d)(5); 

j. Adding entries 63.10(b)(1), 

63.10(b)(2)(i), 63.10(b)(2)(ii), 

63.10(b)(2)(iii), 63.10(b)(2)(iv)–(b)(2)(v), 

63.10(b)(2)(vi)–(b)(2)(xiv), 63.10(b)(3), 

63.10(c)(10), 63.10(c)(11), 63.10(c)(12)– 

(c)(14), 63.10(c)(15), 63.10(d)(4), and 

63.10(d)(5) to read as follows: 

TABLE 1 TO SUBPART KK OF PART 63—APPLICABILITY OF GENERAL PROVISIONS TO SUBPART KK 

General provisions 

reference Applicable to Subpart KK Comment 

*******

§ 63.6(e)(1)(i) ...................... No ................................................ See 63.823(b) for general duty requirement. Any cross-reference to 

63.6(e)(1)(i) in any other general provision incorporated by reference shall 

be treated as a cross-reference to 63.823(b). 

§ 63.6(e)(1)(ii) ..................... No.

§ 63.6(e)(1)(iii) .................... Yes.

§ 63.6(e)(2) ......................... No ................................................ Section reserved. 

§ 63.6(e)(3) ......................... No.

§ 63.6(f)(1) .......................... No.

§ 63.6(f)(2)–(f)(3) ................ Yes.

*******

§ 63.7(a)–(d) ....................... Yes.

§ 63.7(e)(1) ......................... No ................................................ See 63.827 introductory text. Any cross-reference to 63.7(e)(1) in any other 

general provision incorporated by reference shall be treated as a cross-reference to 63.827 introductory text. 

§ 63.7(e)(2)–(e)(4) .............. Yes.

*******

§ 63.8(d)(1)–(2) ................... Yes.

§ 63.8(d)(3) ......................... Yes, except for last sentence.

§ 63.8(e)–(f) ........................ Yes.

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TABLE 1 TO SUBPART KK OF PART 63—APPLICABILITY OF GENERAL PROVISIONS TO SUBPART KK—Continued 

General provisions 

reference Applicable to Subpart KK Comment 

*******

§ 63.10(b)(1) ....................... Yes.

§ 63.10(b)(2)(i) .................... No.

§ 63.10(b)(2)(ii) ................... No ................................................ See 63.829(g) for recordkeeping of occurrence and duration of malfunctions. 

See 63.829(h) for recordkeeping of actions taken during malfunction. Any 

cross-reference to 63.10(b)(2)(ii) in any other general provision incorporated 

by reference shall be treated as a cross-reference to 63.829(g). 

§ 63.10(b)(2)(iii) .................. Yes.

§ 63.10(b)(2)(iv)–(b)(2)(v) ... No.

§ 63.10(b)(2)(vi)–(b)(2)(xiv) Yes.

§ 63.10(b)(3) ....................... Yes.

* * * * * * * 

§ 63.10(c)(10) ..................... No ................................................ See 63.830(b)(6)(v) for reporting malfunctions. Any cross-reference to 

63.10(c)(10) in any other general provision incorporated by reference shall 

be treated as a cross-reference to 63.830(b)(6)(v). 

§ 63.10(c)(11) ..................... No ................................................ See 63.830(b)(6)(v) for reporting malfunctions. Any cross-reference to 

63.10(c)(11) in any other general provision incorporated by reference shall 

be treated as a cross-reference to 63.830(b)(6)(v). 

§ 63.10(c)(12)–(c)(14) ......... Yes.

§ 63.10(c)(15) ..................... No.

* * * * * * * 

§ 63.10(d)(4) ....................... Yes.

§ 63.10(d)(5) ....................... No.

* * * * * * * 

Subpart CCC—[Amended] 

43. Section 63.1155 is amended by 

adding paragraph (d) to read as follows: 

§ 63.1155 Applicability. 

* * * * * 

(d) In response to an action to enforce 

the standards set forth in this subpart, 

you may assert a civil defense to a claim 

for civil penalties for exceedances of 

such standards that are caused by a 

malfunction, as defined in § 63.2. 

Appropriate penalties may be assessed, 

however, if the respondent fails to meet 

its burden of proving all the 

requirements in the affirmative defense. 

The affirmative defense shall not be 

available for claims for injunctive relief. 

(1) To establish the affirmative 

defense in any action to enforce such a 

limit, the owners or operators of 

facilities must timely meet the 

notification requirements of paragraph 

(d)(2) of this section, and must prove by 

a preponderance of evidence that: 

(i) The excess emissions were caused 

by a sudden, short, infrequent, and 

unavoidable failure of air pollution 

control and monitoring equipment, or a 

process to operate in a normal an usual 

manner; and could not have been 

prevented through careful planning, 

proper design, or better operation and 

maintenance practices; and did not stem 

from any activity or event that could 

have been foreseen and avoided, or 

planned for; and were not part of a 

recurring pattern indicative of 

inadequate design, operation, or 

maintenance; and 

(ii) Repairs were made as 

expeditiously as possible when the 

applicable emission limitations were 

being exceeded. Off-shift and overtime 

labor were used, to the extent 

practicable to make these repairs; and 

(iii) The frequency, amount, and 

duration of the excess emissions 

(including any bypass) were minimized 

to the maximum extent practicable 

during periods of such emissions; and 

(iv) If the excess emissions resulted 

from a bypass of control equipment or 

a process, then the bypass was 

unavoidable to prevent loss of life, 

severe personal injury, or severe 

property damage; and 

(v) All possible steps were taken to 

minimize the impact of the excess 

emissions on ambient air quality, the 

environment, and human health; and 

(vi) All emissions monitoring and 

control systems were kept in operation 

if at all possible; and 

(vii) Your actions in response to the 

excess emissions were documented by 

properly signed, contemporaneous 

operating logs; and 

(viii) At all times, the facility was 

operated in a manner consistent with 

good practices for minimizing 

emissions; and 

(ix) The owner or operator has 

prepared a written root cause analysis to 

determine, correct, and eliminate the 

primary causes of the malfunction and 

the excess emissions resulting from the 

malfunction event at issue. The analysis 

shall also specify, using the best 

monitoring methods and engineering 

judgment, the amount of excess 

emissions that were the result of the 

malfunction. 

(2) Notification. The owner or 

operator of the facility experiencing an 

exceedance of its emission limit(s) 

during a malfunction shall notify the 

Administrator by telephone or facsimile 

(FAX) transmission as soon as possible, 

but no later 2 business days after the 

initial occurrence of the malfunction, if 

it wishes to avail itself of an affirmative 

defense to civil penalties for that 

malfunction. The owner or operator 

seeking to assert an affirmative defense 

shall also submit a written report to the 

Administrator within 30 days of the 

initial occurrence of the exceedance of 

the standard in this subpart to 

demonstrate, with all necessary 

supporting documentation, that it has 

met the requirements set forth in 

paragraph (d)(1) of this section. 

44. Section 63.1156 is amended by 

adding in alphabetical order a definition 

for ‘‘affirmative defense’’ to read as 

follows: 

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65144 Federal Register / Vol. 75, No. 203 / Thursday, October 21, 2010 / Proposed Rules 

§ 63.1156 Definitions. 

* * * * * 

Affirmative defense means, in the 

context of an enforcement proceeding, a 

response or a defense put forward by a 

defendant, regarding which the 

defendant has the burden of proof, and 

the merits of which are independently 

and objectively evaluated in a judicial 

or administrative proceeding. 

* * * * * 

45. Section 63.1159 is amended by 

adding paragraph (c) to read as follows: 

§ 63.1159 Operational and equipment 

standards for existing, new, or 

reconstructed sources. 

* * * * * 

(c) At all times, each owner or 

operator must operate and maintain any 

affected source subject to the 

requirements of this subpart, including 

associated air pollution control 

equipment and monitoring equipment, 

in a manner consistent with safety and 

good air pollution control practices for 

minimizing emissions. The general duty 

to minimize emissions does not require 

the owner or operator to make any 

further efforts to reduce emissions if 

levels required by this standard have 

been achieved. Determination of 

whether such operation and 

maintenance procedures are being used 

will be based on information available 

to the Administrator which may 

include, but is not limited to, 

monitoring results, review of operation 

and maintenance procedures, review of 

operation and maintenance records, and 

inspection of the source. 

46. Section 63.1160 is amended by 

revising paragraph (b) to read as follows: 

§ 63.1160 Compliance dates and 

maintenance requirements. 

* * * * * 

(b) Maintenance requirements. (1) The 

owner or operator shall prepare an 

operation and maintenance plan for 

each emission control device to be 

implemented no later than the 

compliance date. The plan shall be 

incorporated by reference into the 

source’s title V permit. All such plans 

must be consistent with good 

maintenance practices, and, for a 

scrubber emission control device, must 

at a minimum: 

(i) Require monitoring and recording 

the pressure drop across the scrubber 

once per shift while the scrubber is 

operating in order to identify changes 

that may indicate a need for 

maintenance; 

(ii) Require the manufacturer’s 

recommended maintenance at the 

recommended intervals on fresh solvent 

pumps, recirculating pumps, discharge 

pumps, and other liquid pumps, in 

addition to exhaust system and scrubber 

fans and motors associated with those 

pumps and fans; 

(iii) Require cleaning of the scrubber 

internals and mist eliminators at 

intervals sufficient to prevent buildup of 

solids or other fouling; 

(iv) Require an inspection of each 

scrubber at intervals of no less than 3 

months with: 

(A) Cleaning or replacement of any 

plugged spray nozzles or other liquid 

delivery devices; 

(B) Repair or replacement of missing, 

misaligned, or damaged baffles, trays, or 

other internal components; 

(C) Repair or replacement of droplet 

eliminator elements as needed; 

(D) Repair or replacement of heat 

exchanger elements used to control the 

temperature of fluids entering or leaving 

the scrubber; and 

(E) Adjustment of damper settings for 

consistency with the required air flow. 

(v) If the scrubber is not equipped 

with a viewport or access hatch 

allowing visual inspection, alternate 

means of inspection approved by the 

Administrator may be used. 

(vi) The owner or operator shall 

initiate procedures for corrective action 

within 1 working day of detection of an 

operating problem and complete all 

corrective actions as soon as practicable. 

Procedures to be initiated are the 

applicable actions that are specified in 

the maintenance plan. Failure to initiate 

or provide appropriate repair, 

replacement, or other corrective action 

is a violation of the maintenance 

requirement of this subpart. 

(vii) The owner or operator shall 

maintain a record of each inspection, 

including each item identified in 

paragraph (b)(2)(iv) of this section, that 

is signed by the responsible 

maintenance official and that shows the 

date of each inspection, the problem 

identified, a description of the repair, 

replacement, or other corrective action 

taken, and the date of the repair, 

replacement, or other corrective action 

taken. 

(2) The owner or operator of each 

hydrochloric acid regeneration plant 

shall develop and implement a written 

maintenance program. The program 

shall require: 

(i) Performance of the manufacturer’s 

recommended maintenance at the 

recommended intervals on all required 

systems and components; 

(ii) Initiation of procedures for 

appropriate and timely repair, 

replacement, or other corrective action 

within 1 working day of detection; and 

(iii) Maintenance of a daily record, 

signed by a responsible maintenance 

official, showing the date of each 

inspection for each requirement, the 

problems found, a description of the 

repair, replacement, or other action 

taken, and the date of repair or 

replacement. 

47. Section 63.1161 is amended by 

revising paragraph (a) introductory text 

to read as follows: 

§ 63.1161 Performance testing and test 

methods. 

(a) Demonstration of compliance. The 

owner or operator shall conduct an 

initial performance test for each process 

or emission control device to determine 

and demonstrate compliance with the 

applicable emission limitation 

according to the requirements in § 63.7 

of subpart A of this part and in this 

section. Performance tests shall be 

conducted under such conditions as the 

Administrator specifies to the owner or 

operator based on representative 

performance of the affected source for 

the period being tested. Upon request, 

the owner or operator shall make 

available to the Administrator such 

records as may be necessary to 

determine the conditions of 

performance tests. 

* * * * * 

48. Section 63.1164 is amended by 

revising paragraph (c) to read as follows: 

§ 63.1164 Reporting requirements. 

* * * * * 

(c) The number, duration, and a brief 

description for each type of malfunction 

which occurred during the reporting 

period and which caused or may have 

caused any applicable emission 

limitation to be exceeded shall be stated 

in a semiannual report. The report must 

also include a description of actions 

taken by an owner or operator during a 

malfunction of an affected source to 

minimize emissions in accordance with 

§ 63.1159(c), including actions taken to 

correct a malfunction. The report, to be 

certified by the owner or operator or 

other responsible official, shall be 

submitted semiannually and delivered 

or postmarked by the 30th day following 

the end of each calendar half. 

49. Section 63.1165 is amended by: 

a. Revising paragraph (a)(1); 

b. Revising paragraph (a)(4); 

c. Removing paragraph (a)(5) and 

redesignating paragraphs (a)(6) through 

(a)(11) as paragraphs (a)(5) through 

(a)(10) to read as follows: 

§ 63.1165 Recordkeeping requirements. 

(a) * * * 

(1) The occurrence and duration of 

each malfunction of operation (i.e., 

process equipment); 

* * * * * 

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(4) Actions taken during periods of 

malfunction to minimize emissions in 

accordance with § 63.1259(c) and the 

dates of such actions (including 

corrective actions to restore 

malfunctioning process and air 

pollution control equipment to its 

normal or usual manner of operation); 

* * * * * 

50. Table 1 to Subpart CCC is 

amended by: 

a. Removing entry 63.6(a)–(g); 

b. Adding entries 63.6(a)–(d), 

63.6(e)(1)(i), 63.6(e)(1)(ii), 63.6(e)(1)(iii), 

63.6(e)(2), 63.6(e)(3), 63.6(f)(1), 

63.6(f)(2)–(3), 63.6(g); 

c. Removing entry 63.7–63.9; 

d. Adding entries 63.7, 63.8(a)–(c), 

63.8(d)(1)–(2), 63.8(d)(3), and 63.8(e)– 

(f); 

e. Removing entry 63.10(a)–(c); 

f. Adding entries 63.10(a), 63.10(b)(1), 

63.10(b)(2)(i), 63.10(b)(2)(ii), 

63.10(b)(2)(iii), 63.10(b)(2)(iv)–(v), 

63.10(b)(2)(vi)–(xvi), 63.10(b)(3), 

63.10(c)(1)–(9), 63.10(c)(10), 

63.10(c)(11), 63.10(c)(12)–(14), and 

63.10(c)(15); 

g. Removing entry 63.10(d)(4)–(5); 

h. Adding entries 63.10(d)(4) and 

63.10(d)(5) to read as follows: 

TABLE 1 TO SUBPART CCC OF PART 63—APPLICABILITY OF GENERAL PROVISIONS (40 CFR PART 63, SUBPART A) TO

SUBPART CCC 

Reference Applies to Subpart CCC Explanation 

*******

63.6 (a)–(d) ......................... Yes.

63.6(e)(1)(i) ......................... No ................................................ See § 63.1259(c) for general duty requirement. Any cross-reference to 

§ 63.6(e)(1)(i) in any other general provision incorporated by reference shall 

be treated as a cross-reference to § 63.1259(c). 

63.6(e)(1)(ii) ........................ No.

63.6(e)(1)(iii) ....................... Yes.

63.6(e)(2) ............................ No ................................................ Section reserved. 

63.6(e)(3) ............................ No.

63.6(f)(1) ............................. No.

63.6(f)(2)–(3) ...................... Yes.

63.6(g) ................................ Yes.

* * * * * * * 

63.7 ..................................... Yes.

63.8(a)–(c) .......................... Yes.

63.8(d)(1)–(2) ..................... Yes.

63.8(d)(3) ............................ Yes, except for last sentence.

63.8(e)–(f) ........................... Yes.

* * * * * * * 

63.10(a) .............................. Yes.

63.10(b)(1) .......................... Yes.

63.10(b)(2)(i) ....................... No.

63.10(b)(2)(ii) ...................... No ................................................ See § 63.1265(a)(1) for recordkeeping of occurrence and duration of malfunctions. See § 63.1265(a)(4) for recordkeeping of actions taken during malfunction. Any cross-reference to § 63.10(b)(2)(ii) in any other general provision 

incorporated by reference shall be treated as a cross-reference to 

§ 63.1265(a)(1). 

63.10(b)(2)(iii) ..................... Yes.

63.10(b)(2)(iv)–(v) ............... No.

63.10(b)(2)(vi)–(xiv) ............ Yes.

63.10(b)(3) .......................... Yes.

*******

63.10(c)(1)–(9) .................... Yes.

63.10(c)(10) ........................ No ................................................ See § 63.1164(c) for reporting malfunctions. Any cross-reference to 

§ 63.10(c)(10) in any other general provision incorporated by reference shall 

be treated as a cross-reference to § 63.1164(c). 

63.10(c)(11) ........................ No ................................................ See § 63.1164(c) for reporting malfunctions. Any cross-reference to 

§ 63.10(c)(11) in any other general provision incorporated by reference shall 

be treated as a cross-reference to § 63.1164(c). 

63.10(c)(12)–(c)(14) ........... Yes.

63.10(c)(15) ........................ No.

63.10(d)(4) .......................... Yes.

63.10(d)(5) .......................... No.

*******

Subpart GGG—[Amended] 

51. Section 63.1250 is amended by 

revising paragraph (g) to read as follows: 

§ 63.1250 Applicability. 

* * * * * 

(g) Applicability of this subpart. (1) 

Each provision set forth in this subpart 

shall apply at all times, except that the 

provisions set forth in § 63.1255 of this 

subpart shall not apply during periods 

of nonoperation of the PMPU (or 

specific portion thereof) in which the 

lines are drained and depressurized 

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resulting in the cessation of the 

emissions to which § 63.1255 of this 

subpart applies. 

(2) The owner or operator shall not 

shut down items of equipment that are 

required or utilized for compliance with 

the emissions limitations of this subpart 

during times when emissions (or, where 

applicable, wastewater streams or 

residuals) are being routed to such items 

of equipment, if the shutdown would 

contravene emissions limitations of this 

subpart applicable to such items of 

equipment. This paragraph does not 

apply if the owner or operator must shut 

down the equipment to avoid damage to 

a PMPU or portion thereof. 

(3) At all times, each owner or 

operator must operate and maintain any 

affected source subject to the 

requirements of this subpart, including 

associated air pollution control 

equipment and monitoring equipment, 

in a manner consistent with safety and 

good air pollution control practices for 

minimizing emissions. The general duty 

to minimize emissions does not require 

the owner or operator to make any 

further efforts to reduce emissions if 

levels required by this standard have 

been achieved. Determination of 

whether such operation and 

maintenance procedures are being used 

will be based on information available 

to the Administrator which may 

include, but is not limited to, 

monitoring results, review of operation 

and maintenance procedures, review of 

operation and maintenance records, and 

inspection of the source. 

(4) In response to an action to enforce 

the standards set forth in this subpart, 

you may assert a civil defense to a claim 

for civil penalties for exceedances of 

such standards that are caused by a 

malfunction, as defined in § 63.2. 

Appropriate penalties may be assessed, 

however, if the respondent fails to meet 

its burden of proving all the 

requirements in the affirmative defense. 

The affirmative defense shall not be 

available for claims for injunctive relief. 

(i) To establish the affirmative defense 

in any action to enforce such a limit, the 

owners or operators of facilities must 

timely meet the notification 

requirements of paragraph (g)(4)(ii) of 

this section, and must prove by a 

preponderance of evidence that: 

(A) The excess emissions were caused 

by a sudden, short, infrequent, and 

unavoidable failure of air pollution 

control and monitoring equipment, or a 

process to operate in a normal and usual 

manner; and could not have been 

prevented through careful planning, 

proper design, or better operation and 

maintenance practices; and did not stem 

from any activity or event that could 

have been foreseen and avoided, or 

planned for; and were not part of a 

recurring pattern indicative of 

inadequate design, operation, or 

maintenance; and 

(B) Repairs were made as 

expeditiously as possible when the 

applicable emission limitations were 

being exceeded. Off-shift and overtime 

labor were used, to the extent 

practicable to make these repairs; and 

(C) The frequency, amount, and 

duration of the excess emissions 

(including any bypass) were minimized 

to the maximum extent practicable 

during periods of such emissions; and 

(D) If the excess emissions resulted 

from a bypass of control equipment or 

a process, then the bypass was 

unavoidable to prevent loss of life, 

severe personal injury, or severe 

property damage; and 

(E) All possible steps were taken to 

minimize the impact of the excess 

emissions on ambient air quality, the 

environment, and human health; and 

(F) All emissions monitoring and 

control systems were kept in operation 

if at all possible; and 

(G) Your actions in response to the 

excess emissions were documented by 

properly signed, contemporaneous 

operating logs; and 

(H) At all times, the facility was 

operated in a manner consistent with 

good practices for minimizing 

emissions; and 

(I) The owner or operator has 

prepared a written root cause analysis to 

determine, correct, and eliminate the 

primary causes of the malfunction and 

the excess emissions resulting from the 

malfunction event at issue. The analysis 

shall also specify, using the best 

monitoring methods and engineering 

judgment, the amount of excess 

emissions that were the result of the 

malfunction. 

(ii) Notification. The owner or 

operator of the facility experiencing an 

exceedance of its emission limit(s) 

during a malfunction shall notify the 

Administrator by telephone or facsimile 

(FAX) transmission as soon as possible, 

but no later 2 business days after the 

initial occurrence of the malfunction, if 

it wishes to avail itself of an affirmative 

defense to civil penalties for that 

malfunction. The owner or operator 

seeking to assert an affirmative defense 

shall also submit a written report to the 

Administrator within 30 days of the 

initial occurrence of the exceedance of 

the standard in this subpart to 

demonstrate, with all necessary 

supporting documentation, that it has 

met the requirements set forth in 

paragraph (g)(4)(i) of this section. 

* * * * * 

52. Section 63.1251 is amended by 

adding in alphabetical order a definition 

for ‘‘affirmative defense’’ to read as 

follow: 

§ 63.1251 Definitions. 

* * * * * 

Affirmative defense means, in the 

context of an enforcement proceeding, a 

response or a defense put forward by a 

defendant, regarding which the 

defendant has the burden of proof, and 

the merits of which are independently 

and objectively evaluated in a judicial 

or administrative proceeding. 

* * * * * 

53. Section 63.1255 is amended by 

revising paragraph (g)(4)(v)(A) to read as 

follow: 

§ 63.1255 Standards: Equipment leaks. 

* * * * * 

(g) * * * 

(4) * * * 

(v) * * * 

(A) The owner or operator may 

develop a written procedure that 

identifies the conditions that justify a 

delay of repair. The written procedures 

shall be included in a document that is 

maintained at the plant site. Reasons for 

delay of repair may be documented by 

citing the relevant sections of the 

written procedure. 

* * * * * 

54. Section 63.1256 is amended by 

revising paragraph (a)(4)(i) introductory 

text, and removing paragraphs (a)(4)(iii) 

and (iv) to read as follows: 

§ 63.1256 Standards: Wastewater. 

* * * * * 

(a) * * * 

(4) * * * 

(i) The owner or operator shall 

prepare a description of maintenance 

procedures for management of 

wastewater generated from the emptying 

and purging of equipment in the process 

during temporary shutdowns for 

inspections, maintenance, and repair 

(i.e., a maintenance turnaround) and 

during periods which are not 

shutdowns (i.e., routine maintenance). 

The descriptions shall be included in a 

document that is maintained at the 

plant site and shall: 

* * * * * 

55. Section 63.1257 is amended by 

revising paragraph (a) introductory text 

and the first sentence of paragraph 

(e)(2)(iii)(A)(6)(ii) to read as follows: 

§ 63.1257 Test methods and compliance 

procedures. 

(a) General. Except as specified in 

paragraph (a)(5) of this section, the 

procedures specified in paragraphs (c), 

(d), (e), and (f) of this section are 

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required to demonstrate initial 

compliance with §§ 63.1253, 63.1254, 

63.1256, and 63.1252(e), respectively. 

The provisions in paragraphs (a)(2) 

through (3) apply to performance tests 

that are specified in paragraphs (c), (d), 

and (e) of this section. The provisions in 

paragraph (a)(5) of this section are used 

to demonstrate initial compliance with 

the alternative standards specified in 

§§ 63.1253(d) and 63.1254(c). The 

provisions in paragraph (a)(6) of this 

section are used to comply with the 

outlet concentration requirements 

specified in §§ 63.1253(c), 

63.1254(a)(2)(i), and (a)(3)(ii)(B), 

63.1254(b)(i), and 63.1256(h)(2). 

Performance tests shall be conducted 

under such conditions as the 

Administrator specifies to the owner or 

operator based on representative 

performance of the affected source for 

the period being tested. Upon request, 

the owner or operator shall make 

available to the Administrator such 

records as may be necessary to 

determine the conditions of 

performance tests. 

* * * * * 

(e) * * * 

(2) * * * 

(iii) * * * 

(A) * * * 

(6) * * * 

(ii) The owner or operator may 

consider the inlet to the equalization 

tank as the inlet to the biological 

treatment process if the wastewater is 

conveyed by hard-piping from either the 

last previous treatment process or the 

point of determination to the 

equalization tank; and the wastewater is 

conveyed from the equalization tank 

exclusively by hard-piping to the 

biological treatment process and no 

treatment processes or other waste 

management units are used to store, 

handle, or convey the wastewater 

between the equalization tank and the 

biological treatment process; and the 

equalization tank is equipped with a 

fixed roof and a closed-vent system that 

routes emissions to a control device that 

meets the requirements of 

§ 63.1256(b)(1)(i) through (iv) and 

§ 63.1256(b)(2)(i). * * * 

* * * * * 

§ 63.1258 [Amended] 

56. Section 63.1258 is amended by 

removing paragraph (b)(8)(iv). 

57. Section 63.1259 is amended by 

revising paragraph (a)(3) to read as 

follows: 

§ 63.1259 Recordkeeping requirements. 

* * * * * 

(a) * * * 

(3) Malfunction records. Each owner 

or operator of an affected source subject 

to this subpart shall maintain records of 

the occurrence and duration of each 

malfunction of operation (i.e., process 

equipment), air pollution control 

equipment, or monitoring equipment. 

Each owner or operator shall maintain 

records of actions taken during periods 

of malfunction to minimize emissions in 

accordance with § 63.1250(g)(3), 

including corrective actions to restore 

malfunctioning process and air 

pollution control and monitoring 

equipment to its normal or usual 

manner of operation. 

* * * * * 

58. Section 63.1260 is amended by 

revising paragraph (i) to read as follows: 

§ 63.1260 Reporting requirements. 

* * * * * 

(i) The number, duration, and a brief 

description for each type of malfunction 

which occurred during the reporting 

period and which caused or may have 

caused any applicable emission 

limitation to be exceeded. The report 

must also include a description of 

actions taken by an owner or operator 

during a malfunction of an affected 

source to minimize emissions in 

accordance with § 63.1250(g)(3), 

including actions taken to correct a 

malfunction. 

* * * * * 

59. Table 1 to Subpart GGG is 

amended by: 

a. Removing entry 63.6(e); 

b. Adding entries 63.6(e)(1)(i), 

63.6(e)(1)(ii), 63.6(e)(1)(iii), 63.6(e)(2), 

and 63.6(e)(3); 

c. Removing entry 63.6(f)–(g); 

d. Adding entries 63.6(f)(1), 

63.6(f)(2)–(3), 63.6(g); 

e. Removing entry 63.7(e); 

f. Adding entries 63.7(e)(1) and 

63.7(e)(2)–(4); 

g. Removing entry 63.8(d); 

h. Adding entries 63.8(d)(1)–(2) and 

63.8(d)(3). 

i. Removing entry 63.10(c)–(d)(2); 

j. Adding entries 63.10(c)(1)–(9), 

63.10(c)(10), 63.10(c)(11), 63.10(c)(12)– 

(14), 63.10(c)(15), and 63.10(d)(1)–(2); 

k. Removing entry 63.10(d)(4–5); and 

l. Adding entries 63.10(d)(4) and 

63.10(d)(5) to read as follows: 

TABLE 1 TO SUBPART GGG OF PART 63—GENERAL PROVISIONS APPLICABILITY TO SUBPART GGG 

General provisions 

reference Summary of requirements Applies to Subpart GGG Comments 

*******

§ 63.6(e)(1)(i) ............. Requirements during periods of startup, shutdown, and malfunction.No .............................. See 63.1250(g)(3) for general duty requirement. Any cross-reference to 63.6(e)(1)(i) in 

any other general provision incorporated by 

reference shall be treated as a cross-reference to 63.1250(g)(3). 

§ 63.6(e)(1)(ii) ............ Malfunction correction requirements ................ No.

§ 63.6(e)(1)(iii) ........... Enforceability of operation and maintenance 

requirements.

Yes.

§ 63.6(e)(2) ................ Reserved ........................................................... No .............................. Section reserved. 

§ 63.6(e)(3) ................ Startup, shutdown, and malfunction plan requirements.No.

* * * * * * * 

63.6(f)(1) .................... Applicability of nonopacity emission standards No.

63.6(f)(2)–(3) ............. Methods of determining compliance and findings compliance.Yes.

63.6(g) ....................... Use of an alternative nonopacity emission 

standard.

Yes.

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TABLE 1 TO SUBPART GGG OF PART 63—GENERAL PROVISIONS APPLICABILITY TO SUBPART GGG—Continued 

General provisions 

reference Summary of requirements Applies to Subpart GGG Comments 

*******

63.7(e)(1) ................... Conduct of performance tests .......................... No .............................. See 63.1257(a) text. Any cross-reference to 

63.7(e)(1) in any other general provision incorporated by reference shall be treated as 

a cross-reference to 63.1257(a). 

63.7 (e)(2)–(4) ........... Performance tests requirements ...................... Yes.

* * * * * * * 

63.8(d)(1)–(2) ............ CMS quality control program requirements ...... Yes.

63.8(d)(3) ................... CMS quality control program recordkeeping 

requirements.

Yes, except for last 

sentence.

* * * * * * * 

63.10(c)(1)–(9) .......... Additional recordkeeping requirements for 

sources with continuous monitoring systems.

Yes.

63.10(c)(10) ............... Malfunction recordkeeping requirement ........... No .............................. Subpart GGG specifies recordkeeping requirements. 

63.10(c)(11) ............... Malfunction corrective action recordkeeping requirement.No .............................. Subpart GGG specifies recordkeeping requirements. 

63.10(c)(12)–(14) ...... Additional recordkeeping requirements for 

sources with continuous monitoring systems.

Yes.

63.10(c)(15) ............... Additional SSM recordkeeping requirements ... No.

* * * * * * * 

63.10(d)(1)–(2) .......... General reporting requirements ........................ Yes.

* * * * * * * 

63.10(d)(4) ................. Progress report requirements ........................... Yes.

63.10(d)(5) ................. Startup, shutdown, and malfunction report requirements.No .............................. Subpart GGG specifies reporting requirements. 

* * * * * * * 

60. Appendix A to part 63, Method 

306–B is amended by: 

a. Revising paragraph 1.2; 

b. Revising paragraph 6.1; 

c. Revising paragraph 11.1; 

d. Adding paragraphs 11.1.1 through 

11.1.4.10; and 

e. Revising paragraph 11.2.2 to read as 

follows: 

Appendix A to Part 63—Test Methods 

Method 306B—Surface Tension 

Measurement for Tanks Used at Decorative 

Chromium Electroplating and Chromium 

Anodizing Facilities 

* * * * * 

1.2 Applicability. This method is 

applicable to all chromium electroplating 

and chromium anodizing operations, and 

continuous chromium plating at iron and 

steel facilities where a wetting agent is used 

in the tank as the primary mechanism for 

reducing emissions from the surface of the 

plating solution. 

* * * * * 

6.1 Stalagmometer. Any commercially 

available stalagmometer or equivalent surface 

tension measuring device may be used to 

measure the surface tension of the plating or 

anodizing tank liquid provided the 

procedures specified in Section 11.1.2 are 

followed. 

* * * * * 

11.1 Procedure. The surface tension of 

the tank bath may be measured using a 

tensiometer, stalagmometer, or any other 

equivalent surface tension measuring device 

for measuring surface tension in dynes per 

centimeter. 

11.1.1 If a tensiometer is used, the 

procedures specified in ASTM Method D 

1331–89 must be followed. 

11.1.2 If a stalagmometer is used, the 

procedures specified in Sections 11.1.2.1 

through 11.1.2.3 must be followed. 

11.1.2.1 Check the stalagmometer for 

visual signs of damage. If the stalagmometer 

appears to be chipped, cracked, or otherwise 

in disrepair, the instrument shall not be used. 

11.1.2.2 Using distilled or deionized 

water and following the procedures provided 

by the manufacturer, count the number of 

drops corresponding to the distilled/ 

deionized water liquid volume between the 

upper and lower etched marks on the 

stalagmometer. If the number of drops for the 

distilled/deionized water is not within ±1 

drop of the number indicated on the 

instrument, the stalagmometer must be 

cleaned, using the procedures specified in 

Sections 11.1.4.1 through 11.1.4.10 of this 

method, before using the instrument to 

measure the surface tension of the tank 

liquid. 

11.1.2.2.1 If the stalagmometer must be 

cleaned, as indicated in Section 11.1.2.2, 

repeat the procedure specified in Section 

11.1.2.2 before proceeding. 

11.1.2.2.2 If, after cleaning and 

performing the procedure in Section 11.1.2.2, 

the number of drops indicated for the 

distilled/deionized water is not within ±1 

drop of the number indicated on the 

instrument, either use the number of drops 

corresponding to the distilled/deionized 

water volume as the reference number of 

drops, or replace the instrument. 

11.1.3 Determine the surface tension of 

the tank liquid using the procedures 

specified by the manufacturer of the 

stalagmometer. 

11.1.4 Stalagmometer cleaning 

procedures. The procedures specified in 

Sections 11.1.4.1 through 11.1.4.10 shall be 

used for cleaning a stalagmometer, as 

required by Section 11.1.2.2. 

11.1.4.1 Set up the stalagmometer on its 

stand in a fume hood. 

11.1.4.2 Place a clean 150 (mL) beaker 

underneath the stalagmometer and fill the 

beaker with reagent grade concentrated nitric 

acid. 

11.1.4.3 Immerse the bottom tip of the 

stalagmometer (approximately 1 centimeter 

(0.5 inches)) into the beaker. 

11.1.4.4 Squeeze the rubber bulb and 

pinch at the arrow up (1) position to collapse. 

11.1.4.5 Place the bulb end securely on 

top end of stalagmometer and carefully draw 

the nitric acid by pinching the arrow up (1) 

position until the level is above the top 

etched line. 

11.1.4.6 Allow the nitric acid to remain 

in stalagmometer for 5 minutes, then 

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carefully remove the bulb, allowing the acid 

to completely drain. 

11.1.4.7 Fill a clean 150 mL beaker with 

distilled or deionized water. 

11.1.4.8 Using the rubber bulb per the 

instructions in Sections 11.1.4.4 and 11.1.4.5, 

rinse and drain stalagmometer with 

deionized or distilled water. 

11.1.4.9 Fill a clean 150 mL beaker with 

isopropyl alcohol. 

11.1.4.10 Again using the rubber bulb per 

the instructions in Sections 11.1.4.4 and 

11.1.4.5, rinse and drain stalagmometer twice 

with isopropyl alcohol and allow the 

stalagmometer to dry completely. 

* * * * * 

11.2.2 If a measurement of the surface 

tension of the solution is above the 45 dynes 

per centimeter limit when measured using a 

stalagmometer, above 35 dynes per 

centimeter when measured using a 

tensiometer, or above an alternate surface 

tension limit established during the 

performance test, the time interval shall 

revert back to the original monitoring 

schedule of once every 4 hours. A subsequent 

decrease in frequency would then be allowed 

according to Section 11.2.1. 

* * * * * 

[FR Doc. 2010–23839 Filed 10–20–10; 8:45 am] 

BILLING CODE 6560–50–P 

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